DO NOT MERGE: Merge Oreo MR1 into master
am: a5d35b1e81  -s ours

Change-Id: If180a5acf1d965439c4d3d2e19ce432c05330b0c
diff --git a/.gitignore b/.gitignore
index abfef7c..162af55 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,8 @@
 .classpath
 .gradle
-.idea/
-!.idea/codeStyleSettings.xml
+**/.idea/**
+!**/.idea/codeStyleSettings.xml
+!**/.idea/copyright
 !.idea/copyright/AndroidCopyright.xml
 !.idea/copyright/profiles_settings.xml
 !.idea/vcs.xml
diff --git a/annotations/build.gradle b/annotations/build.gradle
index dd4a5bc..df521e1 100644
--- a/annotations/build.gradle
+++ b/annotations/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportJavaLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 jar {
     from sourceSets.main.output
@@ -45,8 +50,10 @@
 }
 
 supportLibrary {
-    name 'Android Support Library Annotations'
-    publish true
-    inceptionYear '2013'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs."
+    name = "Android Support Library Annotations"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2013"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs."
 }
\ No newline at end of file
diff --git a/app-toolkit/.idea/codeStyleSettings.xml b/app-toolkit/.idea/codeStyleSettings.xml
new file mode 120000
index 0000000..13e0b76
--- /dev/null
+++ b/app-toolkit/.idea/codeStyleSettings.xml
@@ -0,0 +1 @@
+../../.idea/codeStyleSettings.xml
\ No newline at end of file
diff --git a/app-toolkit/.idea/copyright b/app-toolkit/.idea/copyright
new file mode 120000
index 0000000..51a82b0
--- /dev/null
+++ b/app-toolkit/.idea/copyright
@@ -0,0 +1 @@
+../../.idea/copyright
\ No newline at end of file
diff --git a/app-toolkit/build.gradle b/app-toolkit/build.gradle
index 155a836..9bcb827 100644
--- a/app-toolkit/build.gradle
+++ b/app-toolkit/build.gradle
@@ -18,10 +18,11 @@
     ext.supportRootFolder = new File(project.projectDir, "../")
     apply from: 'buildSrc/repos.gradle'
     apply from: 'init.gradle'
+    apply from: "buildSrc/build_dependencies.gradle"
     repos.addMavenRepositories(repositories)
     dependencies {
-        classpath libs.jacoco
-        classpath libs.gradle
-        classpath libs.kotlin.gradle_plugin
+        classpath build_libs.jacoco
+        classpath build_libs.gradle
+        classpath build_libs.kotlin.gradle_plugin
     }
 }
diff --git a/app-toolkit/common/build.gradle b/app-toolkit/common/build.gradle
index 4f51a49..9604210 100644
--- a/app-toolkit/common/build.gradle
+++ b/app-toolkit/common/build.gradle
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 dependencies {
     compile libs.support.annotations
@@ -28,11 +31,12 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.ARCH_CORE.toString()
 supportLibrary {
-    name 'Android Arch-Common'
-    publish true
-    inceptionYear '2017'
-    description "Android Arch-Common"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Arch-Common"
+    publish = true
+    mavenVersion = LibraryVersions.ARCH_CORE
+    mavenGroup = LibraryGroups.ARCH_CORE
+    inceptionYear = "2017"
+    description = "Android Arch-Common"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/app-toolkit/core-testing/build.gradle b/app-toolkit/core-testing/build.gradle
index 127078d..adb93e6 100644
--- a/app-toolkit/core-testing/build.gradle
+++ b/app-toolkit/core-testing/build.gradle
@@ -14,59 +14,42 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-    }
-
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile project(":arch:runtime")
-    compile libs.support.annotations
-    compile(libs.junit)
-    compile libs.mockito_core, { exclude group: 'net.bytebuddy' }
+    api project(":arch:runtime")
+    api libs.support.annotations
+    api libs.junit
+    api libs.mockito_core, { exclude group: 'net.bytebuddy' }
 
-    testCompile libs.junit
-    testCompile libs.support.annotations
+    testImplementation libs.junit
+    testImplementation libs.support.annotations
 
-    androidTestCompile libs.junit
+    androidTestImplementation libs.junit
     androidTestImplementation libs.test_runner,      { exclude module: 'support-annotations' }
     androidTestImplementation libs.espresso_core,    { exclude module: 'support-annotations' }
 }
 
 createAndroidCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    project.tasks.create(name: "jar${suffix}", type: Jar) {
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.ARCH_CORE_TESTING.toString()
 supportLibrary {
-    name 'Android Core-Testing'
-    publish true
-    inceptionYear '2017'
-    description "Android Core-Testing"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Core-Testing"
+    publish = true
+    mavenVersion = LibraryVersions.ARCH_CORE_TESTING
+    mavenGroup = LibraryGroups.ARCH_CORE
+    inceptionYear = "2017"
+    description = "Android Core-Testing"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/app-toolkit/core-testing/lint-baseline.xml b/app-toolkit/core-testing/lint-baseline.xml
new file mode 100644
index 0000000..3ce85c7
--- /dev/null
+++ b/app-toolkit/core-testing/lint-baseline.xml
@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+    <issue
+        id="InvalidPackage"
+        message="Invalid package reference in library; not included in Android: `java.lang.management`. Referenced from `org.junit.internal.runners.statements.FailOnTimeout`.">
+        <location
+            file="../../../../prebuilts/tools/common/m2/repository/junit/junit/4.12/junit-4.12.jar"/>
+    </issue>
+
+    <issue
+        id="InvalidPackage"
+        message="Invalid package reference in library; not included in Android: `java.lang.instrument`. Referenced from `org.mockito.internal.creation.bytebuddy.InlineByteBuddyMockMaker`.">
+        <location
+            file="../../../../prebuilts/tools/common/m2/repository/org/mockito/mockito-core/2.7.6/mockito-core-2.7.6.jar"/>
+    </issue>
+
+</issues>
diff --git a/app-toolkit/dependencies.gradle b/app-toolkit/dependencies.gradle
index cb68089..e760149 100644
--- a/app-toolkit/dependencies.gradle
+++ b/app-toolkit/dependencies.gradle
@@ -22,7 +22,7 @@
     ffLibs = libs
 }
 def ffVersions = [:]
-ffVersions.kotlin = "1.1.3"
+ffVersions.kotlin = "1.1.51"
 ffVersions.auto_common = "0.6"
 ffVersions.javapoet = "1.8.0"
 ffVersions.compile_testing = "0.11"
@@ -42,7 +42,6 @@
 
 ffLibs.kotlin = [
         stdlib : "org.jetbrains.kotlin:kotlin-stdlib:$ffVersions.kotlin",
-        gradle_plugin : "org.jetbrains.kotlin:kotlin-gradle-plugin:$ffVersions.kotlin"
 ]
 ffLibs.auto_common = "com.google.auto:auto-common:$ffVersions.auto_common"
 ffLibs.apache = [
diff --git a/app-toolkit/gradle/wrapper/gradle-wrapper.properties b/app-toolkit/gradle/wrapper/gradle-wrapper.properties
index d90766a..9d09896 100644
--- a/app-toolkit/gradle/wrapper/gradle-wrapper.properties
+++ b/app-toolkit/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=../../../../../tools/external/gradle/gradle-4.1-bin.zip
+distributionUrl=../../../../../tools/external/gradle/gradle-4.3-bin.zip
diff --git a/app-toolkit/init.gradle b/app-toolkit/init.gradle
index d317d33..1d6b752 100644
--- a/app-toolkit/init.gradle
+++ b/app-toolkit/init.gradle
@@ -92,14 +92,6 @@
 buildServerAnchorTask.dependsOn createDiffArchive
 buildServerAnchorTask.dependsOn createArchive
 
-rootProject.ext.flatfootProjectGroups = [
-        "room" : "android.arch.persistence.room",
-        "persistence" : "android.arch.persistence",
-        "lifecycle" : "android.arch.lifecycle",
-        "arch" : "android.arch.core",
-        "paging" : "android.arch.paging",
-        "navigation" : "android.arch.navigation"]
-
 subprojects {
     repos.addMavenRepositories(project.repositories)
     if (project.name == 'doclava' || project.name == 'jdiff') {
@@ -111,18 +103,6 @@
         return
     }
 
-    def projectPath = project.getPath().split(":")
-    def mavenGroup = projectPath[1]
-    def finalGroup = rootProject.flatfootProjectGroups[mavenGroup]
-
-    if (finalGroup == null) {
-        return
-    }
-    if (projectPath.size() == 2) {// root project.
-        return
-    }
-    project.group = finalGroup
-
     if (project.getPath().contains("integration-tests")) {
         // disable upload tasks
         project.tasks.whenTaskAdded { task ->
diff --git a/app-toolkit/runtime/build.gradle b/app-toolkit/runtime/build.gradle
index 434d42b..3b46384 100644
--- a/app-toolkit/runtime/build.gradle
+++ b/app-toolkit/runtime/build.gradle
@@ -14,53 +14,33 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.SupportLibraryExtension
 import android.support.LibraryVersions
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile libs.support.annotations
-    compile project(":arch:common")
+    api libs.support.annotations
+    api project(":arch:common")
 }
 
 createAndroidCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    def jarTask = project.tasks.create(name: "jar${suffix}", type: Jar){
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.ARCH_RUNTIME.toString()
 supportLibrary {
-    name 'Android Arch-Runtime'
-    publish true
-    inceptionYear '2017'
-    description "Android Arch-Runtime"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Arch-Runtime"
+    publish = true
+    mavenVersion = LibraryVersions.ARCH_RUNTIME
+    mavenGroup = LibraryGroups.ARCH_CORE
+    inceptionYear = "2017"
+    description = "Android Arch-Runtime"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/app-toolkit/runtime/lint-baseline.xml b/app-toolkit/runtime/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/app-toolkit/runtime/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/build.gradle b/build.gradle
index 8c32175..ec83da5 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,14 +17,14 @@
 buildscript {
     ext.supportRootFolder = project.projectDir
     apply from: 'buildSrc/repos.gradle'
-
     apply from: 'buildSrc/init.gradle'
+    apply from: 'buildSrc/build_dependencies.gradle'
     init.setSdkInLocalPropertiesFile()
     repos.addMavenRepositories(repositories)
 
     dependencies {
-        classpath libs.gradle
-        classpath libs.jacoco
+        classpath build_libs.gradle
+        classpath build_libs.jacoco
     }
 }
 
diff --git a/buildSrc/build.gradle b/buildSrc/build.gradle
index 9f648d9..9c0d8af 100644
--- a/buildSrc/build.gradle
+++ b/buildSrc/build.gradle
@@ -1,17 +1,37 @@
-apply plugin: 'groovy'
-apply plugin: 'java'
+buildscript {
+    def supportRootFolder = project.projectDir.getParentFile()
+    repositories {
+        maven {
+            url "${supportRootFolder}/../../prebuilts/tools/common/m2/repository"
+        }
+    }
 
-apply from: "dependencies.gradle"
+    apply from: "build_dependencies.gradle"
+
+    dependencies {
+        classpath build_libs.kotlin.gradle_plugin
+    }
+}
+
+apply from: "build_dependencies.gradle"
 
 ext.supportRootFolder = project.projectDir.getParentFile()
 apply from: 'repos.gradle'
 
 repos.addMavenRepositories(repositories)
 
+apply plugin: 'groovy'
+apply plugin: 'java'
+apply plugin: 'kotlin'
+
+compileGroovy {
+    dependsOn tasks.getByPath('compileKotlin')
+    classpath += files(compileKotlin.destinationDir)
+}
 dependencies {
-    compile libs.gradle
-    compile libs.jacoco
-    compile libs.error_prone
-    compile libs.jarjar_gradle
+    compile build_libs.gradle
+    compile build_libs.jacoco
+    compile build_libs.error_prone
+    compile build_libs.jarjar_gradle
     compile gradleApi()
 }
diff --git a/buildSrc/build_dependencies.gradle b/buildSrc/build_dependencies.gradle
new file mode 100644
index 0000000..dc41841
--- /dev/null
+++ b/buildSrc/build_dependencies.gradle
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+def build_libs = [:]
+
+def androidPluginVersionOverride = System.getenv("GRADLE_PLUGIN_VERSION")
+
+if (androidPluginVersionOverride != null) {
+    build_libs.gradle = 'com.android.tools.build:gradle:' + androidPluginVersionOverride
+} else {
+    // Keep gradle plugin version in sync with ub_supportlib-master manifest.
+    build_libs.gradle = 'com.android.tools.build:gradle:3.0.0'
+}
+
+// jarjar plugin
+build_libs.jarjar_gradle = 'org.anarres.jarjar:jarjar-gradle:1.0.0'
+build_libs.error_prone = 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.10'
+build_libs.jacoco = 'org.jacoco:org.jacoco.core:0.7.8'
+build_libs.kotlin = [gradle_plugin: "org.jetbrains.kotlin:kotlin-gradle-plugin:1.1.51"]
+
+rootProject.ext['build_libs'] = build_libs
diff --git a/buildSrc/dependencies.gradle b/buildSrc/dependencies.gradle
index ebeaa7e..b61cfc6 100644
--- a/buildSrc/dependencies.gradle
+++ b/buildSrc/dependencies.gradle
@@ -24,26 +24,12 @@
 libs.test_rules = 'com.android.support.test:rules:1.0.1'
 libs.espresso_core = 'com.android.support.test.espresso:espresso-core:3.0.1'
 libs.espresso_contrib = 'com.android.support.test.espresso:espresso-contrib:3.0.1'
-libs.jacoco = 'org.jacoco:org.jacoco.core:0.7.8'
-
-def androidPluginVersionOverride = System.getenv("GRADLE_PLUGIN_VERSION")
-
-if (androidPluginVersionOverride != null) {
-    libs.gradle = 'com.android.tools.build:gradle:' + androidPluginVersionOverride
-} else {
-    // Keep gradle plugin version in sync with ub_supportlib-master manifest.
-    libs.gradle = 'com.android.tools.build:gradle:3.0.0'
-}
 
 //arch components
-libs.arch_lifecycle_runtime = "android.arch.lifecycle:runtime:1.0.0@aar"
+libs.arch_lifecycle_runtime = "android.arch.lifecycle:runtime:1.0.3@aar"
 
 // Other dependencies
 libs.xml_parser_apis = 'xerces:xmlParserAPIs:2.6.2'
 libs.xerces_impl = 'xerces:xercesImpl:2.6.2'
-libs.error_prone = 'net.ltgt.gradle:gradle-errorprone-plugin:0.0.10'
-
-// jarjar plugin
-libs.jarjar_gradle = 'org.anarres.jarjar:jarjar-gradle:1.0.0'
 
 rootProject.ext['libs'] = libs
diff --git a/buildSrc/diff_and_docs.gradle b/buildSrc/diff_and_docs.gradle
index 876d1f3..2fcc893 100644
--- a/buildSrc/diff_and_docs.gradle
+++ b/buildSrc/diff_and_docs.gradle
@@ -545,9 +545,11 @@
                         "ignoring API tasks.")
                 return
             }
-            initializeApiChecksForProject(project)
-            registerJavaProjectForDocsTask(project.generateApi, project.compileJava)
-            registerJavaProjectForDocsTask(project.generateDiffs, project.compileJava)
+            project.afterEvaluate {
+                initializeApiChecksForProject(project)
+                registerJavaProjectForDocsTask(project.generateApi, project.compileJava)
+                registerJavaProjectForDocsTask(project.generateDiffs, project.compileJava)
+            }
         }
     }
 }
diff --git a/buildSrc/init.gradle b/buildSrc/init.gradle
index 44116d6..6b613d0 100644
--- a/buildSrc/init.gradle
+++ b/buildSrc/init.gradle
@@ -162,10 +162,6 @@
         }
 
         project.ext.currentSdk = gradle.ext.currentSdk
-        apply plugin: 'maven'
-
-        version = LibraryVersions.SUPPORT_LIBRARY.toString();
-        group = 'com.android.support'
 
         project.plugins.whenPluginAdded { plugin ->
             def isAndroidLibrary = "com.android.build.gradle.LibraryPlugin"
diff --git a/buildSrc/src/main/groovy/android/support/FlatfootAndroidLibraryPlugin.groovy b/buildSrc/src/main/groovy/android/support/FlatfootAndroidLibraryPlugin.groovy
deleted file mode 100644
index 47a72d7..0000000
--- a/buildSrc/src/main/groovy/android/support/FlatfootAndroidLibraryPlugin.groovy
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support
-
-import com.android.build.gradle.LibraryExtension
-import com.google.common.collect.ImmutableMap
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-
-/**
- * Flatfoot Android library specific plugin that sets common configurations needed for
- * flatfoot library modules.
- */
-class FlatfootAndroidLibraryPlugin implements Plugin<Project> {
-    @Override
-    public void apply(Project project) {
-        SupportLibraryExtension supportLibraryExtension =
-                project.extensions.create("supportLibrary", SupportLibraryExtension, project);
-        SupportLibraryMavenUploader.apply(project, supportLibraryExtension);
-        VersionFileWriterTask.setUpAndroidLibrary(project);
-
-        project.apply(ImmutableMap.of("plugin", "com.android.library"));
-
-        LibraryExtension library = project.extensions.findByType(LibraryExtension.class);
-        SourceJarTaskHelper.setUpAndroidProject(project, library);
-    }
-}
\ No newline at end of file
diff --git a/buildSrc/src/main/groovy/android/support/SupportAndroidLibraryPlugin.groovy b/buildSrc/src/main/groovy/android/support/SupportAndroidLibraryPlugin.groovy
deleted file mode 100644
index 86469ee..0000000
--- a/buildSrc/src/main/groovy/android/support/SupportAndroidLibraryPlugin.groovy
+++ /dev/null
@@ -1,163 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support
-
-import com.android.build.gradle.LibraryExtension
-import com.android.build.gradle.api.LibraryVariant
-import com.android.builder.core.BuilderConstants
-import com.google.common.collect.ImmutableMap
-import net.ltgt.gradle.errorprone.ErrorProneBasePlugin
-import net.ltgt.gradle.errorprone.ErrorProneToolChain
-import org.gradle.api.Action
-import org.gradle.api.JavaVersion
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-import org.gradle.api.tasks.bundling.Jar
-
-/**
- * Support library specific com.android.library plugin that sets common configurations needed for
- * support library modules.
- */
-class SupportAndroidLibraryPlugin implements Plugin<Project> {
-    private static final String INSTRUMENTATION_RUNNER =
-            "android.support.test.runner.AndroidJUnitRunner";
-
-    @Override
-    public void apply(Project project) {
-        SupportLibraryExtension supportLibraryExtension =
-                project.extensions.create("supportLibrary", SupportLibraryExtension, project);
-        SupportLibraryMavenUploader.apply(project, supportLibraryExtension);
-
-        project.afterEvaluate {
-            LibraryExtension library = project.extensions.findByType(LibraryExtension.class);
-
-            // Java 8 is only fully supported on API 24+ and not all Java 8 features are binary
-            // compatible with API < 24, so use Java 7 for both source AND target.
-            final JavaVersion javaVersion;
-            if (supportLibraryExtension.java8Library) {
-                if (library.defaultConfig.minSdkVersion.apiLevel < 24) {
-                    throw new IllegalArgumentException("Libraries can only support Java 8 if "
-                            + "minSdkVersion is 24 or higher");
-                }
-                javaVersion = JavaVersion.VERSION_1_8
-            } else {
-                javaVersion = JavaVersion.VERSION_1_7
-            }
-
-            library.compileOptions {
-                sourceCompatibility javaVersion
-                targetCompatibility javaVersion
-            }
-        }
-
-        VersionFileWriterTask.setUpAndroidLibrary(project);
-
-        project.apply(ImmutableMap.of("plugin", "com.android.library"));
-        project.apply(ImmutableMap.of("plugin", ErrorProneBasePlugin.class));
-
-        LibraryExtension library = project.extensions.findByType(LibraryExtension.class);
-
-        library.compileSdkVersion project.currentSdk
-
-        library.defaultConfig {
-            // Update the version meta-data in each Manifest.
-            addManifestPlaceholders(["target-sdk-version": project.currentSdk])
-
-            // Set test related options.
-            testInstrumentationRunner INSTRUMENTATION_RUNNER
-        }
-
-        library.signingConfigs {
-            debug {
-                // Use a local debug keystore to avoid build server issues.
-                storeFile project.rootProject.init.debugKeystore
-            }
-        }
-
-        library.sourceSets {
-            main {
-                // We use a non-standard manifest path.
-                manifest.srcFile 'AndroidManifest.xml'
-            }
-
-            androidTest {
-                // We use a non-standard test directory structure.
-                root 'tests'
-                java.srcDir 'tests/src'
-                res.srcDir 'tests/res'
-                manifest.srcFile 'tests/AndroidManifest.xml'
-            }
-        }
-
-        // Always lint check NewApi as fatal.
-        library.lintOptions {
-            abortOnError true
-            ignoreWarnings true
-
-            // Write output directly to the console (and nowhere else).
-            textOutput 'stderr'
-            textReport true
-            htmlReport false
-            //xmlReport false
-
-            // Format output for convenience.
-            explainIssues true
-            noLines false
-            quiet true
-
-            // Always fail on NewApi.
-            error 'NewApi'
-        }
-
-        // Set baseline file for all legacy lint warnings.
-        if (System.getenv("GRADLE_PLUGIN_VERSION") != null) {
-            library.lintOptions.check 'NewApi'
-        } else {
-            library.lintOptions.baseline new File(project.projectDir, "/lint-baseline.xml")
-        }
-
-        if (project.rootProject.usingFullSdk) {
-            // Library projects don't run lint by default, so set up dependency.
-            project.uploadArchives.dependsOn "lintRelease"
-        }
-
-        SourceJarTaskHelper.setUpAndroidProject(project, library);
-
-        final ErrorProneToolChain toolChain = ErrorProneToolChain.create(project);
-        library.getBuildTypes().create("errorProne")
-        library.getLibraryVariants().all(new Action<LibraryVariant>() {
-            @Override
-            void execute(LibraryVariant libraryVariant) {
-                if (libraryVariant.getBuildType().getName().equals("errorProne")) {
-                    libraryVariant.getJavaCompile().setToolChain(toolChain);
-
-                    libraryVariant.getJavaCompile().options.compilerArgs += [
-                            '-XDcompilePolicy=simple', // Workaround for b/36098770
-
-                            // Enforce the following checks.
-                            '-Xep:MissingOverride:ERROR',
-                            '-Xep:NarrowingCompoundAssignment:ERROR',
-                            '-Xep:ClassNewInstance:ERROR',
-                            '-Xep:ClassCanBeStatic:ERROR',
-                            '-Xep:SynchronizeOnNonFinalField:ERROR',
-                            '-Xep:OperatorPrecedence:ERROR'
-                    ]
-                }
-            }
-        })
-    }
-}
diff --git a/buildSrc/src/main/groovy/android/support/SupportJavaLibraryPlugin.groovy b/buildSrc/src/main/groovy/android/support/SupportJavaLibraryPlugin.groovy
deleted file mode 100644
index 3113e6c..0000000
--- a/buildSrc/src/main/groovy/android/support/SupportJavaLibraryPlugin.groovy
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support
-
-import com.google.common.collect.ImmutableMap
-import org.gradle.api.JavaVersion
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-import org.gradle.api.plugins.JavaPluginConvention
-
-/**
- * Support java library specific plugin that sets common configurations needed for
- * support library modules.
- */
-class SupportJavaLibraryPlugin implements Plugin<Project> {
-    @Override
-    public void apply(Project project) {
-        SupportLibraryExtension supportLibraryExtension =
-                project.extensions.create("supportLibrary", SupportLibraryExtension, project);
-        SupportLibraryMavenUploader.apply(project, supportLibraryExtension);
-
-        project.apply(ImmutableMap.of("plugin", "java"));
-        project.afterEvaluate {
-            project.compileJava {
-                def version = supportLibraryExtension.java8Library ?
-                    JavaVersion.VERSION_1_8 : JavaVersion.VERSION_1_7
-                sourceCompatibility = version
-                targetCompatibility = version
-            }
-        }
-
-        SourceJarTaskHelper.setUpJavaProject(project);
-    }
-}
\ No newline at end of file
diff --git a/buildSrc/src/main/groovy/android/support/SupportKotlinLibraryPlugin.groovy b/buildSrc/src/main/groovy/android/support/SupportKotlinLibraryPlugin.groovy
index 237aa97..78b4777 100644
--- a/buildSrc/src/main/groovy/android/support/SupportKotlinLibraryPlugin.groovy
+++ b/buildSrc/src/main/groovy/android/support/SupportKotlinLibraryPlugin.groovy
@@ -30,7 +30,7 @@
     public void apply(Project project) {
         SupportLibraryExtension supportLibraryExtension =
                 project.extensions.create("supportLibrary", SupportLibraryExtension, project);
-        SupportLibraryMavenUploader.apply(project, supportLibraryExtension);
+        MavenUploadHelperKt.apply(project, supportLibraryExtension);
 
         project.apply(ImmutableMap.of("plugin", "kotlin"));
         project.apply(ImmutableMap.of("plugin", "kotlin-kapt"));
diff --git a/buildSrc/src/main/groovy/android/support/SupportLibraryExtension.groovy b/buildSrc/src/main/groovy/android/support/SupportLibraryExtension.groovy
deleted file mode 100644
index 93afb9a..0000000
--- a/buildSrc/src/main/groovy/android/support/SupportLibraryExtension.groovy
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support;
-
-import org.gradle.api.Project
-
-/**
- * Extension for {@link SupportAndroidLibraryPlugin} and {@link SupportJavaLibraryPlugin}.
- */
-class SupportLibraryExtension {
-    static final String ARCHITECTURE_URL =
-            "https://developer.android.com/topic/libraries/architecture/index.html";
-    static final String SUPPORT_URL =
-            "http://developer.android.com/tools/extras/support-library.html";
-
-    Project project
-    String name;
-    String description;
-    String inceptionYear;
-    String url = SUPPORT_URL;
-    Collection<License> licenses = [];
-    boolean java8Library = false;
-    boolean publish = false;
-
-    SupportLibraryExtension(Project project) {
-        this.project = project
-    }
-
-    License license(Closure closure) {
-        def license = project.configure(new License(), closure)
-        licenses.add(license)
-        return license
-    }
-
-    class License {
-        String name;
-        String url;
-
-        void url(String p) {
-            url = p
-        }
-
-        void name(String p) {
-            name = p
-        }
-    }
-}
\ No newline at end of file
diff --git a/buildSrc/src/main/groovy/android/support/SupportLibraryMavenUploader.groovy b/buildSrc/src/main/groovy/android/support/SupportLibraryMavenUploader.groovy
deleted file mode 100644
index 957cae8..0000000
--- a/buildSrc/src/main/groovy/android/support/SupportLibraryMavenUploader.groovy
+++ /dev/null
@@ -1,112 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support
-
-import com.android.build.gradle.LibraryPlugin
-import com.google.common.collect.ImmutableMap
-import org.gradle.api.Action
-import org.gradle.api.Project
-import org.gradle.api.artifacts.ProjectDependency
-import org.gradle.api.artifacts.maven.MavenDeployer
-import org.gradle.api.tasks.Upload
-
-class SupportLibraryMavenUploader {
-    static void apply(Project project, SupportLibraryExtension supportLibraryExtension) {
-        project.apply(ImmutableMap.of("plugin", "maven"));
-
-        // Set uploadArchives options.
-        Upload uploadTask = (Upload) project.getTasks().getByName("uploadArchives");
-        project.afterEvaluate {
-            if (supportLibraryExtension.publish) {
-                uploadTask.getRepositories().withType(MavenDeployer.class, new Action<MavenDeployer>() {
-                    @Override
-                    public void execute(MavenDeployer mavenDeployer) {
-                        mavenDeployer.getPom().project {
-                            name supportLibraryExtension.getName()
-                            description supportLibraryExtension.getDescription()
-                            url supportLibraryExtension.getUrl()
-                            inceptionYear supportLibraryExtension.getInceptionYear()
-
-                            licenses {
-                                license {
-                                    name 'The Apache Software License, Version 2.0'
-                                    url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                                    distribution 'repo'
-                                }
-
-                                supportLibraryExtension.getLicenses().each {
-                                    SupportLibraryExtension.License supportLicense ->
-                                        license {
-                                            name supportLicense.name
-                                            url supportLicense.url
-                                            distribution 'repo'
-                                        }
-                                }
-                            }
-
-                            scm {
-                                url "http://source.android.com"
-                                connection "scm:git:https://android.googlesource.com/platform/frameworks/support"
-                            }
-                            developers {
-                                developer {
-                                    name 'The Android Open Source Project'
-                                }
-                            }
-                        }
-
-                        uploadTask.doFirst {
-                            Set<ProjectDependency> allDeps = new HashSet<>();
-                            collectDependenciesForConfiguration(allDeps, project, "api");
-                            collectDependenciesForConfiguration(allDeps, project, "implementation");
-                            collectDependenciesForConfiguration(allDeps, project, "compile");
-
-                            mavenDeployer.getPom().whenConfigured {
-                                it.dependencies.forEach { dep ->
-                                    if (isAndroidProject(dep.groupId, dep.artifactId, allDeps)) {
-                                        dep.type = "aar"
-                                    }
-                                }
-                            }
-                        }
-                    }
-                });
-            } else {
-                uploadTask.enabled = false;
-            }
-        }
-    }
-
-    private static void collectDependenciesForConfiguration(Set<ProjectDependency> dependencies,
-            Project project, String name) {
-        def config = project.configurations.findByName(name);
-        if (config != null) {
-            config.dependencies.withType(ProjectDependency.class).forEach {
-                dep -> dependencies.add(dep)
-            }
-        }
-    }
-
-    private static boolean isAndroidProject(String groupId, String artifactId, Set<ProjectDependency> deps) {
-        for (ProjectDependency dep : deps) {
-            if (dep.group == groupId && dep.name == artifactId) {
-                return dep.getDependencyProject().plugins.hasPlugin(LibraryPlugin.class)
-            }
-        }
-        return false;
-    }
-}
\ No newline at end of file
diff --git a/buildSrc/src/main/groovy/android/support/checkapi/CheckApiTask.groovy b/buildSrc/src/main/groovy/android/support/checkapi/CheckApiTask.groovy
deleted file mode 100644
index 4f829f6..0000000
--- a/buildSrc/src/main/groovy/android/support/checkapi/CheckApiTask.groovy
+++ /dev/null
@@ -1,280 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support.checkapi
-
-import org.gradle.api.DefaultTask
-import org.gradle.api.GradleException
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.InputFile
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.TaskAction
-import org.gradle.api.tasks.Optional
-import org.gradle.api.tasks.OutputFile
-
-import java.security.MessageDigest
-
-/**
- * Task used to verify changes between two API files.
- * <p>
- * This task may be configured to ignore, warn, or fail with a message for a specific set of
- * Doclava-defined error codes. See {@link com.google.doclava.Errors} for a complete list of
- * supported error codes.
- * <p>
- * Specific failures may be ignored by specifying a list of SHAs in {@link #whitelistErrors}. Each
- * SHA is unique to a specific API change and is logged to the error output on failure.
- */
-public class CheckApiTask extends DefaultTask {
-    /** Character that resets console output color. */
-    private static final String ANSI_RESET = "\u001B[0m";
-
-    /** Character that sets console output color to red. */
-    private static final String ANSI_RED = "\u001B[31m";
-
-    /** Character that sets console output color to yellow. */
-    private static final String ANSI_YELLOW = "\u001B[33m";
-
-    /** API file that represents the existing API surface. */
-    @Optional
-    @InputFile
-    File oldApiFile
-
-    /** API file that represents the existing API surface's removals. */
-    @Optional
-    @InputFile
-    File oldRemovedApiFile
-
-    /** API file that represents the candidate API surface. */
-    @InputFile
-    File newApiFile
-
-    /** API file that represents the candidate API surface's removals. */
-    @Optional
-    @InputFile
-    File newRemovedApiFile
-
-    /** Optional file containing a newline-delimited list of error SHAs to ignore. */
-    File whitelistErrorsFile
-
-    @Optional
-    @InputFile
-    File getWhiteListErrorsFileInput() {
-        // Gradle requires non-null InputFiles to exist -- even with Optional -- so work around that
-        // by returning null for this field if the file doesn't exist.
-        if (whitelistErrorsFile && whitelistErrorsFile.exists()) {
-            return whitelistErrorsFile;
-        }
-        return null;
-    }
-
-    /**
-     * Optional list of packages to ignore.
-     * <p>
-     * Packages names will be matched exactly; sub-packages are not automatically recognized.
-     */
-    @Optional
-    @Input
-    Collection ignoredPackages
-
-    /**
-     * Optional list of classes to ignore.
-     * <p>
-     * Class names will be matched exactly by their fully-qualified names; inner classes are not
-     * automatically recognized.
-     */
-    @Optional
-    @Input
-    Collection ignoredClasses
-
-    /**
-     * Optional set of error SHAs to ignore.
-     * <p>
-     * Each error SHA is unique to a specific API change.
-     */
-    @Optional
-    @Input
-    Set whitelistErrors = []
-
-    // Errors that were both detected and whitelisted.
-    Set detectedWhitelistErrors = []
-
-    @InputFiles
-    Collection<File> doclavaClasspath
-
-    // A dummy output file meant only to tag when this check was last ran.
-    // Without any outputs, Gradle will run this task every time.
-    @Optional
-    private File mOutputFile
-
-    @OutputFile
-    public File getOutputFile() {
-        return mOutputFile ?: new File(project.buildDir, "checkApi/${name}-completed")
-    }
-
-    @Optional
-    public void setOutputFile(File outputFile) {
-        mOutputFile = outputFile
-    }
-
-    /**
-     * List of Doclava error codes to treat as errors.
-     * <p>
-     * See {@link com.google.doclava.Errors} for a complete list of error codes.
-     */
-    @Input
-    Collection checkApiErrors
-
-    /**
-     * List of Doclava error codes to treat as warnings.
-     * <p>
-     * See {@link com.google.doclava.Errors} for a complete list of error codes.
-     */
-    @Input
-    Collection checkApiWarnings
-
-    /**
-     * List of Doclava error codes to ignore.
-     * <p>
-     * See {@link com.google.doclava.Errors} for a complete list of error codes.
-     */
-    @Input
-    Collection checkApiHidden
-
-    /** Message to display on API check failure. */
-    @Input
-    String onFailMessage
-
-    public CheckApiTask() {
-        group = 'Verification'
-        description = 'Invoke Doclava\'s ApiCheck tool to make sure current.txt is up to date.'
-    }
-
-    private Set<File> collectAndVerifyInputs() {
-        if (getOldRemovedApiFile() != null && getNewRemovedApiFile() != null) {
-            return [getOldApiFile(), getNewApiFile(), getOldRemovedApiFile(),
-                    getNewRemovedApiFile()] as Set
-        } else {
-            return [getOldApiFile(), getNewApiFile()] as Set
-        }
-    }
-
-    public void setCheckApiErrors(Collection errors) {
-        // Make it serializable.
-        checkApiErrors = errors as int[]
-    }
-
-    public void setCheckApiWarnings(Collection warnings) {
-        // Make it serializable.
-        checkApiWarnings = warnings as int[]
-    }
-
-    public void setCheckApiHidden(Collection hidden) {
-        // Make it serializable.
-        checkApiHidden = hidden as int[]
-    }
-
-    @TaskAction
-    public void exec() {
-        if (getOldApiFile() == null) {
-            // Nothing to do.
-            return
-        }
-
-        final def apiFiles = collectAndVerifyInputs()
-
-        OutputStream errStream = new ByteArrayOutputStream()
-
-        // If either of those gets tweaked, then this should be refactored to extend JavaExec.
-        project.javaexec {
-            // Put Doclava on the classpath so we can get the ApiCheck class.
-            classpath(getDoclavaClasspath())
-            main = 'com.google.doclava.apicheck.ApiCheck'
-
-            minHeapSize = '128m'
-            maxHeapSize = '1024m'
-
-            // add -error LEVEL for every error level we want to fail the build on.
-            getCheckApiErrors().each { args('-error', it) }
-            getCheckApiWarnings().each { args('-warning', it) }
-            getCheckApiHidden().each { args('-hide', it) }
-
-            Collection ignoredPackages = getIgnoredPackages()
-            if (ignoredPackages) {
-                ignoredPackages.each { args('-ignorePackage', it) }
-            }
-            Collection ignoredClasses = getIgnoredClasses()
-            if (ignoredClasses) {
-                ignoredClasses.each { args('-ignoreClass', it) }
-            }
-
-            args(apiFiles.collect( { it.absolutePath } ))
-
-            // Redirect error output so that we can whitelist specific errors.
-            errorOutput = errStream
-
-            // We will be handling failures ourselves with a custom message.
-            ignoreExitValue = true
-        }
-
-        // Load the whitelist file, if present.
-        if (whitelistErrorsFile && whitelistErrorsFile.exists()) {
-            whitelistErrors += whitelistErrorsFile.readLines()
-        }
-
-        // Parse the error output.
-        Set unparsedErrors = []
-        Set detectedErrors = []
-        Set parsedErrors = []
-        errStream.toString().split("\n").each {
-            if (it) {
-                def matcher = it =~ ~/^(.+):(.+): (\w+) (\d+): (.+)$/
-                if (!matcher) {
-                    unparsedErrors += [it]
-                } else if (matcher[0][3] == "error") {
-                    def hash = getShortHash(matcher[0][5]);
-                    def error = matcher[0][1..-1] + [hash]
-                    if (hash in whitelistErrors) {
-                        detectedErrors += [error]
-                        detectedWhitelistErrors += error[5]
-                    } else {
-                        parsedErrors += [error]
-                    }
-                }
-            }
-        }
-
-        unparsedErrors.each { error -> logger.error "$ANSI_RED$error$ANSI_RESET" }
-        parsedErrors.each { logger.error "$ANSI_RED${it[5]}$ANSI_RESET ${it[4]}"}
-        detectedErrors.each { logger.warn "$ANSI_YELLOW${it[5]}$ANSI_RESET ${it[4]}"}
-
-        if (unparsedErrors || parsedErrors) {
-            throw new GradleException(onFailMessage)
-        }
-
-        // Just create a dummy file upon completion. Without any outputs, Gradle will run this task
-        // every time.
-        File outputFile = getOutputFile()
-        outputFile.parentFile.mkdirs()
-        outputFile.createNewFile()
-    }
-
-    def getShortHash(src) {
-        return MessageDigest.getInstance("SHA-1")
-                .digest(src.toString().bytes)
-                .encodeHex()
-                .toString()[-7..-1]
-    }
-}
\ No newline at end of file
diff --git a/buildSrc/src/main/groovy/android/support/doclava/DoclavaJavadocOptionFileOption.java b/buildSrc/src/main/groovy/android/support/doclava/DoclavaJavadocOptionFileOption.java
deleted file mode 100644
index db3f318..0000000
--- a/buildSrc/src/main/groovy/android/support/doclava/DoclavaJavadocOptionFileOption.java
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright (C) 2014 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support.doclava;
-
-import org.gradle.external.javadoc.internal.AbstractJavadocOptionFileOption;
-import org.gradle.external.javadoc.internal.JavadocOptionFileWriterContext;
-
-import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Iterator;
-
-/**
- * This class is used to hold complex argument(s) to doclava
- */
-public class DoclavaJavadocOptionFileOption extends
-        AbstractJavadocOptionFileOption<Iterable<String>> {
-
-    public DoclavaJavadocOptionFileOption(String option) {
-        super(option, null);
-    }
-
-    public DoclavaJavadocOptionFileOption(String option, Iterable<String> value) {
-        super(option, value);
-    }
-
-    @Override
-    public void write(JavadocOptionFileWriterContext writerContext) throws IOException {
-        writerContext.writeOptionHeader(getOption());
-
-        final Iterable<String> args = getValue();
-        if (args != null) {
-            final Iterator<String> iter = args.iterator();
-            while (true) {
-                writerContext.writeValue(iter.next());
-                if (!iter.hasNext()) {
-                    break;
-                }
-                writerContext.write(" ");
-            }
-        }
-
-        writerContext.newLine();
-    }
-
-    /**
-     * @return a deep copy of the option
-     */
-    public DoclavaJavadocOptionFileOption duplicate() {
-        final Iterable<String> value = getValue();
-        final ArrayList<String> valueCopy;
-        if (value != null) {
-            valueCopy = new ArrayList<>();
-            for (String item : value) {
-                valueCopy.add(item);
-            }
-        } else {
-            valueCopy = null;
-        }
-        return new DoclavaJavadocOptionFileOption(getOption(), valueCopy);
-    }
-}
diff --git a/buildSrc/src/main/groovy/android/support/doclava/DoclavaTask.groovy b/buildSrc/src/main/groovy/android/support/doclava/DoclavaTask.groovy
deleted file mode 100644
index 651446f..0000000
--- a/buildSrc/src/main/groovy/android/support/doclava/DoclavaTask.groovy
+++ /dev/null
@@ -1,224 +0,0 @@
-/*
- * Copyright (C) 2016 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.support.doclava
-
-import org.gradle.api.tasks.Input
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.javadoc.Javadoc
-import org.gradle.api.tasks.Optional
-import org.gradle.api.tasks.OutputDirectory
-import org.gradle.api.tasks.OutputFile
-import org.gradle.external.javadoc.JavadocOptionFileOption
-
-public class DoclavaTask extends Javadoc {
-
-    // external/doclava/src/com/google/doclava/Errors.java
-    public static final def DEFAULT_DOCLAVA_ERRORS = Collections.unmodifiableSet([
-            101,    // unresolved link
-            103,    // unknown tag
-            104,    // unknown param name
-    ] as Set)
-
-    public static final def DEFAULT_DOCLAVA_WARNINGS = Collections.unmodifiableSet([
-            121,    // hidden type param
-    ] as Set)
-
-
-    public static final def DEFAULT_DOCLAVA_HIDDEN = Collections.unmodifiableSet([
-            111,    // hidden super class
-            113,    // @deprecation mismatch
-    ] as Set)
-
-
-    // All lowercase name to match MinimalJavadocOptions#docletpath
-    private Collection<File> mDocletpath
-
-    // doclava error types which will cause the build to fail
-    @Input
-    Collection doclavaErrors = DEFAULT_DOCLAVA_ERRORS
-    @Input
-    Collection doclavaWarnings = DEFAULT_DOCLAVA_WARNINGS
-    // spammy doclava warnings which we want to hide
-    @Input
-    Collection doclavaHidden = DEFAULT_DOCLAVA_HIDDEN
-
-    /**
-     * If non-null, the list of packages that will be treated as if they were
-     * marked with {@literal @hide}.<br>
-     * Packages names will be matched exactly; sub-packages are not automatically recognized.
-     */
-    @Optional
-    @Input
-    Collection hiddenPackages
-
-    /**
-     * If non-null and not-empty, the whitelist of packages that will be present in the generated
-     * stubs; if null or empty, then all packages have stubs generated.<br>
-     * Wildcards are accepted.
-     */
-    @Optional
-    @Input
-    Set<String> stubPackages
-
-    @Input
-    boolean generateDocs = true
-
-    /**
-     * If non-null, the location of where to place the generated api file.
-     * If this is non-null, then {@link #removedApiFile} must be non-null as well.
-     */
-    @Optional
-    @OutputFile
-    File apiFile
-
-    /**
-     * If non-null, the location of where to place the generated removed api file.
-     * If this is non-null, then {@link #apiFile} must be non-null as well.
-     */
-    @Optional
-    @OutputFile
-    File removedApiFile
-
-    /**
-     * If non-null, the location of the generated keep list.
-     */
-    @Optional
-    @OutputFile
-    File keepListFile
-
-    /**
-     * If non-null, the location to put the generated stub sources.
-     */
-    @Optional
-    @OutputDirectory
-    File stubsDir
-
-    public DoclavaTask() {
-        failOnError = true
-        options.doclet = "com.google.doclava.Doclava"
-        options.encoding("UTF-8")
-        options.quiet()
-        // doclava doesn't understand '-doctitle'
-        title = null
-        maxMemory = "1280m"
-        // If none of generateDocs, apiFile, keepListFile, or stubJarsDir are true, then there is
-        // no work to do.
-        onlyIf( { getGenerateDocs() ||
-                getApiFile() != null ||
-                getKeepListFile() != null ||
-                getStubsDir() != null } )
-    }
-
-    /**
-     * The doclet path which has the {@code com.gogole.doclava.Doclava} class.
-     * This option will override any doclet path set in this instance's {@link #options JavadocOptions}.
-     * @see MinimalJavadocOptions#getDocletpath()
-     */
-    @InputFiles
-    public Collection<File> getDocletpath() {
-        return mDocletpath
-    }
-
-    /**
-     * Sets the doclet path which has the {@code com.gogole.doclava.Doclava} class.
-     * This option will override any doclet path set in this instance's {@link #options JavadocOptions}.
-     * @see MinimalJavadocOptions#setDocletpath(java.util.List)
-     */
-    public void setDocletpath(Collection<File> docletpath) {
-        mDocletpath = docletpath
-        // Go ahead and keep the docletpath in our JavadocOptions object in sync.
-        options.docletpath = docletpath as List
-    }
-
-    public void setDoclavaErrors(Collection errors) {
-        // Make it serializable.
-        doclavaErrors = errors as int[]
-    }
-
-    public void setDoclavaWarnings(Collection warnings) {
-        // Make it serializable.
-        doclavaWarnings = warnings as int[]
-    }
-
-    public void setDoclavaHidden(Collection hidden) {
-        // Make it serializable.
-        doclavaHidden = hidden as int[]
-    }
-
-    /**
-     * "Configures" this DoclavaTask with parameters that might not be at their final values
-     * until this task is run.
-     */
-    private configureDoclava() {
-        options.docletpath = getDocletpath() as List
-
-        // configure doclava error/warning/hide levels
-        JavadocOptionFileOption hide = options.addMultilineMultiValueOption("hide")
-        hide.setValue(getDoclavaHidden().collect({ [it.toString()] }))
-
-        JavadocOptionFileOption warning = options.addMultilineMultiValueOption("warning")
-        warning.setValue(getDoclavaWarnings().collect({ [it.toString()] }))
-
-        JavadocOptionFileOption error = options.addMultilineMultiValueOption("error")
-        error.setValue(getDoclavaErrors().collect({ [it.toString()] }))
-
-        Collection hiddenPackages = getHiddenPackages()
-        if (hiddenPackages) {
-            JavadocOptionFileOption hidePackage =
-                    options.addMultilineMultiValueOption("hidePackage")
-            hidePackage.setValue(hiddenPackages.collect({ [it.toString()] }))
-        }
-
-        if (!getGenerateDocs()) {
-            options.addOption(new DoclavaJavadocOptionFileOption('nodocs'))
-        }
-
-        // If requested, generate the API files.
-        File apiFile = getApiFile()
-        if (apiFile != null) {
-            options.addStringOption('api', apiFile.absolutePath)
-
-            File removedApiFile = getRemovedApiFile()
-            if (removedApiFile != null) {
-                options.addStringOption('removedApi', removedApiFile.absolutePath)
-            }
-        }
-
-        // If requested, generate the keep list.
-        File keepListFile = getKeepListFile()
-        if (keepListFile != null) {
-            options.addStringOption('proguard', keepListFile.absolutePath)
-        }
-        // If requested, generate stubs.
-        File stubsDir = getStubsDir()
-        if (stubsDir != null) {
-            options.addStringOption('stubs', stubsDir.absolutePath)
-            Set<String> stubPackages = getStubPackages()
-            if (stubPackages) {
-                options.addStringOption('stubpackages', stubPackages.join(':'))
-            }
-        }
-        // Always treat this as an Android docs task.
-        options.addOption(new DoclavaJavadocOptionFileOption('android'))
-    }
-
-    @Override
-    public void generate() {
-        configureDoclava()
-        super.generate()
-    }
-}
diff --git a/buildSrc/src/main/java/android/support/LibraryGroups.java b/buildSrc/src/main/java/android/support/LibraryGroups.java
new file mode 100644
index 0000000..feaefbc
--- /dev/null
+++ b/buildSrc/src/main/java/android/support/LibraryGroups.java
@@ -0,0 +1,30 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support;
+
+/**
+ * The list of maven group names of all the libraries in this project.
+ */
+public class LibraryGroups {
+    public static final String SUPPORT = "com.android.support";
+    public static final String ROOM = "android.arch.persistence.room";
+    public static final String PERSISTENCE = "android.arch.persistence";
+    public static final String LIFECYCLE = "android.arch.lifecycle";
+    public static final String ARCH_CORE = "android.arch.core";
+    public static final String PAGING = "android.arch.paging";
+    public static final String NAVIGATION = "android.arch.navigation";
+}
diff --git a/buildSrc/src/main/java/android/support/LibraryVersions.java b/buildSrc/src/main/java/android/support/LibraryVersions.java
index 64f1840..3f160df 100644
--- a/buildSrc/src/main/java/android/support/LibraryVersions.java
+++ b/buildSrc/src/main/java/android/support/LibraryVersions.java
@@ -23,7 +23,7 @@
     /**
      * Version code of the support library components.
      */
-    public static final Version SUPPORT_LIBRARY = new Version("27.0.1");
+    public static final Version SUPPORT_LIBRARY = new Version("27.0.2");
 
     /**
      * Version code for flatfoot 1.0 projects (room, lifecycles)
diff --git a/buildSrc/src/main/kotlin/android/support/GroovyInteroperability.kt b/buildSrc/src/main/kotlin/android/support/GroovyInteroperability.kt
new file mode 100644
index 0000000..ec2d2f6
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/GroovyInteroperability.kt
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2016 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+import groovy.lang.Closure
+import groovy.lang.GroovyObject
+import groovy.lang.MetaClass
+
+import org.codehaus.groovy.runtime.InvokerHelper.getMetaClass
+
+operator fun <T> Closure<T>.invoke(): T = call()
+
+operator fun <T> Closure<T>.invoke(x: Any?): T = call(x)
+
+operator fun <T> Closure<T>.invoke(vararg xs: Any?): T = call(*xs)
+
+
+/**
+ * Executes the given [builder] against this object's [GroovyBuilderScope].
+ *
+ * @see [GroovyBuilderScope]
+ */
+inline
+fun <T> Any.withGroovyBuilder(builder: GroovyBuilderScope.() -> T): T =
+        GroovyBuilderScope.of(this).builder()
+
+
+/**
+ * Provides a dynamic dispatching DSL with Groovy semantics for better integration with
+ * plugins that rely on Groovy builders such as the core `maven` plugin.
+ *
+ * It supports Groovy keyword arguments and arbitrary nesting, for instance, the following Groovy code:
+ *
+ * ```Groovy
+ * repository(url: "scp://repos.mycompany.com/releases") {
+ *   authentication(userName: "me", password: "myPassword")
+ * }
+ * ```
+ *
+ * Can be mechanically translated to the following Kotlin with the aid of `withGroovyBuilder`:
+ *
+ * ```Kotlin
+ * withGroovyBuilder {
+ *   "repository"("url" to "scp://repos.mycompany.com/releases") {
+ *     "authentication"("userName" to "me", "password" to "myPassword")
+ *   }
+ * }
+ * ```
+ *
+ * @see [withGroovyBuilder]
+ */
+interface GroovyBuilderScope : GroovyObject {
+
+    companion object {
+
+        fun of(value: Any): GroovyBuilderScope =
+                when (value) {
+                    is GroovyObject -> GroovyBuilderScopeForGroovyObject(value)
+                    else            -> GroovyBuilderScopeForRegularObject(value)
+                }
+    }
+
+    val delegate: Any
+
+    operator fun String.invoke(vararg arguments: Any?): Any?
+
+    operator fun String.invoke(): Any? =
+            invoke(*emptyArray<Any>())
+
+    operator fun <T> String.invoke(vararg arguments: Any?, builder: GroovyBuilderScope.() -> T): Any? =
+            invoke(*arguments, closureFor(builder))
+
+    operator fun <T> String.invoke(builder: GroovyBuilderScope.() -> T): Any? =
+            invoke(closureFor(builder))
+
+    operator fun <T> String.invoke(vararg keywordArguments: Pair<String, Any?>, builder: GroovyBuilderScope.() -> T): Any? =
+            invoke(keywordArguments.toMap(), closureFor(builder))
+
+    operator fun String.invoke(vararg keywordArguments: Pair<String, Any?>): Any? =
+            invoke(keywordArguments.toMap())
+
+    private
+    fun <T> closureFor(builder: GroovyBuilderScope.() -> T): Closure<Any?> =
+            object : Closure<Any?>(this, this) {
+                @Suppress("unused")
+                fun doCall() = delegate.withGroovyBuilder(builder)
+            }
+}
+
+
+private
+class GroovyBuilderScopeForGroovyObject(override val delegate: GroovyObject) : GroovyBuilderScope, GroovyObject by delegate {
+
+    override fun String.invoke(vararg arguments: Any?): Any? =
+            delegate.invokeMethod(this, arguments)
+}
+
+
+private
+class GroovyBuilderScopeForRegularObject(override val delegate: Any) : GroovyBuilderScope {
+
+    private
+    val groovyMetaClass: MetaClass by lazy {
+        getMetaClass(delegate)
+    }
+
+    override fun invokeMethod(name: String, args: Any?): Any? =
+            groovyMetaClass.invokeMethod(delegate, name, args)
+
+    override fun setProperty(propertyName: String, newValue: Any?) =
+            groovyMetaClass.setProperty(delegate, propertyName, newValue)
+
+    override fun getProperty(propertyName: String): Any =
+            groovyMetaClass.getProperty(delegate, propertyName)
+
+    override fun setMetaClass(metaClass: MetaClass?) =
+            throw IllegalStateException()
+
+    override fun getMetaClass(): MetaClass =
+            groovyMetaClass
+
+    override fun String.invoke(vararg arguments: Any?): Any? =
+            groovyMetaClass.invokeMethod(delegate, this, arguments)
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/KotlinNoOp.kt b/buildSrc/src/main/kotlin/android/support/KotlinNoOp.kt
new file mode 100644
index 0000000..968f6ca
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/KotlinNoOp.kt
@@ -0,0 +1,24 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+class KotlinNoOp {
+
+    fun noOp() {
+    }
+
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/MavenUploadHelper.kt b/buildSrc/src/main/kotlin/android/support/MavenUploadHelper.kt
new file mode 100644
index 0000000..1698bf9
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/MavenUploadHelper.kt
@@ -0,0 +1,136 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+import com.android.build.gradle.LibraryPlugin
+import org.gradle.api.Project
+import org.gradle.api.artifacts.ProjectDependency
+import org.gradle.api.artifacts.maven.MavenDeployer
+import org.gradle.api.tasks.Upload
+
+fun apply(project: Project, extension: SupportLibraryExtension) {
+    project.afterEvaluate {
+        if (extension.publish) {
+            if (extension.mavenGroup == null) {
+                throw Exception("You must specify mavenGroup for " + project.name + " project");
+            }
+            if (extension.mavenVersion == null) {
+                throw Exception("You must specify mavenVersion for " + project.name + " project");
+            }
+            project.group = extension.mavenGroup!!
+            project.version = extension.mavenVersion.toString()
+        }
+    }
+
+    project.apply(mapOf("plugin" to "maven"))
+
+    // Set uploadArchives options.
+    val uploadTask = project.tasks.getByName("uploadArchives") as Upload
+    project.afterEvaluate {
+        if (extension.publish) {
+            uploadTask.repositories.withType(MavenDeployer::class.java) { mavenDeployer ->
+
+                mavenDeployer.getPom().project {
+                    it.withGroovyBuilder {
+                        "name"(extension.name)
+                        "description"(extension.description)
+                        "url"(extension.url)
+                        "inceptionYear"(extension.inceptionYear)
+
+                        "licenses" {
+                            "license" {
+                                "name"("The Apache Software License, Version 2.0")
+                                "url"("http://www.apache.org/licenses/LICENSE-2.0.txt")
+                                "distribution"("repo")
+                            }
+                            for (license in extension.getLicenses()) {
+                                "license" {
+                                    "name"(license.name)
+                                    "url"(license.url)
+                                    "distribution"("repo")
+                                }
+                            }
+                        }
+
+                        "scm" {
+                            "url"("http://source.android.com")
+                            "connection"("scm:git:https://android.googlesource.com/platform/frameworks/support")
+                        }
+
+                        "developers" {
+                            "developer" {
+                                "name"("The Android Open Source Project")
+                            }
+                        }
+                    }
+                }
+
+                // TODO(aurimas): remove this when Gradle bug is fixed.
+                // https://github.com/gradle/gradle/issues/3170
+                uploadTask.doFirst {
+                    val allDeps = HashSet<ProjectDependency>()
+                    collectDependenciesForConfiguration(allDeps, project, "api");
+                    collectDependenciesForConfiguration(allDeps, project, "implementation");
+                    collectDependenciesForConfiguration(allDeps, project, "compile");
+
+                    mavenDeployer.getPom().whenConfigured {
+                        it.dependencies.forEach { dep ->
+                            if (dep == null) {
+                                return@forEach
+                            }
+
+                            val getGroupIdMethod =
+                                    dep::class.java.getDeclaredMethod("getGroupId")
+                            val groupId : String = getGroupIdMethod.invoke(dep) as String
+                            val getArtifactIdMethod =
+                                    dep::class.java.getDeclaredMethod("getArtifactId")
+                            val artifactId : String = getArtifactIdMethod.invoke(dep) as String
+
+                            if (isAndroidProject(groupId, artifactId, allDeps)) {
+                                val setTypeMethod = dep::class.java.getDeclaredMethod("setType",
+                                        java.lang.String::class.java)
+                                setTypeMethod.invoke(dep, "aar")
+                            }
+                        }
+                    }
+                }
+            }
+        } else {
+            uploadTask.enabled = false
+        }
+    }
+}
+
+private fun collectDependenciesForConfiguration(projectDependencies : MutableSet<ProjectDependency>,
+                                                project : Project, name : String) {
+    val config = project.configurations.findByName(name)
+    if (config != null) {
+        config.dependencies.withType(ProjectDependency::class.java).forEach {
+            dep -> projectDependencies.add(dep)
+        }
+    }
+}
+
+private fun isAndroidProject(groupId : String, artifactId : String,
+                             deps : Set<ProjectDependency>) : Boolean {
+    for (dep in deps) {
+        if (dep.group == groupId && dep.name == artifactId) {
+            return dep.getDependencyProject().plugins.hasPlugin(LibraryPlugin::class.java)
+        }
+    }
+    return false
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/SupportAndroidLibraryPlugin.kt b/buildSrc/src/main/kotlin/android/support/SupportAndroidLibraryPlugin.kt
new file mode 100644
index 0000000..b347415
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/SupportAndroidLibraryPlugin.kt
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+import com.android.build.gradle.LibraryExtension
+import com.android.build.gradle.internal.dsl.LintOptions
+import net.ltgt.gradle.errorprone.ErrorProneBasePlugin
+import net.ltgt.gradle.errorprone.ErrorProneToolChain
+import org.gradle.api.JavaVersion
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import java.io.File
+import java.util.*
+
+/**
+ * Support library specific com.android.library plugin that sets common configurations needed for
+ * support library modules.
+ */
+class SupportAndroidLibraryPlugin : Plugin<Project> {
+
+    override fun apply(project: Project) {
+        val supportLibraryExtension = project.extensions.create("supportLibrary",
+                SupportLibraryExtension::class.java, project)
+        apply(project, supportLibraryExtension)
+
+        project.afterEvaluate {
+            val library = project.extensions.findByType(LibraryExtension::class.java)
+                    ?: return@afterEvaluate
+
+            if (supportLibraryExtension.legacySourceLocation) {
+                // We use a non-standard manifest path.
+                library.sourceSets.getByName("main").manifest.srcFile("AndroidManifest.xml")
+
+                // We use a non-standard test directory structure.
+                val androidTest = library.sourceSets.getByName("androidTest")
+                androidTest.setRoot("tests")
+                androidTest.java.srcDir("tests/src")
+                androidTest.res.srcDir("tests/res")
+                androidTest.manifest.srcFile("tests/AndroidManifest.xml")
+            }
+
+            // Java 8 is only fully supported on API 24+ and not all Java 8 features are binary
+            // compatible with API < 24, so use Java 7 for both source AND target.
+            val javaVersion: JavaVersion;
+            if (supportLibraryExtension.java8Library) {
+                if (library.defaultConfig.minSdkVersion.apiLevel < 24) {
+                    throw IllegalArgumentException("Libraries can only support Java 8 if "
+                            + "minSdkVersion is 24 or higher");
+                }
+                javaVersion = JavaVersion.VERSION_1_8
+            } else {
+                javaVersion = JavaVersion.VERSION_1_7
+            }
+
+            library.compileOptions.setSourceCompatibility(javaVersion)
+            library.compileOptions.setTargetCompatibility(javaVersion)
+        }
+
+        VersionFileWriterTask.setUpAndroidLibrary(project)
+
+        project.apply(mapOf("plugin" to "com.android.library"))
+        project.apply(mapOf("plugin" to ErrorProneBasePlugin::class.java))
+
+        val library = project.extensions.findByType(LibraryExtension::class.java)
+                ?: throw Exception("Failed to find Android extension")
+
+        val currentSdk = project.property("currentSdk")
+        when (currentSdk) {
+            is Int -> library.compileSdkVersion(currentSdk)
+            is String -> library.compileSdkVersion(currentSdk)
+        }
+
+        // Update the version meta-data in each Manifest.
+        library.defaultConfig.addManifestPlaceholders(mapOf("target-sdk-version" to currentSdk))
+
+        // Set test runner.
+        library.defaultConfig.testInstrumentationRunner = INSTRUMENTATION_RUNNER
+
+        library.testOptions.unitTests.isReturnDefaultValues = true
+
+        // Use a local debug keystore to avoid build server issues.
+        val key = ((project.rootProject.property("init") as Properties)
+                .getValue("debugKeystore")) as File
+        library.signingConfigs.findByName("debug")?.storeFile = key
+
+        setUpLint(library.lintOptions, File(project.projectDir, "/lint-baseline.xml"))
+
+        if (project.rootProject.property("usingFullSdk") as Boolean) {
+            // Library projects don't run lint by default, so set up dependency.
+            project.tasks.getByName("uploadArchives").dependsOn("lintRelease")
+        }
+
+        SourceJarTaskHelper.setUpAndroidProject(project, library)
+
+        val toolChain = ErrorProneToolChain.create(project)
+        library.buildTypes.create("errorProne")
+        library.libraryVariants.all { libraryVariant ->
+            if (libraryVariant.getBuildType().getName().equals("errorProne")) {
+                @Suppress("DEPRECATION")
+                libraryVariant.getJavaCompile().setToolChain(toolChain);
+
+                @Suppress("DEPRECATION")
+                val compilerArgs = libraryVariant.getJavaCompile().options.compilerArgs
+                compilerArgs += arrayListOf(
+                        "-XDcompilePolicy=simple", // Workaround for b/36098770
+
+                        // Enforce the following checks.
+                        "-Xep:MissingOverride:ERROR",
+                        "-Xep:NarrowingCompoundAssignment:ERROR",
+                        "-Xep:ClassNewInstance:ERROR",
+                        "-Xep:ClassCanBeStatic:ERROR",
+                        "-Xep:SynchronizeOnNonFinalField:ERROR",
+                        "-Xep:OperatorPrecedence:ERROR"
+                )
+            }
+        }
+    }
+
+    companion object {
+        private val INSTRUMENTATION_RUNNER = "android.support.test.runner.AndroidJUnitRunner"
+    }
+}
+
+private fun setUpLint(lintOptions: LintOptions, baseline: File) {
+    // Always lint check NewApi as fatal.
+    lintOptions.isAbortOnError = true
+    lintOptions.isIgnoreWarnings = true
+
+    // Write output directly to the console (and nowhere else).
+    lintOptions.textOutput("stderr")
+    lintOptions.textReport = true
+    lintOptions.htmlReport = false
+
+    // Format output for convenience.
+    lintOptions.isExplainIssues = true
+    lintOptions.isNoLines = false
+    lintOptions.isQuiet = true
+
+    lintOptions.error("NewApi")
+
+    // Set baseline file for all legacy lint warnings.
+    if (System.getenv("GRADLE_PLUGIN_VERSION") != null) {
+        lintOptions.check("NewApi")
+    } else {
+        lintOptions.baseline(baseline)
+    }
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/SupportJavaLibraryPlugin.kt b/buildSrc/src/main/kotlin/android/support/SupportJavaLibraryPlugin.kt
new file mode 100644
index 0000000..8e0714b
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/SupportJavaLibraryPlugin.kt
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+import org.gradle.api.JavaVersion
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.plugins.JavaPluginConvention
+
+/**
+ * Support java library specific plugin that sets common configurations needed for
+ * support library modules.
+ */
+class SupportJavaLibraryPlugin : Plugin<Project> {
+
+    override fun apply(project: Project) {
+        val supportLibraryExtension = project.extensions.create("supportLibrary",
+                SupportLibraryExtension::class.java, project)
+        apply(project, supportLibraryExtension)
+
+        project.apply(mapOf("plugin" to "java"))
+        project.afterEvaluate {
+            val convention = project.convention.getPlugin(JavaPluginConvention::class.java)
+            if (supportLibraryExtension.java8Library) {
+                convention.sourceCompatibility = JavaVersion.VERSION_1_8
+                convention.targetCompatibility = JavaVersion.VERSION_1_8
+            } else {
+                convention.sourceCompatibility = JavaVersion.VERSION_1_7
+                convention.targetCompatibility = JavaVersion.VERSION_1_7
+            }
+        }
+
+        SourceJarTaskHelper.setUpJavaProject(project)
+    }
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/SupportLibraryExtension.kt b/buildSrc/src/main/kotlin/android/support/SupportLibraryExtension.kt
new file mode 100644
index 0000000..088e169
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/SupportLibraryExtension.kt
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support
+
+import groovy.lang.Closure
+import org.gradle.api.Project
+import java.util.ArrayList
+
+/**
+ * Extension for [SupportAndroidLibraryPlugin] and [SupportJavaLibraryPlugin].
+ */
+open class SupportLibraryExtension(val project: Project) {
+    var name: String? = null
+    var mavenVersion: Version? = null
+    var mavenGroup: String? = null
+    var description: String? = null
+    var inceptionYear: String? = null
+    var url = SUPPORT_URL
+    private var licenses: MutableCollection<License> = ArrayList()
+    var java8Library = false
+    var legacySourceLocation = false
+    var publish = false
+
+    fun license(closure: Closure<*>): License {
+        val license = project.configure(License(), closure) as License
+        licenses.add(license)
+        return license
+    }
+
+    fun getLicenses(): Collection<License> {
+        return licenses
+    }
+
+    companion object {
+        @JvmField
+        val ARCHITECTURE_URL = "https://developer.android.com/topic/libraries/architecture/index.html"
+        @JvmField
+        val SUPPORT_URL = "http://developer.android.com/tools/extras/support-library.html"
+    }
+}
+
+class License {
+    var name: String? = null
+    var url: String? = null
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/checkapi/CheckApiTask.kt b/buildSrc/src/main/kotlin/android/support/checkapi/CheckApiTask.kt
new file mode 100644
index 0000000..8f96b2e
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/checkapi/CheckApiTask.kt
@@ -0,0 +1,251 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.checkapi
+
+import org.gradle.api.DefaultTask
+import org.gradle.api.GradleException
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputFile
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.TaskAction
+import java.io.*
+import java.security.MessageDigest
+
+
+/** Character that resets console output color. */
+private const val ANSI_RESET = "\u001B[0m"
+
+/** Character that sets console output color to red. */
+private const val ANSI_RED = "\u001B[31m"
+
+/** Character that sets console output color to yellow. */
+private const val ANSI_YELLOW = "\u001B[33m"
+
+private val ERROR_REGEX = Regex("^(.+):(.+): (\\w+) (\\d+): (.+)$")
+
+private fun ByteArray.encodeHex() = fold(StringBuilder(), { builder, byte ->
+    val hexString = Integer.toHexString(byte.toInt() and 0xFF)
+    if (hexString.length < 2) {
+        builder.append("0")
+    }
+    builder.append(hexString)
+}).toString()
+
+private fun getShortHash(src: String): String {
+    val str = MessageDigest.getInstance("SHA-1")
+            .digest(src.toByteArray()).encodeHex()
+    val len = str.length
+    return str.substring(len - 7, len)
+}
+
+/**
+ * Task used to verify changes between two API files.
+ * <p>
+ * This task may be configured to ignore, warn, or fail with a message for a specific set of
+ * Doclava-defined error codes. See {@link com.google.doclava.Errors} for a complete list of
+ * supported error codes.
+ * <p>
+ * Specific failures may be ignored by specifying a list of SHAs in {@link #whitelistErrors}. Each
+ * SHA is unique to a specific API change and is logged to the error output on failure.
+ */
+open class CheckApiTask : DefaultTask() {
+
+    /** API file that represents the existing API surface. */
+    @Optional
+    @InputFile
+    var oldApiFile: File? = null
+
+    /** API file that represents the existing API surface's removals. */
+    @Optional
+    @InputFile
+    var oldRemovedApiFile: File? = null
+
+    /** API file that represents the candidate API surface. */
+    @InputFile
+    var newApiFile: File? = null
+
+    /** API file that represents the candidate API surface's removals. */
+    @Optional
+    @InputFile
+    var newRemovedApiFile: File? = null
+
+    /** Optional file containing a newline-delimited list of error SHAs to ignore. */
+    var whitelistErrorsFile: File? = null
+
+    @Optional
+    @InputFile
+    fun getWhiteListErrorsFileInput(): File? {
+        // Gradle requires non-null InputFiles to exist -- even with Optional -- so work around that
+        // by returning null for this field if the file doesn't exist.
+        if (whitelistErrorsFile?.exists() == true) {
+            return whitelistErrorsFile
+        }
+        return null
+    }
+
+    /**
+     * Optional set of error SHAs to ignore.
+     * <p>
+     * Each error SHA is unique to a specific API change.
+     */
+    @Optional
+    @Input
+    var whitelistErrors = emptySet<String>()
+
+    var detectedWhitelistErrors = mutableSetOf<String>()
+
+    @InputFiles
+    var doclavaClasspath: Collection<File> = emptyList()
+
+    // A dummy output file meant only to tag when this check was last ran.
+    // Without any outputs, Gradle will run this task every time.
+    @Optional
+    private var mOutputFile: File? = null
+
+    @OutputFile
+    fun getOutputFile(): File {
+        return if (mOutputFile != null)
+            mOutputFile!!
+        else File(project.buildDir, "checkApi/${name}-completed")
+    }
+
+    @Optional
+    fun setOutputFile(outputFile: File) {
+        mOutputFile = outputFile
+    }
+
+    /**
+     * List of Doclava error codes to treat as errors.
+     * <p>
+     * See {@link com.google.doclava.Errors} for a complete list of error codes.
+     */
+    @Input
+    var checkApiErrors: Collection<Int> = emptyList()
+
+    /**
+     * List of Doclava error codes to treat as warnings.
+     * <p>
+     * See {@link com.google.doclava.Errors} for a complete list of error codes.
+     */
+    @Input
+    var checkApiWarnings: Collection<Int> = emptyList()
+
+    /**
+     * List of Doclava error codes to ignore.
+     * <p>
+     * See {@link com.google.doclava.Errors} for a complete list of error codes.
+     */
+    @Input
+    var checkApiHidden: Collection<Int> = emptyList()
+
+    /** Message to display on API check failure. */
+    @Input
+    var onFailMessage: String = "Failed."
+
+    init {
+        group = "Verification"
+        description = "Invoke Doclava\'s ApiCheck tool to make sure current.txt is up to date."
+    }
+
+    private fun collectAndVerifyInputs(): Set<File> {
+        if (oldRemovedApiFile != null && newRemovedApiFile != null) {
+            return setOf(oldApiFile!!, newApiFile!!, oldRemovedApiFile!!, newRemovedApiFile!!)
+        } else {
+            return setOf(oldApiFile!!, newApiFile!!)
+        }
+    }
+
+    @TaskAction
+    fun exec() {
+        if (oldApiFile == null) {
+            // Nothing to do.
+            return
+        }
+
+        val apiFiles = collectAndVerifyInputs()
+
+        val errStream = ByteArrayOutputStream()
+
+        // If either of those gets tweaked, then this should be refactored to extend JavaExec.
+        project.javaexec { spec ->
+            spec.apply {
+                // Put Doclava on the classpath so we can get the ApiCheck class.
+                classpath(doclavaClasspath)
+                main = "com.google.doclava.apicheck.ApiCheck"
+
+                minHeapSize = "128m"
+                maxHeapSize = "1024m"
+
+                // add -error LEVEL for every error level we want to fail the build on.
+                checkApiErrors.forEach { args("-error", it) }
+                checkApiWarnings.forEach { args("-warning", it) }
+                checkApiHidden.forEach { args("-hide", it) }
+
+                spec.args(apiFiles.map { it.absolutePath })
+
+                // Redirect error output so that we can whitelist specific errors.
+                errorOutput = errStream
+                // We will be handling failures ourselves with a custom message.
+                setIgnoreExitValue(true)
+            }
+        }
+
+
+        // Load the whitelist file, if present.
+        val whitelistFile = whitelistErrorsFile
+        if (whitelistFile?.exists() == true) {
+            whitelistErrors += whitelistFile.readLines()
+        }
+
+        // Parse the error output.
+        val unparsedErrors = mutableSetOf<String>()
+        val detectedErrors = mutableSetOf<List<String>>()
+        val parsedErrors = mutableSetOf<List<String>>()
+        ByteArrayInputStream(errStream.toByteArray()).bufferedReader().lines().forEach {
+            val match = ERROR_REGEX.matchEntire(it)
+
+            if (match == null) {
+                unparsedErrors.add(it)
+            } else if (match.groups[3]?.value == "error") {
+                val hash = getShortHash(match.groups[5]?.value!!)
+                val error = match.groupValues.subList(1, match.groupValues.size) + listOf(hash)
+                if (hash in whitelistErrors) {
+                    detectedErrors.add(error)
+                    detectedWhitelistErrors.add(error[5])
+                } else {
+                    parsedErrors.add(error)
+                }
+            }
+        }
+
+        unparsedErrors.forEach { error -> logger.error("$ANSI_RED$error$ANSI_RESET") }
+        parsedErrors.forEach { logger.error("$ANSI_RED${it[5]}$ANSI_RESET ${it[4]}") }
+        detectedErrors.forEach { logger.warn("$ANSI_YELLOW${it[5]}$ANSI_RESET ${it[4]}") }
+
+        if (unparsedErrors.isNotEmpty() || parsedErrors.isNotEmpty()) {
+            throw GradleException(onFailMessage)
+        }
+
+        // Just create a dummy file upon completion. Without any outputs, Gradle will run this task
+        // every time.
+        val outputFile = getOutputFile()
+        outputFile.parentFile.mkdirs()
+        outputFile.createNewFile()
+    }
+}
\ No newline at end of file
diff --git a/buildSrc/src/main/kotlin/android/support/doclava/DoclavaJavadocOptionFileOption.kt b/buildSrc/src/main/kotlin/android/support/doclava/DoclavaJavadocOptionFileOption.kt
new file mode 100644
index 0000000..828fb25
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/doclava/DoclavaJavadocOptionFileOption.kt
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.doclava
+
+import org.gradle.external.javadoc.internal.AbstractJavadocOptionFileOption
+import org.gradle.external.javadoc.internal.JavadocOptionFileWriterContext
+import java.io.IOException
+import java.util.ArrayList
+
+//TODO: remove this once https://github.com/gradle/gradle/issues/2354 is fixed
+class DoclavaJavadocOptionFileOption : AbstractJavadocOptionFileOption<Iterable<String>> {
+
+    constructor(option: String) : super(option, null)
+
+    constructor(option: String, value: Iterable<String>?) : super(option, value)
+
+    @Throws(IOException::class)
+    override fun write(writerContext: JavadocOptionFileWriterContext) {
+        writerContext.writeOptionHeader(getOption())
+        val args = getValue()
+        if (args != null) {
+            val iter = args.iterator()
+            while (true) {
+                writerContext.writeValue(iter.next())
+                if (!iter.hasNext()) {
+                    break
+                }
+                writerContext.write(" ")
+            }
+        }
+        writerContext.newLine()
+    }
+    /**
+     * @return a deep copy of the option
+     */
+    override fun duplicate(): DoclavaJavadocOptionFileOption {
+        val value = getValue()
+        val valueCopy: ArrayList<String>?
+        if (value != null) {
+            valueCopy = ArrayList()
+            valueCopy += value
+        } else {
+            valueCopy = null
+        }
+        return DoclavaJavadocOptionFileOption(getOption(), valueCopy)
+    }
+}
diff --git a/buildSrc/src/main/kotlin/android/support/doclava/DoclavaTask.kt b/buildSrc/src/main/kotlin/android/support/doclava/DoclavaTask.kt
new file mode 100644
index 0000000..1007535
--- /dev/null
+++ b/buildSrc/src/main/kotlin/android/support/doclava/DoclavaTask.kt
@@ -0,0 +1,210 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.doclava
+
+import org.gradle.api.tasks.Input
+import org.gradle.api.tasks.InputFiles
+import org.gradle.api.tasks.Optional
+import org.gradle.api.tasks.OutputDirectory
+import org.gradle.api.tasks.OutputFile
+import org.gradle.api.tasks.javadoc.Javadoc
+import org.gradle.external.javadoc.CoreJavadocOptions
+import java.io.File
+
+// external/doclava/src/com/google/doclava/Errors.java
+private val DEFAULT_DOCLAVA_ERRORS = setOf<Int>(
+        101,  // unresolved link
+        103,  // unknown tag
+        104   // unknown param name
+)
+
+private val DEFAULT_DOCLAVA_WARNINGS = setOf<Int>(121 /* hidden type param */)
+
+private val DEFAULT_DOCLAVA_HIDDEN = setOf<Int>(
+        111,  // hidden super class
+        113   // @deprecation mismatch
+)
+
+private fun <E> CoreJavadocOptions.addMultilineMultiValueOption(
+        name: String, values: Collection<E>) {
+    addMultilineMultiValueOption(name).setValue(values.map { listOf(it.toString()) })
+}
+
+open class DoclavaTask : Javadoc() {
+
+    // All lowercase name to match MinimalJavadocOptions#docletpath
+    private var docletpath: List<File> = emptyList()
+
+    // doclava error types which will cause the build to fail
+    @Input
+    var doclavaErrors = DEFAULT_DOCLAVA_ERRORS
+
+    @Input
+    var doclavaWarnings = DEFAULT_DOCLAVA_WARNINGS
+
+    // spammy doclava warnings which we want to hide
+    @Input
+    var doclavaHidden = DEFAULT_DOCLAVA_HIDDEN
+
+    /**
+     * If non-null, the list of packages that will be treated as if they were
+     * marked with {@literal @hide}.<br>
+     * Packages names will be matched exactly; sub-packages are not automatically recognized.
+     */
+    @Optional
+    @Input
+    var hiddenPackages: Collection<String>? = null
+
+    /**
+     * If non-null and not-empty, the whitelist of packages that will be present in the generated
+     * stubs; if null or empty, then all packages have stubs generated.<br>
+     * Wildcards are accepted.
+     */
+    @Optional
+    @Input
+    var stubPackages: Set<String>? = null
+
+    @Input
+    var generateDocs = true
+
+    /**
+     * If non-null, the location of where to place the generated api file.
+     * If this is non-null, then {@link #removedApiFile} must be non-null as well.
+     */
+    @Optional
+    @OutputFile
+    var apiFile: File? = null
+
+    /**
+     * If non-null, the location of where to place the generated removed api file.
+     * If this is non-null, then {@link #apiFile} must be non-null as well.
+     */
+    @Optional
+    @OutputFile
+    var removedApiFile: File? = null
+
+    /**
+     * If non-null, the location of the generated keep list.
+     */
+    @Optional
+    @OutputFile
+    var keepListFile: File? = null
+
+    /**
+     * If non-null, the location to put the generated stub sources.
+     */
+    @Optional
+    @OutputDirectory
+    var stubsDir: File? = null
+
+    init {
+        setFailOnError(true)
+        options.doclet = "com.google.doclava.Doclava"
+        options.encoding("UTF-8")
+        options.quiet()
+        // doclava doesn't understand '-doctitle'
+        title = null
+        maxMemory = "1280m"
+        // If none of generateDocs, apiFile, keepListFile, or stubJarsDir are true, then there is
+        // no work to do.
+        onlyIf({ generateDocs || apiFile != null || keepListFile != null || stubsDir != null })
+    }
+
+    /**
+     * The doclet path which has the {@code com.gogole.doclava.Doclava} class.
+     * This option will override any doclet path set in this instance's {@link #options JavadocOptions}.
+     * @see MinimalJavadocOptions#getDocletpath()
+     */
+    @InputFiles
+    fun getDocletpath(): List<File> {
+        return docletpath
+    }
+
+    /**
+     * Sets the doclet path which has the {@code com.gogole.doclava.Doclava} class.
+     * This option will override any doclet path set in this instance's {@link #options JavadocOptions}.
+     * @see MinimalJavadocOptions#setDocletpath(java.util.List)
+     */
+    fun setDocletpath(docletpath: Collection<File>) {
+        this.docletpath = docletpath.toList()
+        // Go ahead and keep the docletpath in our JavadocOptions object in sync.
+        options.docletpath = docletpath.toList()
+    }
+
+    fun setDoclavaErrors(errors: List<Int> ) {
+        // Make it serializable.
+        doclavaErrors = errors.toSet()
+    }
+
+    fun setDoclavaWarnings(warnings: List<Int>) {
+        // Make it serializable.
+        doclavaWarnings = warnings.toSet()
+    }
+
+    fun setDoclavaHidden(hidden: List<Int>) {
+        // Make it serializable.
+        doclavaHidden = hidden.toSet()
+    }
+
+    /**
+     * "Configures" this DoclavaTask with parameters that might not be at their final values
+     * until this task is run.
+     */
+    private fun configureDoclava() = (options as CoreJavadocOptions).apply {
+
+        docletpath = this@DoclavaTask.docletpath
+
+        // configure doclava error/warning/hide levels
+        addMultilineMultiValueOption("hide", doclavaHidden)
+        addMultilineMultiValueOption("warning", doclavaWarnings)
+        addMultilineMultiValueOption("error", doclavaErrors)
+
+        if (hiddenPackages != null) {
+            addMultilineMultiValueOption("hidePackage", hiddenPackages!!)
+        }
+
+        if (!generateDocs) {
+            addOption(DoclavaJavadocOptionFileOption("nodocs"))
+        }
+
+        // If requested, generate the API files.
+        if (apiFile != null) {
+            addFileOption("api", apiFile)
+            addFileOption("removedApi", removedApiFile)
+        }
+
+        // If requested, generate the keep list.
+        addFileOption("proguard", keepListFile)
+
+        // If requested, generate stubs.
+        if (stubsDir != null) {
+            addFileOption("stubs", stubsDir)
+            val stubs = stubPackages
+            if (stubs != null) {
+                addStringOption("stubpackages", stubs.joinToString(":"))
+            }
+        }
+        // Always treat this as an Android docs task.
+        addOption(DoclavaJavadocOptionFileOption("android"))
+    }
+
+    override fun generate() {
+        configureDoclava()
+        super.generate()
+    }
+}
+
diff --git a/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportAndroidLibraryPlugin.properties b/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportAndroidLibraryPlugin.properties
new file mode 100644
index 0000000..222602b
--- /dev/null
+++ b/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportAndroidLibraryPlugin.properties
@@ -0,0 +1 @@
+implementation-class=android.support.SupportAndroidLibraryPlugin
\ No newline at end of file
diff --git a/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportJavaLibraryPlugin.properties b/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportJavaLibraryPlugin.properties
new file mode 100644
index 0000000..89755b7
--- /dev/null
+++ b/buildSrc/src/main/resources/META-INF/gradle-plugins/SupportJavaLibraryPlugin.properties
@@ -0,0 +1 @@
+implementation-class=android.support.SupportJavaLibraryPlugin
\ No newline at end of file
diff --git a/compat/build.gradle b/compat/build.gradle
index 1e5d847..82d503c 100644
--- a/compat/build.gradle
+++ b/compat/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -30,8 +35,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library compat'
-    publish true
-    inceptionYear '2015'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library compat"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/compat/src/main/java/android/support/v4/graphics/TypefaceCompatApi26Impl.java b/compat/src/main/java/android/support/v4/graphics/TypefaceCompatApi26Impl.java
index 1b55a2e..a608403 100644
--- a/compat/src/main/java/android/support/v4/graphics/TypefaceCompatApi26Impl.java
+++ b/compat/src/main/java/android/support/v4/graphics/TypefaceCompatApi26Impl.java
@@ -196,10 +196,9 @@
     /**
      * Call FontFamily#abortCreation()
      */
-    private static boolean abortCreation(Object family) {
+    private static void abortCreation(Object family) {
         try {
-            Boolean result = (Boolean) sAbortCreation.invoke(family);
-            return result.booleanValue();
+            sAbortCreation.invoke(family);
         } catch (IllegalAccessException | InvocationTargetException e) {
             throw new RuntimeException(e);
         }
diff --git a/compat/src/main/java/android/support/v4/view/NestedScrollingParent2.java b/compat/src/main/java/android/support/v4/view/NestedScrollingParent2.java
index db41c46..2ab463e 100644
--- a/compat/src/main/java/android/support/v4/view/NestedScrollingParent2.java
+++ b/compat/src/main/java/android/support/v4/view/NestedScrollingParent2.java
@@ -18,7 +18,6 @@
 package android.support.v4.view;
 
 import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 import android.support.v4.view.ViewCompat.NestedScrollType;
 import android.support.v4.view.ViewCompat.ScrollAxis;
 import android.view.MotionEvent;
@@ -144,7 +143,7 @@
      * @param consumed Output. The horizontal and vertical scroll distance consumed by this parent
      * @param type the type of input which cause this scroll event
      */
-    void onNestedPreScroll(@NonNull View target, int dx, int dy, @Nullable int[] consumed,
+    void onNestedPreScroll(@NonNull View target, int dx, int dy, @NonNull int[] consumed,
             @NestedScrollType int type);
 
 }
diff --git a/content/build.gradle b/content/build.gradle
index af33423..3639301 100644
--- a/content/build.gradle
+++ b/content/build.gradle
@@ -14,7 +14,12 @@
  * limitations under the License.
  */
 
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -32,8 +37,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Content'
-    publish true
-    inceptionYear '2017'
-    description 'Library providing support for paging across content exposed via a ContentProvider. Use of this library allows a client to avoid expensive interprocess "cursor window swaps" on the UI thread.'
+    name = "Android Support Content"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "Library providing support for paging across content exposed via a ContentProvider. Use of this library allows a client to avoid expensive interprocess \"cursor window swaps\" on the UI thread."
+    legacySourceLocation = true
 }
diff --git a/core-ui/build.gradle b/core-ui/build.gradle
index 38a4fe2..cd70447 100644
--- a/core-ui/build.gradle
+++ b/core-ui/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -22,8 +27,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library core UI'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library core UI"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/core-utils/build.gradle b/core-utils/build.gradle
index 55fe2bb..b384a37 100644
--- a/core-utils/build.gradle
+++ b/core-utils/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -17,8 +22,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library core utils'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library core utils"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/customtabs/build.gradle b/customtabs/build.gradle
index fc90301..28b5f99 100644
--- a/customtabs/build.gradle
+++ b/customtabs/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -20,8 +25,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Custom Tabs'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support Custom Tabs'
+    name = "Android Support Custom Tabs"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support Custom Tabs"
+    legacySourceLocation = true
 }
diff --git a/design/build.gradle b/design/build.gradle
index 4a82051..3af966d 100644
--- a/design/build.gradle
+++ b/design/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-v4')
@@ -59,8 +64,11 @@
 }
 
 supportLibrary {
-    name 'Android Design Support Library'
-    publish true
-    inceptionYear '2015'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Design Support Library"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/design/src/android/support/design/widget/BottomSheetBehavior.java b/design/src/android/support/design/widget/BottomSheetBehavior.java
index aaa9b80..00ce8f9 100644
--- a/design/src/android/support/design/widget/BottomSheetBehavior.java
+++ b/design/src/android/support/design/widget/BottomSheetBehavior.java
@@ -559,7 +559,7 @@
      * Gets the current state of the bottom sheet.
      *
      * @return One of {@link #STATE_EXPANDED}, {@link #STATE_COLLAPSED}, {@link #STATE_DRAGGING},
-     * and {@link #STATE_SETTLING}.
+     * {@link #STATE_SETTLING}, and {@link #STATE_HIDDEN}.
      */
     @State
     public final int getState() {
diff --git a/design/src/android/support/design/widget/TextInputEditText.java b/design/src/android/support/design/widget/TextInputEditText.java
index 7235ec2..ee6c32c 100644
--- a/design/src/android/support/design/widget/TextInputEditText.java
+++ b/design/src/android/support/design/widget/TextInputEditText.java
@@ -18,6 +18,7 @@
 
 import android.content.Context;
 import android.support.v7.widget.AppCompatEditText;
+import android.support.v7.widget.WithHint;
 import android.util.AttributeSet;
 import android.view.View;
 import android.view.ViewParent;
@@ -48,12 +49,12 @@
     public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
         final InputConnection ic = super.onCreateInputConnection(outAttrs);
         if (ic != null && outAttrs.hintText == null) {
-            // If we don't have a hint and our parent is a TextInputLayout, use it's hint for the
+            // If we don't have a hint and our parent implements WithHint, use its hint for the
             // EditorInfo. This allows us to display a hint in 'extract mode'.
             ViewParent parent = getParent();
             while (parent instanceof View) {
-                if (parent instanceof TextInputLayout) {
-                    outAttrs.hintText = ((TextInputLayout) parent).getHint();
+                if (parent instanceof WithHint) {
+                    outAttrs.hintText = ((WithHint) parent).getHint();
                     break;
                 }
                 parent = parent.getParent();
diff --git a/design/src/android/support/design/widget/TextInputLayout.java b/design/src/android/support/design/widget/TextInputLayout.java
index c9e8010..2ed79e4 100644
--- a/design/src/android/support/design/widget/TextInputLayout.java
+++ b/design/src/android/support/design/widget/TextInputLayout.java
@@ -53,6 +53,7 @@
 import android.support.v7.widget.AppCompatDrawableManager;
 import android.support.v7.widget.AppCompatTextView;
 import android.support.v7.widget.TintTypedArray;
+import android.support.v7.widget.WithHint;
 import android.text.Editable;
 import android.text.TextUtils;
 import android.text.TextWatcher;
@@ -113,7 +114,7 @@
  * may not return the TextInputLayout itself, but rather an intermediate View. If you need
  * to access a View directly, set an {@code android:id} and use {@link View#findViewById(int)}.
  */
-public class TextInputLayout extends LinearLayout {
+public class TextInputLayout extends LinearLayout implements WithHint {
 
     private static final int ANIMATION_DURATION = 200;
     private static final int INVALID_MAX_LENGTH = -1;
@@ -497,6 +498,7 @@
      *
      * @attr ref android.support.design.R.styleable#TextInputLayout_android_hint
      */
+    @Override
     @Nullable
     public CharSequence getHint() {
         return mHintEnabled ? mHint : null;
diff --git a/dynamic-animation/build.gradle b/dynamic-animation/build.gradle
index 220758d..5069a73 100644
--- a/dynamic-animation/build.gradle
+++ b/dynamic-animation/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-core-utils')
@@ -16,8 +21,11 @@
 }
 
 supportLibrary {
-    name 'Android Support DynamicAnimation'
-    publish true
-    inceptionYear '2017'
-    description "Physics-based animation in support library, where the animations are driven by physics force. You can use this Animation library to create smooth and realistic animations."
+    name = "Android Support DynamicAnimation"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "Physics-based animation in support library, where the animations are driven by physics force. You can use this Animation library to create smooth and realistic animations."
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/emoji/appcompat/build.gradle b/emoji/appcompat/build.gradle
index e22000c..7912c52 100644
--- a/emoji/appcompat/build.gradle
+++ b/emoji/appcompat/build.gradle
@@ -14,7 +14,12 @@
  * limitations under the License.
  */
 
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api fileTree(include: ['*.jar'], dir: 'libs')
@@ -29,8 +34,11 @@
 }
 
 supportLibrary {
-    name 'Android Emoji AppCompat'
-    publish true
-    inceptionYear '2017'
-    description 'EmojiCompat Widgets for AppCompat integration'
+    name = "Android Emoji AppCompat"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "EmojiCompat Widgets for AppCompat integration"
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/emoji/bundled/build.gradle b/emoji/bundled/build.gradle
index 766d165..c0613f2 100644
--- a/emoji/bundled/build.gradle
+++ b/emoji/bundled/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 ext {
     fontDir = project(':noto-emoji-compat').projectDir
@@ -19,18 +24,21 @@
 }
 
 supportLibrary {
-    name 'Android Emoji Compat'
-    publish true
-    inceptionYear '2017'
-    description 'Library bundled with assets to enable emoji compatibility in Kitkat and newer devices to avoid the empty emoji characters.'
+    name = "Android Emoji Compat"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "Library bundled with assets to enable emoji compatibility in Kitkat and newer devices to avoid the empty emoji characters."
 
     license {
-        name 'SIL Open Font License, Version 1.1'
-        url  'http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web'
+        name = "SIL Open Font License, Version 1.1"
+        url = "http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web"
     }
 
     license {
-        name 'Unicode, Inc. License'
-        url 'http://www.unicode.org/copyright.html#License'
+        name = "Unicode, Inc. License"
+        url = "http://www.unicode.org/copyright.html#License"
     }
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/emoji/core/build.gradle b/emoji/core/build.gradle
index b4cd3fc..f07c277 100644
--- a/emoji/core/build.gradle
+++ b/emoji/core/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 ext {
     fontDir = project(':noto-emoji-compat').projectDir
@@ -29,13 +34,22 @@
     }
 
     sourceSets {
-        main.res.srcDirs += 'src/main/res-public'
-        main.resources {
-            srcDirs = [fontDir.getAbsolutePath()]
-            includes = ["LICENSE_UNICODE", "LICENSE_OFL"]
+        main {
+            // We use a non-standard manifest path.
+            manifest.srcFile 'AndroidManifest.xml'
+            res.srcDirs += 'src/main/res-public'
+            resources {
+                srcDirs = [fontDir.getAbsolutePath()]
+                includes = ["LICENSE_UNICODE", "LICENSE_OFL"]
+            }
         }
 
         androidTest {
+            // We use a non-standard test directory structure.
+            root 'tests'
+            java.srcDir 'tests/src'
+            res.srcDir 'tests/res'
+            manifest.srcFile 'tests/AndroidManifest.xml'
             assets {
                 srcDirs = [new File(fontDir, "font").getAbsolutePath(),
                            new File(fontDir, "supported-emojis").getAbsolutePath()]
@@ -45,18 +59,20 @@
 }
 
 supportLibrary {
-    name 'Android Emoji Compat'
-    publish true
-    inceptionYear '2017'
-    description 'Core library to enable emoji compatibility in Kitkat and newer devices to avoid the empty emoji characters.'
+    name = "Android Emoji Compat"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "Core library to enable emoji compatibility in Kitkat and newer devices to avoid the empty emoji characters."
 
     license {
-        name 'SIL Open Font License, Version 1.1'
-        url  'http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web'
+        name = "SIL Open Font License, Version 1.1"
+        url = "http://scripts.sil.org/cms/scripts/page.php?item_id=OFL_web"
     }
 
     license {
-        name 'Unicode, Inc. License'
-        url 'http://www.unicode.org/copyright.html#License'
+        name = "Unicode, Inc. License"
+        url = "http://www.unicode.org/copyright.html#License"
     }
 }
diff --git a/exifinterface/build.gradle b/exifinterface/build.gradle
index 3e034b1..b7218f9 100644
--- a/exifinterface/build.gradle
+++ b/exifinterface/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -13,8 +18,11 @@
 }
 
 supportLibrary {
-    name 'Android Support ExifInterface'
-    publish true
-    inceptionYear '2016'
-    description 'Android Support ExifInterface'
+    name = "Android Support ExifInterface"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2016"
+    description = "Android Support ExifInterface"
+    legacySourceLocation = true
 }
diff --git a/fragment/build.gradle b/fragment/build.gradle
index 3a86f38..dfb6ca9 100644
--- a/fragment/build.gradle
+++ b/fragment/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -19,9 +24,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library fragment'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library fragment"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
-
diff --git a/fragment/src/main/java/android/support/v4/app/FragmentActivity.java b/fragment/src/main/java/android/support/v4/app/FragmentActivity.java
index 614ff35..78161a8 100644
--- a/fragment/src/main/java/android/support/v4/app/FragmentActivity.java
+++ b/fragment/src/main/java/android/support/v4/app/FragmentActivity.java
@@ -536,7 +536,7 @@
     @Override
     protected void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
-        markState(getSupportFragmentManager(), Lifecycle.State.CREATED);
+        markFragmentsCreated();
         Parcelable p = mFragments.saveAllState();
         if (p != null) {
             outState.putParcelable(FRAGMENTS_TAG, p);
@@ -591,7 +591,7 @@
         super.onStop();
 
         mStopped = true;
-        markState(getSupportFragmentManager(), Lifecycle.State.CREATED);
+        markFragmentsCreated();
         mHandler.sendEmptyMessage(MSG_REALLY_STOPPED);
 
         mFragments.dispatchStop();
@@ -970,18 +970,30 @@
         }
     }
 
-    private static void markState(FragmentManager manager, Lifecycle.State state) {
+    private void markFragmentsCreated() {
+        boolean reiterate;
+        do {
+            reiterate = markState(getSupportFragmentManager(), Lifecycle.State.CREATED);
+        } while (reiterate);
+    }
+
+    private static boolean markState(FragmentManager manager, Lifecycle.State state) {
+        boolean hadNotMarked = false;
         Collection<Fragment> fragments = manager.getFragments();
         for (Fragment fragment : fragments) {
             if (fragment == null) {
                 continue;
             }
-            fragment.mLifecycleRegistry.markState(state);
+            if (fragment.getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)) {
+                fragment.mLifecycleRegistry.markState(state);
+                hadNotMarked = true;
+            }
 
             FragmentManager childFragmentManager = fragment.peekChildFragmentManager();
             if (childFragmentManager != null) {
-                markState(childFragmentManager, state);
+                hadNotMarked |= markState(childFragmentManager, state);
             }
         }
+        return hadNotMarked;
     }
 }
diff --git a/fragment/tests/java/android/support/v4/app/FragmentArchLifecycleTest.java b/fragment/tests/java/android/support/v4/app/FragmentArchLifecycleTest.java
new file mode 100644
index 0000000..7e8ed1f
--- /dev/null
+++ b/fragment/tests/java/android/support/v4/app/FragmentArchLifecycleTest.java
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.v4.app;
+
+import android.arch.lifecycle.Lifecycle;
+import android.arch.lifecycle.LifecycleObserver;
+import android.arch.lifecycle.OnLifecycleEvent;
+import android.os.Bundle;
+import android.support.test.annotation.UiThreadTest;
+import android.support.test.filters.SmallTest;
+import android.support.test.rule.ActivityTestRule;
+import android.support.test.runner.AndroidJUnit4;
+import android.support.v4.app.test.EmptyFragmentTestActivity;
+
+import junit.framework.Assert;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class FragmentArchLifecycleTest {
+
+    @Rule
+    public ActivityTestRule<EmptyFragmentTestActivity> mActivityRule =
+            new ActivityTestRule<>(EmptyFragmentTestActivity.class);
+
+    @Test
+    @UiThreadTest
+    public void testFragmentAdditionDuringOnStop() {
+        final EmptyFragmentTestActivity activity = mActivityRule.getActivity();
+        final FragmentManager fm = activity.getSupportFragmentManager();
+
+        final Fragment first = new Fragment();
+        final Fragment second = new Fragment();
+        fm.beginTransaction().add(first, "first").commitNow();
+        first.getLifecycle().addObserver(new LifecycleObserver() {
+            @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
+            public void onStop() {
+                fm.beginTransaction().add(second, "second").commitNow();
+                first.getLifecycle().removeObserver(this);
+            }
+        });
+        activity.onSaveInstanceState(new Bundle());
+        Assert.assertEquals(Lifecycle.State.CREATED, first.getLifecycle().getCurrentState());
+        Assert.assertEquals(Lifecycle.State.CREATED, second.getLifecycle().getCurrentState());
+        Assert.assertEquals(Lifecycle.State.CREATED, activity.getLifecycle().getCurrentState());
+    }
+}
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 6314766..96e6dab 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=../../../../tools/external/gradle/gradle-4.1-bin.zip
+distributionUrl=../../../../tools/external/gradle/gradle-4.3-bin.zip
diff --git a/graphics/drawable/animated/build.gradle b/graphics/drawable/animated/build.gradle
index 6036284..bfe405f 100644
--- a/graphics/drawable/animated/build.gradle
+++ b/graphics/drawable/animated/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-vector-drawable')
@@ -25,8 +30,11 @@
 }
 
 supportLibrary {
-    name 'Android Support AnimatedVectorDrawable'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support AnimatedVectorDrawable'
+    name = "Android Support AnimatedVectorDrawable"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support AnimatedVectorDrawable"
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/graphics/drawable/static/build.gradle b/graphics/drawable/static/build.gradle
index 949ba89..b8ab699 100644
--- a/graphics/drawable/static/build.gradle
+++ b/graphics/drawable/static/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -20,8 +25,11 @@
 }
 
 supportLibrary {
-    name 'Android Support VectorDrawable'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support VectorDrawable'
-}
+    name = "Android Support VectorDrawable"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support VectorDrawable"
+    legacySourceLocation = true
+}
\ No newline at end of file
diff --git a/lifecycle/common-java8/build.gradle b/lifecycle/common-java8/build.gradle
index fccc813..7877b81 100644
--- a/lifecycle/common-java8/build.gradle
+++ b/lifecycle/common-java8/build.gradle
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions;
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 dependencies {
     testCompile libs.junit
@@ -28,12 +31,13 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.LIFECYCLES_EXT.toString()
 supportLibrary {
-    name 'Android Lifecycle-Common for Java 8 Language'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycle-Common for Java 8 Language"
-    url SupportLibraryExtension.ARCHITECTURE_URL
-    java8Library true
+    name = "Android Lifecycle-Common for Java 8 Language"
+    publish = true
+    mavenVersion = LibraryVersions.LIFECYCLES_EXT
+    mavenGroup = LibraryGroups.LIFECYCLE
+    inceptionYear = "2017"
+    description = "Android Lifecycle-Common for Java 8 Language"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
+    java8Library = true
 }
diff --git a/lifecycle/common/build.gradle b/lifecycle/common/build.gradle
index 57cfd00..a3b06dd 100644
--- a/lifecycle/common/build.gradle
+++ b/lifecycle/common/build.gradle
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions;
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 dependencies {
     testCompile libs.junit
@@ -27,11 +30,12 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.LIFECYCLES_CORE.toString()
 supportLibrary {
-    name 'Android Lifecycle-Common'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycle-Common"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Lifecycle-Common"
+    publish = true
+    mavenVersion = LibraryVersions.LIFECYCLES_CORE
+    mavenGroup = LibraryGroups.LIFECYCLE
+    inceptionYear = "2017"
+    description = "Android Lifecycle-Common"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/lifecycle/compiler/build.gradle b/lifecycle/compiler/build.gradle
index e784f80..edc54b0 100644
--- a/lifecycle/compiler/build.gradle
+++ b/lifecycle/compiler/build.gradle
@@ -1,3 +1,4 @@
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 apply plugin: android.support.SupportKotlinLibraryPlugin
@@ -40,9 +41,11 @@
 }
 
 supportLibrary {
-    name 'Android Lifecycles Compiler'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycles annotation processor"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Lifecycles Compiler"
+    publish = true
+    mavenVersion = LibraryVersions.LIFECYCLES_CORE
+    mavenGroup = LibraryGroups.LIFECYCLE
+    inceptionYear = "2017"
+    description = "Android Lifecycles annotation processor"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
diff --git a/lifecycle/compiler/src/main/kotlin/android/arch/lifecycle/LifecycleProcessor.kt b/lifecycle/compiler/src/main/kotlin/android/arch/lifecycle/LifecycleProcessor.kt
index 2edb234..5355615 100644
--- a/lifecycle/compiler/src/main/kotlin/android/arch/lifecycle/LifecycleProcessor.kt
+++ b/lifecycle/compiler/src/main/kotlin/android/arch/lifecycle/LifecycleProcessor.kt
@@ -24,7 +24,6 @@
 import javax.lang.model.element.TypeElement
 
 @SupportedAnnotationTypes("android.arch.lifecycle.OnLifecycleEvent")
-@SupportedSourceVersion(SourceVersion.RELEASE_7)
 class LifecycleProcessor : AbstractProcessor() {
     override fun process(annotations: MutableSet<out TypeElement>,
                          roundEnv: RoundEnvironment): Boolean {
@@ -32,4 +31,8 @@
         writeModels(transformToOutput(processingEnv, input), processingEnv)
         return true
     }
+
+    override fun getSupportedSourceVersion(): SourceVersion {
+        return SourceVersion.latest()
+    }
 }
diff --git a/lifecycle/extensions/build.gradle b/lifecycle/extensions/build.gradle
index 79be36c..6bd1bce 100644
--- a/lifecycle/extensions/build.gradle
+++ b/lifecycle/extensions/build.gradle
@@ -14,40 +14,34 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes.all {
         consumerProguardFiles 'proguard-rules.pro'
     }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
 }
-dependencies {
-    compile project(":lifecycle:runtime")
-    compile project(":arch:common")
-    compile project(":arch:runtime")
-    compile libs.support.fragments, libs.support_exclude_config
-    compile project(":lifecycle:common")
 
-    testCompile project(":arch:core-testing")
-    testCompile libs.junit
-    testCompile libs.mockito_core
+dependencies {
+    api project(":lifecycle:runtime")
+    api project(":arch:common")
+    api project(":arch:runtime")
+    api libs.support.fragments, libs.support_exclude_config
+    api project(":lifecycle:common")
+
+    testImplementation project(":arch:core-testing")
+    testImplementation libs.junit
+    testImplementation libs.mockito_core
 
     androidTestImplementation libs.test_runner,      { exclude module: 'support-annotations' }
     androidTestImplementation libs.espresso_core,    { exclude module: 'support-annotations' }
@@ -56,11 +50,12 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.LIFECYCLES_EXT.toString()
 supportLibrary {
-    name 'Android Lifecycle Extensions'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycle Extensions"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Lifecycle Extensions"
+    publish = true
+    mavenVersion = LibraryVersions.LIFECYCLES_EXT
+    mavenGroup = LibraryGroups.LIFECYCLE
+    inceptionYear = "2017"
+    description = "Android Lifecycle Extensions"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/lifecycle/extensions/lint-baseline.xml b/lifecycle/extensions/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/lifecycle/extensions/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/lifecycle/extensions/src/main/java/android/arch/lifecycle/AndroidViewModel.java b/lifecycle/extensions/src/main/java/android/arch/lifecycle/AndroidViewModel.java
index 106b2ef..e8895bd 100644
--- a/lifecycle/extensions/src/main/java/android/arch/lifecycle/AndroidViewModel.java
+++ b/lifecycle/extensions/src/main/java/android/arch/lifecycle/AndroidViewModel.java
@@ -37,6 +37,7 @@
     /**
      * Return the application.
      */
+    @SuppressWarnings("TypeParameterUnusedInFormals")
     @NonNull
     public <T extends Application> T getApplication() {
         //noinspection unchecked
diff --git a/lifecycle/extensions/src/main/java/android/arch/lifecycle/ViewModelProvider.java b/lifecycle/extensions/src/main/java/android/arch/lifecycle/ViewModelProvider.java
index 29cbab8..a7b3aeb 100644
--- a/lifecycle/extensions/src/main/java/android/arch/lifecycle/ViewModelProvider.java
+++ b/lifecycle/extensions/src/main/java/android/arch/lifecycle/ViewModelProvider.java
@@ -138,6 +138,7 @@
      */
     public static class NewInstanceFactory implements Factory {
 
+        @SuppressWarnings("ClassNewInstance")
         @NonNull
         @Override
         public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
diff --git a/lifecycle/gradle/wrapper/gradle-wrapper.properties b/lifecycle/gradle/wrapper/gradle-wrapper.properties
index 467c103..b519e0a 100644
--- a/lifecycle/gradle/wrapper/gradle-wrapper.properties
+++ b/lifecycle/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.4-bin.zip
diff --git a/lifecycle/integration-tests/testapp/build.gradle b/lifecycle/integration-tests/testapp/build.gradle
index a1a16cb..64159bd 100644
--- a/lifecycle/integration-tests/testapp/build.gradle
+++ b/lifecycle/integration-tests/testapp/build.gradle
@@ -32,6 +32,13 @@
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
+    signingConfigs {
+        debug {
+            // Use a local debug keystore to avoid build server issues.
+            storeFile project.rootProject.init.debugKeystore
+        }
+    }
+
     testOptions {
         unitTests.returnDefaultValues = true
     }
@@ -53,19 +60,21 @@
 
 dependencies {
     // IJ canont figure out transitive dependencies so need to declare them.
-    compile project(":lifecycle:common")
-    compile project(":lifecycle:runtime")
-    compile project(":lifecycle:extensions")
+    implementation project(":lifecycle:common")
+    implementation project(":lifecycle:runtime")
+    implementation project(":lifecycle:extensions")
     annotationProcessor project(":lifecycle:compiler")
+
     androidTestAnnotationProcessor project(":lifecycle:compiler")
-    androidTestCompile(libs.test_runner) {
+    androidTestImplementation(libs.test_runner) {
         exclude module: 'support-annotations'
     }
-    androidTestCompile(libs.espresso_core, {
+    androidTestImplementation(libs.espresso_core, {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
-    testCompile libs.junit
-    testCompile libs.mockito_core
+
+    testImplementation libs.junit
+    testImplementation libs.mockito_core
     testAnnotationProcessor project(":lifecycle:compiler")
 }
 createAndroidCheckstyle(project)
diff --git a/lifecycle/reactivestreams/build.gradle b/lifecycle/reactivestreams/build.gradle
index bd64a32..d2beeed 100644
--- a/lifecycle/reactivestreams/build.gradle
+++ b/lifecycle/reactivestreams/build.gradle
@@ -14,53 +14,47 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
     }
 }
 
 allprojects {
     dependencies {
-        compile project(":arch:common")
-        compile project(":lifecycle:common")
-        compile project(":lifecycle:extensions")
-        compile project(":lifecycle:runtime")
-        compile libs.support.annotations
-        compile libs.reactive_streams
+        api project(":arch:common")
+        api project(":lifecycle:common")
+        api project(":lifecycle:extensions")
+        api project(":lifecycle:runtime")
+        api libs.support.annotations
+        api libs.reactive_streams
 
-        testCompile libs.junit
-        testCompile libs.rx_java
+        testImplementation libs.junit
+        testImplementation libs.rx_java
 
-        testCompile(libs.test_runner) {
+        testImplementation(libs.test_runner) {
             exclude module: 'support-annotations'
         }
-        androidTestCompile libs.support.app_compat, libs.support_exclude_config
+        androidTestImplementation libs.support.app_compat, libs.support_exclude_config
     }
 }
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.LIFECYCLES_EXT.toString()
 supportLibrary {
-    name 'Android Lifecycle Reactivestreams'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycle Reactivestreams"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Lifecycle Reactivestreams"
+    publish = true
+    mavenVersion = LibraryVersions.LIFECYCLES_EXT
+    mavenGroup = LibraryGroups.LIFECYCLE
+    inceptionYear = "2017"
+    description = "Android Lifecycle Reactivestreams"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/lifecycle/reactivestreams/lint-baseline.xml b/lifecycle/reactivestreams/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/lifecycle/reactivestreams/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/lifecycle/runtime/build.gradle b/lifecycle/runtime/build.gradle
index 111429c..01a8abb 100644
--- a/lifecycle/runtime/build.gradle
+++ b/lifecycle/runtime/build.gradle
@@ -1,37 +1,29 @@
+import android.support.LibraryGroups
 import android.support.LibraryVersions
-
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
 
     buildTypes.all {
         consumerProguardFiles 'proguard-rules.pro'
     }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
 }
 
 dependencies {
-    compile project(":lifecycle:common")
-    compile project(":arch:common")
+    api project(":lifecycle:common")
+    api project(":arch:common")
     // necessary for IJ to resolve dependencies.
-    compile libs.support.annotations
+    api libs.support.annotations
 
-    testCompile libs.junit
-    testCompile libs.mockito_core
+    testImplementation libs.junit
+    testImplementation libs.mockito_core
 
     androidTestImplementation libs.junit
     androidTestImplementation libs.test_runner,      { exclude module: 'support-annotations' }
@@ -39,10 +31,11 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.LIFECYCLES_RUNTIME.toString()
 supportLibrary {
     name 'Android Lifecycle Runtime'
     publish true
+    mavenVersion = LibraryVersions.LIFECYCLES_RUNTIME
+    mavenGroup LibraryGroups.LIFECYCLE
     inceptionYear '2017'
     description "Android Lifecycle Runtime"
     url SupportLibraryExtension.ARCHITECTURE_URL
diff --git a/lifecycle/runtime/lint-baseline.xml b/lifecycle/runtime/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/lifecycle/runtime/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/media-compat-test-client/build.gradle b/media-compat-test-client/build.gradle
index e4cec1d..47141db 100644
--- a/media-compat-test-client/build.gradle
+++ b/media-compat-test-client/build.gradle
@@ -13,7 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-apply plugin: android.support.SupportAndroidLibraryPlugin
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     androidTestImplementation project(':support-annotations')
@@ -30,4 +33,8 @@
     defaultConfig {
         minSdkVersion 14
     }
+}
+
+supportLibrary {
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/media-compat-test-service/build.gradle b/media-compat-test-service/build.gradle
index 1912719..946d48b 100644
--- a/media-compat-test-service/build.gradle
+++ b/media-compat-test-service/build.gradle
@@ -13,7 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-apply plugin: android.support.SupportAndroidLibraryPlugin
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     androidTestImplementation project(':support-annotations')
@@ -30,3 +33,7 @@
         minSdkVersion 14
     }
 }
+
+supportLibrary {
+    legacySourceLocation = true
+}
diff --git a/media-compat/build.gradle b/media-compat/build.gradle
index c504996..ec4504e 100644
--- a/media-compat/build.gradle
+++ b/media-compat/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -35,8 +40,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library media compat'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library media compat"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/media-compat/java/android/support/v4/media/MediaBrowserCompat.java b/media-compat/java/android/support/v4/media/MediaBrowserCompat.java
index 85f5a51..1b27925 100644
--- a/media-compat/java/android/support/v4/media/MediaBrowserCompat.java
+++ b/media-compat/java/android/support/v4/media/MediaBrowserCompat.java
@@ -41,10 +41,12 @@
 import static android.support.v4.media.MediaBrowserProtocol.DATA_SEARCH_QUERY;
 import static android.support.v4.media.MediaBrowserProtocol.EXTRA_CLIENT_VERSION;
 import static android.support.v4.media.MediaBrowserProtocol.EXTRA_MESSENGER_BINDER;
+import static android.support.v4.media.MediaBrowserProtocol.EXTRA_SERVICE_VERSION;
 import static android.support.v4.media.MediaBrowserProtocol.EXTRA_SESSION_BINDER;
 import static android.support.v4.media.MediaBrowserProtocol.SERVICE_MSG_ON_CONNECT;
 import static android.support.v4.media.MediaBrowserProtocol.SERVICE_MSG_ON_CONNECT_FAILED;
 import static android.support.v4.media.MediaBrowserProtocol.SERVICE_MSG_ON_LOAD_CHILDREN;
+import static android.support.v4.media.MediaBrowserProtocol.SERVICE_VERSION_2;
 
 import android.content.ComponentName;
 import android.content.Context;
@@ -676,17 +678,15 @@
         WeakReference<Subscription> mSubscriptionRef;
 
         public SubscriptionCallback() {
+            mToken = new Binder();
             if (Build.VERSION.SDK_INT >= 26) {
                 mSubscriptionCallbackObj =
                         MediaBrowserCompatApi26.createSubscriptionCallback(new StubApi26());
-                mToken = null;
             } else if (Build.VERSION.SDK_INT >= 21) {
                 mSubscriptionCallbackObj =
                         MediaBrowserCompatApi21.createSubscriptionCallback(new StubApi21());
-                mToken = new Binder();
             } else {
                 mSubscriptionCallbackObj = null;
-                mToken = new Binder();
             }
         }
 
@@ -1583,6 +1583,7 @@
         protected final CallbackHandler mHandler = new CallbackHandler(this);
         private final ArrayMap<String, Subscription> mSubscriptions = new ArrayMap<>();
 
+        protected int mServiceVersion;
         protected ServiceBinderWrapper mServiceBinderWrapper;
         protected Messenger mCallbacksMessenger;
         private MediaSessionCompat.Token mMediaSessionToken;
@@ -1852,6 +1853,7 @@
             if (extras == null) {
                 return;
             }
+            mServiceVersion = extras.getInt(EXTRA_SERVICE_VERSION, 0);
             IBinder serviceBinder = BundleCompat.getBinder(extras, EXTRA_MESSENGER_BINDER);
             if (serviceBinder != null) {
                 mServiceBinderWrapper = new ServiceBinderWrapper(serviceBinder, mRootHints);
@@ -1958,22 +1960,34 @@
         @Override
         public void subscribe(@NonNull String parentId, @Nullable Bundle options,
                 @NonNull SubscriptionCallback callback) {
-            if (options == null) {
-                MediaBrowserCompatApi21.subscribe(
-                        mBrowserObj, parentId, callback.mSubscriptionCallbackObj);
+            // From service v2, we use compat code when subscribing.
+            // This is to prevent ClassNotFoundException when options has Parcelable in it.
+            if (mServiceBinderWrapper == null || mServiceVersion < SERVICE_VERSION_2) {
+                if (options == null) {
+                    MediaBrowserCompatApi21.subscribe(
+                            mBrowserObj, parentId, callback.mSubscriptionCallbackObj);
+                } else {
+                    MediaBrowserCompatApi26.subscribe(
+                            mBrowserObj, parentId, options, callback.mSubscriptionCallbackObj);
+                }
             } else {
-                MediaBrowserCompatApi26.subscribe(
-                        mBrowserObj, parentId, options, callback.mSubscriptionCallbackObj);
+                super.subscribe(parentId, options, callback);
             }
         }
 
         @Override
         public void unsubscribe(@NonNull String parentId, SubscriptionCallback callback) {
-            if (callback == null) {
-                MediaBrowserCompatApi21.unsubscribe(mBrowserObj, parentId);
+            // From service v2, we use compat code when subscribing.
+            // This is to prevent ClassNotFoundException when options has Parcelable in it.
+            if (mServiceBinderWrapper == null || mServiceVersion < SERVICE_VERSION_2) {
+                if (callback == null) {
+                    MediaBrowserCompatApi21.unsubscribe(mBrowserObj, parentId);
+                } else {
+                    MediaBrowserCompatApi26.unsubscribe(mBrowserObj, parentId,
+                            callback.mSubscriptionCallbackObj);
+                }
             } else {
-                MediaBrowserCompatApi26.unsubscribe(mBrowserObj, parentId,
-                        callback.mSubscriptionCallbackObj);
+                super.unsubscribe(parentId, callback);
             }
         }
     }
diff --git a/media-compat/java/android/support/v4/media/MediaBrowserProtocol.java b/media-compat/java/android/support/v4/media/MediaBrowserProtocol.java
index 7c23d26..8ed152d 100644
--- a/media-compat/java/android/support/v4/media/MediaBrowserProtocol.java
+++ b/media-compat/java/android/support/v4/media/MediaBrowserProtocol.java
@@ -45,7 +45,15 @@
      * MediaBrowserServiceCompat.
      */
     public static final int SERVICE_VERSION_1 = 1;
-    public static final int SERVICE_VERSION_CURRENT = SERVICE_VERSION_1;
+
+    /**
+     * To prevent ClassNotFoundException from Parcelables, MediaBrowser(Service)Compat tries to
+     * avoid using framework code as much as possible (b/62648808). For backward compatibility,
+     * service v2 is introduced so that the browser can distinguish whether the service supports
+     * subscribing through compat code.
+     */
+    public static final int SERVICE_VERSION_2 = 2;
+    public static final int SERVICE_VERSION_CURRENT = SERVICE_VERSION_2;
 
     /*
      * Messages sent from the media browser service compat to the media browser compat.
diff --git a/media-compat/java/android/support/v4/media/MediaBrowserServiceCompat.java b/media-compat/java/android/support/v4/media/MediaBrowserServiceCompat.java
index 53b111a..27bf0e3 100644
--- a/media-compat/java/android/support/v4/media/MediaBrowserServiceCompat.java
+++ b/media-compat/java/android/support/v4/media/MediaBrowserServiceCompat.java
@@ -278,28 +278,8 @@
 
         @Override
         public void notifyChildrenChanged(final String parentId, final Bundle options) {
-            if (mMessenger == null) {
-                MediaBrowserServiceCompatApi21.notifyChildrenChanged(mServiceObj, parentId);
-            } else {
-                mHandler.post(new Runnable() {
-                    @Override
-                    public void run() {
-                        for (IBinder binder : mConnections.keySet()) {
-                            ConnectionRecord connection = mConnections.get(binder);
-                            List<Pair<IBinder, Bundle>> callbackList =
-                                    connection.subscriptions.get(parentId);
-                            if (callbackList != null) {
-                                for (Pair<IBinder, Bundle> callback : callbackList) {
-                                    if (MediaBrowserCompatUtils.hasDuplicatedItems(
-                                            options, callback.second)) {
-                                        performLoadChildren(parentId, connection, callback.second);
-                                    }
-                                }
-                            }
-                        }
-                    }
-                });
-            }
+            notifyChildrenChangedForFramework(parentId, options);
+            notifyChildrenChangedForCompat(parentId, options);
         }
 
         @Override
@@ -373,6 +353,31 @@
             };
             MediaBrowserServiceCompat.this.onLoadChildren(parentId, result);
         }
+
+        void notifyChildrenChangedForFramework(final String parentId, final Bundle options) {
+            MediaBrowserServiceCompatApi21.notifyChildrenChanged(mServiceObj, parentId);
+        }
+
+        void notifyChildrenChangedForCompat(final String parentId, final Bundle options) {
+            mHandler.post(new Runnable() {
+                @Override
+                public void run() {
+                    for (IBinder binder : mConnections.keySet()) {
+                        ConnectionRecord connection = mConnections.get(binder);
+                        List<Pair<IBinder, Bundle>> callbackList =
+                                connection.subscriptions.get(parentId);
+                        if (callbackList != null) {
+                            for (Pair<IBinder, Bundle> callback : callbackList) {
+                                if (MediaBrowserCompatUtils.hasDuplicatedItems(
+                                        options, callback.second)) {
+                                    performLoadChildren(parentId, connection, callback.second);
+                                }
+                            }
+                        }
+                    }
+                }
+            });
+        }
     }
 
     @RequiresApi(23)
@@ -421,16 +426,6 @@
         }
 
         @Override
-        public void notifyChildrenChanged(final String parentId, final Bundle options) {
-            if (options == null) {
-                MediaBrowserServiceCompatApi21.notifyChildrenChanged(mServiceObj, parentId);
-            } else {
-                MediaBrowserServiceCompatApi26.notifyChildrenChanged(mServiceObj, parentId,
-                        options);
-            }
-        }
-
-        @Override
         public void onLoadChildren(String parentId,
                 final MediaBrowserServiceCompatApi26.ResultWrapper resultWrapper, Bundle options) {
             final Result<List<MediaBrowserCompat.MediaItem>> result
@@ -466,6 +461,16 @@
             }
             return MediaBrowserServiceCompatApi26.getBrowserRootHints(mServiceObj);
         }
+
+        @Override
+        void notifyChildrenChangedForFramework(final String parentId, final Bundle options) {
+            if (options != null) {
+                MediaBrowserServiceCompatApi26.notifyChildrenChanged(mServiceObj, parentId,
+                        options);
+            } else {
+                super.notifyChildrenChangedForFramework(parentId, options);
+            }
+        }
     }
 
     private final class ServiceHandler extends Handler {
diff --git a/media-compat/java/android/support/v4/media/MediaMetadataCompat.java b/media-compat/java/android/support/v4/media/MediaMetadataCompat.java
index 3ddf255..00f16cb 100644
--- a/media-compat/java/android/support/v4/media/MediaMetadataCompat.java
+++ b/media-compat/java/android/support/v4/media/MediaMetadataCompat.java
@@ -365,10 +365,12 @@
 
     MediaMetadataCompat(Bundle bundle) {
         mBundle = new Bundle(bundle);
+        mBundle.setClassLoader(MediaMetadataCompat.class.getClassLoader());
     }
 
     MediaMetadataCompat(Parcel in) {
         mBundle = in.readBundle();
+        mBundle.setClassLoader(MediaMetadataCompat.class.getClassLoader());
     }
 
     /**
diff --git a/media-compat/tests/src/android/support/v4/media/MediaBrowserCompatTest.java b/media-compat/tests/src/android/support/v4/media/MediaBrowserCompatTest.java
index df700cc..6356e33 100644
--- a/media-compat/tests/src/android/support/v4/media/MediaBrowserCompatTest.java
+++ b/media-compat/tests/src/android/support/v4/media/MediaBrowserCompatTest.java
@@ -176,6 +176,39 @@
 
     @Test
     @SmallTest
+    public void testSubscriptionWithCustomOptionsWithRemoteService() throws Exception {
+        final String mediaId = "1000";
+        createMediaBrowser(TEST_REMOTE_BROWSER_SERVICE);
+        assertFalse(mMediaBrowser.isConnected());
+
+        connectMediaBrowserService();
+        assertTrue(mMediaBrowser.isConnected());
+
+        MediaMetadataCompat mediaMetadataCompat = new MediaMetadataCompat.Builder()
+                .putString(MediaMetadataCompat.METADATA_KEY_MEDIA_ID, mediaId)
+                .putString(MediaMetadataCompat.METADATA_KEY_TITLE, "title")
+                .putRating(MediaMetadataCompat.METADATA_KEY_RATING,
+                        RatingCompat.newPercentageRating(0.5f))
+                .putRating(MediaMetadataCompat.METADATA_KEY_USER_RATING,
+                        RatingCompat.newPercentageRating(0.8f))
+                .build();
+        Bundle options = new Bundle();
+        options.putParcelable(
+                StubRemoteMediaBrowserServiceCompat.MEDIA_METADATA, mediaMetadataCompat);
+
+        // Remote MediaBrowserService will create a media item with the given MediaMetadataCompat
+        mMediaBrowser.subscribe(mMediaBrowser.getRoot(), options, mSubscriptionCallback);
+        synchronized (mSubscriptionCallback.mWaitLock) {
+            mSubscriptionCallback.mWaitLock.wait(TIME_OUT_MS);
+            assertEquals(1, mSubscriptionCallback.mChildrenLoadedWithOptionCount);
+            assertEquals(1, mSubscriptionCallback.mLastChildMediaItems.size());
+            assertEquals(mediaId, mSubscriptionCallback.mLastChildMediaItems.get(0).getMediaId());
+        }
+        mMediaBrowser.disconnect();
+    }
+
+    @Test
+    @SmallTest
     public void testConnectTwice() throws Exception {
         createMediaBrowser(TEST_BROWSER_SERVICE);
         connectMediaBrowserService();
@@ -185,6 +218,7 @@
         } catch (IllegalStateException e) {
             // expected
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -199,6 +233,7 @@
         assertTrue(mConnectionCallback.mConnectionFailedCount > 0);
         assertEquals(0, mConnectionCallback.mConnectedCount);
         assertEquals(0, mConnectionCallback.mConnectionSuspendedCount);
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -256,6 +291,7 @@
             assertEquals(StubMediaBrowserServiceCompat.MEDIA_ID_CHILDREN[0],
                     mItemCallback.mLastMediaItem.getMediaId());
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -330,6 +366,7 @@
         }
         // onChildrenLoaded should not be called.
         assertEquals(0, mSubscriptionCallback.mChildrenLoadedCount);
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -386,6 +423,7 @@
         }
         // onChildrenLoaded should not be called.
         assertEquals(0, mSubscriptionCallback.mChildrenLoadedCount);
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -401,6 +439,7 @@
             assertEquals(StubMediaBrowserServiceCompat.MEDIA_ID_INVALID,
                     mSubscriptionCallback.mLastErrorId);
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -427,6 +466,7 @@
             assertEquals(pageSize,
                     mSubscriptionCallback.mLastOptions.getInt(MediaBrowserCompat.EXTRA_PAGE_SIZE));
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -474,6 +514,7 @@
         for (StubSubscriptionCallback callback : subscriptionCallbacks) {
             assertEquals(0, callback.mChildrenLoadedWithOptionCount);
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -533,6 +574,7 @@
                 }
             }
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -549,6 +591,7 @@
             assertEquals(StubMediaBrowserServiceCompat.MEDIA_ID_CHILDREN[0],
                     mItemCallback.mLastMediaItem.getMediaId());
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -564,6 +607,7 @@
             assertEquals(StubMediaBrowserServiceCompat.MEDIA_ID_ON_LOAD_ITEM_NOT_IMPLEMENTED,
                     mItemCallback.mLastErrorId);
         }
+        mMediaBrowser.disconnect();
     }
 
     @Test
@@ -580,6 +624,7 @@
             assertNull(mItemCallback.mLastMediaItem);
             assertNull(mItemCallback.mLastErrorId);
         }
+        mMediaBrowser.disconnect();
     }
 
     private void createMediaBrowser(final ComponentName component) {
diff --git a/media-compat/tests/src/android/support/v4/media/StubRemoteMediaBrowserServiceCompat.java b/media-compat/tests/src/android/support/v4/media/StubRemoteMediaBrowserServiceCompat.java
index 9d7e73d..8e03ab2 100644
--- a/media-compat/tests/src/android/support/v4/media/StubRemoteMediaBrowserServiceCompat.java
+++ b/media-compat/tests/src/android/support/v4/media/StubRemoteMediaBrowserServiceCompat.java
@@ -31,6 +31,7 @@
     static final String EXTRAS_VALUE = "test_extras_value";
 
     static final String MEDIA_ID_ROOT = "test_media_id_root";
+    static final String MEDIA_METADATA = "test_media_metadata";
 
     static final String[] MEDIA_ID_CHILDREN = new String[]{
             "test_media_id_children_0", "test_media_id_children_1",
@@ -66,6 +67,19 @@
         }
     }
 
+    @Override
+    public void onLoadChildren(final String parentMediaId, final Result<List<MediaItem>> result,
+            final Bundle options) {
+        MediaMetadataCompat metadata = options.getParcelable(MEDIA_METADATA);
+        if (metadata == null) {
+            super.onLoadChildren(parentMediaId, result, options);
+        } else {
+            List<MediaItem> mediaItems = new ArrayList<>();
+            mediaItems.add(new MediaItem(metadata.getDescription(), MediaItem.FLAG_PLAYABLE));
+            result.sendResult(mediaItems);
+        }
+    }
+
     private MediaItem createMediaItem(String id) {
         return new MediaItem(new MediaDescriptionCompat.Builder()
                 .setMediaId(id).setExtras(getBrowserRootHints()).build(),
diff --git a/paging/common/build.gradle b/paging/common/build.gradle
index bb9ad6b..d07103f 100644
--- a/paging/common/build.gradle
+++ b/paging/common/build.gradle
@@ -14,11 +14,14 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
-apply plugin: 'kotlin'
+plugins {
+    id("SupportJavaLibraryPlugin")
+    id("kotlin")
+}
 
 dependencies {
     compile libs.support.annotations
@@ -34,11 +37,12 @@
 createAndroidCheckstyle(project)
 createKotlinCheckstyle(project)
 
-version = LibraryVersions.PAGING.toString()
 supportLibrary {
-    name 'Android Paging-Common'
-    publish true
-    inceptionYear '2017'
-    description "Android Paging-Common"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Paging-Common"
+    publish = true
+    mavenVersion = LibraryVersions.PAGING
+    mavenGroup = LibraryGroups.PAGING
+    inceptionYear = "2017"
+    description = "Android Paging-Common"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/paging/common/src/main/java/android/arch/paging/BoundedDataSource.java b/paging/common/src/main/java/android/arch/paging/BoundedDataSource.java
deleted file mode 100644
index 0656490..0000000
--- a/paging/common/src/main/java/android/arch/paging/BoundedDataSource.java
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.arch.paging;
-
-import android.support.annotation.Nullable;
-import android.support.annotation.RestrictTo;
-import android.support.annotation.WorkerThread;
-
-import java.util.ArrayList;
-import java.util.List;
-
-/**
- * Simplest data source form that provides all of its data through a single loadRange() method.
- * <p>
- * Requires that your data resides in positions <code>0</code> through <code>N</code>, where
- * <code>N</code> is the value returned from {@link #countItems()}. You must return the exact number
- * requested, so that the data as returned can be safely prepended/appended to what has already
- * been loaded.
- * <p>
- * For more flexibility in how many items to load, or to avoid counting your data source, override
- * {@link PositionalDataSource} directly.
- *
- * @param <Value> Value type returned by the data source.
- *
- * @hide
- */
-@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
-public abstract class BoundedDataSource<Value> extends PositionalDataSource<Value> {
-    /**
-     * Called to load items at from the specified position range.
-     *
-     * @param startPosition Index of first item to load.
-     * @param loadCount     Exact number of items to load. Returning a different number will cause
-     *                      an exception to be thrown.
-     * @return List of loaded items. Null if the BoundedDataSource is no longer valid, and should
-     *         not be queried again.
-     */
-    @WorkerThread
-    @Nullable
-    public abstract List<Value> loadRange(int startPosition, int loadCount);
-
-    @WorkerThread
-    @Nullable
-    @Override
-    public List<Value> loadAfter(int startIndex, int pageSize) {
-        return loadRange(startIndex, pageSize);
-    }
-
-    @WorkerThread
-    @Nullable
-    @Override
-    public List<Value> loadBefore(int startIndex, int pageSize) {
-        if (startIndex < 0) {
-            return new ArrayList<>();
-        }
-        int loadSize = Math.min(pageSize, startIndex + 1);
-        startIndex = startIndex - loadSize + 1;
-        List<Value> result = loadRange(startIndex, loadSize);
-        if (result != null) {
-            if (result.size() != loadSize) {
-                throw new IllegalStateException("invalid number of items returned.");
-            }
-        }
-        return result;
-    }
-}
diff --git a/paging/common/src/main/java/android/arch/paging/ContiguousDataSource.java b/paging/common/src/main/java/android/arch/paging/ContiguousDataSource.java
index 414c4ff..03f2e86 100644
--- a/paging/common/src/main/java/android/arch/paging/ContiguousDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/ContiguousDataSource.java
@@ -19,44 +19,21 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
-import java.util.List;
-
 abstract class ContiguousDataSource<Key, Value> extends DataSource<Key, Value> {
     @Override
     boolean isContiguous() {
         return true;
     }
 
-    abstract void loadInitial(Key key, int initialLoadSize, boolean enablePlaceholders,
-            @NonNull PageResult.Receiver<Key, Value> receiver);
+    public abstract void loadInitial(@Nullable Key key, int initialLoadSize,
+            boolean enablePlaceholders,
+            @NonNull InitialLoadCallback<Value> callback);
 
-    void loadAfter(int currentEndIndex, @NonNull Value currentEndItem, int pageSize,
-            @NonNull PageResult.Receiver<Key, Value> receiver) {
-        if (!isInvalid()) {
-            List<Value> list = loadAfterImpl(currentEndIndex, currentEndItem, pageSize);
+    abstract void loadAfter(int currentEndIndex, @NonNull Value currentEndItem, int pageSize,
+            @NonNull LoadCallback<Value> callback);
 
-            if (list != null && !isInvalid()) {
-                receiver.postOnPageResult(new PageResult<>(
-                        PageResult.APPEND, new Page<Key, Value>(list), 0, 0, 0));
-                return;
-            }
-        }
-        receiver.postOnPageResult(new PageResult<Key, Value>(PageResult.APPEND));
-    }
-
-    void loadBefore(int currentBeginIndex, @NonNull Value currentBeginItem, int pageSize,
-            @NonNull PageResult.Receiver<Key, Value> receiver) {
-        if (!isInvalid()) {
-            List<Value> list = loadBeforeImpl(currentBeginIndex, currentBeginItem, pageSize);
-
-            if (list != null && !isInvalid()) {
-                receiver.postOnPageResult(new PageResult<>(
-                        PageResult.PREPEND, new Page<Key, Value>(list), 0, 0, 0));
-                return;
-            }
-        }
-        receiver.postOnPageResult(new PageResult<Key, Value>(PageResult.PREPEND));
-    }
+    abstract void loadBefore(int currentBeginIndex, @NonNull Value currentBeginItem, int pageSize,
+            @NonNull LoadCallback<Value> callback);
 
     /**
      * Get the key from either the position, or item, or null if position/item invalid.
@@ -65,12 +42,4 @@
      * that isn't yet loaded, a fallback item (last loaded item accessed) will be passed.
      */
     abstract Key getKey(int position, Value item);
-
-    @Nullable
-    abstract List<Value> loadAfterImpl(int currentEndIndex,
-            @NonNull Value currentEndItem, int pageSize);
-
-    @Nullable
-    abstract List<Value> loadBeforeImpl(int currentBeginIndex,
-            @NonNull Value currentBeginItem, int pageSize);
 }
diff --git a/paging/common/src/main/java/android/arch/paging/ContiguousPagedList.java b/paging/common/src/main/java/android/arch/paging/ContiguousPagedList.java
index cdff391..b54cb84 100644
--- a/paging/common/src/main/java/android/arch/paging/ContiguousPagedList.java
+++ b/paging/common/src/main/java/android/arch/paging/ContiguousPagedList.java
@@ -21,6 +21,7 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
+import java.util.List;
 import java.util.concurrent.Executor;
 
 class ContiguousPagedList<K, V> extends PagedList<V> implements PagedStorage.Callback {
@@ -31,28 +32,14 @@
     private int mPrependItemsRequested = 0;
     private int mAppendItemsRequested = 0;
 
-    @SuppressWarnings("unchecked")
-    private final PagedStorage<K, V> mKeyedStorage = (PagedStorage<K, V>) mStorage;
-
-    private final PageResult.Receiver<K, V> mReceiver = new PageResult.Receiver<K, V>() {
-        @AnyThread
-        @Override
-        public void postOnPageResult(@NonNull final PageResult<K, V> pageResult) {
-            // NOTE: if we're already on main thread, this can delay page receive by a frame
-            mMainThreadExecutor.execute(new Runnable() {
-                @Override
-                public void run() {
-                    onPageResult(pageResult);
-                }
-            });
-        }
-
+    private PageResult.Receiver<V> mReceiver = new PageResult.Receiver<V>() {
         // Creation thread for initial synchronous load, otherwise main thread
         // Safe to access main thread only state - no other thread has reference during construction
         @AnyThread
         @Override
-        public void onPageResult(@NonNull PageResult<K, V> pageResult) {
-            if (pageResult.page == null) {
+        public void onPageResult(@PageResult.ResultType int resultType,
+                @NonNull PageResult<V> pageResult) {
+            if (pageResult.isInvalid()) {
                 detach();
                 return;
             }
@@ -62,25 +49,25 @@
                 return;
             }
 
-            Page<K, V> page = pageResult.page;
-            if (pageResult.type == PageResult.INIT) {
-                mKeyedStorage.init(pageResult.leadingNulls, page, pageResult.trailingNulls,
+            List<V> page = pageResult.page;
+            if (resultType == PageResult.INIT) {
+                mStorage.init(pageResult.leadingNulls, page, pageResult.trailingNulls,
                         pageResult.positionOffset, ContiguousPagedList.this);
-                notifyInserted(0, mKeyedStorage.size());
-            } else if (pageResult.type == PageResult.APPEND) {
-                mKeyedStorage.appendPage(page, ContiguousPagedList.this);
-            } else if (pageResult.type == PageResult.PREPEND) {
-                mKeyedStorage.prependPage(page, ContiguousPagedList.this);
+                mLastLoad = pageResult.leadingNulls + pageResult.positionOffset + page.size() / 2;
+            } else if (resultType == PageResult.APPEND) {
+                mStorage.appendPage(page, ContiguousPagedList.this);
+            } else if (resultType == PageResult.PREPEND) {
+                mStorage.prependPage(page, ContiguousPagedList.this);
             }
 
             if (mBoundaryCallback != null) {
                 boolean deferEmpty = mStorage.size() == 0;
                 boolean deferBegin = !deferEmpty
-                        && pageResult.type == PageResult.PREPEND
-                        && pageResult.page.items.size() == 0;
+                        && resultType == PageResult.PREPEND
+                        && pageResult.page.size() == 0;
                 boolean deferEnd = !deferEmpty
-                        && pageResult.type == PageResult.APPEND
-                        && pageResult.page.items.size() == 0;
+                        && resultType == PageResult.APPEND
+                        && pageResult.page.size() == 0;
                 deferBoundaryCallbacks(deferEmpty, deferBegin, deferEnd);
             }
         }
@@ -93,24 +80,36 @@
             @Nullable BoundaryCallback<V> boundaryCallback,
             @NonNull Config config,
             final @Nullable K key) {
-        super(new PagedStorage<K, V>(), mainThreadExecutor, backgroundThreadExecutor,
+        super(new PagedStorage<V>(), mainThreadExecutor, backgroundThreadExecutor,
                 boundaryCallback, config);
         mDataSource = dataSource;
 
-        // blocking init just triggers the initial load on the construction thread -
-        // Could still be posted with callback, if desired.
-        mDataSource.loadInitial(key,
-                mConfig.initialLoadSizeHint,
-                mConfig.enablePlaceholders,
-                mReceiver);
+        if (mDataSource.isInvalid()) {
+            detach();
+        } else {
+            @DataSource.LoadCountType int type = mConfig.enablePlaceholders
+                    ? DataSource.LOAD_COUNT_ACCEPTED
+                    : DataSource.LOAD_COUNT_PREVENTED;
+
+            DataSource.InitialLoadCallback<V> callback = new DataSource.InitialLoadCallback<>(
+                    type, mConfig.pageSize, mDataSource, mReceiver);
+            mDataSource.loadInitial(key,
+                    mConfig.initialLoadSizeHint,
+                    mConfig.enablePlaceholders,
+                    callback);
+
+            // If initialLoad's callback is not called within the body, we force any following calls
+            // to post to the UI thread. This constructor may be run on a background thread, but
+            // after constructor, mutation must happen on UI thread.
+            callback.setPostExecutor(mMainThreadExecutor);
+        }
     }
 
     @MainThread
     @Override
     void dispatchUpdatesSinceSnapshot(
             @NonNull PagedList<V> pagedListSnapshot, @NonNull Callback callback) {
-
-        final PagedStorage<?, V> snapshot = pagedListSnapshot.mStorage;
+        final PagedStorage<V> snapshot = pagedListSnapshot.mStorage;
 
         final int newlyAppended = mStorage.getNumberAppended() - snapshot.getNumberAppended();
         final int newlyPrepended = mStorage.getNumberPrepended() - snapshot.getNumberPrepended();
@@ -120,7 +119,8 @@
 
         // Validate that the snapshot looks like a previous version of this list - if it's not,
         // we can't be sure we'll dispatch callbacks safely
-        if (newlyAppended < 0
+        if (snapshot.isEmpty()
+                || newlyAppended < 0
                 || newlyPrepended < 0
                 || mStorage.getTrailingNullCount() != Math.max(previousTrailing - newlyAppended, 0)
                 || mStorage.getLeadingNullCount() != Math.max(previousLeading - newlyPrepended, 0)
@@ -190,7 +190,14 @@
                 if (isDetached()) {
                     return;
                 }
-                mDataSource.loadBefore(position, item, mConfig.pageSize, mReceiver);
+                if (mDataSource.isInvalid()) {
+                    detach();
+                } else {
+                    DataSource.LoadCallback<V> callback = new DataSource.LoadCallback<>(
+                            PageResult.PREPEND, mMainThreadExecutor, mDataSource, mReceiver);
+                    mDataSource.loadBefore(position, item, mConfig.pageSize, callback);
+                }
+
             }
         });
     }
@@ -213,7 +220,13 @@
                 if (isDetached()) {
                     return;
                 }
-                mDataSource.loadAfter(position, item, mConfig.pageSize, mReceiver);
+                if (mDataSource.isInvalid()) {
+                    detach();
+                } else {
+                    DataSource.LoadCallback<V> callback = new DataSource.LoadCallback<>(
+                            PageResult.APPEND, mMainThreadExecutor, mDataSource, mReceiver);
+                    mDataSource.loadAfter(position, item, mConfig.pageSize, callback);
+                }
             }
         });
     }
diff --git a/paging/common/src/main/java/android/arch/paging/DataSource.java b/paging/common/src/main/java/android/arch/paging/DataSource.java
index ff44521..2e41cf6 100644
--- a/paging/common/src/main/java/android/arch/paging/DataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/DataSource.java
@@ -16,30 +16,76 @@
 
 package android.arch.paging;
 
+import static java.lang.annotation.RetentionPolicy.SOURCE;
+
 import android.support.annotation.AnyThread;
+import android.support.annotation.IntDef;
 import android.support.annotation.NonNull;
 import android.support.annotation.WorkerThread;
 
+import java.lang.annotation.Retention;
+import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
- * Base class for incremental data loading, used in list paging. To implement, extend either the
- * {@link KeyedDataSource}, or {@link TiledDataSource} subclass.
+ * Base class for loading pages of snapshot data into a {@link PagedList}.
  * <p>
- * Choose based on whether each load operation is based on the position of the data in the list.
+ * DataSource is queried to load pages of content into a {@link PagedList}. A PagedList can grow as
+ * it loads more data, but the data loaded cannot be updated.
  * <p>
- * Use {@link KeyedDataSource} if you need to use data from item <code>N-1</code> to load item
- * <code>N</code>. For example, if requesting the backend for the next comments in the list
+ * A PagedList / DataSource pair serve as a snapshot of the data set being loaded. If the
+ * underlying data set is modified, a new PagedList / DataSource pair must be created to represent
+ * the new data.
+ * <h4>Loading Pages</h4>
+ * PagedList queries data from its DataSource in response to loading hints. {@link PagedListAdapter}
+ * calls {@link PagedList#loadAround(int)} to load content as the user scrolls in a RecyclerView.
+ * <p>
+ * To control how and when a PagedList queries data from its DataSource, see
+ * {@link PagedList.Config}. The Config object defines things like load sizes and prefetch distance.
+ * <h4>Updating Paged Data</h4>
+ * A PagedList / DataSource pair are a snapshot of the data set. A new pair of
+ * PagedList / DataSource must be created if an update occurs, such as a reorder, insert, delete, or
+ * content update occurs. A DataSource must detect that it cannot continue loading its
+ * snapshot (for instance, when Database query notices a table being invalidated), and call
+ * {@link #invalidate()}. Then a new PagedList / DataSource pair would be created to load data from
+ * the new state of the Database query.
+ * <p>
+ * To page in data that doesn't update, you can create a single DataSource, and pass it to a single
+ * PagedList. For example, loading from network when the network's paging API doesn't provide
+ * updates.
+ * <p>
+ * To page in data from a source that does provide updates, you can create a
+ * {@link DataSource.Factory}, where each DataSource created is invalidated when an update to the
+ * data set occurs that makes the current snapshot invalid. For example, when paging a query from
+ * the Database, and the table being queried inserts or removes items. You can also use a
+ * DataSource.Factory to provide multiple versions of network-paged lists. If reloading all content
+ * (e.g. in response to an action like swipe-to-refresh) is required to get a new version of data,
+ * you can connect an explicit refresh signal to call {@link #invalidate()} on the current
+ * DataSource.
+ * <p>
+ * If you have more granular update signals, such as a network API signaling an update to a single
+ * item in the list, it's recommended to load data from network into memory. Then present that
+ * data to the PagedList via a DataSource that wraps an in-memory snapshot. Each time the in-memory
+ * copy changes, invalidate the previous DataSource, and a new one wrapping the new state of the
+ * snapshot can be created.
+ * <h4>Implementing a DataSource</h4>
+ * To implement, extend either the {@link KeyedDataSource}, or {@link PositionalDataSource}
+ * subclass. Choose based on whether each load operation is based on the position of the data in the
+ * list.
+ * <p>
+ * Use {@link KeyedDataSource} if you need to use data from item {@code N-1} to load item
+ * {@code N}. For example, if requesting the backend for the next comments in the list
  * requires the ID or timestamp of the most recent loaded comment, or if querying the next users
  * from a name-sorted database query requires the name and unique ID of the previous.
  * <p>
- * Use {@link TiledDataSource} if you can load arbitrary pages based solely on position information,
- * and can provide a fixed item count. TiledDataSource supports querying pages at arbitrary
- * positions, so can provide data to PagedLists in arbitrary order.
+ * Use {@link PositionalDataSource} if you can load arbitrary pages based solely on position
+ * information, and can provide a fixed item count. PositionalDataSource supports querying pages at
+ * arbitrary positions, so can provide data to PagedLists in arbitrary order.
  * <p>
- * Because a <code>null</code> item indicates a placeholder in {@link PagedList}, DataSource may not
- * return <code>null</code> items in lists that it loads. This is so that users of the PagedList
+ * Because a {@code null} item indicates a placeholder in {@link PagedList}, DataSource may not
+ * return {@code null} items in lists that it loads. This is so that users of the PagedList
  * can differentiate unloaded placeholder items from content that has been paged in.
  *
  * @param <Key> Input used to trigger initial load from the DataSource. Often an Integer position.
@@ -47,8 +93,36 @@
  */
 @SuppressWarnings("unused") // suppress warning to remove Key/Value, needed for subclass type safety
 public abstract class DataSource<Key, Value> {
-
+    /**
+     * Factory for DataSources.
+     * <p>
+     * Data-loading systems of an application or library can implement this interface to allow
+     * {@code LiveData<PagedList>}s to be created. For example, Room can provide a
+     * DataSource.Factory for a given SQL query:
+     *
+     * <pre>
+     * {@literal @}Dao
+     * interface UserDao {
+     *    {@literal @}Query("SELECT * FROM user ORDER BY lastName ASC")
+     *    public abstract DataSource.Factory&lt;Integer, User> usersByLastName();
+     * }
+     * </pre>
+     * In the above sample, {@code Integer} is used because it is the {@code Key} type of
+     * PositionalDataSource. Currently, Room uses the {@code LIMIT}/{@code OFFSET} SQL keywords to
+     * page a large query with a PositionalDataSource.
+     *
+     * @param <Key> Key identifying items in DataSource.
+     * @param <Value> Type of items in the list loaded by the DataSources.
+     */
     public interface Factory<Key, Value> {
+        /**
+         * Create a DataSource.
+         * <p>
+         * The DataSource should invalidate itself if the snapshot is no longer valid, and a new
+         * DataSource should be queried from the Factory.
+         *
+         * @return the new DataSource.
+         */
         DataSource<Key, Value> create();
     }
 
@@ -58,19 +132,206 @@
     }
 
     /**
-     * If returned by countItems(), indicates an undefined number of items are provided by the data
-     * source. Continued querying in either direction may continue to produce more data.
-     */
-    @SuppressWarnings("WeakerAccess")
-    public static int COUNT_UNDEFINED = -1;
-
-    /**
      * Returns true if the data source guaranteed to produce a contiguous set of items,
      * never producing gaps.
      */
     abstract boolean isContiguous();
 
     /**
+     * Callback for DataSource initial loading methods to return data and position/count
+     * information.
+     * <p>
+     * A callback can be called only once, and will throw if called again.
+     * <p>
+     * It is always valid for a DataSource loading method that takes a callback to stash the
+     * callback and call it later. This enables DataSources to be fully asynchronous, and to handle
+     * temporary, recoverable error states (such as a network error that can be retried).
+     *
+     * @param <T> Type of items being loaded.
+     */
+    public static class InitialLoadCallback<T> extends LoadCallback<T> {
+        private final int mPageSize;
+
+        InitialLoadCallback(@LoadCountType int countType, int pageSize,
+                DataSource dataSource, PageResult.Receiver<T> receiver) {
+            super(PageResult.INIT, countType, dataSource, receiver);
+            mPageSize = pageSize;
+            if (mPageSize < 1) {
+                throw new IllegalArgumentException("Page size must be non-negative");
+            }
+        }
+
+        /**
+         * Called to pass initial load state from a DataSource.
+         * <p>
+         * Call this method from your DataSource's {@code loadInitial} function to return data,
+         * and inform how many placeholders should be shown before and after. If counting is cheap
+         * to compute (for example, if a network load returns the information regardless), it's
+         * recommended to pass data back through this method.
+         *
+         * @param data List of items loaded from the DataSource. If this is empty, the DataSource
+         *             is treated as empty, and no further loads will occur.
+         * @param position Position of the item at the front of the list, relative to the total
+         *                 count. If there are {@code N} items before the items in data that can be
+         *                 loaded from this DataSource, pass {@code N}.
+         * @param totalCount Total number of items that may be returned from this DataSource.
+         *                   Includes the number in the initial {@code data} parameter
+         *                   as well as any items that can be loaded in front or behind of
+         *                   {@code data}.
+         */
+        public void onResult(@NonNull List<T> data, int position, int totalCount) {
+            if (position < 0) {
+                throw new IllegalArgumentException("Position must be non-negative");
+            }
+            if (data.size() + position > totalCount) {
+                throw new IllegalArgumentException(
+                        "List size + position too large; last item in list beyond totalCount");
+            }
+            if (data.size() == 0 && totalCount > 0) {
+                throw new IllegalArgumentException(
+                        "Initial result cannot be empty if items are present in data set.");
+            }
+            if (mCountType == LOAD_COUNT_REQUIRED_TILED
+                    && position + data.size() != totalCount
+                    && data.size() % mPageSize != 0) {
+                throw new IllegalArgumentException("PositionalDataSource requires initial load size"
+                        + " to be a multiple of page size to support internal tiling.");
+            }
+
+            int trailingUnloadedCount = totalCount - position - data.size();
+            if (mCountType == LOAD_COUNT_REQUIRED_TILED || mCountType == LOAD_COUNT_ACCEPTED) {
+                dispatchResultToReceiver(new PageResult<>(
+                        data, position, trailingUnloadedCount, 0));
+            } else {
+                dispatchResultToReceiver(new PageResult<>(data, position));
+            }
+        }
+
+        /**
+         * Called to pass initial load state from a DataSource without supporting placeholders.
+         * <p>
+         * Call this method from your DataSource's {@code loadInitial} function to return data,
+         * if position is known but total size is not. If counting is not expensive, consider
+         * calling the three parameter variant: {@link #onResult(List, int, int)}.
+         *
+         * @param data List of items loaded from the DataSource. If this is empty, the DataSource
+         *             is treated as empty, and no further loads will occur.
+         * @param position Position of the item at the front of the list. If there are {@code N}
+         *                 items before the items in data that can be provided by this DataSource,
+         *                 pass {@code N}.
+         */
+        void onResult(@NonNull List<T> data, int position) {
+            // not counting, don't need to check mAcceptCount
+            dispatchResultToReceiver(new PageResult<>(
+                    data, 0, 0, position));
+        }
+    }
+
+    @Retention(SOURCE)
+    @IntDef({LOAD_COUNT_PREVENTED, LOAD_COUNT_ACCEPTED, LOAD_COUNT_REQUIRED_TILED})
+    @interface LoadCountType {}
+    static final int LOAD_COUNT_PREVENTED = 0;
+    static final int LOAD_COUNT_ACCEPTED = 1;
+    static final int LOAD_COUNT_REQUIRED_TILED = 2;
+
+    /**
+     * Callback for DataSource loading methods to return data.
+     * <p>
+     * A callback can be called only once, and will throw if called again.
+     * <p>
+     * It is always valid for a DataSource loading method that takes a callback to stash the
+     * callback and call it later. This enables DataSources to be fully asynchronous, and to handle
+     * temporary, recoverable error states (such as a network error that can be retried).
+     *
+     * @param <T> Type of items being loaded.
+     */
+    public static class LoadCallback<T> {
+        @PageResult.ResultType
+        final int mResultType;
+        @LoadCountType
+        final int mCountType;
+        private final DataSource mDataSource;
+        private final PageResult.Receiver<T> mReceiver;
+
+        private int mPositionOffset = 0;
+
+        // mSignalLock protects mPostExecutor, and mHasSignalled
+        private final Object mSignalLock = new Object();
+        private Executor mPostExecutor = null;
+        private boolean mHasSignalled = false;
+
+        private LoadCallback(@PageResult.ResultType int resultType, @LoadCountType int countType,
+                DataSource dataSource, PageResult.Receiver<T> receiver) {
+            mResultType = resultType;
+            mCountType = countType;
+            mDataSource = dataSource;
+            mReceiver = receiver;
+        }
+
+        LoadCallback(int type, Executor mainThreadExecutor,
+                DataSource dataSource, PageResult.Receiver<T> receiver) {
+            mResultType = type;
+            mCountType = LOAD_COUNT_PREVENTED;
+            mPostExecutor = mainThreadExecutor;
+            mDataSource = dataSource;
+            mReceiver = receiver;
+        }
+
+        void setPositionOffset(int positionOffset) {
+            mPositionOffset = positionOffset;
+        }
+
+        void setPostExecutor(Executor postExecutor) {
+            synchronized (mSignalLock) {
+                mPostExecutor = postExecutor;
+            }
+        }
+
+        /**
+         * Called to pass loaded data from a DataSource.
+         * <p>
+         * Call this method from your DataSource's {@code load} methods to return data.
+         *
+         * @param data List of items loaded from the DataSource.
+         */
+        public void onResult(@NonNull List<T> data) {
+            if (mCountType == LOAD_COUNT_REQUIRED_TILED && !data.isEmpty()) {
+                throw new IllegalArgumentException(
+                        "PositionalDataSource requires calling the three argument version of"
+                                + " InitialLoadCallback.onResult() to pass position information");
+            }
+            dispatchResultToReceiver(new PageResult<>(
+                    data, 0, 0, mPositionOffset));
+        }
+
+        void dispatchResultToReceiver(final @NonNull PageResult<T> result) {
+            Executor executor;
+            synchronized (mSignalLock) {
+                if (mHasSignalled) {
+                    throw new IllegalStateException(
+                            "LoadCallback already dispatched, cannot dispatch again.");
+                }
+                mHasSignalled = true;
+                executor = mPostExecutor;
+            }
+
+            final PageResult<T> resolvedResult =
+                    mDataSource.isInvalid() ? PageResult.<T>getInvalidResult() : result;
+
+            if (executor != null) {
+                executor.execute(new Runnable() {
+                    @Override
+                    public void run() {
+                        mReceiver.onPageResult(mResultType, result);
+                    }
+                });
+            } else {
+                mReceiver.onPageResult(mResultType, result);
+            }
+        }
+    }
+
+    /**
      * Invalidation callback for DataSource.
      * <p>
      * Used to signal when a DataSource a data source has become invalid, and that a new data source
diff --git a/paging/common/src/main/java/android/arch/paging/KeyedDataSource.java b/paging/common/src/main/java/android/arch/paging/KeyedDataSource.java
index 3214a4e..b6656f3 100644
--- a/paging/common/src/main/java/android/arch/paging/KeyedDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/KeyedDataSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 The Android Open Source Project
+ * Copyright 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,223 +16,127 @@
 
 package android.arch.paging;
 
-import android.support.annotation.AnyThread;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
-import android.support.annotation.WorkerThread;
 
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
-
 /**
  * Incremental data loader for paging keyed content, where loaded content uses previously loaded
  * items as input to future loads.
  * <p>
- * Implement a DataSource using KeyedDataSource if you need to use data from item <code>N-1</code>
- * to load item <code>N</code>. This is common, for example, in sorted database queries where
+ * Implement a DataSource using KeyedDataSource if you need to use data from item {@code N - 1}
+ * to load item {@code N}. This is common, for example, in sorted database queries where
  * attributes of the item such just before the next query define how to execute it.
- * <p>
- * A compute usage pattern with Room SQL queries would look like this (though note, Room plans to
- * provide generation of much of this code in the future):
- * <pre>
- * {@literal @}Dao
- * interface UserDao {
- *     {@literal @}Query("SELECT * from user ORDER BY name DESC LIMIT :limit")
- *     public abstract List&lt;User> userNameInitial(int limit);
- *
- *     {@literal @}Query("SELECT * from user WHERE name &lt; :key ORDER BY name DESC LIMIT :limit")
- *     public abstract List&lt;User> userNameLoadAfter(String key, int limit);
- *
- *     {@literal @}Query("SELECT * from user WHERE name > :key ORDER BY name ASC LIMIT :limit")
- *     public abstract List&lt;User> userNameLoadBefore(String key, int limit);
- * }
- *
- * public class KeyedUserQueryDataSource extends KeyedDataSource&lt;String, User> {
- *     private MyDatabase mDb;
- *     private final UserDao mUserDao;
- *     {@literal @}SuppressWarnings("FieldCanBeLocal")
- *     private final InvalidationTracker.Observer mObserver;
- *
- *     public KeyedUserQueryDataSource(MyDatabase db) {
- *         mDb = db;
- *         mUserDao = db.getUserDao();
- *         mObserver = new InvalidationTracker.Observer("user") {
- *             {@literal @}Override
- *             public void onInvalidated({@literal @}NonNull Set&lt;String> tables) {
- *                 // the user table has been invalidated, invalidate the DataSource
- *                 invalidate();
- *             }
- *         };
- *         db.getInvalidationTracker().addWeakObserver(mObserver);
- *     }
- *
- *     {@literal @}Override
- *     public boolean isInvalid() {
- *         mDb.getInvalidationTracker().refreshVersionsSync();
- *         return super.isInvalid();
- *     }
- *
- *     {@literal @}Override
- *     public String getKey({@literal @}NonNull User item) {
- *         return item.getName();
- *     }
- *
- *     {@literal @}Override
- *     public List&lt;User> loadInitial(int pageSize) {
- *         return mUserDao.userNameInitial(pageSize);
- *     }
- *
- *     {@literal @}Override
- *     public List&lt;User> loadBefore({@literal @}NonNull String userName, int pageSize) {
- *         // Return items adjacent to 'userName' in reverse order
- *         // it's valid to return a different-sized list of items than pageSize, if it's easier
- *         return mUserDao.userNameLoadBefore(userName, pageSize);
- *     }
- *
- *     {@literal @}Override
- *     public List&lt;User> loadAfter({@literal @}Nullable String userName, int pageSize) {
- *         // Return items adjacent to 'userName'
- *         // it's valid to return a different-sized list of items than pageSize, if it's easier
- *         return mUserDao.userNameLoadAfter(userName, pageSize);
- *     }
- * }</pre>
  *
  * @param <Key> Type of data used to query Value types out of the DataSource.
  * @param <Value> Type of items being loaded by the DataSource.
  */
 public abstract class KeyedDataSource<Key, Value> extends ContiguousDataSource<Key, Value> {
-
-    @Nullable
     @Override
-    List<Value> loadAfterImpl(int currentEndIndex, @NonNull Value currentEndItem, int pageSize) {
-        return loadAfter(getKey(currentEndItem), pageSize);
+    final void loadAfter(int currentEndIndex, @NonNull Value currentEndItem, int pageSize,
+            @NonNull LoadCallback<Value> callback) {
+        loadAfter(getKey(currentEndItem), pageSize, callback);
+    }
+
+    @Override
+    final void loadBefore(int currentBeginIndex, @NonNull Value currentBeginItem, int pageSize,
+            @NonNull LoadCallback<Value> callback) {
+        loadBefore(getKey(currentBeginItem), pageSize, callback);
     }
 
     @Nullable
     @Override
-    List<Value> loadBeforeImpl(
-            int currentBeginIndex, @NonNull Value currentBeginItem, int pageSize) {
-        List<Value> list = loadBefore(getKey(currentBeginItem), pageSize);
-
-        if (list != null && list.size() > 1) {
-            // TODO: move out of keyed entirely, into the DB DataSource.
-            list = new ArrayList<>(list);
-            Collections.reverse(list);
+    final Key getKey(int position, Value item) {
+        if (item == null) {
+            return null;
         }
-        return list;
+
+        return getKey(item);
     }
 
 
-    @Override
-    void loadInitial(Key key, int initialLoadSize, boolean enablePlaceholders,
-            @NonNull PageResult.Receiver<Key, Value> receiver) {
-
-        PageResult<Key, Value> pageResult =
-                loadInitialInternal(key, initialLoadSize, enablePlaceholders);
-        if (pageResult == null) {
-            // loading failed, return empty page
-            receiver.onPageResult(new PageResult<Key, Value>(PageResult.INIT));
-        } else {
-            receiver.onPageResult(pageResult);
-        }
-    }
-
     /**
-     * Try initial load, and either return the successful initial load to the receiver,
-     * or null if unsuccessful.
+     * Load initial data.
+     * <p>
+     * This method is called first to initialize a PagedList with data. If it's possible to count
+     * the items that can be loaded by the DataSource, it's recommended to pass the loaded data to
+     * the callback via the three-parameter
+     * {@link DataSource.InitialLoadCallback#onResult(List, int, int)}. This enables PagedLists
+     * presenting data from this source to display placeholders to represent unloaded items.
+     * <p>
+     * {@code initialLoadKey} and {@code requestedLoadSize} are hints, not requirements, so if it is
+     * difficult or impossible to respect them, they may be altered. Note that ignoring the
+     * {@code initialLoadKey} can prevent subsequent PagedList/DataSource pairs from initializing at
+     * the same location. If your data source never invalidates (for example, loading from the
+     * network without the network ever signalling that old data must be reloaded), it's fine to
+     * ignore the {@code initialLoadKey} and always start from the beginning of the data set.
+     *
+     * @param initialLoadKey Load items around this key, or at the beginning of the data set if null
+     *                       is passed.
+     * @param requestedLoadSize Suggested number of items to load.
+     * @param enablePlaceholders Signals whether counting is requested. If false, you can
+     *                           potentially save work by calling the single-parameter variant of
+     *                           {@link DataSource.LoadCallback#onResult(List)} and not counting the
+     *                           number of items in the data set.
+     * @param callback DataSource.LoadCallback that receives initial load data.
      */
-    @Nullable
-    private PageResult<Key, Value> loadInitialInternal(
-            @Nullable Key key, int initialLoadSize, boolean enablePlaceholders) {
-        // check if invalid at beginning, and before returning a valid list
-        if (isInvalid()) {
-            return null;
-        }
+    @Override
+    public abstract void loadInitial(@Nullable Key initialLoadKey, int requestedLoadSize,
+            boolean enablePlaceholders, @NonNull InitialLoadCallback<Value> callback);
 
-        List<Value> list;
-        if (key == null) {
-            // no key, so load initial.
-            list = loadInitial(initialLoadSize);
-            if (list == null) {
-                return null;
-            }
-        } else {
-            List<Value> after = loadAfter(key, initialLoadSize / 2);
-            if (after == null) {
-                return null;
-            }
+    /**
+     * Load list data after the specified item.
+     * <p>
+     * It's valid to return a different list size than the page size, if it's easier for this data
+     * source. It is generally safer to increase the number loaded than reduce.
+     * <p>
+     * Data may be passed synchronously during the loadAfter method, or deferred and called at a
+     * later time. Further loads going down will be blocked until the callback is called.
+     * <p>
+     * If data cannot be loaded (for example, if the request is invalid, or the data would be stale
+     * and inconsistent, it is valid to call {@link #invalidate()} to invalidate the data source,
+     * and prevent further loading.
+     *
+     * @param currentEndKey Load items after this key. May be null on initial load, to indicate load
+     *                      from beginning.
+     * @param pageSize Suggested number of items to load.
+     * @param callback DataSource.LoadCallback that receives loaded data.
+     */
+    public abstract void loadAfter(@NonNull Key currentEndKey, int pageSize,
+            @NonNull LoadCallback<Value> callback);
 
-            Key loadBeforeKey = after.isEmpty() ? key : getKey(after.get(0));
-            List<Value> before = loadBefore(loadBeforeKey, initialLoadSize / 2);
-            if (before == null) {
-                return null;
-            }
-            if (!after.isEmpty() || !before.isEmpty()) {
-                // one of the lists has data
-                if (after.isEmpty()) {
-                    // retry loading after, since it may be that the key passed points to the end of
-                    // the list, so we need to load after the last item in the before list
-                    after = loadAfter(getKey(before.get(0)), initialLoadSize / 2);
-                    if (after == null) {
-                        return null;
-                    }
-                }
-                // assemble full list
-                list = new ArrayList<>();
-                list.addAll(before);
-                // Note - we reverse the list instead of before, in case before is immutable
-                Collections.reverse(list);
-                list.addAll(after);
-            } else {
-                // load before(key) and load after(key) failed - try load initial to be *sure* we
-                // catch the case where there's only one item, which is loaded by the key case
-                list = loadInitial(initialLoadSize);
-                if (list == null) {
-                    return null;
-                }
-            }
-        }
-
-        final Page<Key, Value> page = new Page<>(list);
-
-        if (list.isEmpty()) {
-            if (isInvalid()) {
-                return null;
-            }
-            // wasn't able to load any items, but not invalid - return an empty page.
-            return new PageResult<>(PageResult.INIT, page, 0, 0, 0);
-        }
-
-        int itemsBefore = COUNT_UNDEFINED;
-        int itemsAfter = COUNT_UNDEFINED;
-        if (enablePlaceholders) {
-            itemsBefore = countItemsBefore(getKey(list.get(0)));
-            itemsAfter = countItemsAfter(getKey(list.get(list.size() - 1)));
-        }
-
-        if (isInvalid()) {
-            return null;
-        }
-        if (itemsBefore == COUNT_UNDEFINED || itemsAfter == COUNT_UNDEFINED) {
-            itemsBefore = 0;
-            itemsAfter = 0;
-        }
-        return new PageResult<>(
-                PageResult.INIT,
-                page,
-                itemsBefore,
-                itemsAfter,
-                0);
-    }
+    /**
+     * Load data before the currently loaded content.
+     * <p>
+     * It's valid to return a different list size than the page size, if it's easier for this data
+     * source. It is generally safer to increase the number loaded than reduce. Note that the last
+     * item returned must be directly adjacent to the key passed, so varying size from the pageSize
+     * requested should effectively grow or shrink the list by modifying the beginning, not the end.
+     * <p>
+     * Data may be passed synchronously during the loadBefore method, or deferred and called at a
+     * later time. Further loads going up will be blocked until the callback is called.
+     * <p>
+     * If data cannot be loaded (for example, if the request is invalid, or the data would be stale
+     * and inconsistent, it is valid to call {@link #invalidate()} to invalidate the data source,
+     * and prevent further loading.
+     * <p class="note"><strong>Note:</strong> Data must be returned in the order it will be
+     * presented in the list.
+     *
+     * @param currentBeginKey Load items before this key.
+     * @param pageSize Suggested number of items to load.
+     * @param callback DataSource.LoadCallback that receives loaded data.
+     */
+    public abstract void loadBefore(@NonNull Key currentBeginKey, int pageSize,
+            @NonNull LoadCallback<Value> callback);
 
     /**
      * Return a key associated with the given item.
      * <p>
      * If your KeyedDataSource is loading from a source that is sorted and loaded by a unique
      * integer ID, you would return {@code item.getID()} here. This key can then be passed to
-     * {@link #loadBefore(Key, int)} or {@link #loadAfter(Key, int)} to load additional items
-     * adjacent to the item passed to this function.
+     * {@link #loadBefore(Object, int, LoadCallback)} or
+     * {@link #loadAfter(Object, int, LoadCallback)} to load additional items adjacent to the item
+     * passed to this function.
      * <p>
      * If your key is more complex, such as when you're sorting by name, then resolving collisions
      * with integer ID, you'll need to return both. In such a case you would use a wrapper class,
@@ -243,101 +147,5 @@
      * @return Key associated with given item.
      */
     @NonNull
-    @AnyThread
     public abstract Key getKey(@NonNull Value item);
-
-    /**
-     * Return the number of items that occur before the item uniquely identified by {@code key} in
-     * the data set.
-     * <p>
-     * For example, if you're loading items sorted by ID, then this would return the total number of
-     * items with ID less than {@code key}.
-     * <p>
-     * If you return {@link #COUNT_UNDEFINED} here, or from {@link #countItemsAfter(Key)}, your
-     * data source will not present placeholder null items in place of unloaded data.
-     *
-     * @param key A unique identifier of an item in the data set.
-     * @return Number of items in the data set before the item identified by {@code key}, or
-     *         {@link #COUNT_UNDEFINED}.
-     *
-     * @see #countItemsAfter(Key)
-     */
-    @WorkerThread
-    public int countItemsBefore(@NonNull Key key) {
-        return COUNT_UNDEFINED;
-    }
-
-    /**
-     * Return the number of items that occur after the item uniquely identified by {@code key} in
-     * the data set.
-     * <p>
-     * For example, if you're loading items sorted by ID, then this would return the total number of
-     * items with ID greater than {@code key}.
-     * <p>
-     * If you return {@link #COUNT_UNDEFINED} here, or from {@link #countItemsBefore(Key)}, your
-     * data source will not present placeholder null items in place of unloaded data.
-     *
-     * @param key A unique identifier of an item in the data set.
-     * @return Number of items in the data set after the item identified by {@code key}, or
-     *         {@link #COUNT_UNDEFINED}.
-     *
-     * @see #countItemsBefore(Key)
-     */
-    @WorkerThread
-    public int countItemsAfter(@NonNull Key key) {
-        return COUNT_UNDEFINED;
-    }
-
-    @WorkerThread
-    @Nullable
-    public abstract List<Value> loadInitial(int pageSize);
-
-    /**
-     * Load list data after the specified item.
-     * <p>
-     * It's valid to return a different list size than the page size, if it's easier for this data
-     * source. It is generally safer to increase the number loaded than reduce.
-     *
-     * @param currentEndKey Load items after this key. May be null on initial load, to indicate load
-     *                      from beginning.
-     * @param pageSize      Suggested number of items to load.
-     * @return List of items, starting after the specified item. Null if the data source is
-     * no longer valid, and should not be queried again.
-     */
-    @SuppressWarnings("WeakerAccess")
-    @WorkerThread
-    @Nullable
-    public abstract List<Value> loadAfter(@NonNull Key currentEndKey, int pageSize);
-
-    /**
-     * Load data before the currently loaded content, starting at the provided index,
-     * in reverse-display order.
-     * <p>
-     * It's valid to return a different list size than the page size, if it's easier for this data
-     * source. It is generally safer to increase the number loaded than reduce.
-     * <p class="note"><strong>Note:</strong> Items returned from loadBefore <em>must</em> be in
-     * reverse order from how they will be presented in the list. The first item in the return list
-     * will be prepended immediately before the current beginning of the list. This is so that the
-     * KeyedDataSource may return a different number of items from the requested {@code pageSize} by
-     * shortening or lengthening the return list as it desires.
-     * <p>
-     *
-     * @param currentBeginKey Load items before this key.
-     * @param pageSize         Suggested number of items to load.
-     * @return List of items, in descending order, starting after the specified item. Null if the
-     * data source is no longer valid, and should not be queried again.
-     */
-    @SuppressWarnings("WeakerAccess")
-    @WorkerThread
-    @Nullable
-    public abstract List<Value> loadBefore(@NonNull Key currentBeginKey, int pageSize);
-
-    @Nullable
-    @Override
-    Key getKey(int position, Value item) {
-        if (item == null) {
-            return null;
-        }
-        return getKey(item);
-    }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/ListDataSource.java b/paging/common/src/main/java/android/arch/paging/ListDataSource.java
index d3a171e..b6f366a 100644
--- a/paging/common/src/main/java/android/arch/paging/ListDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/ListDataSource.java
@@ -16,10 +16,12 @@
 
 package android.arch.paging;
 
+import android.support.annotation.NonNull;
+
 import java.util.ArrayList;
 import java.util.List;
 
-public class ListDataSource<T> extends TiledDataSource<T> {
+class ListDataSource<T> extends PositionalDataSource<T> {
     private final List<T> mList;
 
     public ListDataSource(List<T> list) {
@@ -27,13 +29,22 @@
     }
 
     @Override
-    public int countItems() {
-        return mList.size();
+    public void loadInitial(int requestedStartPosition, int requestedLoadSize, int pageSize,
+            @NonNull InitialLoadCallback<T> callback) {
+        final int totalCount = mList.size();
+
+        final int firstLoadPosition = computeFirstLoadPosition(
+                requestedStartPosition, requestedLoadSize, pageSize, totalCount);
+        final int firstLoadSize = Math.min(totalCount - firstLoadPosition, requestedLoadSize);
+
+        // for simplicity, we could return everything immediately,
+        // but we tile here since it's expected behavior
+        List<T> sublist = mList.subList(firstLoadPosition, firstLoadPosition + firstLoadSize);
+        callback.onResult(sublist, firstLoadPosition, totalCount);
     }
 
     @Override
-    public List<T> loadRange(int startPosition, int count) {
-        int endExclusive = Math.min(mList.size(), startPosition + count);
-        return mList.subList(startPosition, endExclusive);
+    public void loadRange(int startPosition, int count, @NonNull LoadCallback<T> callback) {
+        callback.onResult(mList.subList(startPosition, startPosition + count));
     }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/Page.java b/paging/common/src/main/java/android/arch/paging/Page.java
deleted file mode 100644
index e9890ed..0000000
--- a/paging/common/src/main/java/android/arch/paging/Page.java
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright (C) 2017 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package android.arch.paging;
-
-import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
-
-import java.util.List;
-
-/**
- * Immutable class representing a page of data loaded from a DataSource.
- * <p>
- * Optionally stores before/after keys for cases where they cannot be computed, but the DataSource
- * can provide them as part of loading a page.
- * <p>
- * A page's list must never be modified.
- */
-class Page<K, V> {
-    @SuppressWarnings("WeakerAccess")
-    @Nullable
-    public final K beforeKey;
-    @NonNull
-    public final List<V> items;
-    @SuppressWarnings("WeakerAccess")
-    @Nullable
-    public K afterKey;
-
-    Page(@NonNull List<V> items) {
-        this(null, items, null);
-    }
-
-    Page(@Nullable K beforeKey, @NonNull List<V> items, @Nullable K afterKey) {
-        this.beforeKey = beforeKey;
-        this.items = items;
-        this.afterKey = afterKey;
-    }
-}
diff --git a/paging/common/src/main/java/android/arch/paging/PageResult.java b/paging/common/src/main/java/android/arch/paging/PageResult.java
index 55d5fb7..cf2216f 100644
--- a/paging/common/src/main/java/android/arch/paging/PageResult.java
+++ b/paging/common/src/main/java/android/arch/paging/PageResult.java
@@ -16,11 +16,31 @@
 
 package android.arch.paging;
 
-import android.support.annotation.AnyThread;
+import static java.lang.annotation.RetentionPolicy.SOURCE;
+
+import android.support.annotation.IntDef;
 import android.support.annotation.MainThread;
 import android.support.annotation.NonNull;
 
-class PageResult<K, V> {
+import java.lang.annotation.Retention;
+import java.util.Collections;
+import java.util.List;
+
+class PageResult<T> {
+    @SuppressWarnings("unchecked")
+    private static final PageResult INVALID_RESULT =
+            new PageResult(Collections.EMPTY_LIST, 0);
+
+    @SuppressWarnings("unchecked")
+    static <T> PageResult<T> getInvalidResult() {
+        return INVALID_RESULT;
+    }
+
+
+    @Retention(SOURCE)
+    @IntDef({INIT, APPEND, PREPEND, TILE})
+    @interface ResultType {}
+
     static final int INIT = 0;
 
     // contiguous results
@@ -30,8 +50,8 @@
     // non-contiguous, tile result
     static final int TILE = 3;
 
-    public final int type;
-    public final Page<K, V> page;
+    @NonNull
+    public final List<T> page;
     @SuppressWarnings("WeakerAccess")
     public final int leadingNulls;
     @SuppressWarnings("WeakerAccess")
@@ -39,26 +59,34 @@
     @SuppressWarnings("WeakerAccess")
     public final int positionOffset;
 
-    PageResult(int type, Page<K, V> page, int leadingNulls, int trailingNulls, int positionOffset) {
-        this.type = type;
-        this.page = page;
+    PageResult(@NonNull List<T> list, int leadingNulls, int trailingNulls, int positionOffset) {
+        this.page = list;
         this.leadingNulls = leadingNulls;
         this.trailingNulls = trailingNulls;
         this.positionOffset = positionOffset;
     }
 
-    PageResult(int type) {
-        this.type = type;
-        this.page = null;
+    PageResult(@NonNull List<T> list, int positionOffset) {
+        this.page = list;
         this.leadingNulls = 0;
         this.trailingNulls = 0;
-        this.positionOffset = 0;
+        this.positionOffset = positionOffset;
     }
 
-    interface Receiver<K, V> {
-        @AnyThread
-        void postOnPageResult(@NonNull PageResult<K, V> pageResult);
+    @Override
+    public String toString() {
+        return "Result " + leadingNulls
+                + ", " + page
+                + ", " + trailingNulls
+                + ", offset " + positionOffset;
+    }
+
+    public boolean isInvalid() {
+        return this == INVALID_RESULT;
+    }
+
+    abstract static class Receiver<T> {
         @MainThread
-        void onPageResult(@NonNull PageResult<K, V> pageResult);
+        public abstract void onPageResult(@ResultType int type, @NonNull PageResult<T> pageResult);
     }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/PagedList.java b/paging/common/src/main/java/android/arch/paging/PagedList.java
index f18e108..70d4075 100644
--- a/paging/common/src/main/java/android/arch/paging/PagedList.java
+++ b/paging/common/src/main/java/android/arch/paging/PagedList.java
@@ -17,6 +17,7 @@
 package android.arch.paging;
 
 import android.support.annotation.AnyThread;
+import android.support.annotation.MainThread;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.RestrictTo;
@@ -51,7 +52,7 @@
  * PagedList can present data for an unbounded, infinite scrolling list, or a very large but
  * countable list. Use {@link Config} to control how many items a PagedList loads, and when.
  * <p>
- * If you use {@link LivePagedListProvider} to get a
+ * If you use {@link LivePagedListBuilder} to get a
  * {@link android.arch.lifecycle.LiveData}&lt;PagedList>, it will initialize PagedLists on a
  * background thread for you.
  * <h4>Placeholders</h4>
@@ -88,9 +89,8 @@
  * </ul>
  * <p>
  * Placeholders are enabled by default, but can be disabled in two ways. They are disabled if the
- * DataSource returns {@link DataSource#COUNT_UNDEFINED} from any item counting method, or if
- * {@code false} is passed to {@link Config.Builder#setEnablePlaceholders(boolean)} when building a
- * {@link Config}.
+ * DataSource does not count its data set in its initial load, or if  {@code false} is passed to
+ * {@link Config.Builder#setEnablePlaceholders(boolean)} when building a {@link Config}.
  *
  * @param <T> The type of the entries in the list.
  */
@@ -104,7 +104,7 @@
     @NonNull
     final Config mConfig;
     @NonNull
-    final PagedStorage<?, T> mStorage;
+    final PagedStorage<T> mStorage;
 
     int mLastLoad = 0;
     T mLastItem = null;
@@ -123,7 +123,7 @@
 
     protected final ArrayList<WeakReference<Callback>> mCallbacks = new ArrayList<>();
 
-    PagedList(@NonNull PagedStorage<?, T> storage,
+    PagedList(@NonNull PagedStorage<T> storage,
             @NonNull Executor mainThreadExecutor,
             @NonNull Executor backgroundThreadExecutor,
             @Nullable BoundaryCallback<T> boundaryCallback,
@@ -162,7 +162,8 @@
         if (dataSource.isContiguous() || !config.enablePlaceholders) {
             if (!dataSource.isContiguous()) {
                 //noinspection unchecked
-                dataSource = (DataSource<K, T>) ((TiledDataSource<T>) dataSource).getAsContiguous();
+                dataSource = (DataSource<K, T>) ((PositionalDataSource<T>) dataSource)
+                        .wrapAsContiguousWithoutPlaceholders();
             }
             ContiguousDataSource<K, T> contigDataSource = (ContiguousDataSource<K, T>) dataSource;
             return new ContiguousPagedList<>(contigDataSource,
@@ -172,7 +173,7 @@
                     config,
                     key);
         } else {
-            return new TiledPagedList<>((TiledDataSource<T>) dataSource,
+            return new TiledPagedList<>((PositionalDataSource<T>) dataSource,
                     mainThreadExecutor,
                     backgroundThreadExecutor,
                     boundaryCallback,
@@ -184,18 +185,14 @@
     /**
      * Builder class for PagedList.
      * <p>
-     * DataSource, main thread and background executor, and Config must all be provided.
+     * DataSource, Config, main thread and background executor must all be provided.
      * <p>
-     * A valid PagedList may not be constructed without data, so building a PagedList queries
-     * initial data from the data source. This is done because it's generally undesired to present a
-     * PagedList with no data in it to the UI. It's better to present initial data, so that the UI
-     * doesn't show an empty list, or placeholders for a few frames, just before showing initial
-     * content.
+     * A PagedList queries initial data from its DataSource during construction, to avoid empty
+     * PagedLists being presented to the UI when possible. It's preferred to present initial data,
+     * so that the UI doesn't show an empty list, or placeholders for a few frames, just before
+     * showing initial content.
      * <p>
-     * Because PagedLists are initialized with data, PagedLists must be built on a background
-     * thread.
-     * <p>
-     * {@link LivePagedListProvider} does this creation on a background thread automatically, if you
+     * {@link LivePagedListBuilder} does this creation on a background thread automatically, if you
      * want to receive a {@code LiveData<PagedList<...>>}.
      *
      * @param <Key> Type of key used to load data from the DataSource.
@@ -203,26 +200,48 @@
      */
     @SuppressWarnings("WeakerAccess")
     public static class Builder<Key, Value> {
-        private DataSource<Key, Value> mDataSource;
+        private final DataSource<Key, Value> mDataSource;
+        private final Config mConfig;
         private Executor mMainThreadExecutor;
         private Executor mBackgroundThreadExecutor;
         private BoundaryCallback mBoundaryCallback;
-        private Config mConfig;
         private Key mInitialKey;
 
         /**
-         * The source of data that the PagedList should load from.
-         * @param dataSource Source of data for the PagedList.
+         * Create a PagedList.Builder with the provided {@link DataSource} and {@link Config}.
          *
-         * @return this
+         * @param dataSource DataSource the PagedList will load from.
+         * @param config Config that defines how the PagedList loads data from its DataSource.
          */
-        @NonNull
-        public Builder<Key, Value> setDataSource(@NonNull DataSource<Key, Value> dataSource) {
+        public Builder(@NonNull DataSource<Key, Value> dataSource, @NonNull Config config) {
+            //noinspection ConstantConditions
+            if (dataSource == null) {
+                throw new IllegalArgumentException("DataSource may not be null");
+            }
+            //noinspection ConstantConditions
+            if (config == null) {
+                throw new IllegalArgumentException("Config may not be null");
+            }
             mDataSource = dataSource;
-            return this;
+            mConfig = config;
         }
 
         /**
+         * Create a PagedList.Builder with the provided {@link DataSource} and page size.
+         * <p>
+         * This method is a convenience for:
+         * <pre>
+         * PagedList.Builder(dataSource,
+         *         new PagedList.Config.Builder().setPageSize(pageSize).build());
+         * </pre>
+         *
+         * @param dataSource DataSource the PagedList will load from.
+         * @param pageSize Config that defines how the PagedList loads data from its DataSource.
+         */
+        public Builder(@NonNull DataSource<Key, Value> dataSource, int pageSize) {
+            this(dataSource, new PagedList.Config.Builder().setPageSize(pageSize).build());
+        }
+        /**
          * The executor defining where main/UI thread for page loading updates.
          *
          * @param mainThreadExecutor Executor for main/UI thread to receive {@link Callback} calls.
@@ -250,6 +269,15 @@
             return this;
         }
 
+        /**
+         * The BoundaryCallback for out of data events.
+         * <p>
+         * Pass a BoundaryCallback to listen to when the PagedList runs out of data to load.
+         *
+         * @param boundaryCallback BoundaryCallback for listening to out-of-data events.
+         * @return this
+         */
+        @SuppressWarnings("unused")
         @NonNull
         public Builder<Key, Value> setBoundaryCallback(
                 @Nullable BoundaryCallback boundaryCallback) {
@@ -257,20 +285,6 @@
             return this;
         }
 
-
-        /**
-         * The Config defining how the PagedList should load from the DataSource.
-         *
-         * @param config The config that will define how the PagedList loads from the DataSource.
-         *
-         * @return this
-         */
-        @NonNull
-        public Builder<Key, Value> setConfig(@NonNull Config config) {
-            mConfig = config;
-            return this;
-        }
-
         /**
          * Sets the initial key the DataSource should load around as part of initialization.
          *
@@ -286,8 +300,21 @@
         /**
          * Creates a {@link PagedList} with the given parameters.
          * <p>
-         * This call will initial data and perform any counting needed to initialize the PagedList,
-         * therefore it should only be called on a worker thread.
+         * This call will dispatch the {@link DataSource}'s loadInitial method immediately. If a
+         * DataSource posts all of its work (e.g. to a network thread), the PagedList will
+         * be immediately created as empty, and grow to its initial size when the initial load
+         * completes.
+         * <p>
+         * If the DataSource implements its load synchronously, doing the load work immediately in
+         * the loadInitial method, the PagedList will block on that load before completing
+         * construction. In this case, use a background thread to create a PagedList.
+         * <p>
+         * It's fine to create a PagedList with an async DataSource on the main thread, such as in
+         * the constructor of a ViewModel. An async network load won't block the initialLoad
+         * function. For a synchronous DataSource such as one created from a Room database, a
+         * {@code LiveData<PagedList>} can be safely constructed with {@link LivePagedListBuilder}
+         * on the main thread, since actual construction work is deferred, and done on a background
+         * thread.
          * <p>
          * While build() will always return a PagedList, it's important to note that the PagedList
          * initial load may fail to acquire data from the DataSource. This can happen for example if
@@ -300,18 +327,13 @@
         @WorkerThread
         @NonNull
         public PagedList<Value> build() {
-            if (mDataSource == null) {
-                throw new IllegalArgumentException("DataSource required");
-            }
+            // TODO: define defaults, once they can be used in module without android dependency
             if (mMainThreadExecutor == null) {
                 throw new IllegalArgumentException("MainThreadExecutor required");
             }
             if (mBackgroundThreadExecutor == null) {
                 throw new IllegalArgumentException("BackgroundThreadExecutor required");
             }
-            if (mConfig == null) {
-                throw new IllegalArgumentException("Config required");
-            }
 
             //noinspection unchecked
             return PagedList.create(
@@ -451,13 +473,11 @@
         // safe to deref mBoundaryCallback here, since we only defer if mBoundaryCallback present
         if (begin) {
             //noinspection ConstantConditions
-            mBoundaryCallback.onItemAtFrontLoaded(
-                    snapshot(), mStorage.getFirstLoadedItem(), mStorage.size());
+            mBoundaryCallback.onItemAtFrontLoaded(mStorage.getFirstLoadedItem());
         }
         if (end) {
             //noinspection ConstantConditions
-            mBoundaryCallback.onItemAtEndLoaded(
-                    snapshot(), mStorage.getLastLoadedItem(), mStorage.size());
+            mBoundaryCallback.onItemAtEndLoaded(mStorage.getLastLoadedItem());
         }
     }
 
@@ -501,7 +521,6 @@
         if (isImmutable()) {
             return this;
         }
-
         return new SnapshotPagedList<>(this);
     }
 
@@ -522,7 +541,7 @@
      * <p>
      * When a PagedList is invalidated, you can pass the key returned by this function to initialize
      * the next PagedList. This ensures (depending on load times) that the next PagedList that
-     * arrives will have data that overlaps. If you use {@link LivePagedListProvider}, it will do
+     * arrives will have data that overlaps. If you use {@link LivePagedListBuilder}, it will do
      * this for you.
      *
      * @return Key of position most recently passed to {@link #loadAround(int)}.
@@ -556,8 +575,8 @@
     /**
      * Position offset of the data in the list.
      * <p>
-     * If data is supplied by a {@link TiledDataSource}, the item returned from <code>get(i)</code>
-     * has a position of <code>i + getPositionOffset()</code>.
+     * If data is supplied by a {@link PositionalDataSource}, the item returned from
+     * <code>get(i)</code> has a position of <code>i + getPositionOffset()</code>.
      * <p>
      * If the DataSource is a {@link KeyedDataSource}, and thus doesn't use positions, returns 0.
      */
@@ -583,15 +602,25 @@
      * GC'd.
      *
      * @param previousSnapshot Snapshot previously captured from this List, or null.
-     * @param callback         Callback to dispatch to.
+     * @param callback         LoadCallback to dispatch to.
      * @see #removeWeakCallback(Callback)
      */
     @SuppressWarnings("WeakerAccess")
     public void addWeakCallback(@Nullable List<T> previousSnapshot, @NonNull Callback callback) {
         if (previousSnapshot != null && previousSnapshot != this) {
-            PagedList<T> storageSnapshot = (PagedList<T>) previousSnapshot;
-            //noinspection unchecked
-            dispatchUpdatesSinceSnapshot(storageSnapshot, callback);
+
+            if (previousSnapshot.isEmpty()) {
+                if (!mStorage.isEmpty()) {
+                    // If snapshot is empty, diff is trivial - just notify number new items.
+                    // Note: occurs in async init, when snapshot taken before init page arrives
+                    callback.onInserted(0, mStorage.size());
+                }
+            } else {
+                PagedList<T> storageSnapshot = (PagedList<T>) previousSnapshot;
+
+                //noinspection unchecked
+                dispatchUpdatesSinceSnapshot(storageSnapshot, callback);
+            }
         }
 
         // first, clean up any empty weak refs
@@ -608,7 +637,7 @@
     /**
      * Removes a previously added callback.
      *
-     * @param callback Callback, previously added.
+     * @param callback LoadCallback, previously added.
      * @see #addWeakCallback(List, Callback)
      */
     @SuppressWarnings("WeakerAccess")
@@ -645,6 +674,14 @@
         }
     }
 
+
+
+    /**
+     * Dispatch updates since the non-empty snapshot was taken.
+     *
+     * @param snapshot Non-empty snapshot.
+     * @param callback LoadCallback for updates that have occurred since snapshot.
+     */
     abstract void dispatchUpdatesSinceSnapshot(@NonNull PagedList<T> snapshot,
             @NonNull Callback callback);
 
@@ -826,13 +863,6 @@
              * This value is typically larger than page size, so on first load data there's a large
              * enough range of content loaded to cover small scrolls.
              * <p>
-             * If used with a {@link TiledDataSource}, this value is rounded to the nearest number
-             * of pages, with a minimum of two pages, and loaded with a single call to
-             * {@link TiledDataSource#loadRange(int, int)}.
-             * <p>
-             * If used with a {@link KeyedDataSource}, this value will be passed to
-             * {@link KeyedDataSource#loadInitial(int)}.
-             * <p>
              * If not set, defaults to three times page size.
              *
              * @param initialLoadSizeHint Number of items to load while initializing the PagedList.
@@ -873,13 +903,43 @@
     }
 
     /**
-     * WIP API for load-more-into-local-storage callbacks
+     * Signals when a PagedList has reached the end of available data.
+     * <p>
+     * This can be used to implement paging from the network into a local database - when the
+     * database has no more data to present, a BoundaryCallback can be used to fetch more data.
+     * <p>
+     * If an instance is shared across multiple PagedLists (e.g. when passed to
+     * {@link LivePagedListBuilder#setBoundaryCallback}), the callbacks may be issued multiple
+     * times. If for example {@link #onItemAtEndLoaded(Object)} triggers a network load, it should
+     * avoid triggering it again while the load is ongoing.
+     *
+     * @param <T> Type loaded by the PagedList.
      */
+    @MainThread
     public abstract static class BoundaryCallback<T> {
+        /**
+         * Called when zero items are returned from an initial load of the PagedList's data source.
+         */
         public abstract void onZeroItemsLoaded();
-        public abstract void onItemAtFrontLoaded(@NonNull List<T> pagedListSnapshot,
-                @NonNull T itemAtFront, int pagedListSize);
-        public abstract void onItemAtEndLoaded(@NonNull List<T> pagedListSnapshot,
-                @NonNull T itemAtEnd, int pagedListSize);
+
+        /**
+         * Called when the item at the front of the PagedList has been loaded, and access has
+         * occurred within {@link Config#prefetchDistance} of it.
+         * <p>
+         * No more data will be prepended to the PagedList before this item.
+         *
+         * @param itemAtFront The first item of PagedList
+         */
+        public abstract void onItemAtFrontLoaded(@NonNull T itemAtFront);
+
+        /**
+         * Called when the item at the end of the PagedList has been loaded, and access has
+         * occurred within {@link Config#prefetchDistance} of it.
+         * <p>
+         * No more data will be appended to the PagedList after this item.
+         *
+         * @param itemAtEnd The first item of PagedList
+         */
+        public abstract void onItemAtEndLoaded(@NonNull T itemAtEnd);
     }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/PagedStorage.java b/paging/common/src/main/java/android/arch/paging/PagedStorage.java
index b857462..d4531d3 100644
--- a/paging/common/src/main/java/android/arch/paging/PagedStorage.java
+++ b/paging/common/src/main/java/android/arch/paging/PagedStorage.java
@@ -17,13 +17,21 @@
 package android.arch.paging;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import java.util.AbstractList;
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
-final class PagedStorage<K, V> extends AbstractList<V> {
+final class PagedStorage<T> extends AbstractList<T> {
+    /**
+     * Lists instances are compared (with instance equality) to PLACEHOLDER_LIST to check if an item
+     * in that position is already loading. We use a singleton placeholder list that is distinct
+     * from Collections.EMPTY_LIST for safety.
+     */
+    @SuppressWarnings("MismatchedQueryAndUpdateOfCollection")
+    private static final List PLACEHOLDER_LIST = new ArrayList();
+
     // Always set
     private int mLeadingNullCount;
     /**
@@ -37,7 +45,7 @@
      * Non-contiguous - mPages may have nulls or a placeholder page, isTiled() always returns true.
      *     mPages may have nulls, or placeholder (empty) pages while content is loading.
      */
-    private final ArrayList<Page<K, V>> mPages;
+    private final ArrayList<List<T>> mPages;
     private int mTrailingNullCount;
 
     private int mPositionOffset;
@@ -53,9 +61,6 @@
     private int mNumberPrepended;
     private int mNumberAppended;
 
-    // only used in tiling case
-    private Page<K, V> mPlaceholderPage;
-
     PagedStorage() {
         mLeadingNullCount = 0;
         mPages = new ArrayList<>();
@@ -67,12 +72,12 @@
         mNumberAppended = 0;
     }
 
-    PagedStorage(int leadingNulls, Page<K, V> page, int trailingNulls) {
+    PagedStorage(int leadingNulls, List<T> page, int trailingNulls) {
         this();
         init(leadingNulls, page, trailingNulls, 0);
     }
 
-    private PagedStorage(PagedStorage<K, V> other) {
+    private PagedStorage(PagedStorage<T> other) {
         mLeadingNullCount = other.mLeadingNullCount;
         mPages = new ArrayList<>(other.mPages);
         mTrailingNullCount = other.mTrailingNullCount;
@@ -81,40 +86,37 @@
         mPageSize = other.mPageSize;
         mNumberPrepended = other.mNumberPrepended;
         mNumberAppended = other.mNumberAppended;
-
-        // preserve placeholder page so we can locate placeholder pages if needed later
-        mPlaceholderPage = other.mPlaceholderPage;
     }
 
-    PagedStorage<K, V> snapshot() {
+    PagedStorage<T> snapshot() {
         return new PagedStorage<>(this);
     }
 
-    private void init(int leadingNulls, Page<K, V> page, int trailingNulls, int positionOffset) {
+    private void init(int leadingNulls, List<T> page, int trailingNulls, int positionOffset) {
         mLeadingNullCount = leadingNulls;
         mPages.clear();
         mPages.add(page);
         mTrailingNullCount = trailingNulls;
 
         mPositionOffset = positionOffset;
-        mStorageCount = page.items.size();
+        mStorageCount = page.size();
 
         // initialized as tiled. There may be 3 nulls, 2 items, but we still call this tiled
         // even if it will break if nulls convert.
-        mPageSize = page.items.size();
+        mPageSize = page.size();
 
         mNumberPrepended = 0;
         mNumberAppended = 0;
     }
 
-    void init(int leadingNulls, Page<K, V> page, int trailingNulls, int positionOffset,
+    void init(int leadingNulls, @NonNull List<T> page, int trailingNulls, int positionOffset,
             @NonNull Callback callback) {
         init(leadingNulls, page, trailingNulls, positionOffset);
         callback.onInitialized(size());
     }
 
     @Override
-    public V get(int i) {
+    public T get(int i) {
         if (i < 0 || i >= size()) {
             throw new IndexOutOfBoundsException("Index: " + i + ", Size: " + size());
         }
@@ -138,7 +140,7 @@
             pageInternalIndex = localIndex;
             final int localPageCount = mPages.size();
             for (localPageIndex = 0; localPageIndex < localPageCount; localPageIndex++) {
-                int pageSize = mPages.get(localPageIndex).items.size();
+                int pageSize = mPages.get(localPageIndex).size();
                 if (pageSize > pageInternalIndex) {
                     // stop, found the page
                     break;
@@ -147,12 +149,12 @@
             }
         }
 
-        Page<?, V> page = mPages.get(localPageIndex);
-        if (page == null || page.items.size() == 0) {
+        List<T> page = mPages.get(localPageIndex);
+        if (page == null || page.size() == 0) {
             // can only occur in tiled case, with untouched inner/placeholder pages
             return null;
         }
-        return page.items.get(pageInternalIndex);
+        return page.get(pageInternalIndex);
     }
 
     /**
@@ -207,8 +209,8 @@
         int total = mLeadingNullCount;
         final int pageCount = mPages.size();
         for (int i = 0; i < pageCount; i++) {
-            Page page = mPages.get(i);
-            if (page != null && page != mPlaceholderPage) {
+            List page = mPages.get(i);
+            if (page != null && page != PLACEHOLDER_LIST) {
                 break;
             }
             total += mPageSize;
@@ -219,8 +221,8 @@
     int computeTrailingNulls() {
         int total = mTrailingNullCount;
         for (int i = mPages.size() - 1; i >= 0; i--) {
-            Page page = mPages.get(i);
-            if (page != null && page != mPlaceholderPage) {
+            List page = mPages.get(i);
+            if (page != null && page != PLACEHOLDER_LIST) {
                 break;
             }
             total += mPageSize;
@@ -230,21 +232,21 @@
 
     // ---------------- Contiguous API -------------------
 
-    V getFirstLoadedItem() {
+    T getFirstLoadedItem() {
         // safe to access first page's first item here:
         // If contiguous, mPages can't be empty, can't hold null Pages, and items can't be empty
-        return mPages.get(0).items.get(0);
+        return mPages.get(0).get(0);
     }
 
-    V getLastLoadedItem() {
+    T getLastLoadedItem() {
         // safe to access last page's last item here:
         // If contiguous, mPages can't be empty, can't hold null Pages, and items can't be empty
-        Page<K, V> page = mPages.get(mPages.size() - 1);
-        return page.items.get(page.items.size() - 1);
+        List<T> page = mPages.get(mPages.size() - 1);
+        return page.get(page.size() - 1);
     }
 
-    public void prependPage(@NonNull Page<K, V> page, @NonNull Callback callback) {
-        final int count = page.items.size();
+    void prependPage(@NonNull List<T> page, @NonNull Callback callback) {
+        final int count = page.size();
         if (count == 0) {
             // Nothing returned from source, stop loading in this direction
             return;
@@ -274,8 +276,8 @@
         callback.onPagePrepended(mLeadingNullCount, changedCount, addedCount);
     }
 
-    public void appendPage(@NonNull Page<K, V> page, @NonNull Callback callback) {
-        final int count = page.items.size();
+    void appendPage(@NonNull List<T> page, @NonNull Callback callback) {
+        final int count = page.size();
         if (count == 0) {
             // Nothing returned from source, stop loading in this direction
             return;
@@ -284,7 +286,7 @@
         if (mPageSize > 0) {
             // if the previous page was smaller than mPageSize,
             // or if this page is larger than the previous, disable tiling
-            if (mPages.get(mPages.size() - 1).items.size() != mPageSize
+            if (mPages.get(mPages.size() - 1).size() != mPageSize
                     || count > mPageSize) {
                 mPageSize = -1;
             }
@@ -306,8 +308,30 @@
 
     // ------------------ Non-Contiguous API (tiling required) ----------------------
 
-    public void insertPage(int position, @NonNull Page<K, V> page, Callback callback) {
-        final int newPageSize = page.items.size();
+    void initAndSplit(int leadingNulls, @NonNull List<T> multiPageList,
+            int trailingNulls, int positionOffset, int pageSize, @NonNull Callback callback) {
+
+        int pageCount = (multiPageList.size() + (pageSize - 1)) / pageSize;
+        for (int i = 0; i < pageCount; i++) {
+            int beginInclusive = i * pageSize;
+            int endExclusive = Math.min(multiPageList.size(), (i + 1) * pageSize);
+
+            List<T> sublist = multiPageList.subList(beginInclusive, endExclusive);
+
+            if (i == 0) {
+                // Trailing nulls for first page includes other pages in multiPageList
+                int initialTrailingNulls = trailingNulls + multiPageList.size() - sublist.size();
+                init(leadingNulls, sublist, initialTrailingNulls, positionOffset);
+            } else {
+                int insertPosition = leadingNulls + beginInclusive;
+                insertPage(insertPosition, sublist, null);
+            }
+        }
+        callback.onInitialized(size());
+    }
+
+    public void insertPage(int position, @NonNull List<T> page, @Nullable Callback callback) {
+        final int newPageSize = page.size();
         if (newPageSize != mPageSize) {
             // differing page size is OK in 2 cases, when the page is being added:
             // 1) to the end (in which case, ignore new smaller size)
@@ -334,22 +358,15 @@
 
         int localPageIndex = pageIndex - mLeadingNullCount / mPageSize;
 
-        Page<K, V> oldPage = mPages.get(localPageIndex);
-        if (oldPage != null && oldPage != mPlaceholderPage) {
+        List<T> oldPage = mPages.get(localPageIndex);
+        if (oldPage != null && oldPage != PLACEHOLDER_LIST) {
             throw new IllegalArgumentException(
                     "Invalid position " + position + ": data already loaded");
         }
         mPages.set(localPageIndex, page);
-        callback.onPageInserted(position, page.items.size());
-    }
-
-    private Page<K, V> getPlaceholderPage() {
-        if (mPlaceholderPage == null) {
-            @SuppressWarnings("unchecked")
-            List<V> list = Collections.emptyList();
-            mPlaceholderPage = new Page<>(null, list, null);
+        if (callback != null) {
+            callback.onPageInserted(position, page.size());
         }
-        return mPlaceholderPage;
     }
 
     private void allocatePageRange(final int minimumPage, final int maximumPage) {
@@ -399,7 +416,8 @@
         for (int pageIndex = minimumPage; pageIndex <= maximumPage; pageIndex++) {
             int localPageIndex = pageIndex - leadingNullPages;
             if (mPages.get(localPageIndex) == null) {
-                mPages.set(localPageIndex, getPlaceholderPage());
+                //noinspection unchecked
+                mPages.set(localPageIndex, PLACEHOLDER_LIST);
                 callback.onPagePlaceholderInserted(pageIndex);
             }
         }
@@ -414,9 +432,9 @@
             return false;
         }
 
-        Page<K, V> page = mPages.get(index - leadingNullPages);
+        List<T> page = mPages.get(index - leadingNullPages);
 
-        return page != null && page != mPlaceholderPage;
+        return page != null && page != PLACEHOLDER_LIST;
     }
 
     @Override
diff --git a/paging/common/src/main/java/android/arch/paging/PositionalDataSource.java b/paging/common/src/main/java/android/arch/paging/PositionalDataSource.java
index fa2932a..5dd3a83 100644
--- a/paging/common/src/main/java/android/arch/paging/PositionalDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/PositionalDataSource.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 The Android Open Source Project
+ * Copyright 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,115 +20,139 @@
 import android.support.annotation.Nullable;
 import android.support.annotation.WorkerThread;
 
-import java.util.List;
+import java.util.Collections;
 
 /**
- * Incremental data loader for paging positional content, where content can be loaded based on its
- * integer position.
+ * Position-based data loader for a fixed-size, countable data set, supporting loads at arbitrary
+ * positions.
  * <p>
- * Use PositionalDataSource if you only need position as input for item loading - if for example,
- * you're asking the backend for items at positions 10 through 20, or using a limit/offset database
- * query to load items at query position 10 through 20.
+ * Extend PositionalDataSource if you can support counting your data set, and loading based on
+ * position information.
  * <p>
- * Implement a DataSource using PositionalDataSource if position is the only information you need to
- * load items.
+ * Note that unless {@link PagedList.Config#enablePlaceholders placeholders are disabled}
+ * PositionalDataSource requires counting the size of the dataset. This allows pages to be tiled in
+ * at arbitrary, non-contiguous locations based upon what the user observes in a {@link PagedList}.
  * <p>
- * Note that {@link BoundedDataSource} provides a simpler API for positional loading, if your
- * backend or data store doesn't require
- * <p>
- * @param <Value> Value type of items being loaded by the DataSource.
+ * Room can generate a Factory of PositionalDataSources for you:
+ * <pre>
+ * {@literal @}Dao
+ * interface UserDao {
+ *     {@literal @}Query("SELECT * FROM user ORDER BY mAge DESC")
+ *     public abstract DataSource.Factory&lt;Integer, User> loadUsersByAgeDesc();
+ * }</pre>
+ *
+ * @param <T> Type of items being loaded by the PositionalDataSource.
  */
-abstract class PositionalDataSource<Value> extends ContiguousDataSource<Integer, Value> {
+public abstract class PositionalDataSource<T> extends DataSource<Integer, T> {
 
     /**
-     * Number of items that this DataSource can provide in total, or COUNT_UNDEFINED.
-     *
-     * @return number of items that this DataSource can provide in total, or COUNT_UNDEFINED
-     * if difficult or undesired to compute.
-     */
-    public int countItems() {
-        return COUNT_UNDEFINED;
-    }
-
-    @Nullable
-    @Override
-    List<Value> loadAfterImpl(int currentEndIndex, @NonNull Value currentEndItem, int pageSize) {
-        return loadAfter(currentEndIndex + 1, pageSize);
-    }
-
-    @Nullable
-    @Override
-    List<Value> loadBeforeImpl(int currentBeginIndex, @NonNull Value currentBeginItem,
-            int pageSize) {
-        return loadBefore(currentBeginIndex - 1, pageSize);
-    }
-
-    @Override
-    void loadInitial(Integer position, int initialLoadSize, boolean enablePlaceholders,
-            @NonNull PageResult.Receiver<Integer, Value> receiver) {
-
-        final int convertPosition = position == null ? 0 : position;
-        final int loadPosition = Math.max(0, (convertPosition - initialLoadSize / 2));
-
-        int count = COUNT_UNDEFINED;
-        if (enablePlaceholders) {
-            count = countItems();
-        }
-        List<Value> data = loadAfter(loadPosition, initialLoadSize);
-
-        if (data == null) {
-            receiver.onPageResult(new PageResult<Integer, Value>(PageResult.INIT));
-            return;
-        }
-
-        final boolean uncounted = count == COUNT_UNDEFINED;
-        int leadingNullCount = uncounted ? 0 : loadPosition;
-        int trailingNullCount = uncounted ? 0 : count - leadingNullCount - data.size();
-        int positionOffset = uncounted ? loadPosition : 0;
-
-        receiver.onPageResult(new PageResult<>(
-                PageResult.INIT,
-                new Page<Integer, Value>(data),
-                leadingNullCount,
-                trailingNullCount,
-                positionOffset));
-    }
-
-    /**
-     * Load data after currently loaded content, starting at the provided index.
+     * Load initial list data.
      * <p>
-     * It's valid to return a different list size than the page size, if it's easier for this data
-     * source. It is generally safer to increase the number loaded than reduce.
+     * This method is called to load the initial page(s) from the DataSource.
+     * <p>
+     * Result list must be a multiple of pageSize to enable efficient tiling.
      *
-     * @param startIndex Load items starting at this index.
-     * @param pageSize Suggested number of items to load.
-     * @return List of items, starting at position currentEndIndex + 1. Null if the data source is
-     *         no longer valid, and should not be queried again.
+     * @param requestedStartPosition Initial load position requested. Note that this may not be
+     *                               within the bounds of your data set, it should be corrected
+     *                               before you make your query.
+     * @param requestedLoadSize Requested number of items to load. Note that this may be larger than
+     *                          available data.
+     * @param pageSize Defines page size acceptable for return values. List of items passed to the
+     *                 callback must be an integer multiple of page size.
+     * @param callback DataSource.InitialLoadCallback that receives initial load data, including
+     *                 position and total data set size.
      */
     @WorkerThread
-    @Nullable
-    public abstract List<Value> loadAfter(int startIndex, int pageSize);
+    public abstract void loadInitial(int requestedStartPosition, int requestedLoadSize,
+            int pageSize, @NonNull InitialLoadCallback<T> callback);
 
     /**
-     * Load data before the currently loaded content, starting at the provided index.
+     * Called to load a range of data from the DataSource.
      * <p>
-     * It's valid to return a different list size than the page size, if it's easier for this data
-     * source. It is generally safer to increase the number loaded than reduce.
+     * This method is called to load additional pages from the DataSource after the
+     * InitialLoadCallback passed to loadInitial has initialized a PagedList.
+     * <p>
+     * Unlike {@link #loadInitial(int, int, int, InitialLoadCallback)}, this method must return the
+     * number of items requested, at the position requested.
      *
-     * @param startIndex Load items, starting at this index.
-     * @param pageSize Suggested number of items to load.
-     * @return List of items, in descending order, starting at position currentBeginIndex - 1. Null
-     *         if the data source is no longer valid, and should not be queried again.
+     * @param startPosition Initial load position.
+     * @param count Number of items to load.
+     * @param callback DataSource.LoadCallback that receives loaded data.
      */
     @WorkerThread
-    @Nullable
-    public abstract List<Value> loadBefore(int startIndex, int pageSize);
+    public abstract void loadRange(int startPosition, int count,
+            @NonNull LoadCallback<T> callback);
 
     @Override
-    Integer getKey(int position, Value item) {
-        if (position < 0) {
-            return null;
+    boolean isContiguous() {
+        return false;
+    }
+
+    @NonNull
+    ContiguousDataSource<Integer, T> wrapAsContiguousWithoutPlaceholders() {
+        return new ContiguousWithoutPlaceholdersWrapper<>(this);
+    }
+
+    static int computeFirstLoadPosition(int position, int firstLoadSize, int pageSize, int size) {
+        int roundedPageStart = Math.round(position / pageSize) * pageSize;
+
+        // maximum start pos is that which will encompass end of list
+        int maximumLoadPage = ((size - firstLoadSize + pageSize - 1) / pageSize) * pageSize;
+        roundedPageStart = Math.min(maximumLoadPage, roundedPageStart);
+
+        // minimum start position is 0
+        roundedPageStart = Math.max(0, roundedPageStart);
+
+        return roundedPageStart;
+    }
+
+    @SuppressWarnings("deprecation")
+    static class ContiguousWithoutPlaceholdersWrapper<Value>
+            extends ContiguousDataSource<Integer, Value> {
+
+        @NonNull
+        final PositionalDataSource<Value> mPositionalDataSource;
+
+        ContiguousWithoutPlaceholdersWrapper(
+                @NonNull PositionalDataSource<Value> positionalDataSource) {
+            mPositionalDataSource = positionalDataSource;
         }
-        return position;
+
+        @Override
+        public void loadInitial(@Nullable Integer position, int initialLoadSize,
+                boolean enablePlaceholders, @NonNull InitialLoadCallback<Value> callback) {
+            final int convertPosition = position == null ? 0 : position;
+
+            // Note enablePlaceholders will be false here, but we don't have a way to communicate
+            // this to PositionalDataSource. This is fine, because only the list and its position
+            // offset will be consumed by the InitialLoadCallback.
+            mPositionalDataSource.loadInitial(
+                    convertPosition, initialLoadSize, initialLoadSize, callback);
+        }
+
+        @Override
+        void loadAfter(int currentEndIndex, @NonNull Value currentEndItem, int pageSize,
+                @NonNull LoadCallback<Value> callback) {
+            int startIndex = currentEndIndex + 1;
+            mPositionalDataSource.loadRange(startIndex, pageSize, callback);
+        }
+
+        @Override
+        void loadBefore(int currentBeginIndex, @NonNull Value currentBeginItem, int pageSize,
+                @NonNull LoadCallback<Value> callback) {
+            int startIndex = currentBeginIndex - 1;
+            if (startIndex < 0) {
+                callback.onResult(Collections.<Value>emptyList());
+            } else {
+                int loadSize = Math.min(pageSize, startIndex + 1);
+                startIndex = startIndex - loadSize + 1;
+                mPositionalDataSource.loadRange(startIndex, loadSize, callback);
+            }
+        }
+
+        @Override
+        Integer getKey(int position, Value item) {
+            return position;
+        }
     }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/TiledDataSource.java b/paging/common/src/main/java/android/arch/paging/TiledDataSource.java
index 0ea9428..27aeda0 100644
--- a/paging/common/src/main/java/android/arch/paging/TiledDataSource.java
+++ b/paging/common/src/main/java/android/arch/paging/TiledDataSource.java
@@ -16,84 +16,24 @@
 
 package android.arch.paging;
 
-import android.support.annotation.Nullable;
+import android.support.annotation.NonNull;
+import android.support.annotation.RestrictTo;
 import android.support.annotation.WorkerThread;
 
 import java.util.Collections;
 import java.util.List;
 
 /**
- * Position-based data loader for fixed size, arbitrary positioned loading.
- * <p>
- * Extend TiledDataSource if you want to load arbitrary pages based solely on position information,
- * and can generate pages of a provided fixed size.
- * <p>
- * Room can generate a TiledDataSource for you:
- * <pre>
- * {@literal @}Dao
- * interface UserDao {
- *     {@literal @}Query("SELECT * FROM user ORDER BY mAge DESC")
- *     public abstract TiledDataSource&lt;User> loadUsersByAgeDesc();
- * }</pre>
+ * @param <T> Type loaded by the TiledDataSource.
  *
- * Under the hood, Room will generate code equivalent to the below, using a limit/offset SQL query:
- * <pre>
- * {@literal @}Dao
- * interface UserDao {
- *     {@literal @}Query("SELECT COUNT(*) from user")
- *     public abstract Integer getUserCount();
- *
- *     {@literal @}Query("SELECT * from user ORDER BY mName DESC LIMIT :limit OFFSET :offset")
- *     public abstract List&lt;User> userNameLimitOffset(int limit, int offset);
- * }
- *
- * public class OffsetUserQueryDataSource extends TiledDataSource&lt;User> {
- *     private MyDatabase mDb;
- *     private final UserDao mUserDao;
- *     {@literal @}SuppressWarnings("FieldCanBeLocal")
- *     private final InvalidationTracker.Observer mObserver;
- *
- *     public OffsetUserQueryDataSource(MyDatabase db) {
- *         mDb = db;
- *         mUserDao = db.getUserDao();
- *         mObserver = new InvalidationTracker.Observer("user") {
- *             {@literal @}Override
- *             public void onInvalidated({@literal @}NonNull Set&lt;String> tables) {
- *                 // the user table has been invalidated, invalidate the DataSource
- *                 invalidate();
- *             }
- *         };
- *         db.getInvalidationTracker().addWeakObserver(mObserver);
- *     }
- *
- *     {@literal @}Override
- *     public boolean isInvalid() {
- *         mDb.getInvalidationTracker().refreshVersionsSync();
- *         return super.isInvalid();
- *     }
- *
- *     {@literal @}Override
- *     public int countItems() {
- *         return mUserDao.getUserCount();
- *     }
- *
- *     {@literal @}Override
- *     public List&lt;User> loadRange(int startPosition, int loadCount) {
- *         return mUserDao.userNameLimitOffset(loadCount, startPosition);
- *     }
- * }</pre>
- *
- * @param <Type> Type of items being loaded by the TiledDataSource.
+ * @deprecated Use {@link PositionalDataSource}
+ * @hide
  */
-public abstract class TiledDataSource<Type> extends DataSource<Integer, Type> {
+@SuppressWarnings("DeprecatedIsStillUsed")
+@Deprecated
+@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
+public abstract class TiledDataSource<T> extends PositionalDataSource<T> {
 
-    private int mItemCount;
-
-    /**
-     * Number of items that this DataSource can provide in total.
-     *
-     * @return Number of items this DataSource can provide. Must be <code>0</code> or greater.
-     */
     @WorkerThread
     public abstract int countItems();
 
@@ -102,111 +42,39 @@
         return false;
     }
 
-    /**
-     * Called to load items at from the specified position range.
-     * <p>
-     * This method must return a list of requested size, unless at the end of list. Fixed size pages
-     * enable TiledDataSource to navigate tiles efficiently, and quickly accesss any position in the
-     * data set.
-     * <p>
-     * If a list of a different size is returned, but it is not the last list in the data set based
-     * on the return value from {@link #countItems()}, an exception will be thrown.
-     *
-     * @param startPosition Index of first item to load.
-     * @param count         Number of items to load.
-     * @return List of loaded items, of the requested length unless at end of list. Null if the
-     *         DataSource is no longer valid, and should not be queried again.
-     */
     @WorkerThread
-    public abstract List<Type> loadRange(int startPosition, int count);
+    public abstract List<T> loadRange(int startPosition, int count);
 
-    /**
-     * blocking, and splits pages
-     */
-    void loadRangeInitial(int startPosition, int count, int pageSize, int itemCount,
-            PageResult.Receiver<Integer, Type> receiver) {
-        mItemCount = itemCount;
-
-        if (itemCount == 0) {
-            // no data to load, just immediately return empty
-            receiver.onPageResult(new PageResult<>(
-                    PageResult.INIT, new Page<Integer, Type>(Collections.<Type>emptyList()),
-                    0, 0, startPosition));
+    @Override
+    public void loadInitial(int requestedStartPosition, int requestedLoadSize, int pageSize,
+            @NonNull InitialLoadCallback<T> callback) {
+        int totalCount = countItems();
+        if (totalCount == 0) {
+            callback.onResult(Collections.<T>emptyList());
             return;
         }
 
-        List<Type> list = loadRangeWrapper(startPosition, count);
+        // bound the size requested, based on known count
+        final int firstLoadPosition = computeFirstLoadPosition(
+                requestedStartPosition, requestedLoadSize, pageSize, totalCount);
+        final int firstLoadSize = Math.min(totalCount - firstLoadPosition, requestedLoadSize);
 
-        count = Math.min(count, itemCount - startPosition);
-
-        if (list == null) {
-            // invalid data, pass to receiver
-            receiver.onPageResult(new PageResult<Integer, Type>(
-                    PageResult.INIT, null, 0, 0, startPosition));
-            return;
-        }
-
-        if (list.size() != count) {
-            throw new IllegalStateException("Invalid list, requested size: " + count
-                    + ", returned size: " + list.size());
-        }
-
-        // emit the results as multiple pages
-        int pageCount = (count + (pageSize - 1)) / pageSize;
-        for (int i = 0; i < pageCount; i++) {
-            int beginInclusive = i * pageSize;
-            int endExclusive = Math.min(count, (i + 1) * pageSize);
-
-            Page<Integer, Type> page = new Page<>(list.subList(beginInclusive, endExclusive));
-
-            int leadingNulls = startPosition + beginInclusive;
-            int trailingNulls = itemCount - leadingNulls - page.items.size();
-            receiver.onPageResult(new PageResult<>(
-                    PageResult.INIT, page, leadingNulls, trailingNulls, 0));
-        }
-    }
-
-    void loadRange(int startPosition, int count, PageResult.Receiver<Integer, Type> receiver) {
-        List<Type> list = loadRangeWrapper(startPosition, count);
-
-        Page<Integer, Type> page = null;
-        int trailingNulls = mItemCount - startPosition;
-
+        // convert from legacy behavior
+        List<T> list = loadRange(firstLoadPosition, firstLoadSize);
         if (list != null) {
-            page = new Page<Integer, Type>(list);
-            trailingNulls -= list.size();
+            callback.onResult(list, firstLoadPosition, totalCount);
+        } else {
+            invalidate();
         }
-        receiver.postOnPageResult(new PageResult<>(
-                PageResult.TILE, page, startPosition, trailingNulls, 0));
     }
 
-    private List<Type> loadRangeWrapper(int startPosition, int count) {
-        if (isInvalid()) {
-            return null;
-        }
-        List<Type> list = loadRange(startPosition, count);
-        if (isInvalid()) {
-            return null;
-        }
-        return list;
-    }
-
-    ContiguousDataSource<Integer, Type> getAsContiguous() {
-        return new TiledAsBoundedDataSource<>(this);
-    }
-
-    static class TiledAsBoundedDataSource<Value> extends BoundedDataSource<Value> {
-        final TiledDataSource<Value> mTiledDataSource;
-
-        TiledAsBoundedDataSource(TiledDataSource<Value> tiledDataSource) {
-            mTiledDataSource = tiledDataSource;
-        }
-
-        @WorkerThread
-        @Nullable
-        @Override
-        public List<Value> loadRange(int startPosition, int loadCount) {
-            return mTiledDataSource.loadRange(startPosition, loadCount);
+    @Override
+    public void loadRange(int startPosition, int count, @NonNull LoadCallback<T> callback) {
+        List<T> list = loadRange(startPosition, count);
+        if (list != null) {
+            callback.onResult(list);
+        } else {
+            invalidate();
         }
     }
 }
diff --git a/paging/common/src/main/java/android/arch/paging/TiledPagedList.java b/paging/common/src/main/java/android/arch/paging/TiledPagedList.java
index 76bb682..652b489 100644
--- a/paging/common/src/main/java/android/arch/paging/TiledPagedList.java
+++ b/paging/common/src/main/java/android/arch/paging/TiledPagedList.java
@@ -25,32 +25,16 @@
 
 class TiledPagedList<T> extends PagedList<T>
         implements PagedStorage.Callback {
+    private final PositionalDataSource<T> mDataSource;
 
-    private final TiledDataSource<T> mDataSource;
-
-    @SuppressWarnings("unchecked")
-    private final PagedStorage<Integer, T> mKeyedStorage = (PagedStorage<Integer, T>) mStorage;
-
-    private final PageResult.Receiver<Integer, T> mReceiver =
-            new PageResult.Receiver<Integer, T>() {
-        @AnyThread
-        @Override
-        public void postOnPageResult(@NonNull final PageResult<Integer, T> pageResult) {
-            // NOTE: if we're already on main thread, this can delay page receive by a frame
-            mMainThreadExecutor.execute(new Runnable() {
-                @Override
-                public void run() {
-                    onPageResult(pageResult);
-                }
-            });
-        }
-
+    private PageResult.Receiver<T> mReceiver = new PageResult.Receiver<T>() {
         // Creation thread for initial synchronous load, otherwise main thread
         // Safe to access main thread only state - no other thread has reference during construction
         @AnyThread
         @Override
-        public void onPageResult(@NonNull PageResult<Integer, T> pageResult) {
-            if (pageResult.page == null) {
+        public void onPageResult(@PageResult.ResultType int type,
+                @NonNull PageResult<T> pageResult) {
+            if (pageResult.isInvalid()) {
                 detach();
                 return;
             }
@@ -61,60 +45,63 @@
             }
 
             if (mStorage.getPageCount() == 0) {
-                mKeyedStorage.init(
+                mStorage.initAndSplit(
                         pageResult.leadingNulls, pageResult.page, pageResult.trailingNulls,
-                        pageResult.positionOffset, TiledPagedList.this);
+                        pageResult.positionOffset, mConfig.pageSize, TiledPagedList.this);
             } else {
-                mKeyedStorage.insertPage(pageResult.leadingNulls, pageResult.page,
+                mStorage.insertPage(pageResult.positionOffset, pageResult.page,
                         TiledPagedList.this);
             }
 
             if (mBoundaryCallback != null) {
                 boolean deferEmpty = mStorage.size() == 0;
-                boolean deferBegin = !deferEmpty && pageResult.leadingNulls == 0;
-                boolean deferEnd = !deferEmpty && pageResult.trailingNulls == 0;
+                boolean deferBegin = !deferEmpty
+                        && pageResult.leadingNulls == 0
+                        && pageResult.positionOffset == 0;
+                int size = size();
+                boolean deferEnd = !deferEmpty
+                        && ((type == PageResult.INIT && pageResult.trailingNulls == 0)
+                                || (type == PageResult.TILE
+                                        && pageResult.positionOffset
+                                                == (size - size % mConfig.pageSize)));
                 deferBoundaryCallbacks(deferEmpty, deferBegin, deferEnd);
             }
         }
     };
 
     @WorkerThread
-    TiledPagedList(@NonNull TiledDataSource<T> dataSource,
+    TiledPagedList(@NonNull PositionalDataSource<T> dataSource,
             @NonNull Executor mainThreadExecutor,
             @NonNull Executor backgroundThreadExecutor,
             @Nullable BoundaryCallback<T> boundaryCallback,
             @NonNull Config config,
             int position) {
-        super(new PagedStorage<Integer, T>(), mainThreadExecutor, backgroundThreadExecutor,
+        super(new PagedStorage<T>(), mainThreadExecutor, backgroundThreadExecutor,
                 boundaryCallback, config);
         mDataSource = dataSource;
 
         final int pageSize = mConfig.pageSize;
+        mLastLoad = position;
 
-        final int itemCount = mDataSource.countItems();
+        if (mDataSource.isInvalid()) {
+            detach();
+        } else {
+            final int firstLoadSize =
+                    (Math.max(Math.round(mConfig.initialLoadSizeHint / pageSize), 2)) * pageSize;
 
-        final int firstLoadSize = Math.min(itemCount,
-                (Math.max(mConfig.initialLoadSizeHint / pageSize, 2)) * pageSize);
-        final int firstLoadPosition = computeFirstLoadPosition(
-                position, firstLoadSize, pageSize, itemCount);
+            final int idealStart = position - firstLoadSize / 2;
+            final int roundedPageStart = Math.max(0, Math.round(idealStart / pageSize) * pageSize);
 
-        mDataSource.loadRangeInitial(firstLoadPosition, firstLoadSize, pageSize,
-                itemCount, mReceiver);
-    }
+            DataSource.InitialLoadCallback<T> callback = new DataSource.InitialLoadCallback<>(
+                            DataSource.LOAD_COUNT_REQUIRED_TILED,
+                    mConfig.pageSize, mDataSource, mReceiver);
+            mDataSource.loadInitial(roundedPageStart, firstLoadSize, pageSize, callback);
 
-    static int computeFirstLoadPosition(int position, int firstLoadSize, int pageSize, int size) {
-        int idealStart = position - firstLoadSize / 2;
-
-        int roundedPageStart = Math.round(idealStart / pageSize) * pageSize;
-
-        // minimum start position is 0
-        roundedPageStart = Math.max(0, roundedPageStart);
-
-        // maximum start pos is that which will encompass end of list
-        int maximumLoadPage = ((size - firstLoadSize + pageSize - 1) / pageSize) * pageSize;
-        roundedPageStart = Math.min(maximumLoadPage, roundedPageStart);
-
-        return roundedPageStart;
+            // If initialLoad's callback is not called within the body, we force any following calls
+            // to post to the UI thread. This constructor may be run on a background thread, but
+            // after constructor, mutation must happen on UI thread.
+            callback.setPostExecutor(mMainThreadExecutor);
+        }
     }
 
     @Override
@@ -132,7 +119,13 @@
     protected void dispatchUpdatesSinceSnapshot(@NonNull PagedList<T> pagedListSnapshot,
             @NonNull Callback callback) {
         //noinspection UnnecessaryLocalVariable
-        final PagedStorage<?, T> snapshot = pagedListSnapshot.mStorage;
+        final PagedStorage<T> snapshot = pagedListSnapshot.mStorage;
+
+        if (snapshot.isEmpty()
+                || mStorage.size() != snapshot.size()) {
+            throw new IllegalArgumentException("Invalid snapshot provided - doesn't appear"
+                    + " to be a snapshot of this PagedList");
+        }
 
         // loop through each page and signal the callback for any pages that are present now,
         // but not in the snapshot.
@@ -186,7 +179,17 @@
                     return;
                 }
                 final int pageSize = mConfig.pageSize;
-                mDataSource.loadRange(pageIndex * pageSize, pageSize, mReceiver);
+
+                if (mDataSource.isInvalid()) {
+                    detach();
+                } else {
+                    int startPosition = pageIndex * pageSize;
+                    int count = Math.min(pageSize, mStorage.size() - startPosition);
+                    DataSource.LoadCallback<T> callback = new DataSource.LoadCallback<>(
+                            PageResult.TILE, mMainThreadExecutor, mDataSource, mReceiver);
+                    callback.setPositionOffset(startPosition);
+                    mDataSource.loadRange(startPosition, count, callback);
+                }
             }
         });
     }
diff --git a/paging/common/src/test/java/android/arch/paging/AsyncListDataSource.kt b/paging/common/src/test/java/android/arch/paging/AsyncListDataSource.kt
new file mode 100644
index 0000000..48d6e29
--- /dev/null
+++ b/paging/common/src/test/java/android/arch/paging/AsyncListDataSource.kt
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.arch.paging
+
+class AsyncListDataSource<T>(list: List<T>)
+    : PositionalDataSource<T>() {
+    val workItems: MutableList<() -> Unit> = ArrayList()
+    private val listDataSource = ListDataSource(list)
+
+    override fun loadInitial(requestedStartPosition: Int, requestedLoadSize: Int, pageSize: Int,
+            callback: InitialLoadCallback<T>) {
+        workItems.add {
+            listDataSource.loadInitial(requestedStartPosition, requestedLoadSize, pageSize, callback)
+        }
+    }
+
+    override fun loadRange(startPosition: Int, count: Int, callback: LoadCallback<T>) {
+        workItems.add {
+            listDataSource.loadRange(startPosition, count, callback)
+        }
+    }
+
+    fun flush() {
+        workItems.map { it() }
+        workItems.clear()
+    }
+}
diff --git a/paging/common/src/test/java/android/arch/paging/ContiguousPagedListTest.kt b/paging/common/src/test/java/android/arch/paging/ContiguousPagedListTest.kt
index 7331bfe..d8b8034 100644
--- a/paging/common/src/test/java/android/arch/paging/ContiguousPagedListTest.kt
+++ b/paging/common/src/test/java/android/arch/paging/ContiguousPagedListTest.kt
@@ -18,17 +18,16 @@
 
 import org.junit.Assert.assertArrayEquals
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.junit.runners.Parameterized
-import org.mockito.ArgumentCaptor
-import org.mockito.Mockito.any
-import org.mockito.Mockito.eq
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.verifyNoMoreInteractions
 import org.mockito.Mockito.verifyZeroInteractions
-import java.util.Collections
+
 
 @RunWith(Parameterized::class)
 class ContiguousPagedListTest(private val mCounted: Boolean) {
@@ -44,33 +43,46 @@
     }
 
     private inner class TestSource(val listData: List<Item> = ITEMS)
-            : PositionalDataSource<Item>() {
-        override fun countItems(): Int {
-            return if (mCounted) {
-                listData.size
+            : ContiguousDataSource<Int, Item>() {
+        override fun loadInitial(key: Int?, initialLoadSize: Int,
+                enablePlaceholders: Boolean, callback: InitialLoadCallback<Item>) {
+
+            val convertPosition = key ?: 0
+            val loadPosition = Math.max(0, (convertPosition - initialLoadSize / 2))
+
+            val data = getClampedRange(loadPosition, loadPosition + initialLoadSize)
+
+
+            if (enablePlaceholders && mCounted) {
+                callback.onResult(data, loadPosition, listData.size)
             } else {
-                DataSource.COUNT_UNDEFINED
+                // still must pass offset, even if not counted
+                callback.onResult(data, loadPosition)
             }
         }
 
-        private fun getClampedRange(startInc: Int, endExc: Int, reverse: Boolean): List<Item> {
-            val list = listData.subList(Math.max(0, startInc), Math.min(listData.size, endExc))
-            if (reverse) {
-                Collections.reverse(list)
-            }
-            return list
+        override fun loadAfter(currentEndIndex: Int, currentEndItem: Item, pageSize: Int,
+                callback: LoadCallback<Item>) {
+            val startIndex = currentEndIndex + 1
+            callback.onResult(getClampedRange(startIndex, startIndex + pageSize))
         }
 
-        override fun loadAfter(startIndex: Int, pageSize: Int): List<Item>? {
-            return getClampedRange(startIndex, startIndex + pageSize, false)
+        override fun loadBefore(currentBeginIndex: Int, currentBeginItem: Item, pageSize: Int,
+                callback: LoadCallback<Item>) {
+            val startIndex = currentBeginIndex - 1
+            callback.onResult(getClampedRange(startIndex - pageSize + 1, startIndex + 1))
         }
 
-        override fun loadBefore(startIndex: Int, pageSize: Int): List<Item>? {
-            return getClampedRange(startIndex - pageSize + 1, startIndex + 1, true)
+        override fun getKey(position: Int, item: Item?): Int {
+            return 0
+        }
+
+        private fun getClampedRange(startInc: Int, endExc: Int): List<Item> {
+            return listData.subList(Math.max(0, startInc), Math.min(listData.size, endExc))
         }
     }
 
-    private fun verifyRange(start: Int, count: Int, actual: PagedStorage<*, Item>) {
+    private fun verifyRange(start: Int, count: Int, actual: PagedStorage<Item>) {
         if (mCounted) {
             // assert nulls + content
             val expected = arrayOfNulls<Item>(ITEMS.size)
@@ -98,41 +110,6 @@
         verifyRange(start, count, actual.mStorage)
     }
 
-    private fun verifyRange(start: Int, count: Int, actual: PageResult<Int, Item>) {
-        if (mCounted) {
-            assertEquals(start, actual.leadingNulls)
-            assertEquals(ITEMS.size - start - count, actual.trailingNulls)
-            assertEquals(0, actual.positionOffset)
-        } else {
-            assertEquals(0, actual.leadingNulls)
-            assertEquals(0, actual.trailingNulls)
-            assertEquals(start, actual.positionOffset)
-        }
-        assertEquals(ITEMS.subList(start, start + count), actual.page.items)
-    }
-
-    private fun verifyInitialLoad(start: Int, count : Int, initialPosition: Int, initialLoadSize: Int) {
-        @Suppress("UNCHECKED_CAST")
-        val receiver = mock(PageResult.Receiver::class.java) as PageResult.Receiver<Int, Item>
-
-        @Suppress("UNCHECKED_CAST")
-        val captor = ArgumentCaptor.forClass(PageResult::class.java)
-                as ArgumentCaptor<PageResult<Int, Item>>
-
-        TestSource().loadInitial(initialPosition, initialLoadSize, true, receiver)
-
-        verify(receiver).onPageResult(captor.capture())
-        verifyNoMoreInteractions(receiver)
-        verifyRange(start, count, captor.value)
-    }
-
-    @Test
-    fun initialLoad() {
-        verifyInitialLoad(30, 40, 50, 40)
-        verifyInitialLoad(0, 10, 5, 10)
-        verifyInitialLoad(90, 10, 95, 10)
-    }
-
     private fun createCountedPagedList(
             initialPosition: Int,
             pageSize: Int = 20,
@@ -182,7 +159,6 @@
         verifyNoMoreInteractions(callback)
     }
 
-
     @Test
     fun prepend() {
         val pagedList = createCountedPagedList(80)
@@ -311,6 +287,65 @@
     }
 
     @Test
+    fun initialLoadAsync() {
+        // Note: ignores Parameterized param
+        val asyncDataSource = AsyncListDataSource(ITEMS)
+        val dataSource = asyncDataSource.wrapAsContiguousWithoutPlaceholders()
+        val pagedList = ContiguousPagedList(
+                dataSource, mMainThread, mBackgroundThread, null,
+                PagedList.Config.Builder().setPageSize(10).build(), null)
+        val callback = mock(PagedList.Callback::class.java)
+        pagedList.addWeakCallback(null, callback)
+
+        assertTrue(pagedList.isEmpty())
+        drain()
+        assertTrue(pagedList.isEmpty())
+        asyncDataSource.flush()
+        assertTrue(pagedList.isEmpty())
+        mBackgroundThread.executeAll()
+        assertTrue(pagedList.isEmpty())
+        verifyZeroInteractions(callback)
+
+        // Data source defers callbacks until flush, which posts result to main thread
+        mMainThread.executeAll()
+        assertFalse(pagedList.isEmpty())
+        // callback onInsert called once with initial size
+        verify(callback).onInserted(0, pagedList.size)
+        verifyNoMoreInteractions(callback)
+    }
+
+    @Test
+    fun addWeakCallbackEmpty() {
+        // Note: ignores Parameterized param
+        val asyncDataSource = AsyncListDataSource(ITEMS)
+        val dataSource = asyncDataSource.wrapAsContiguousWithoutPlaceholders()
+        val pagedList = ContiguousPagedList(
+                dataSource, mMainThread, mBackgroundThread, null,
+                PagedList.Config.Builder().setPageSize(10).build(), null)
+        val callback = mock(PagedList.Callback::class.java)
+
+        // capture empty snapshot
+        val emptySnapshot = pagedList.snapshot()
+        assertTrue(pagedList.isEmpty())
+        assertTrue(emptySnapshot.isEmpty())
+
+        // verify that adding callback notifies nothing going from empty -> empty
+        pagedList.addWeakCallback(emptySnapshot, callback)
+        verifyZeroInteractions(callback)
+        pagedList.removeWeakCallback(callback)
+
+        // data added in asynchronously
+        asyncDataSource.flush()
+        drain()
+        assertFalse(pagedList.isEmpty())
+
+        // verify that adding callback notifies insert going from empty -> content
+        pagedList.addWeakCallback(emptySnapshot, callback)
+        verify(callback).onInserted(0, pagedList.size)
+        verifyNoMoreInteractions(callback)
+    }
+
+    @Test
     fun boundaryCallback_empty() {
         @Suppress("UNCHECKED_CAST")
         val boundaryCallback =
@@ -347,8 +382,7 @@
         pagedList.loadAround(if (mCounted) 99 else 19)
         drain()
         verifyRange(80, 20, pagedList)
-        verify(boundaryCallback).onItemAtEndLoaded(
-                any(), eq(ITEMS.last()), eq(if (mCounted) 100 else 20))
+        verify(boundaryCallback).onItemAtEndLoaded(ITEMS.last())
         verifyNoMoreInteractions(boundaryCallback)
 
 
@@ -371,7 +405,7 @@
         // ... finally try prepend, see 0 items, which will dispatch front callback
         pagedList.loadAround(0)
         drain()
-        verify(boundaryCallback).onItemAtFrontLoaded(any(), eq(ITEMS.first()), eq(100))
+        verify(boundaryCallback).onItemAtFrontLoaded(ITEMS.first())
         verifyNoMoreInteractions(boundaryCallback)
     }
 
diff --git a/paging/common/src/test/java/android/arch/paging/KeyedDataSourceTest.kt b/paging/common/src/test/java/android/arch/paging/KeyedDataSourceTest.kt
index 115fea2..82ad9ac 100644
--- a/paging/common/src/test/java/android/arch/paging/KeyedDataSourceTest.kt
+++ b/paging/common/src/test/java/android/arch/paging/KeyedDataSourceTest.kt
@@ -16,7 +16,6 @@
 
 package android.arch.paging
 
-import org.junit.Assert.assertArrayEquals
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertNotNull
 import org.junit.Assert.assertTrue
@@ -24,6 +23,7 @@
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.anyInt
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.verifyNoMoreInteractions
@@ -33,31 +33,20 @@
 
     // ----- STANDARD -----
 
-    @Test
-    fun loadInitial_validateTestDataSource() {
-        val dataSource = ItemDataSource()
-
-        // all
-        assertEquals(ITEMS_BY_NAME_ID, dataSource.loadInitial(ITEMS_BY_NAME_ID.size))
-
-        // 10
-        assertEquals(ITEMS_BY_NAME_ID.subList(0, 10), dataSource.loadInitial(10))
-
-        // too many
-        assertEquals(ITEMS_BY_NAME_ID, dataSource.loadInitial(ITEMS_BY_NAME_ID.size + 10))
-    }
-
     private fun loadInitial(dataSource: ItemDataSource, key: Key?, initialLoadSize: Int,
-            enablePlaceholders: Boolean): PageResult<Key, Item> {
+            enablePlaceholders: Boolean): PageResult<Item> {
         @Suppress("UNCHECKED_CAST")
-        val receiver = mock(PageResult.Receiver::class.java) as PageResult.Receiver<Key, Item>
+        val receiver = mock(PageResult.Receiver::class.java) as PageResult.Receiver<Item>
         @Suppress("UNCHECKED_CAST")
         val captor = ArgumentCaptor.forClass(PageResult::class.java)
-                as ArgumentCaptor<PageResult<Key, Item>>
+                as ArgumentCaptor<PageResult<Item>>
 
-        dataSource.loadInitial(key, initialLoadSize, enablePlaceholders, receiver)
+        val callback = DataSource.InitialLoadCallback(
+                DataSource.LOAD_COUNT_ACCEPTED, /* ignored page size */ 10, dataSource, receiver)
 
-        verify(receiver).onPageResult(captor.capture())
+        dataSource.loadInitial(key, initialLoadSize, enablePlaceholders, callback)
+
+        verify(receiver).onPageResult(anyInt(), captor.capture())
         verifyNoMoreInteractions(receiver)
         assertNotNull(captor.value)
         return captor.value
@@ -69,7 +58,7 @@
         val result = loadInitial(dataSource, dataSource.getKey(ITEMS_BY_NAME_ID[49]), 10, true)
 
         assertEquals(45, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page)
         assertEquals(45, result.trailingNulls)
     }
 
@@ -81,7 +70,7 @@
         val result = loadInitial(dataSource, dataSource.getKey(ITEMS_BY_NAME_ID[0]), 20, true)
 
         assertEquals(0, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(0, 1), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(0, 1), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -93,8 +82,8 @@
         val key = dataSource.getKey(ITEMS_BY_NAME_ID.last())
         val result = loadInitial(dataSource, key, 20, true)
 
-        assertEquals(89, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(89, 100), result.page.items)
+        assertEquals(90, result.leadingNulls)
+        assertEquals(ITEMS_BY_NAME_ID.subList(90, 100), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -106,7 +95,7 @@
         val result = loadInitial(dataSource, null, 10, true)
 
         assertEquals(0, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(0, 10), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(0, 10), result.page)
         assertEquals(90, result.trailingNulls)
     }
 
@@ -122,7 +111,7 @@
         // do: load after was empty, so pass full size to load before, since this can incur larger
         // loads than requested (see keyMatchesLastItem test)
         assertEquals(95, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(95, 100), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(95, 100), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -137,7 +126,7 @@
         val result = loadInitial(dataSource, key, 10, false)
 
         assertEquals(0, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -150,7 +139,7 @@
         val result = loadInitial(dataSource, key, 10, true)
 
         assertEquals(0, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(45, 55), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -162,7 +151,7 @@
         val result = loadInitial(dataSource, null, 10, true)
 
         assertEquals(0, result.leadingNulls)
-        assertEquals(ITEMS_BY_NAME_ID.subList(0, 10), result.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(0, 10), result.page)
         assertEquals(0, result.trailingNulls)
     }
 
@@ -177,7 +166,7 @@
         val result = loadInitial(dataSource, key, 10, true)
 
         assertEquals(0, result.leadingNulls)
-        assertTrue(result.page.items.isEmpty())
+        assertTrue(result.page.isEmpty())
         assertEquals(0, result.trailingNulls)
     }
 
@@ -187,7 +176,7 @@
         val result = loadInitial(dataSource, null, 10, true)
 
         assertEquals(0, result.leadingNulls)
-        assertTrue(result.page.items.isEmpty())
+        assertTrue(result.page.isEmpty())
         assertEquals(0, result.trailingNulls)
     }
 
@@ -197,21 +186,18 @@
     fun loadBefore() {
         val dataSource = ItemDataSource()
         @Suppress("UNCHECKED_CAST")
-        val receiver = mock(PageResult.Receiver::class.java)
-                as PageResult.Receiver<Key, Item>
+        val callback = mock(DataSource.LoadCallback::class.java) as DataSource.LoadCallback<Item>
 
-        dataSource.loadBefore(5, ITEMS_BY_NAME_ID[5], 5, receiver)
+        dataSource.loadBefore(5, ITEMS_BY_NAME_ID[5], 5, callback)
 
         @Suppress("UNCHECKED_CAST")
-        val argument = ArgumentCaptor.forClass(PageResult::class.java)
-                as ArgumentCaptor<PageResult<Key, Item>>
-        verify(receiver).postOnPageResult(argument.capture())
-        verifyNoMoreInteractions(receiver)
+        val argument = ArgumentCaptor.forClass(List::class.java) as ArgumentCaptor<List<Item>>
+        verify(callback).onResult(argument.capture())
+        verifyNoMoreInteractions(callback)
 
         val observed = argument.value
 
-        assertEquals(PageResult.PREPEND, observed.type)
-        assertEquals(ITEMS_BY_NAME_ID.subList(0, 5), observed.page.items)
+        assertEquals(ITEMS_BY_NAME_ID.subList(0, 5), observed)
     }
 
     internal data class Key(val name: String, val id: Int)
@@ -219,62 +205,53 @@
     internal data class Item(
             val name: String, val id: Int, val balance: Double, val address: String)
 
-    internal class ItemDataSource(val counted: Boolean = true,
-                                  val items: List<Item> = ITEMS_BY_NAME_ID)
+    internal class ItemDataSource(private val counted: Boolean = true,
+                                  private val items: List<Item> = ITEMS_BY_NAME_ID)
             : KeyedDataSource<Key, Item>() {
+        override fun loadInitial(initialLoadKey: Key?, initialLoadSize: Int,
+                enablePlaceholders: Boolean, callback: InitialLoadCallback<Item>) {
+            val key = initialLoadKey ?: Key("", Integer.MAX_VALUE)
+            val start = Math.max(0, findFirstIndexAfter(key) - initialLoadSize / 2)
+            val endExclusive = Math.min(start + initialLoadSize, items.size)
+
+
+            if (enablePlaceholders && counted) {
+                callback.onResult(items.subList(start, endExclusive), start, items.size)
+            } else {
+                callback.onResult(items.subList(start, endExclusive))
+            }
+        }
+
+        override fun loadAfter(currentEndKey: Key, pageSize: Int, callback: LoadCallback<Item>) {
+            val start = findFirstIndexAfter(currentEndKey)
+            val endExclusive = Math.min(start + pageSize, items.size)
+
+            callback.onResult(items.subList(start, endExclusive))
+        }
+
+        override fun loadBefore(currentBeginKey: Key, pageSize: Int, callback: LoadCallback<Item>) {
+            val firstIndexBefore = findFirstIndexBefore(currentBeginKey)
+            val endExclusive = Math.max(0, firstIndexBefore + 1)
+            val start = Math.max(0, firstIndexBefore - pageSize + 1)
+
+            callback.onResult(items.subList(start, endExclusive))
+        }
 
         override fun getKey(item: Item): Key {
             return Key(item.name, item.id)
         }
 
-        override fun loadInitial(pageSize: Int): List<Item>? {
-            // call loadAfter with a default key
-            return loadAfter(Key("", Integer.MAX_VALUE), pageSize)
-        }
-
-        fun findFirstIndexAfter(key: Key): Int {
+        private fun findFirstIndexAfter(key: Key): Int {
             return items.indices.firstOrNull {
                 KEY_COMPARATOR.compare(key, getKey(items[it])) < 0
             } ?: items.size
         }
 
-        fun findFirstIndexBefore(key: Key): Int {
+        private fun findFirstIndexBefore(key: Key): Int {
             return items.indices.reversed().firstOrNull {
                 KEY_COMPARATOR.compare(key, getKey(items[it])) > 0
             } ?: -1
         }
-
-        override fun countItemsBefore(key: Key): Int {
-            if (!counted) {
-                return DataSource.COUNT_UNDEFINED
-            }
-
-            return findFirstIndexBefore(key) + 1
-        }
-
-        override fun countItemsAfter(key: Key): Int {
-            if (!counted) {
-                return DataSource.COUNT_UNDEFINED
-            }
-
-            return items.size - findFirstIndexAfter(key)
-        }
-
-        override fun loadAfter(key: Key, pageSize: Int): List<Item>? {
-            val start = findFirstIndexAfter(key)
-            val endExclusive = Math.min(start + pageSize, items.size)
-
-            return items.subList(start, endExclusive)
-        }
-
-        override fun loadBefore(key: Key, pageSize: Int): List<Item>? {
-            val firstIndexBefore = findFirstIndexBefore(key)
-            val endExclusive = Math.max(0, firstIndexBefore + 1)
-            val start = Math.max(0, firstIndexBefore - pageSize + 1)
-
-            val list = items.subList(start, endExclusive)
-            return list.reversed()
-        }
     }
 
     companion object {
diff --git a/paging/common/src/test/java/android/arch/paging/PagedStorageTest.kt b/paging/common/src/test/java/android/arch/paging/PagedStorageTest.kt
index 92b6c87..8fb54e0 100644
--- a/paging/common/src/test/java/android/arch/paging/PagedStorageTest.kt
+++ b/paging/common/src/test/java/android/arch/paging/PagedStorageTest.kt
@@ -29,8 +29,8 @@
 
 @RunWith(JUnit4::class)
 class PagedStorageTest {
-    private fun createPage(vararg strings: String): Page<Int, String> {
-        return Page(strings.asList())
+    private fun createPage(vararg strings: String): List<String> {
+        return strings.asList()
     }
 
     @Test
@@ -216,7 +216,7 @@
     @Test
     fun insertOne() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c", "d"), 3, 0, callback)
 
@@ -236,7 +236,7 @@
     @Test
     fun insertThree() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c", "d"), 3, 0, callback)
 
@@ -273,7 +273,7 @@
     @Test
     fun insertLastFirst() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(6, createPage("g"), 0, 0, callback)
 
@@ -294,7 +294,7 @@
     @Test(expected = IllegalArgumentException::class)
     fun insertFailure_decreaseLast() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c", "d"), 0, 0, callback)
 
@@ -305,7 +305,7 @@
     @Test(expected = IllegalArgumentException::class)
     fun insertFailure_increase() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(0, createPage("a", "b"), 3, 0, callback)
 
@@ -316,7 +316,7 @@
     @Test
     fun allocatePlaceholders_simple() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c"), 2, 0, callback)
 
@@ -334,7 +334,7 @@
     @Test
     fun allocatePlaceholders_adoptPageSize() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(4, createPage("e"), 0, 0, callback)
 
@@ -352,7 +352,7 @@
     @Test(expected = IllegalArgumentException::class)
     fun allocatePlaceholders_cannotShrinkPageSize() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(4, createPage("e", "f"), 0, 0, callback)
 
@@ -365,7 +365,7 @@
     @Test(expected = IllegalArgumentException::class)
     fun allocatePlaceholders_cannotAdoptPageSize() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c", "d"), 2, 0, callback)
 
@@ -377,7 +377,7 @@
     @Test
     fun get_placeholdersMulti() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(2, createPage("c", "d"), 3, 0, callback)
 
@@ -392,7 +392,7 @@
     @Test
     fun hasPage() {
         val callback = mock(PagedStorage.Callback::class.java)
-        val storage = PagedStorage<Int, String>()
+        val storage = PagedStorage<String>()
 
         storage.init(4, createPage("e"), 0, 0, callback)
 
diff --git a/paging/common/src/test/java/android/arch/paging/PositionalDataSourceTest.kt b/paging/common/src/test/java/android/arch/paging/PositionalDataSourceTest.kt
new file mode 100644
index 0000000..34e0a57
--- /dev/null
+++ b/paging/common/src/test/java/android/arch/paging/PositionalDataSourceTest.kt
@@ -0,0 +1,50 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.arch.paging
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.junit.runners.JUnit4
+
+@RunWith(JUnit4::class)
+class PositionalDataSourceTest {
+    @Test
+    fun computeFirstLoadPositionZero() {
+        assertEquals(0, PositionalDataSource.computeFirstLoadPosition(0, 30, 10, 100))
+    }
+
+    @Test
+    fun computeFirstLoadPositionRequestedPositionIncluded() {
+        assertEquals(10, PositionalDataSource.computeFirstLoadPosition(10, 10, 10, 100))
+    }
+
+    @Test
+    fun computeFirstLoadPositionRound() {
+        assertEquals(10, PositionalDataSource.computeFirstLoadPosition(13, 30, 10, 100))
+    }
+
+    @Test
+    fun computeFirstLoadPositionEndAdjusted() {
+        assertEquals(70, PositionalDataSource.computeFirstLoadPosition(99, 30, 10, 100))
+    }
+
+    @Test
+    fun computeFirstLoadPositionEndAdjustedAndAligned() {
+        assertEquals(70, PositionalDataSource.computeFirstLoadPosition(99, 35, 10, 100))
+    }
+}
diff --git a/paging/common/src/test/java/android/arch/paging/TiledDataSourceTest.kt b/paging/common/src/test/java/android/arch/paging/TiledDataSourceTest.kt
index 2b16fb2..fe8b9e8 100644
--- a/paging/common/src/test/java/android/arch/paging/TiledDataSourceTest.kt
+++ b/paging/common/src/test/java/android/arch/paging/TiledDataSourceTest.kt
@@ -1,3 +1,19 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
 package android.arch.paging
 
 import org.junit.Assert.assertEquals
@@ -5,41 +21,66 @@
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
 import org.mockito.ArgumentCaptor
+import org.mockito.ArgumentMatchers.eq
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.verifyNoMoreInteractions
 import java.util.Collections
 
-
+@Suppress("DEPRECATION")
 @RunWith(JUnit4::class)
 class TiledDataSourceTest {
-    @Test
-    fun loadInitialEmpty() {
+
+    fun TiledDataSource<String>.loadInitial(startPosition: Int, count: Int, pageSize: Int)
+            : List<String> {
         @Suppress("UNCHECKED_CAST")
-        val receiver = mock(PageResult.Receiver::class.java) as PageResult.Receiver<Int, String>
-        val dataSource = EmptyDataSource()
-        dataSource.loadRangeInitial(0, 0, 1, 0, receiver)
+        val receiver = mock(PageResult.Receiver::class.java) as PageResult.Receiver<String>
+
+        val callback = DataSource.InitialLoadCallback(
+                DataSource.LOAD_COUNT_REQUIRED_TILED, pageSize, this, receiver)
+
+        this.loadInitial(startPosition, count, pageSize, callback)
 
         @Suppress("UNCHECKED_CAST")
         val argument = ArgumentCaptor.forClass(PageResult::class.java)
-                as ArgumentCaptor<PageResult<Int, String>>
-        verify(receiver).onPageResult(argument.capture())
+                as ArgumentCaptor<PageResult<String>>
+        verify(receiver).onPageResult(eq(PageResult.INIT), argument.capture())
         verifyNoMoreInteractions(receiver)
 
         val observed = argument.value
 
-        assertEquals(PageResult.INIT, observed.type)
-        assertEquals(Collections.EMPTY_LIST, observed.page.items)
+        return observed.page
     }
 
-    class EmptyDataSource : TiledDataSource<String>() {
-        override fun countItems(): Int {
-            return 0
+    @Test
+    fun loadInitialEmpty() {
+        class EmptyDataSource : TiledDataSource<String>() {
+            override fun countItems(): Int {
+                return 0
+            }
+
+            override fun loadRange(startPosition: Int, count: Int): List<String> {
+                return emptyList()
+            }
         }
 
-        override fun loadRange(startPosition: Int, count: Int): List<String> {
-            @Suppress("UNCHECKED_CAST")
-            return Collections.EMPTY_LIST as List<String>
-        }
+        assertEquals(Collections.EMPTY_LIST, EmptyDataSource().loadInitial(0, 1, 5))
     }
-}
\ No newline at end of file
+
+    @Test
+    fun loadInitialTooLong() {
+        val list = List(26) { "" + 'a' + it}
+        class AlphabetDataSource : TiledDataSource<String>() {
+            override fun countItems(): Int {
+                return list.size
+            }
+
+            override fun loadRange(startPosition: Int, count: Int): List<String> {
+                return list.subList(startPosition, startPosition + count)
+            }
+        }
+        // baseline behavior
+        assertEquals(list, AlphabetDataSource().loadInitial(0, 26, 10))
+        assertEquals(list, AlphabetDataSource().loadInitial(50, 26, 10))
+    }
+}
diff --git a/paging/common/src/test/java/android/arch/paging/TiledPagedListTest.kt b/paging/common/src/test/java/android/arch/paging/TiledPagedListTest.kt
index 6524008..3e2a60d 100644
--- a/paging/common/src/test/java/android/arch/paging/TiledPagedListTest.kt
+++ b/paging/common/src/test/java/android/arch/paging/TiledPagedListTest.kt
@@ -17,14 +17,14 @@
 package android.arch.paging
 
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertNull
 import org.junit.Assert.assertSame
 import org.junit.Assert.assertTrue
+import org.junit.Assert.fail
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.junit.runners.JUnit4
-import org.mockito.Mockito.any
-import org.mockito.Mockito.eq
 import org.mockito.Mockito.mock
 import org.mockito.Mockito.verify
 import org.mockito.Mockito.verifyNoMoreInteractions
@@ -43,12 +43,12 @@
         }
     }
 
-    private fun verifyLoadedPages(list: List<Item>, vararg loadedPages: Int, expected: List<Item> = ITEMS) {
+    private fun verifyLoadedPages(list: List<Item>, vararg loadedPages: Int) {
         val loadedPageList = loadedPages.asList()
-        assertEquals(expected.size, list.size)
+        assertEquals(ITEMS.size, list.size)
         for (i in list.indices) {
             if (loadedPageList.contains(i / PAGE_SIZE)) {
-                assertSame("Index $i", expected[i], list[i])
+                assertSame("Index $i", ITEMS[i], list[i])
             } else {
                 assertNull("Index $i", list[i])
             }
@@ -70,21 +70,6 @@
     }
 
     @Test
-    fun computeFirstLoadPosition_zero() {
-        assertEquals(0, TiledPagedList.computeFirstLoadPosition(0, 30, 10, 100))
-    }
-
-    @Test
-    fun computeFirstLoadPosition_requestedPositionIncluded() {
-        assertEquals(0, TiledPagedList.computeFirstLoadPosition(10, 10, 10, 100))
-    }
-
-    @Test
-    fun computeFirstLoadPosition_endAdjusted() {
-        assertEquals(70, TiledPagedList.computeFirstLoadPosition(99, 30, 10, 100))
-    }
-
-    @Test
     fun initialLoad_onePage() {
         val pagedList = createTiledPagedList(loadPosition = 0, initPageCount = 1)
         verifyLoadedPages(pagedList, 0, 1)
@@ -121,6 +106,56 @@
     }
 
     @Test
+    fun initialLoad_initializesLastKey() {
+        val pagedList = createTiledPagedList(loadPosition = 44, initPageCount = 2)
+        assertEquals(44, pagedList.lastKey)
+    }
+
+    @Test
+    fun initialLoadAsync() {
+        val dataSource = AsyncListDataSource(ITEMS)
+        val pagedList = TiledPagedList(
+                dataSource, mMainThread, mBackgroundThread, null,
+                PagedList.Config.Builder().setPageSize(10).build(), 0)
+
+        assertTrue(pagedList.isEmpty())
+        drain()
+        assertTrue(pagedList.isEmpty())
+        dataSource.flush()
+        assertTrue(pagedList.isEmpty())
+        mBackgroundThread.executeAll()
+        assertTrue(pagedList.isEmpty())
+
+        // Data source defers callbacks until flush, which posts result to main thread
+        mMainThread.executeAll()
+        assertFalse(pagedList.isEmpty())
+    }
+
+    @Test
+    fun addWeakCallbackEmpty() {
+        val dataSource = AsyncListDataSource(ITEMS)
+        val pagedList = TiledPagedList(
+                dataSource, mMainThread, mBackgroundThread, null,
+                PagedList.Config.Builder().setPageSize(10).build(), 0)
+
+        // capture empty snapshot
+        val emptySnapshot = pagedList.snapshot()
+        assertTrue(pagedList.isEmpty())
+        assertTrue(emptySnapshot.isEmpty())
+
+        // data added in asynchronously
+        dataSource.flush()
+        drain()
+        assertFalse(pagedList.isEmpty())
+
+        // verify that adding callback works with empty start point
+        val callback = mock(PagedList.Callback::class.java)
+        pagedList.addWeakCallback(emptySnapshot, callback)
+        verify(callback).onInserted(0, pagedList.size)
+        verifyNoMoreInteractions(callback)
+    }
+
+    @Test
     fun append() {
         val pagedList = createTiledPagedList(loadPosition = 0, initPageCount = 1)
         val callback = mock(PagedList.Callback::class.java)
@@ -251,16 +286,15 @@
     @Test
     fun placeholdersDisabled() {
         // disable placeholders with config, so we create a contiguous version of the pagedlist
-        val pagedList = PagedList.Builder<Int, Item>()
-                .setDataSource(ListDataSource(ITEMS))
+        val config = PagedList.Config.Builder()
+                .setPageSize(PAGE_SIZE)
+                .setPrefetchDistance(PAGE_SIZE)
+                .setInitialLoadSizeHint(PAGE_SIZE)
+                .setEnablePlaceholders(false)
+                .build()
+        val pagedList = PagedList.Builder<Int, Item>(ListDataSource(ITEMS), config)
                 .setMainThreadExecutor(mMainThread)
                 .setBackgroundThreadExecutor(mBackgroundThread)
-                .setConfig(PagedList.Config.Builder()
-                        .setPageSize(PAGE_SIZE)
-                        .setPrefetchDistance(PAGE_SIZE)
-                        .setInitialLoadSizeHint(PAGE_SIZE)
-                        .setEnablePlaceholders(false)
-                        .build())
                 .setInitialKey(20)
                 .build()
 
@@ -305,8 +339,8 @@
 
         // callbacks posted, since creation often happens on BG thread
         drain()
-        verify(boundaryCallback).onItemAtFrontLoaded(any(), eq(ITEMS[0]), eq(2))
-        verify(boundaryCallback).onItemAtEndLoaded(any(), eq(ITEMS[1]), eq(2))
+        verify(boundaryCallback).onItemAtFrontLoaded(ITEMS[0])
+        verify(boundaryCallback).onItemAtEndLoaded(ITEMS[1])
         verifyNoMoreInteractions(boundaryCallback)
     }
 
@@ -332,8 +366,8 @@
 
         drain()
         // first/last items loaded now, so callbacks dispatched
-        verify(boundaryCallback).onItemAtFrontLoaded(any(), eq(ITEMS.first()), eq(45))
-        verify(boundaryCallback).onItemAtEndLoaded(any(), eq(ITEMS.last()), eq(45))
+        verify(boundaryCallback).onItemAtFrontLoaded(ITEMS.first())
+        verify(boundaryCallback).onItemAtEndLoaded(ITEMS.last())
         verifyNoMoreInteractions(boundaryCallback)
     }
 
@@ -360,11 +394,79 @@
         drain()
 
         // items accessed, so now posted callbacks are run
-        verify(boundaryCallback).onItemAtFrontLoaded(any(), eq(ITEMS.first()), eq(45))
-        verify(boundaryCallback).onItemAtEndLoaded(any(), eq(ITEMS.last()), eq(45))
+        verify(boundaryCallback).onItemAtFrontLoaded(ITEMS.first())
+        verify(boundaryCallback).onItemAtEndLoaded(ITEMS.last())
         verifyNoMoreInteractions(boundaryCallback)
     }
 
+    private fun performInitialLoad(
+            callbackInvoker: (callback: DataSource.InitialLoadCallback<String>) -> Unit) {
+        val dataSource = object: PositionalDataSource<String>() {
+            override fun loadInitial(requestedStartPosition: Int, requestedLoadSize: Int,
+                    pageSize: Int, callback: InitialLoadCallback<String>) {
+                callbackInvoker(callback)
+            }
+            override fun loadRange(startPosition: Int, count: Int, callback: LoadCallback<String>) {
+                fail("loadRange not expected")
+            }
+        }
+        TiledPagedList(
+                dataSource, mMainThread, mBackgroundThread, null,
+                PagedList.Config.Builder()
+                        .setPageSize(PAGE_SIZE)
+                        .build(),
+                0)
+    }
+
+    @Test
+    fun initialLoadCallbackSuccess() = performInitialLoad {
+        // InitialLoadCallback correct usage
+        it.onResult(listOf("a", "b"), 0, 2)
+    }
+
+    @Test
+    fun initialLoadCallbackEmptySuccess() = performInitialLoad {
+        // InitialLoadCallback correct usage - empty special case
+        it.onResult(emptyList())
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackNotPageSizeMultiple() = performInitialLoad {
+        // Positional InitialLoadCallback can't accept result that's not a multiple of page size
+        val elevenLetterList = List(11) { "" + 'a' + it }
+        it.onResult(elevenLetterList, 0, 12)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackMissingPlaceholders() = performInitialLoad {
+        // Positional InitialLoadCallback can't accept list-only call
+        it.onResult(listOf("a", "b"))
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackListTooBig() = performInitialLoad {
+        // InitialLoadCallback can't accept pos + list > totalCount
+        it.onResult(listOf("a", "b", "c"), 0, 2)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackPositionTooLarge() = performInitialLoad {
+        // InitialLoadCallback can't accept pos + list > totalCount
+        it.onResult(listOf("a", "b"), 1, 2)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackPositionNegative() = performInitialLoad {
+        // InitialLoadCallback can't accept negative position
+        it.onResult(listOf("a", "b", "c"), -1, 2)
+    }
+
+    @Test(expected = IllegalArgumentException::class)
+    fun initialLoadCallbackEmptyCannotHavePlaceholders() = performInitialLoad {
+        // Positional InitialLoadCallback can't accept empty result unless data set is empty
+        it.onResult(emptyList(), 0, 2)
+    }
+
     private fun drain() {
         var executed: Boolean
         do {
diff --git a/paging/integration-tests/testapp/build.gradle b/paging/integration-tests/testapp/build.gradle
index 47f45d1..fb19ba0 100644
--- a/paging/integration-tests/testapp/build.gradle
+++ b/paging/integration-tests/testapp/build.gradle
@@ -27,6 +27,14 @@
         versionCode 1
         versionName "1.0"
     }
+
+    signingConfigs {
+        debug {
+            // Use a local debug keystore to avoid build server issues.
+            storeFile project.rootProject.init.debugKeystore
+        }
+    }
+
     testOptions {
         unitTests.returnDefaultValues = true
     }
@@ -37,17 +45,17 @@
 }
 
 dependencies {
-    compile project(':arch:runtime')
-    compile project(':arch:common')
-    compile project(':paging:common')
-    compile project(':lifecycle:extensions')
-    compile project(':lifecycle:runtime')
-    compile project(':lifecycle:common')
-    compile project(':paging:runtime')
-    compile 'com.android.support:multidex:1.0.1'
+    implementation project(':arch:runtime')
+    implementation project(':arch:common')
+    implementation project(':paging:common')
+    implementation project(':lifecycle:extensions')
+    implementation project(':lifecycle:runtime')
+    implementation project(':lifecycle:common')
+    implementation project(':paging:runtime')
+    implementation 'com.android.support:multidex:1.0.1'
 
-    compile libs.support.recyclerview, libs.support_exclude_config
-    compile libs.support.app_compat, libs.support_exclude_config
+    implementation libs.support.recyclerview, libs.support_exclude_config
+    implementation libs.support.app_compat, libs.support_exclude_config
 }
 
 createAndroidCheckstyle(project)
diff --git a/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/ItemDataSource.java b/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/ItemDataSource.java
index 4690533..bbbfabb 100644
--- a/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/ItemDataSource.java
+++ b/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/ItemDataSource.java
@@ -16,9 +16,10 @@
 
 package android.arch.paging.integration.testapp;
 
-import android.arch.paging.BoundedDataSource;
+import android.arch.paging.PositionalDataSource;
 import android.graphics.Color;
 import android.support.annotation.ColorInt;
+import android.support.annotation.NonNull;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -26,7 +27,7 @@
 /**
  * Sample data source with artificial data.
  */
-class ItemDataSource extends BoundedDataSource<Item> {
+class ItemDataSource extends PositionalDataSource<Item> {
     private static final int COUNT = 500;
 
     @ColorInt
@@ -39,18 +40,7 @@
     private static int sGenerationId;
     private final int mGenerationId = sGenerationId++;
 
-    @Override
-    public int countItems() {
-        return COUNT;
-    }
-
-    @Override
-    public List<Item> loadRange(int startPosition, int loadCount) {
-        if (isInvalid()) {
-            // abort!
-            return null;
-        }
-
+    private List<Item> loadRangeInternal(int startPosition, int loadCount) {
         List<Item> items = new ArrayList<>();
         int end = Math.min(COUNT, startPosition + loadCount);
         int bgColor = COLORS[mGenerationId % COLORS.length];
@@ -63,11 +53,38 @@
         for (int i = startPosition; i != end; i++) {
             items.add(new Item(i, "item " + i, bgColor));
         }
-
-        if (isInvalid()) {
-            // abort!
-            return null;
-        }
         return items;
     }
+
+    // TODO: open up this API in PositionalDataSource?
+    private static int computeFirstLoadPosition(int position, int firstLoadSize,
+            int pageSize, int size) {
+        int roundedPageStart = Math.round(position / pageSize) * pageSize;
+
+        // minimum start position is 0
+        roundedPageStart = Math.max(0, roundedPageStart);
+
+        // maximum start pos is that which will encompass end of list
+        int maximumLoadPage = ((size - firstLoadSize + pageSize - 1) / pageSize) * pageSize;
+        roundedPageStart = Math.min(maximumLoadPage, roundedPageStart);
+
+        return roundedPageStart;
+    }
+
+    @Override
+    public void loadInitial(int requestedStartPosition, int requestedLoadSize,
+            int pageSize, @NonNull InitialLoadCallback<Item> callback) {
+        requestedStartPosition = computeFirstLoadPosition(
+                requestedStartPosition, requestedLoadSize, pageSize, COUNT);
+
+        requestedLoadSize = Math.min(COUNT - requestedStartPosition, requestedLoadSize);
+        List<Item> data = loadRangeInternal(requestedStartPosition, requestedLoadSize);
+        callback.onResult(data, requestedStartPosition, COUNT);
+    }
+
+    @Override
+    public void loadRange(int startPosition, int count, @NonNull LoadCallback<Item> callback) {
+        List<Item> data = loadRangeInternal(startPosition, count);
+        callback.onResult(data);
+    }
 }
diff --git a/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/PagedListItemViewModel.java b/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/PagedListItemViewModel.java
index 974eab9..be14bc1 100644
--- a/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/PagedListItemViewModel.java
+++ b/paging/integration-tests/testapp/src/main/java/android/arch/paging/integration/testapp/PagedListItemViewModel.java
@@ -27,10 +27,24 @@
  */
 @SuppressWarnings("WeakerAccess")
 public class PagedListItemViewModel extends ViewModel {
-    private LiveData<PagedList<Item>> mLivePagedList;
     private ItemDataSource mDataSource;
     private final Object mDataSourceLock = new Object();
 
+    private final DataSource.Factory<Integer, Item> mFactory =
+            new DataSource.Factory<Integer, Item>() {
+        @Override
+        public DataSource<Integer, Item> create() {
+            ItemDataSource newDataSource = new ItemDataSource();
+            synchronized (mDataSourceLock) {
+                mDataSource = newDataSource;
+                return mDataSource;
+            }
+        }
+    };
+
+    private LiveData<PagedList<Item>> mLivePagedList =
+            new LivePagedListBuilder<>(mFactory, 20).build();
+
     void invalidateList() {
         synchronized (mDataSourceLock) {
             if (mDataSource != null) {
@@ -40,22 +54,6 @@
     }
 
     LiveData<PagedList<Item>> getLivePagedList() {
-        if (mLivePagedList == null) {
-            mLivePagedList = new LivePagedListBuilder<Integer, Item>()
-                    .setPagingConfig(20)
-                    .setDataSourceFactory(new DataSource.Factory<Integer, Item>() {
-                        @Override
-                        public DataSource<Integer, Item> create() {
-                            ItemDataSource newDataSource = new ItemDataSource();
-                            synchronized (mDataSourceLock) {
-                                mDataSource = newDataSource;
-                                return mDataSource;
-                            }
-                        }
-                    })
-                    .build();
-        }
-
         return mLivePagedList;
     }
 }
diff --git a/paging/runtime/build.gradle b/paging/runtime/build.gradle
index c318c65..187acb9 100644
--- a/paging/runtime/build.gradle
+++ b/paging/runtime/build.gradle
@@ -14,36 +14,28 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
-apply plugin: 'kotlin-android'
+plugins {
+    id("SupportAndroidLibraryPlugin")
+    id("kotlin-android")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-    }
-
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile project(":arch:runtime")
-    compile project(":paging:common")
-    compile project(":lifecycle:runtime")
-    compile project(':lifecycle:extensions')
+    api project(":arch:runtime")
+    api project(":paging:common")
+    api project(":lifecycle:runtime")
+    api project(':lifecycle:extensions')
 
-    compile libs.support.recyclerview, libs.support_exclude_config
+    api libs.support.recyclerview, libs.support_exclude_config
 
     androidTestImplementation libs.junit
     androidTestImplementation libs.mockito_core,     { exclude group: 'net.bytebuddy' } // DexMaker has it"s own MockMaker
@@ -57,21 +49,12 @@
 createAndroidCheckstyle(project)
 createKotlinCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    project.tasks.create(name: "jar${suffix}", type: Jar){
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.PAGING.toString()
 supportLibrary {
-    name 'Android Lifecycle Extensions'
-    publish true
-    inceptionYear '2017'
-    description "Android Lifecycle Extensions"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Lifecycle Extensions"
+    publish = true
+    mavenVersion = LibraryVersions.PAGING
+    mavenGroup = LibraryGroups.PAGING
+    inceptionYear = "2017"
+    description = "Android Lifecycle Extensions"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/paging/runtime/lint-baseline.xml b/paging/runtime/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/paging/runtime/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/paging/runtime/src/androidTest/java/android/arch/paging/PagedListAdapterHelperTest.kt b/paging/runtime/src/androidTest/java/android/arch/paging/PagedListAdapterHelperTest.kt
index 735a61f..d3a910d 100644
--- a/paging/runtime/src/androidTest/java/android/arch/paging/PagedListAdapterHelperTest.kt
+++ b/paging/runtime/src/androidTest/java/android/arch/paging/PagedListAdapterHelperTest.kt
@@ -42,8 +42,8 @@
     private val mPageLoadingThread = TestExecutor()
 
 
-    private fun <T> createHelper(
-            listUpdateCallback: ListUpdateCallback, diffCallback: DiffCallback<T>): PagedListAdapterHelper<T> {
+    private fun <T> createHelper(listUpdateCallback: ListUpdateCallback,
+                                 diffCallback: DiffCallback<T>): PagedListAdapterHelper<T> {
         return PagedListAdapterHelper(listUpdateCallback,
                 ListAdapterConfig.Builder<T>()
                         .setDiffCallback(diffCallback)
@@ -54,12 +54,10 @@
 
     private fun <V> createPagedListFromListAndPos(
             config: PagedList.Config, data: List<V>, initialKey: Int): PagedList<V> {
-        return PagedList.Builder<Int, V>()
+        return PagedList.Builder<Int, V>(ListDataSource(data), config)
                 .setInitialKey(initialKey)
-                .setConfig(config)
                 .setMainThreadExecutor(mMainThread)
                 .setBackgroundThreadExecutor(mPageLoadingThread)
-                .setDataSource(ListDataSource(data))
                 .build()
     }
 
diff --git a/paging/runtime/src/androidTest/java/android/arch/paging/PagedStorageDiffHelperTest.kt b/paging/runtime/src/androidTest/java/android/arch/paging/PagedStorageDiffHelperTest.kt
index 64501f7..b64b27b 100644
--- a/paging/runtime/src/androidTest/java/android/arch/paging/PagedStorageDiffHelperTest.kt
+++ b/paging/runtime/src/androidTest/java/android/arch/paging/PagedStorageDiffHelperTest.kt
@@ -35,17 +35,17 @@
     @Test
     fun sameListNoUpdates() {
         validateTwoListDiff(
-                PagedStorage(5, createPage("a", "b", "c"), 5),
-                PagedStorage(5, createPage("a", "b", "c"), 5)) {
+                PagedStorage(5, listOf("a", "b", "c"), 5),
+                PagedStorage(5, listOf("a", "b", "c"), 5)) {
             verifyZeroInteractions(it)
         }
     }
 
     @Test
     fun sameListNoUpdatesPlaceholder() {
-        val storageNoPlaceholder = PagedStorage(0, createPage("a", "b", "c"), 10)
+        val storageNoPlaceholder = PagedStorage(0, listOf("a", "b", "c"), 10)
 
-        val storageWithPlaceholder = PagedStorage(0, createPage("a", "b", "c"), 10)
+        val storageWithPlaceholder = PagedStorage(0, listOf("a", "b", "c"), 10)
         storageWithPlaceholder.allocatePlaceholders(3, 0, 3,
                 /* ignored */ mock(PagedStorage.Callback::class.java))
 
@@ -64,8 +64,8 @@
     @Test
     fun appendFill() {
         validateTwoListDiff(
-                PagedStorage(5, createPage("a", "b"), 5),
-                PagedStorage(5, createPage("a", "b", "c"), 4)) {
+                PagedStorage(5, listOf("a", "b"), 5),
+                PagedStorage(5, listOf("a", "b", "c"), 4)) {
             verify(it).onRemoved(11, 1)
             verify(it).onInserted(7, 1)
             // NOTE: ideally would be onChanged(7, 1, null)
@@ -76,8 +76,8 @@
     @Test
     fun prependFill() {
         validateTwoListDiff(
-                PagedStorage(5, createPage("b", "c"), 5),
-                PagedStorage(4, createPage("a", "b", "c"), 5)) {
+                PagedStorage(5, listOf("b", "c"), 5),
+                PagedStorage(4, listOf("a", "b", "c"), 5)) {
             verify(it).onRemoved(0, 1)
             verify(it).onInserted(4, 1)
             //NOTE: ideally would be onChanged(4, 1, null);
@@ -88,8 +88,8 @@
     @Test
     fun change() {
         validateTwoListDiff(
-                PagedStorage(5, createPage("a1", "b1", "c1"), 5),
-                PagedStorage(5, createPage("a2", "b1", "c2"), 5)) {
+                PagedStorage(5, listOf("a1", "b1", "c1"), 5),
+                PagedStorage(5, listOf("a2", "b1", "c2"), 5)) {
             verify(it).onChanged(5, 1, null)
             verify(it).onChanged(7, 1, null)
             verifyNoMoreInteractions(it)
@@ -108,12 +108,8 @@
             }
         }
 
-        private fun createPage(vararg items: String): Page<Int, String> {
-            return Page(items.toList())
-        }
-
-        private fun validateTwoListDiff(oldList: PagedStorage<*, String>,
-                                        newList: PagedStorage<*, String>,
+        private fun validateTwoListDiff(oldList: PagedStorage<String>,
+                                        newList: PagedStorage<String>,
                                         validator: (callback: ListUpdateCallback) -> Unit) {
             val diffResult = PagedStorageDiffHelper.computeDiff(
                     oldList, newList, DIFF_CALLBACK)
diff --git a/paging/runtime/src/androidTest/java/android/arch/paging/StringPagedList.kt b/paging/runtime/src/androidTest/java/android/arch/paging/StringPagedList.kt
index c2e5ec7..48d51bc 100644
--- a/paging/runtime/src/androidTest/java/android/arch/paging/StringPagedList.kt
+++ b/paging/runtime/src/androidTest/java/android/arch/paging/StringPagedList.kt
@@ -17,13 +17,13 @@
 package android.arch.paging
 
 class StringPagedList constructor(leadingNulls: Int, trailingNulls: Int, vararg items: String)
-        : PagedList<String>(PagedStorage<Int, String>(), TestExecutor(), TestExecutor(), null,
+        : PagedList<String>(PagedStorage<String>(), TestExecutor(), TestExecutor(), null,
                 PagedList.Config.Builder().setPageSize(1).build()), PagedStorage.Callback {
     init {
         @Suppress("UNCHECKED_CAST")
-        val keyedStorage = mStorage as PagedStorage<Int, String>
+        val keyedStorage = mStorage as PagedStorage<String>
         keyedStorage.init(leadingNulls,
-                Page<Int, String>(null, items.toList(), null),
+                items.toList(),
                 trailingNulls,
                 0,
                 this)
diff --git a/paging/runtime/src/androidTest/java/android/support/v7/recyclerview/extensions/ListAdapterHelperTest.kt b/paging/runtime/src/androidTest/java/android/support/v7/recyclerview/extensions/ListAdapterHelperTest.kt
index 4c06f25..433f4c1 100644
--- a/paging/runtime/src/androidTest/java/android/support/v7/recyclerview/extensions/ListAdapterHelperTest.kt
+++ b/paging/runtime/src/androidTest/java/android/support/v7/recyclerview/extensions/ListAdapterHelperTest.kt
@@ -34,8 +34,8 @@
     private val mMainThread = TestExecutor()
     private val mBackgroundThread = TestExecutor()
 
-    private fun <T> createHelper(
-            listUpdateCallback: ListUpdateCallback, diffCallback: DiffCallback<T>): ListAdapterHelper<T> {
+    private fun <T> createHelper(listUpdateCallback: ListUpdateCallback,
+                                 diffCallback: DiffCallback<T>): ListAdapterHelper<T> {
         return ListAdapterHelper(listUpdateCallback,
                 ListAdapterConfig.Builder<T>()
                         .setDiffCallback(diffCallback)
diff --git a/paging/runtime/src/main/java/android/arch/paging/LivePagedListBuilder.java b/paging/runtime/src/main/java/android/arch/paging/LivePagedListBuilder.java
index ee1810b..b0fddba 100644
--- a/paging/runtime/src/main/java/android/arch/paging/LivePagedListBuilder.java
+++ b/paging/runtime/src/main/java/android/arch/paging/LivePagedListBuilder.java
@@ -25,42 +25,76 @@
 
 import java.util.concurrent.Executor;
 
+/**
+ * Builder for {@code LiveData<PagedList>}, given a {@link DataSource.Factory} and a
+ * {@link PagedList.Config}.
+ * <p>
+ * The required parameters are in the constructor, so you can simply construct and build, or
+ * optionally enable extra features (such as initial load key, or BoundaryCallback.
+ *
+ * @param <Key> Type of input valued used to load data from the DataSource. Must be integer if
+ *             you're using PositionalDataSource.
+ * @param <Value> Item type being presented.
+ */
 public class LivePagedListBuilder<Key, Value> {
     private Key mInitialLoadKey;
     private PagedList.Config mConfig;
     private DataSource.Factory<Key, Value> mDataSourceFactory;
     private PagedList.BoundaryCallback mBoundaryCallback;
-    private Executor mMainThreadExecutor;
     private Executor mBackgroundThreadExecutor;
 
-    @SuppressWarnings("WeakerAccess")
+    /**
+     * Creates a LivePagedListBuilder with required parameters.
+     *
+     * @param dataSourceFactory DataSource factory providing DataSource generations.
+     * @param config Paging configuration.
+     */
+    public LivePagedListBuilder(@NonNull DataSource.Factory<Key, Value> dataSourceFactory,
+            @NonNull PagedList.Config config) {
+        mDataSourceFactory = dataSourceFactory;
+        mConfig = config;
+    }
+
+    /**
+     * Creates a LivePagedListBuilder with required parameters.
+     * <p>
+     * This method is a convenience for:
+     * <pre>
+     * LivePagedListBuilder(dataSourceFactory,
+     *         new PagedList.Config.Builder().setPageSize(pageSize).build())
+     * </pre>
+     *
+     * @param dataSourceFactory DataSource.Factory providing DataSource generations.
+     * @param pageSize Size of pages to load.
+     */
+    public LivePagedListBuilder(@NonNull DataSource.Factory<Key, Value> dataSourceFactory,
+            int pageSize) {
+        this(dataSourceFactory, new PagedList.Config.Builder().setPageSize(pageSize).build());
+    }
+
+    /**
+     * First loading key passed to the first PagedList/DataSource.
+     * <p>
+     * When a new PagedList/DataSource pair is created after the first, it acquires a load key from
+     * the previous generation so that data is loaded around the position already being observed.
+     *
+     * @param key Initial load key passed to the first PagedList/DataSource.
+     * @return this
+     */
     @NonNull
     public LivePagedListBuilder<Key, Value> setInitialLoadKey(@Nullable Key key) {
         mInitialLoadKey = key;
         return this;
     }
 
-    @SuppressWarnings("WeakerAccess")
-    @NonNull
-    public LivePagedListBuilder<Key, Value> setPagingConfig(@NonNull PagedList.Config config) {
-        mConfig = config;
-        return this;
-    }
-
-    @SuppressWarnings("WeakerAccess")
-    @NonNull
-    public LivePagedListBuilder<Key, Value> setPagingConfig(int pageSize) {
-        mConfig = new PagedList.Config.Builder().setPageSize(pageSize).build();
-        return this;
-    }
-
-    @NonNull
-    public LivePagedListBuilder<Key, Value> setDataSourceFactory(
-            @NonNull DataSource.Factory<Key, Value> dataSourceFactory) {
-        mDataSourceFactory = dataSourceFactory;
-        return this;
-    }
-
+    /**
+     * Sets a {@link PagedList.BoundaryCallback} on each PagedList created.
+     * <p>
+     * This can be used to
+     *
+     * @param boundaryCallback The boundary callback for listening to PagedList load state.
+     * @return this
+     */
     @SuppressWarnings("unused")
     @NonNull
     public LivePagedListBuilder<Key, Value> setBoundaryCallback(
@@ -69,14 +103,15 @@
         return this;
     }
 
-    @SuppressWarnings("unused")
-    @NonNull
-    public LivePagedListBuilder<Key, Value> setMainThreadExecutor(
-            @NonNull Executor mainThreadExecutor) {
-        mMainThreadExecutor = mainThreadExecutor;
-        return this;
-    }
-
+    /**
+     * Sets executor which will be used for background loading of pages.
+     * <p>
+     * Does not affect initial load, which will be always be done on done on the Arch components
+     * I/O thread.
+     *
+     * @param backgroundThreadExecutor Executor for background DataSource loading.
+     * @return this
+     */
     @SuppressWarnings("unused")
     @NonNull
     public LivePagedListBuilder<Key, Value> setBackgroundThreadExecutor(
@@ -85,6 +120,14 @@
         return this;
     }
 
+    /**
+     * Constructs the {@code LiveData<PagedList>}.
+     * <p>
+     * No work (such as loading) is done immediately, the creation of the first PagedList is is
+     * deferred until the LiveData is observed.
+     *
+     * @return The LiveData of PagedLists
+     */
     @NonNull
     public LiveData<PagedList<Value>> build() {
         if (mConfig == null) {
@@ -93,20 +136,17 @@
         if (mDataSourceFactory == null) {
             throw new IllegalArgumentException("DataSource.Factory must be provided");
         }
-        if (mMainThreadExecutor == null) {
-            mMainThreadExecutor = ArchTaskExecutor.getMainThreadExecutor();
-        }
         if (mBackgroundThreadExecutor == null) {
             mBackgroundThreadExecutor = ArchTaskExecutor.getIOThreadExecutor();
         }
 
         return create(mInitialLoadKey, mConfig, mBoundaryCallback, mDataSourceFactory,
-                mMainThreadExecutor, mBackgroundThreadExecutor);
+                ArchTaskExecutor.getMainThreadExecutor(), mBackgroundThreadExecutor);
     }
 
     @AnyThread
     @NonNull
-    public static <Key, Value> LiveData<PagedList<Value>> create(
+    private static <Key, Value> LiveData<PagedList<Value>> create(
             @Nullable final Key initialLoadKey,
             @NonNull final PagedList.Config config,
             @Nullable final PagedList.BoundaryCallback boundaryCallback,
@@ -143,12 +183,10 @@
                     mDataSource = dataSourceFactory.create();
                     mDataSource.addInvalidatedCallback(mCallback);
 
-                    mList = new PagedList.Builder<Key, Value>()
-                            .setDataSource(mDataSource)
+                    mList = new PagedList.Builder<>(mDataSource, config)
                             .setMainThreadExecutor(mainThreadExecutor)
                             .setBackgroundThreadExecutor(backgroundThreadExecutor)
                             .setBoundaryCallback(boundaryCallback)
-                            .setConfig(config)
                             .setInitialKey(initializeKey)
                             .build();
                 } while (mList.isDetached());
diff --git a/paging/runtime/src/main/java/android/arch/paging/LivePagedListProvider.java b/paging/runtime/src/main/java/android/arch/paging/LivePagedListProvider.java
index e0a03cb..44b71a8 100644
--- a/paging/runtime/src/main/java/android/arch/paging/LivePagedListProvider.java
+++ b/paging/runtime/src/main/java/android/arch/paging/LivePagedListProvider.java
@@ -22,45 +22,30 @@
 import android.support.annotation.Nullable;
 import android.support.annotation.WorkerThread;
 
+// NOTE: Room 1.0 depends on this class, so it should not be removed
+// until Room switches to using DataSource.Factory directly
 /**
  * Provides a {@code LiveData<PagedList>}, given a means to construct a DataSource.
  * <p>
  * Return type for data-loading system of an application or library to produce a
  * {@code LiveData<PagedList>}, while leaving the details of the paging mechanism up to the
  * consumer.
- * <p>
- * If you're using Room, it can generate a LivePagedListProvider from a query:
- * <pre>
- * {@literal @}Dao
- * interface UserDao {
- *     {@literal @}Query("SELECT * FROM user ORDER BY lastName ASC")
- *     public abstract LivePagedListProvider&lt;Integer, User> usersByLastName();
- * }</pre>
- * In the above sample, {@code Integer} is used because it is the {@code Key} type of
- * {@link TiledDataSource}. Currently, Room can only generate a {@code LIMIT}/{@code OFFSET},
- * position based loader that uses TiledDataSource under the hood, and specifying {@code Integer}
- * here lets you pass an initial loading position as an integer.
- * <p>
- * In the future, Room plans to offer other key types to support paging content with a
- * {@link KeyedDataSource}.
  *
  * @param <Key> Type of input valued used to load data from the DataSource. Must be integer if
- *             you're using TiledDataSource.
+ *             you're using PositionalDataSource.
  * @param <Value> Data type produced by the DataSource, and held by the PagedLists.
  *
  * @see PagedListAdapter
  * @see DataSource
  * @see PagedList
  *
- * @deprecated To construct a {@code LiveData<PagedList>}, use {@link LivePagedListBuilder}, which
- * provides the same construction capability with more customization, and better defaults. The role
+ * @deprecated use {@link LivePagedListBuilder} to construct a {@code LiveData<PagedList>}. It
+ * provides the same construction capability with more customization, and simpler defaults. The role
  * of DataSource construction has been separated out to {@link DataSource.Factory} to access or
  * provide a self-invalidating sequence of DataSources. If you were acquiring this from Room, you
- * can switch to having your Dao return a {@link DataSource.Factory} instead, and create a LiveData
- * of PagedList with a {@link LivePagedListBuilder}.
+ * can switch to having your Dao return a {@link DataSource.Factory} instead, and create a
+ * {@code LiveData<PagedList>} with a {@link LivePagedListBuilder}.
  */
-// NOTE: Room 1.0 depends on this class, so it should not be removed
-// until Room switches to using DataSource.Factory directly
 @Deprecated
 public abstract class LivePagedListProvider<Key, Value> implements DataSource.Factory<Key, Value> {
 
@@ -93,10 +78,8 @@
     @AnyThread
     @NonNull
     public LiveData<PagedList<Value>> create(@Nullable Key initialLoadKey, int pageSize) {
-        return new LivePagedListBuilder<Key, Value>()
+        return new LivePagedListBuilder<>(this, pageSize)
                 .setInitialLoadKey(initialLoadKey)
-                .setPagingConfig(pageSize)
-                .setDataSourceFactory(this)
                 .build();
     }
 
@@ -116,10 +99,8 @@
     @NonNull
     public LiveData<PagedList<Value>> create(@Nullable Key initialLoadKey,
             @NonNull PagedList.Config config) {
-        return new LivePagedListBuilder<Key, Value>()
+        return new LivePagedListBuilder<>(this, config)
                 .setInitialLoadKey(initialLoadKey)
-                .setPagingConfig(config)
-                .setDataSourceFactory(this)
                 .build();
     }
 }
diff --git a/paging/runtime/src/main/java/android/arch/paging/PagedListAdapter.java b/paging/runtime/src/main/java/android/arch/paging/PagedListAdapter.java
index 89b9c2e..a8158c2 100644
--- a/paging/runtime/src/main/java/android/arch/paging/PagedListAdapter.java
+++ b/paging/runtime/src/main/java/android/arch/paging/PagedListAdapter.java
@@ -44,18 +44,14 @@
  * {@literal @}Dao
  * interface UserDao {
  *     {@literal @}Query("SELECT * FROM user ORDER BY lastName ASC")
- *     public abstract LivePagedListProvider&lt;Integer, User> usersByLastName();
+ *     public abstract DataSource.Factory&lt;Integer, User> usersByLastName();
  * }
  *
  * class MyViewModel extends ViewModel {
  *     public final LiveData&lt;PagedList&lt;User>> usersList;
  *     public MyViewModel(UserDao userDao) {
- *         usersList = userDao.usersByLastName().create(
- *                 /* initial load position {@literal *}/ 0,
- *                 new PagedList.Config.Builder()
- *                         .setPageSize(50)
- *                         .setPrefetchDistance(50)
- *                         .build());
+ *         usersList = LivePagedListBuilder&lt;>(
+ *                 userDao.usersByLastName(), /* page size {@literal *}/ 20).build();
  *     }
  * }
  *
diff --git a/paging/runtime/src/main/java/android/arch/paging/PagedListAdapterHelper.java b/paging/runtime/src/main/java/android/arch/paging/PagedListAdapterHelper.java
index 51a6e37..7a0b81a 100644
--- a/paging/runtime/src/main/java/android/arch/paging/PagedListAdapterHelper.java
+++ b/paging/runtime/src/main/java/android/arch/paging/PagedListAdapterHelper.java
@@ -48,18 +48,14 @@
  * {@literal @}Dao
  * interface UserDao {
  *     {@literal @}Query("SELECT * FROM user ORDER BY lastName ASC")
- *     public abstract LivePagedListProvider&lt;Integer, User> usersByLastName();
+ *     public abstract DataSource.Factory&lt;Integer, User> usersByLastName();
  * }
  *
  * class MyViewModel extends ViewModel {
  *     public final LiveData&lt;PagedList&lt;User>> usersList;
  *     public MyViewModel(UserDao userDao) {
- *         usersList = userDao.usersByLastName().create(
- *                 /* initial load position {@literal *}/ 0,
- *                 new PagedList.Config.Builder()
- *                         .setPageSize(50)
- *                         .setPrefetchDistance(50)
- *                         .build());
+ *         usersList = LivePagedListBuilder&lt;>(
+ *                 userDao.usersByLastName(), /* page size {@literal *}/ 20).build();
  *     }
  * }
  *
diff --git a/paging/runtime/src/main/java/android/arch/paging/PagedStorageDiffHelper.java b/paging/runtime/src/main/java/android/arch/paging/PagedStorageDiffHelper.java
index 6fc7039..d991b72 100644
--- a/paging/runtime/src/main/java/android/arch/paging/PagedStorageDiffHelper.java
+++ b/paging/runtime/src/main/java/android/arch/paging/PagedStorageDiffHelper.java
@@ -26,8 +26,8 @@
     }
 
     static <T> DiffUtil.DiffResult computeDiff(
-            final PagedStorage<?, T> oldList,
-            final PagedStorage<?, T> newList,
+            final PagedStorage<T> oldList,
+            final PagedStorage<T> newList,
             final DiffCallback<T> diffCallback) {
         final int oldOffset = oldList.computeLeadingNulls();
         final int newOffset = newList.computeLeadingNulls();
@@ -131,8 +131,8 @@
      * immediately after dispatching this diff.
      */
     static <T> void dispatchDiff(ListUpdateCallback callback,
-            final PagedStorage<?, T> oldList,
-            final PagedStorage<?, T> newList,
+            final PagedStorage<T> oldList,
+            final PagedStorage<T> newList,
             final DiffUtil.DiffResult diffResult) {
 
         final int trailingOld = oldList.computeTrailingNulls();
diff --git a/percent/build.gradle b/percent/build.gradle
index aecaa28..ccee3d2 100644
--- a/percent/build.gradle
+++ b/percent/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -18,8 +23,11 @@
 }
 
 supportLibrary {
-    name 'Android Percent Support Library'
-    publish true
-    inceptionYear '2015'
-    description 'Android Percent Support Library'
+    name = "Android Percent Support Library"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Percent Support Library"
+    legacySourceLocation = true
 }
diff --git a/persistence/db-framework/build.gradle b/persistence/db-framework/build.gradle
index 0961ba5..8607bf6 100644
--- a/persistence/db-framework/build.gradle
+++ b/persistence/db-framework/build.gradle
@@ -14,53 +14,33 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile libs.support.annotations
-    compile project(":persistence:db")
+    api libs.support.annotations
+    api project(":persistence:db")
 }
+
 createAndroidCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    def jarTask = project.tasks.create(name: "jar${suffix}", type: Jar){
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Support SQLite - Framework Implementation'
-    publish true
-    inceptionYear '2017'
-    description "The implementation of Support SQLite library using the framework code."
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Support SQLite - Framework Implementation"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.PERSISTENCE
+    inceptionYear = "2017"
+    description = "The implementation of Support SQLite library using the framework code."
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/persistence/db-framework/lint-baseline.xml b/persistence/db-framework/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/persistence/db-framework/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/persistence/db/build.gradle b/persistence/db/build.gradle
index 4757a79..085676d 100644
--- a/persistence/db/build.gradle
+++ b/persistence/db/build.gradle
@@ -14,37 +14,27 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile libs.support.annotations
+    api libs.support.annotations
 }
+
 createAndroidCheckstyle(project)
 
+// Used by testCompile in room-compiler
 android.libraryVariants.all { variant ->
     def name = variant.buildType.name
     def suffix = name.capitalize()
@@ -55,11 +45,12 @@
     }
 }
 
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android DB'
-    publish true
-    inceptionYear '2017'
-    description "Android DB"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android DB"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.PERSISTENCE
+    inceptionYear = "2017"
+    description = "Android DB"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/persistence/db/lint-baseline.xml b/persistence/db/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/persistence/db/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/recommendation/build.gradle b/recommendation/build.gradle
index 0c38487..f6adcb9 100644
--- a/recommendation/build.gradle
+++ b/recommendation/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -11,8 +16,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Recommendation'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support Recommendation'
+    name = "Android Support Recommendation"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support Recommendation"
+    legacySourceLocation = true
 }
diff --git a/room/common/build.gradle b/room/common/build.gradle
index 4336583..21441a2 100644
--- a/room/common/build.gradle
+++ b/room/common/build.gradle
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 dependencies {
     compile libs.support.annotations
@@ -27,11 +30,12 @@
 
 createAndroidCheckstyle(project)
 
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Room-Common'
-    publish true
-    inceptionYear '2017'
-    description "Android Room-Common"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room-Common"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room-Common"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/room/compiler/build.gradle b/room/compiler/build.gradle
index 222a338..eb9628c 100644
--- a/room/compiler/build.gradle
+++ b/room/compiler/build.gradle
@@ -13,6 +13,8 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
@@ -78,9 +80,11 @@
 createKotlinCheckstyle(project)
 
 supportLibrary {
-    name 'Android Room Compiler'
-    publish true
-    inceptionYear '2017'
-    description "Android Room annotation processor"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room Compiler"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room annotation processor"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
diff --git a/room/compiler/src/main/kotlin/android/arch/persistence/room/RoomProcessor.kt b/room/compiler/src/main/kotlin/android/arch/persistence/room/RoomProcessor.kt
index ad7621f..76051c8 100644
--- a/room/compiler/src/main/kotlin/android/arch/persistence/room/RoomProcessor.kt
+++ b/room/compiler/src/main/kotlin/android/arch/persistence/room/RoomProcessor.kt
@@ -34,7 +34,6 @@
 /**
  * The annotation processor for Room.
  */
-@SupportedSourceVersion(SourceVersion.RELEASE_7)
 class RoomProcessor : BasicAnnotationProcessor() {
     override fun initSteps(): MutableIterable<ProcessingStep>? {
         val context = Context(processingEnv)
@@ -45,6 +44,10 @@
         return Context.ARG_OPTIONS.toMutableSet()
     }
 
+    override fun getSupportedSourceVersion(): SourceVersion {
+        return SourceVersion.latest()
+    }
+
     class DatabaseProcessingStep(context: Context) : ContextBoundProcessingStep(context) {
         override fun process(elementsByAnnotation: SetMultimap<Class<out Annotation>, Element>)
                 : MutableSet<Element> {
diff --git a/room/compiler/src/main/kotlin/android/arch/persistence/room/parser/SqlParser.kt b/room/compiler/src/main/kotlin/android/arch/persistence/room/parser/SqlParser.kt
index 85e89d1..d165b55 100644
--- a/room/compiler/src/main/kotlin/android/arch/persistence/room/parser/SqlParser.kt
+++ b/room/compiler/src/main/kotlin/android/arch/persistence/room/parser/SqlParser.kt
@@ -85,7 +85,8 @@
                 syntaxErrors)
     }
 
-    override fun visitCommon_table_expression(ctx: SQLiteParser.Common_table_expressionContext): Void? {
+    override fun visitCommon_table_expression(
+            ctx: SQLiteParser.Common_table_expressionContext): Void? {
         val tableName = ctx.table_name()?.text
         if (tableName != null) {
             withClauseNames.add(unescapeIdentifier(tableName))
diff --git a/room/compiler/src/main/kotlin/android/arch/persistence/room/processor/PojoProcessor.kt b/room/compiler/src/main/kotlin/android/arch/persistence/room/processor/PojoProcessor.kt
index 535e116..f4cd5f3 100644
--- a/room/compiler/src/main/kotlin/android/arch/persistence/room/processor/PojoProcessor.kt
+++ b/room/compiler/src/main/kotlin/android/arch/persistence/room/processor/PojoProcessor.kt
@@ -333,7 +333,8 @@
                                      relationElement: VariableElement)
             : android.arch.persistence.room.vo.Relation? {
 
-        val asTypeElement = MoreTypes.asTypeElement(MoreElements.asVariable(relationElement).asType())
+        val asTypeElement = MoreTypes.asTypeElement(
+                MoreElements.asVariable(relationElement).asType())
 
         if (detectReferenceRecursion(asTypeElement)) {
             return null
diff --git a/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/EntityProcessorTest.kt b/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/EntityProcessorTest.kt
index 4abf13d..631f511 100644
--- a/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/EntityProcessorTest.kt
+++ b/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/EntityProcessorTest.kt
@@ -1808,7 +1808,9 @@
                 @Embedded
                 MyEntity myEntity;
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyEntity -> foo.bar.MyEntity"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyEntity -> foo.bar.MyEntity"))
     }
 
     @Test
@@ -1825,7 +1827,9 @@
                     MyEntity myEntity;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
     }
 
     @Test
@@ -1840,7 +1844,9 @@
                     MyEntity myEntity;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
     }
 
     @Test
@@ -1856,7 +1862,9 @@
                     MyEntity myEntity;
                 }
                 """) { _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyEntity -> foo.bar.MyEntity.A -> foo.bar.MyEntity"))
     }
     fun okTableName() {
         val annotation = mapOf("tableName" to "\"foo bar\"")
diff --git a/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/PojoProcessorTest.kt b/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/PojoProcessorTest.kt
index 4f14fdb..6fdb300 100644
--- a/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/PojoProcessorTest.kt
+++ b/room/compiler/src/test/kotlin/android/arch/persistence/room/processor/PojoProcessorTest.kt
@@ -715,7 +715,9 @@
                 @Embedded
                 MyPojo myPojo;
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -735,7 +737,9 @@
                     MyPojo myPojo;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.MyEntity -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.MyEntity -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -751,7 +755,9 @@
                     MyPojo myPojo;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -765,7 +771,9 @@
                     MyPojo myPojo;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -783,7 +791,9 @@
                     MyPojo myPojo;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo.B -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo.B -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -801,7 +811,9 @@
                     A a;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo.A -> foo.bar.MyPojo.B -> foo.bar.MyPojo.A"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo.A -> foo.bar.MyPojo.B -> foo.bar.MyPojo.A"))
     }
 
     @Test
@@ -825,7 +837,9 @@
                     MyPojo myPojo;
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.C -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.C -> foo.bar.MyPojo"))
     }
 
     @Test
@@ -849,7 +863,9 @@
                 static class C {
                 }
                 """){ _, _ ->
-        }.failsToCompile().withErrorContaining(ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format("foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
+        }.failsToCompile().withErrorContaining(
+                ProcessorErrors.RECURSIVE_REFERENCE_DETECTED.format(
+                        "foo.bar.MyPojo -> foo.bar.MyPojo.A -> foo.bar.MyPojo"))
     }
 
     fun singleRun(code: String, vararg jfos:JavaFileObject, handler: (Pojo) -> Unit)
diff --git a/room/gradle/wrapper/gradle-wrapper.properties b/room/gradle/wrapper/gradle-wrapper.properties
index a5292b0..2f8bf03 100644
--- a/room/gradle/wrapper/gradle-wrapper.properties
+++ b/room/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.4-bin.zip
diff --git a/room/integration-tests/kotlintestapp/build.gradle b/room/integration-tests/kotlintestapp/build.gradle
index f4df9cf..f1f5139 100644
--- a/room/integration-tests/kotlintestapp/build.gradle
+++ b/room/integration-tests/kotlintestapp/build.gradle
@@ -36,6 +36,14 @@
             }
         }
     }
+
+    signingConfigs {
+        debug {
+            // Use a local debug keystore to avoid build server issues.
+            storeFile project.rootProject.init.debugKeystore
+        }
+    }
+
     testOptions {
         unitTests.returnDefaultValues = true
     }
@@ -59,11 +67,11 @@
     kapt project(":room:compiler")
     kaptAndroidTest project(":room:compiler")
 
-    androidTestCompile(libs.test_runner) {
+    androidTestImplementation(libs.test_runner) {
         exclude module: 'support-annotations'
         exclude module: 'hamcrest-core'
     }
-    androidTestCompile(libs.espresso_core, {
+    androidTestImplementation(libs.espresso_core, {
         exclude group: 'com.android.support', module: 'support-annotations'
         exclude module: "hamcrest-core"
     })
diff --git a/room/integration-tests/kotlintestapp/src/androidTest/java/android/arch/persistence/room/integration/kotlintestapp/vo/StringToIntListConverters.kt b/room/integration-tests/kotlintestapp/src/androidTest/java/android/arch/persistence/room/integration/kotlintestapp/vo/StringToIntListConverters.kt
index 5c6620d..ec8fd4a 100644
--- a/room/integration-tests/kotlintestapp/src/androidTest/java/android/arch/persistence/room/integration/kotlintestapp/vo/StringToIntListConverters.kt
+++ b/room/integration-tests/kotlintestapp/src/androidTest/java/android/arch/persistence/room/integration/kotlintestapp/vo/StringToIntListConverters.kt
@@ -8,9 +8,11 @@
     // Specifying that a static method should be generated. Otherwise, the compiler looks for the
     // constructor of the class, and a object has a private constructor.
     @JvmStatic
-    fun stringToIntList(data: String?): List<Int>? = if (data == null) null else StringUtil.splitToIntList(data)
+    fun stringToIntList(data: String?): List<Int>? =
+            if (data == null) null else StringUtil.splitToIntList(data)
 
     @TypeConverter
     @JvmStatic
-    fun intListToString(ints: List<Int>?): String? = if (ints == null) null else StringUtil.joinIntoString(ints)
+    fun intListToString(ints: List<Int>?): String? =
+            if (ints == null) null else StringUtil.joinIntoString(ints)
 }
diff --git a/room/integration-tests/testapp/build.gradle b/room/integration-tests/testapp/build.gradle
index 6fefc29..b063595 100644
--- a/room/integration-tests/testapp/build.gradle
+++ b/room/integration-tests/testapp/build.gradle
@@ -34,6 +34,14 @@
             }
         }
     }
+
+    signingConfigs {
+        debug {
+            // Use a local debug keystore to avoid build server issues.
+            storeFile project.rootProject.init.debugKeystore
+        }
+    }
+
     testOptions {
         unitTests.returnDefaultValues = true
     }
@@ -47,42 +55,42 @@
 }
 
 dependencies {
-    compile project(":room:common")
-    compile project(":persistence:db")
-    compile project(":persistence:db-framework")
-    compile project(':room:runtime')
-    compile project(':arch:runtime')
-    compile project(':arch:common')
-    compile project(':paging:common')
-    compile project(':lifecycle:extensions')
-    compile project(':lifecycle:runtime')
-    compile project(':lifecycle:common')
-    compile project(':room:rxjava2')
-    compile project(':paging:runtime')
+    implementation project(":room:common")
+    implementation project(":persistence:db")
+    implementation project(":persistence:db-framework")
+    implementation project(':room:runtime')
+    implementation project(':arch:runtime')
+    implementation project(':arch:common')
+    implementation project(':paging:common')
+    implementation project(':lifecycle:extensions')
+    implementation project(':lifecycle:runtime')
+    implementation project(':lifecycle:common')
+    implementation project(':room:rxjava2')
+    implementation project(':paging:runtime')
 
-    compile libs.support.recyclerview, libs.support_exclude_config
-    compile libs.support.app_compat, libs.support_exclude_config
+    implementation libs.support.recyclerview, libs.support_exclude_config
+    implementation libs.support.app_compat, libs.support_exclude_config
     annotationProcessor project(":room:compiler")
     androidTestAnnotationProcessor project(":room:compiler")
 
     // IJ's gradle integration just cannot figure this out ...
-    androidTestCompile project(':lifecycle:extensions')
-    androidTestCompile project(':lifecycle:common')
-    androidTestCompile project(':lifecycle:runtime')
-    androidTestCompile project(':room:testing')
-    androidTestCompile project(':room:rxjava2')
-    androidTestCompile project(':arch:core-testing')
-    androidTestCompile libs.rx_java
-    androidTestCompile(libs.test_runner) {
+    androidTestImplementation project(':lifecycle:extensions')
+    androidTestImplementation project(':lifecycle:common')
+    androidTestImplementation project(':lifecycle:runtime')
+    androidTestImplementation project(':room:testing')
+    androidTestImplementation project(':room:rxjava2')
+    androidTestImplementation project(':arch:core-testing')
+    androidTestImplementation libs.rx_java
+    androidTestImplementation(libs.test_runner) {
         exclude module: 'support-annotations'
     }
-    androidTestCompile(libs.espresso_core, {
+    androidTestImplementation(libs.espresso_core, {
         exclude group: 'com.android.support', module: 'support-annotations'
     })
     androidTestImplementation libs.mockito_core,     { exclude group: 'net.bytebuddy' } // DexMaker has it's own MockMaker
     androidTestImplementation libs.dexmaker_mockito, { exclude group: 'net.bytebuddy' } // DexMaker has it's own MockMaker
 
-    testCompile libs.junit
+    testImplementation libs.junit
 }
 
 createAndroidCheckstyle(project)
diff --git a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/dao/UserDao.java b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/dao/UserDao.java
index cb2bb03..0b184a9 100644
--- a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/dao/UserDao.java
+++ b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/dao/UserDao.java
@@ -190,8 +190,12 @@
     @Query("SELECT * FROM user where mAge > :age")
     public abstract LivePagedListProvider<Integer, User> loadPagedByAge_legacy(int age);
 
+    // TODO: switch to PositionalDataSource once Room supports it
     @Query("SELECT * FROM user ORDER BY mAge DESC")
-    public abstract TiledDataSource<User> loadUsersByAgeDesc();
+    public abstract DataSource.Factory<Integer, User> loadUsersByAgeDesc();
+
+    @Query("SELECT * FROM user ORDER BY mAge DESC")
+    public abstract TiledDataSource<User> loadUsersByAgeDesc_legacy();
 
     @Query("DELETE FROM User WHERE mId IN (:ids) AND mAge == :age")
     public abstract int deleteByAgeAndIds(int age, List<Integer> ids);
diff --git a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/DataSourceFactoryTest.java b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/DataSourceFactoryTest.java
index c546531..b54abe8 100644
--- a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/DataSourceFactoryTest.java
+++ b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/DataSourceFactoryTest.java
@@ -63,12 +63,12 @@
         validateUsersAsPagedList(new LivePagedListFactory() {
             @Override
             public LiveData<PagedList<User>> create() {
-                return new LivePagedListBuilder<Integer, User>()
-                        .setPagingConfig(new PagedList.Config.Builder()
+                return new LivePagedListBuilder<>(
+                        mUserDao.loadPagedByAge(3),
+                        new PagedList.Config.Builder()
                                 .setPageSize(10)
                                 .setPrefetchDistance(1)
                                 .setInitialLoadSizeHint(10).build())
-                        .setDataSourceFactory(mUserDao.loadPagedByAge(3))
                         .build();
             }
         });
diff --git a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/LimitOffsetDataSourceTest.java b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/LimitOffsetDataSourceTest.java
index 8226759..f0285a0 100644
--- a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/LimitOffsetDataSourceTest.java
+++ b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/paging/LimitOffsetDataSourceTest.java
@@ -45,8 +45,17 @@
         mUserDao.deleteEverything();
     }
 
+    // TODO: delete this and factory abstraction when LivePagedListProvider is removed
+    @Test
+    public void limitOffsetDataSource_legacyTiledDataSource() {
+        // Simple verification that loading a TiledDataSource still works.
+        LimitOffsetDataSource<User> dataSource =
+                (LimitOffsetDataSource<User>) mUserDao.loadUsersByAgeDesc_legacy();
+        assertThat(dataSource.countItems(), is(0));
+    }
+
     private LimitOffsetDataSource<User> loadUsersByAgeDesc() {
-        return (LimitOffsetDataSource<User>) mUserDao.loadUsersByAgeDesc();
+        return (LimitOffsetDataSource<User>) mUserDao.loadUsersByAgeDesc().create();
     }
 
     @Test
diff --git a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/test/QueryTransactionTest.java b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/test/QueryTransactionTest.java
index 291cfd6..f076cf1 100644
--- a/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/test/QueryTransactionTest.java
+++ b/room/integration-tests/testapp/src/androidTest/java/android/arch/persistence/room/integration/testapp/test/QueryTransactionTest.java
@@ -203,10 +203,8 @@
 
     @Test
     public void pagedList() {
-        LiveData<PagedList<Entity1>> pagedList = new LivePagedListBuilder<Integer, Entity1>()
-                .setDataSourceFactory(mDao.pagedList())
-                .setPagingConfig(10)
-                .build();
+        LiveData<PagedList<Entity1>> pagedList =
+                new LivePagedListBuilder<>(mDao.pagedList(), 10).build();
         observeForever(pagedList);
         drain();
         assertThat(sStartedTransactionCount.get(), is(mUseTransactionDao ? 0 : 0));
@@ -228,6 +226,7 @@
         mDao.insert(new Entity1(2, "bar"));
         drain();
         resetTransactionCount();
+        @SuppressWarnings("deprecation")
         TiledDataSource<Entity1> dataSource = mDao.dataSource();
         dataSource.loadRange(0, 10);
         assertThat(sStartedTransactionCount.get(), is(mUseTransactionDao ? 1 : 0));
diff --git a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/CustomerViewModel.java b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/CustomerViewModel.java
index 89d16b7..d8cd8d4 100644
--- a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/CustomerViewModel.java
+++ b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/CustomerViewModel.java
@@ -83,13 +83,12 @@
 
     private static <K> LiveData<PagedList<Customer>> getLivePagedList(
             K initialLoadKey, DataSource.Factory<K, Customer> dataSourceFactory) {
-        return new LivePagedListBuilder<K, Customer>()
+        PagedList.Config config = new PagedList.Config.Builder()
+                .setPageSize(10)
+                .setEnablePlaceholders(false)
+                .build();
+        return new LivePagedListBuilder<>(dataSourceFactory, config)
                 .setInitialLoadKey(initialLoadKey)
-                .setPagingConfig(new PagedList.Config.Builder()
-                        .setPageSize(10)
-                        .setEnablePlaceholders(false)
-                        .build())
-                .setDataSourceFactory(dataSourceFactory)
                 .build();
     }
 
diff --git a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/RoomPagedListActivity.java b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/RoomPagedListActivity.java
index cdd464e..0c79aee 100644
--- a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/RoomPagedListActivity.java
+++ b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/RoomPagedListActivity.java
@@ -16,7 +16,6 @@
 
 package android.arch.persistence.room.integration.testapp;
 
-import android.arch.lifecycle.LifecycleRegistry;
 import android.arch.lifecycle.LiveData;
 import android.arch.lifecycle.Observer;
 import android.arch.lifecycle.ViewModelProviders;
@@ -75,7 +74,7 @@
                 mAdapter.setList(items);
             }
         });
-        final Button button = findViewById(R.id.button);
+        final Button button = findViewById(R.id.addButton);
         button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -114,11 +113,4 @@
     protected boolean useKeyedQuery() {
         return false;
     }
-
-    private LifecycleRegistry mLifecycleRegistry = new LifecycleRegistry(this);
-
-    @Override
-    public LifecycleRegistry getLifecycle() {
-        return mLifecycleRegistry;
-    }
 }
diff --git a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/database/LastNameAscCustomerDataSource.java b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/database/LastNameAscCustomerDataSource.java
index a38d6ae..2db543b 100644
--- a/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/database/LastNameAscCustomerDataSource.java
+++ b/room/integration-tests/testapp/src/main/java/android/arch/persistence/room/integration/testapp/database/LastNameAscCustomerDataSource.java
@@ -21,6 +21,7 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
+import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -60,7 +61,6 @@
     @Override
     public boolean isInvalid() {
         mDb.getInvalidationTracker().refreshVersionsSync();
-
         return super.isInvalid();
     }
 
@@ -76,30 +76,48 @@
     }
 
     @Override
-    public int countItemsBefore(@NonNull String customerName) {
-        return mCustomerDao.customerNameCountBefore(customerName);
+    public void loadInitial(@Nullable String customerName, int initialLoadSize,
+            boolean enablePlaceholders, @NonNull InitialLoadCallback<Customer> callback) {
+        List<Customer> list;
+        if (customerName != null) {
+            // initial keyed load - load before 'customerName',
+            // and load after last item in before list
+            int pageSize = initialLoadSize / 2;
+            String key = customerName;
+            list = mCustomerDao.customerNameLoadBefore(key, pageSize);
+            Collections.reverse(list);
+            if (!list.isEmpty()) {
+                key = getKey(list.get(list.size() - 1));
+            }
+            list.addAll(mCustomerDao.customerNameLoadAfter(key, pageSize));
+        } else {
+            list = mCustomerDao.customerNameInitial(initialLoadSize);
+        }
+
+        if (enablePlaceholders && !list.isEmpty()) {
+            String firstKey = getKey(list.get(0));
+            String lastKey = getKey(list.get(list.size() - 1));
+
+            // only bother counting if placeholders are desired
+            final int position = mCustomerDao.customerNameCountBefore(firstKey);
+            final int count = position + list.size() + mCustomerDao.customerNameCountAfter(lastKey);
+            callback.onResult(list, position, count);
+        } else {
+            callback.onResult(list);
+        }
     }
 
     @Override
-    public int countItemsAfter(@NonNull String customerName) {
-        return mCustomerDao.customerNameCountAfter(customerName);
+    public void loadAfter(@NonNull String currentEndKey, int pageSize,
+            @NonNull LoadCallback<Customer> callback) {
+        callback.onResult(mCustomerDao.customerNameLoadAfter(currentEndKey, pageSize));
     }
 
-    @Nullable
     @Override
-    public List<Customer> loadInitial(int pageSize) {
-        return mCustomerDao.customerNameInitial(pageSize);
-    }
-
-    @Nullable
-    @Override
-    public List<Customer> loadBefore(@NonNull String customerName, int pageSize) {
-        return mCustomerDao.customerNameLoadBefore(customerName, pageSize);
-    }
-
-    @Nullable
-    @Override
-    public List<Customer> loadAfter(@Nullable String customerName, int pageSize) {
-        return mCustomerDao.customerNameLoadAfter(customerName, pageSize);
+    public void loadBefore(@NonNull String currentBeginKey, int pageSize,
+            @NonNull LoadCallback<Customer> callback) {
+        List<Customer> list = mCustomerDao.customerNameLoadBefore(currentBeginKey, pageSize);
+        Collections.reverse(list);
+        callback.onResult(list);
     }
 }
diff --git a/room/integration-tests/testapp/src/main/res/layout/activity_recycler_view.xml b/room/integration-tests/testapp/src/main/res/layout/activity_recycler_view.xml
index 71dae1b..34e4491 100644
--- a/room/integration-tests/testapp/src/main/res/layout/activity_recycler_view.xml
+++ b/room/integration-tests/testapp/src/main/res/layout/activity_recycler_view.xml
@@ -35,7 +35,7 @@
         android:paddingTop="@dimen/activity_vertical_margin"
     />
     <Button
-        android:id="@+id/button"
+        android:id="@+id/addButton"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentBottom="true"
diff --git a/room/migration/build.gradle b/room/migration/build.gradle
index 3f5bdd6..086aac7 100644
--- a/room/migration/build.gradle
+++ b/room/migration/build.gradle
@@ -14,10 +14,13 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension;
 
-apply plugin: android.support.SupportJavaLibraryPlugin
+plugins {
+    id("SupportJavaLibraryPlugin")
+}
 
 sourceSets {
     test.java.srcDirs += 'src/tests/kotlin'
@@ -31,11 +34,12 @@
     testCompile libs.mockito_core
 }
 
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Room Migration'
-    publish true
-    inceptionYear '2017'
-    description "Android Room Migration"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room Migration"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room Migration"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/room/runtime/build.gradle b/room/runtime/build.gradle
index a170c8e..0570fe8 100644
--- a/room/runtime/build.gradle
+++ b/room/runtime/build.gradle
@@ -14,34 +14,22 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
     }
 
     buildTypes.all {
         consumerProguardFiles 'proguard-rules.pro'
     }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
-    }
 }
 
 dependencies {
@@ -49,15 +37,15 @@
     api project(":persistence:db-framework")
     api project(":persistence:db")
     api project(":arch:runtime")
-    provided project(":paging:common")
-    provided project(":lifecycle:runtime")
-    provided project(":lifecycle:extensions")
-    compile libs.support.core_utils, libs.support_exclude_config
+    compileOnly project(":paging:common")
+    compileOnly project(":lifecycle:runtime")
+    compileOnly project(":lifecycle:extensions")
+    api libs.support.core_utils, libs.support_exclude_config
 
-    testCompile project(":arch:core-testing")
-    testCompile libs.junit
-    testCompile libs.mockito_core
-    testCompile libs.support.annotations
+    testImplementation project(":arch:core-testing")
+    testImplementation libs.junit
+    testImplementation libs.mockito_core
+    testImplementation libs.support.annotations
 
     androidTestImplementation libs.junit
     androidTestImplementation libs.test_runner,      { exclude module: 'support-annotations' }
@@ -66,6 +54,7 @@
 
 createAndroidCheckstyle(project)
 
+// Used by testCompile in room-compiler
 android.libraryVariants.all { variant ->
     def name = variant.buildType.name
     def suffix = name.capitalize()
@@ -76,11 +65,12 @@
     }
 }
 
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Room-Runtime'
-    publish true
-    inceptionYear '2017'
-    description "Android Room-Runtime"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room-Runtime"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room-Runtime"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/room/runtime/lint-baseline.xml b/room/runtime/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/room/runtime/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/room/runtime/src/main/java/android/arch/persistence/room/EntityDeletionOrUpdateAdapter.java b/room/runtime/src/main/java/android/arch/persistence/room/EntityDeletionOrUpdateAdapter.java
index 6f4aa68..373b122 100644
--- a/room/runtime/src/main/java/android/arch/persistence/room/EntityDeletionOrUpdateAdapter.java
+++ b/room/runtime/src/main/java/android/arch/persistence/room/EntityDeletionOrUpdateAdapter.java
@@ -45,6 +45,7 @@
      *
      * @return An SQL query that can delete or update instances of T.
      */
+    @Override
     protected abstract String createQuery();
 
     /**
diff --git a/room/runtime/src/main/java/android/arch/persistence/room/Room.java b/room/runtime/src/main/java/android/arch/persistence/room/Room.java
index 2850b55..9b168fc 100644
--- a/room/runtime/src/main/java/android/arch/persistence/room/Room.java
+++ b/room/runtime/src/main/java/android/arch/persistence/room/Room.java
@@ -72,6 +72,7 @@
         return new RoomDatabase.Builder<>(context, klass, null);
     }
 
+    @SuppressWarnings({"TypeParameterUnusedInFormals", "ClassNewInstance"})
     @NonNull
     static <T, C> T getGeneratedImplementation(Class<C> klass, String suffix) {
         final String fullPackage = klass.getPackage().getName();
diff --git a/room/rxjava2/build.gradle b/room/rxjava2/build.gradle
index 7f86842..efdfc48 100644
--- a/room/rxjava2/build.gradle
+++ b/room/rxjava2/build.gradle
@@ -14,66 +14,39 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-
-    }
-    buildTypes {
-        release {
-            minifyEnabled false
-            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
-        }
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile project(":room:common")
-    compile project(":room:runtime")
-    compile project(":arch:runtime")
-    compile libs.support.core_utils, libs.support_exclude_config
-    compile libs.rx_java
-    testCompile libs.junit
-    testCompile libs.mockito_core
-    testCompile project(":arch:core-testing")
+    api project(":room:common")
+    api project(":room:runtime")
+    api project(":arch:runtime")
+    api libs.support.core_utils, libs.support_exclude_config
+    api libs.rx_java
+    testImplementation libs.junit
+    testImplementation libs.mockito_core
+    testImplementation project(":arch:core-testing")
 }
 
 createAndroidCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    project.tasks.create(name: "jar${suffix}", type: Jar){
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Room RXJava2'
-    publish true
-    inceptionYear '2017'
-    description "Android Room RXJava2"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room RXJava2"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room RXJava2"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/room/rxjava2/lint-baseline.xml b/room/rxjava2/lint-baseline.xml
new file mode 100644
index 0000000..2cadde1
--- /dev/null
+++ b/room/rxjava2/lint-baseline.xml
@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+</issues>
diff --git a/room/testing/build.gradle b/room/testing/build.gradle
index 078de88..876300a 100644
--- a/room/testing/build.gradle
+++ b/room/testing/build.gradle
@@ -14,59 +14,39 @@
  * limitations under the License.
  */
 
+import android.support.LibraryGroups
 import android.support.LibraryVersions
 import android.support.SupportLibraryExtension
 
-apply plugin: android.support.FlatfootAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 android {
-    compileSdkVersion tools.current_sdk
-    buildToolsVersion tools.build_tools_version
-
     defaultConfig {
         minSdkVersion flatfoot.min_sdk
-        targetSdkVersion tools.current_sdk
-
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
-    }
-
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-    compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_7
-        targetCompatibility JavaVersion.VERSION_1_7
     }
 }
 
 dependencies {
-    compile project(":room:common")
-    compile project(":room:runtime")
-    compile project(":persistence:db")
-    compile project(":persistence:db-framework")
-    compile project(":room:migration")
-    compile project(":arch:runtime")
-    compile libs.support.core_utils, libs.support_exclude_config
-    compile libs.junit
+    api project(":room:common")
+    api project(":room:runtime")
+    api project(":persistence:db")
+    api project(":persistence:db-framework")
+    api project(":room:migration")
+    api project(":arch:runtime")
+    api libs.support.core_utils, libs.support_exclude_config
+    api libs.junit
 }
 
 createAndroidCheckstyle(project)
 
-android.libraryVariants.all { variant ->
-    def name = variant.buildType.name
-    def suffix = name.capitalize()
-    project.tasks.create(name: "jar${suffix}", type: Jar){
-        dependsOn variant.javaCompile
-        from variant.javaCompile.destinationDir
-        destinationDir new File(project.buildDir, "libJar")
-    }
-}
-
-version = LibraryVersions.ROOM.toString()
 supportLibrary {
-    name 'Android Room Testimg'
-    publish true
-    inceptionYear '2017'
-    description "Android Room Testing"
-    url SupportLibraryExtension.ARCHITECTURE_URL
+    name = "Android Room Testing"
+    publish = true
+    mavenVersion = LibraryVersions.ROOM
+    mavenGroup = LibraryGroups.ROOM
+    inceptionYear = "2017"
+    description = "Android Room Testing"
+    url = SupportLibraryExtension.ARCHITECTURE_URL
 }
\ No newline at end of file
diff --git a/room/testing/lint-baseline.xml b/room/testing/lint-baseline.xml
new file mode 100644
index 0000000..dee4355
--- /dev/null
+++ b/room/testing/lint-baseline.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<issues format="4" by="lint 3.0.0">
+
+    <issue
+        id="InvalidPackage"
+        message="Invalid package reference in library; not included in Android: `java.lang.management`. Referenced from `org.junit.internal.runners.statements.FailOnTimeout`.">
+        <location
+            file="../../../../prebuilts/tools/common/m2/repository/junit/junit/4.12/junit-4.12.jar"/>
+    </issue>
+
+</issues>
diff --git a/room/testing/src/main/java/android/arch/persistence/room/testing/MigrationTestHelper.java b/room/testing/src/main/java/android/arch/persistence/room/testing/MigrationTestHelper.java
index 18e0a14..2e93bbe 100644
--- a/room/testing/src/main/java/android/arch/persistence/room/testing/MigrationTestHelper.java
+++ b/room/testing/src/main/java/android/arch/persistence/room/testing/MigrationTestHelper.java
@@ -341,7 +341,7 @@
         return 0;
     }
 
-    class MigratingDelegate extends RoomOpenHelperDelegate {
+    static class MigratingDelegate extends RoomOpenHelperDelegate {
         private final boolean mVerifyDroppedTables;
 
         MigratingDelegate(DatabaseBundle databaseBundle, boolean verifyDroppedTables) {
diff --git a/samples/SupportDesignDemos/src/main/res/layout/design_text_input.xml b/samples/SupportDesignDemos/src/main/res/layout/design_text_input.xml
index 6dbbb92..fc9ff00 100644
--- a/samples/SupportDesignDemos/src/main/res/layout/design_text_input.xml
+++ b/samples/SupportDesignDemos/src/main/res/layout/design_text_input.xml
@@ -96,6 +96,22 @@
         </android.support.design.widget.TextInputLayout>
 
         <android.support.design.widget.TextInputLayout
+            android:id="@+id/input_auto_complete"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            app:counterEnabled="true"
+            app:counterMaxLength="30">
+
+            <AutoCompleteTextView
+                android:id="@+id/edit_auto_complete"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:hint="@string/form_auto_complete" />
+
+        </android.support.design.widget.TextInputLayout>
+
+        <android.support.design.widget.TextInputLayout
             android:id="@+id/input_password"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
diff --git a/samples/SupportDesignDemos/src/main/res/values/strings.xml b/samples/SupportDesignDemos/src/main/res/values/strings.xml
index 74630d9..6ebe24c 100644
--- a/samples/SupportDesignDemos/src/main/res/values/strings.xml
+++ b/samples/SupportDesignDemos/src/main/res/values/strings.xml
@@ -69,6 +69,7 @@
     <string name="form_username">Username</string>
     <string name="form_email">Email address</string>
     <string name="form_description">Description</string>
+    <string name="form_auto_complete">Auto complete</string>
     <string name="form_password">Password field</string>
     <string name="show_error">Show error</string>
     <string name="toggle_enabled">Toggle enabled</string>
diff --git a/testutils/build.gradle b/testutils/build.gradle
index f1be70d..15eabaf 100644
--- a/testutils/build.gradle
+++ b/testutils/build.gradle
@@ -14,7 +14,9 @@
  * limitations under the License.
  */
 
-apply plugin: android.support.SupportAndroidLibraryPlugin
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     compile libs.junit
@@ -27,4 +29,8 @@
     lintOptions {
         disable 'InvalidPackage' // Lint is unhappy about junit package
     }
+}
+
+supportLibrary {
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/transition/build.gradle b/transition/build.gradle
index be366d6..326a681 100644
--- a/transition/build.gradle
+++ b/transition/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -44,8 +49,11 @@
 }
 
 supportLibrary {
-    name 'Android Transition Support Library'
-    publish true
-    inceptionYear '2016'
-    description 'Android Transition Support Library'
+    name = "Android Transition Support Library"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2016"
+    description = "Android Transition Support Library"
+    legacySourceLocation = true
 }
diff --git a/tv-provider/build.gradle b/tv-provider/build.gradle
index 0545458..60c2b2e 100644
--- a/tv-provider/build.gradle
+++ b/tv-provider/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -14,8 +19,11 @@
 }
 
 supportLibrary {
-    name 'Android Support TV Provider'
-    publish true
-    inceptionYear '2017'
-    description 'Android Support Library for TV Provider'
+    name = "Android Support TV Provider"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2017"
+    description = "Android Support Library for TV Provider"
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/v13/build.gradle b/v13/build.gradle
index 06774fd..bd01c55 100644
--- a/v13/build.gradle
+++ b/v13/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -23,8 +28,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library v13'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library v13"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/v14/preference/build.gradle b/v14/preference/build.gradle
index 8c66d6a..f68379a 100644
--- a/v14/preference/build.gradle
+++ b/v14/preference/build.gradle
@@ -14,7 +14,12 @@
  * limitations under the License
  */
 
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-v4')
@@ -34,8 +39,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Preference v14'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support Preference v14'
+    name = "Android Support Preference v14"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support Preference v14"
+    legacySourceLocation = true
 }
diff --git a/v17/leanback/build.gradle b/v17/leanback/build.gradle
index baefe46..4ebec71 100644
--- a/v17/leanback/build.gradle
+++ b/v17/leanback/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -31,8 +36,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Leanback v17'
-    publish true
-    inceptionYear '2014'
-    description 'Android Support Leanback v17'
+    name = "Android Support Leanback v17"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2014"
+    description = "Android Support Leanback v17"
+    legacySourceLocation = true
 }
diff --git a/v17/preference-leanback/build.gradle b/v17/preference-leanback/build.gradle
index f573908..85d2577 100644
--- a/v17/preference-leanback/build.gradle
+++ b/v17/preference-leanback/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-v4')
@@ -24,8 +29,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Leanback Preference v17'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support Leanback Preference v17'
+    name = "Android Support Leanback Preference v17"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support Leanback Preference v17"
+    legacySourceLocation = true
 }
\ No newline at end of file
diff --git a/v4/build.gradle b/v4/build.gradle
index 737db27..0a17101 100644
--- a/v4/build.gradle
+++ b/v4/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -17,8 +22,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Library v4'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android Support Library v4"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren't a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/v7/appcompat/build.gradle b/v7/appcompat/build.gradle
index 2d57ac4..308a122 100644
--- a/v7/appcompat/build.gradle
+++ b/v7/appcompat/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -32,8 +37,11 @@
 }
 
 supportLibrary {
-    name 'Android AppCompat Library v7'
-    publish true
-    inceptionYear '2011'
-    description "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    name = "Android AppCompat Library v7"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "The Support Library is a static library that you can add to your Android application in order to use APIs that are either not available for older platform versions or utility APIs that aren\'t a part of the framework APIs. Compatible on devices running API 14 or later."
+    legacySourceLocation = true
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatAutoCompleteTextView.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatAutoCompleteTextView.java
index 5b0a2f8..e41bec7 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatAutoCompleteTextView.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatAutoCompleteTextView.java
@@ -29,6 +29,8 @@
 import android.support.v7.appcompat.R;
 import android.support.v7.content.res.AppCompatResources;
 import android.util.AttributeSet;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
 import android.widget.AutoCompleteTextView;
 
 /**
@@ -177,4 +179,10 @@
             mTextHelper.onSetTextAppearance(context, resId);
         }
     }
+
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+        return AppCompatHintHelper.onCreateInputConnection(super.onCreateInputConnection(outAttrs),
+                outAttrs, this);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatCheckedTextView.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatCheckedTextView.java
index 921f0a2..dca409c 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatCheckedTextView.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatCheckedTextView.java
@@ -20,6 +20,8 @@
 import android.support.annotation.DrawableRes;
 import android.support.v7.content.res.AppCompatResources;
 import android.util.AttributeSet;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
 import android.widget.CheckedTextView;
 
 /**
@@ -79,4 +81,10 @@
             mTextHelper.applyCompoundDrawablesTints();
         }
     }
+
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+        return AppCompatHintHelper.onCreateInputConnection(super.onCreateInputConnection(outAttrs),
+                outAttrs, this);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatEditText.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatEditText.java
index 406e364..6831fcb 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatEditText.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatEditText.java
@@ -28,6 +28,8 @@
 import android.support.v4.view.TintableBackgroundView;
 import android.support.v7.appcompat.R;
 import android.util.AttributeSet;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
 import android.widget.EditText;
 
 /**
@@ -159,4 +161,10 @@
             mTextHelper.onSetTextAppearance(context, resId);
         }
     }
+
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+        return AppCompatHintHelper.onCreateInputConnection(super.onCreateInputConnection(outAttrs),
+                outAttrs, this);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatHintHelper.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatHintHelper.java
new file mode 100644
index 0000000..0d30fb7
--- /dev/null
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatHintHelper.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.v7.widget;
+
+import android.view.View;
+import android.view.ViewParent;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
+
+class AppCompatHintHelper {
+
+    static InputConnection onCreateInputConnection(InputConnection ic, EditorInfo outAttrs,
+            View view) {
+        if (ic != null && outAttrs.hintText == null) {
+            // If we don't have a hint and the parent implements WithHint, use its hint for the
+            // EditorInfo. This allows us to display a hint in 'extract mode'.
+            ViewParent parent = view.getParent();
+            while (parent instanceof View) {
+                if (parent instanceof WithHint) {
+                    outAttrs.hintText = ((WithHint) parent).getHint();
+                    break;
+                }
+                parent = parent.getParent();
+            }
+        }
+        return ic;
+    }
+
+}
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatMultiAutoCompleteTextView.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatMultiAutoCompleteTextView.java
index 8060d7d..b71b08a 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatMultiAutoCompleteTextView.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatMultiAutoCompleteTextView.java
@@ -29,6 +29,8 @@
 import android.support.v7.appcompat.R;
 import android.support.v7.content.res.AppCompatResources;
 import android.util.AttributeSet;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
 import android.widget.MultiAutoCompleteTextView;
 
 /**
@@ -177,4 +179,10 @@
             mTextHelper.onSetTextAppearance(context, resId);
         }
     }
+
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+        return AppCompatHintHelper.onCreateInputConnection(super.onCreateInputConnection(outAttrs),
+                outAttrs, this);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatTextView.java b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatTextView.java
index cfa6a2a..d813277 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatTextView.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/AppCompatTextView.java
@@ -31,6 +31,8 @@
 import android.support.v4.widget.TextViewCompat;
 import android.support.v7.appcompat.R;
 import android.util.AttributeSet;
+import android.view.inputmethod.EditorInfo;
+import android.view.inputmethod.InputConnection;
 import android.widget.TextView;
 
 /**
@@ -361,4 +363,10 @@
         }
         return new int[0];
     }
+
+    @Override
+    public InputConnection onCreateInputConnection(EditorInfo outAttrs) {
+        return AppCompatHintHelper.onCreateInputConnection(super.onCreateInputConnection(outAttrs),
+                outAttrs, this);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/Toolbar.java b/v7/appcompat/src/main/java/android/support/v7/widget/Toolbar.java
index 45e2583..f383e90 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/Toolbar.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/Toolbar.java
@@ -56,6 +56,7 @@
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewParent;
 import android.widget.ImageButton;
 import android.widget.ImageView;
 import android.widget.TextView;
@@ -2366,12 +2367,20 @@
         @Override
         public boolean expandItemActionView(MenuBuilder menu, MenuItemImpl item) {
             ensureCollapseButtonView();
-            if (mCollapseButtonView.getParent() != Toolbar.this) {
+            ViewParent collapseButtonParent = mCollapseButtonView.getParent();
+            if (collapseButtonParent != Toolbar.this) {
+                if (collapseButtonParent instanceof ViewGroup) {
+                    ((ViewGroup) collapseButtonParent).removeView(mCollapseButtonView);
+                }
                 addView(mCollapseButtonView);
             }
             mExpandedActionView = item.getActionView();
             mCurrentExpandedItem = item;
-            if (mExpandedActionView.getParent() != Toolbar.this) {
+            ViewParent expandedActionParent = mExpandedActionView.getParent();
+            if (expandedActionParent != Toolbar.this) {
+                if (expandedActionParent instanceof ViewGroup) {
+                    ((ViewGroup) expandedActionParent).removeView(mExpandedActionView);
+                }
                 final LayoutParams lp = generateDefaultLayoutParams();
                 lp.gravity = GravityCompat.START | (mButtonGravity & Gravity.VERTICAL_GRAVITY_MASK);
                 lp.mViewType = LayoutParams.EXPANDED;
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/TooltipCompatHandler.java b/v7/appcompat/src/main/java/android/support/v7/widget/TooltipCompatHandler.java
index 5ce1f8b..3d3c300 100644
--- a/v7/appcompat/src/main/java/android/support/v7/widget/TooltipCompatHandler.java
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/TooltipCompatHandler.java
@@ -66,6 +66,10 @@
     private TooltipPopup mPopup;
     private boolean mFromTouch;
 
+    // The handler currently scheduled to show a tooltip, triggered by a hover
+    // (there can be only one).
+    private static TooltipCompatHandler sPendingHandler;
+
     // The handler currently showing a tooltip (there can be only one).
     private static TooltipCompatHandler sActiveHandler;
 
@@ -76,6 +80,15 @@
      * @param tooltipText the tooltip text
      */
     public static void setTooltipText(View view, CharSequence tooltipText) {
+        // The code below is not attempting to update the tooltip text
+        // for a pending or currently active tooltip, because it may lead
+        // to updating the wrong tooltipin in some rare cases (e.g. when
+        // action menu item views are recycled). Instead, the tooltip is
+        // canceled/hidden. This might still be the wrong tooltip,
+        // but hiding wrong tooltip is less disruptive UX.
+        if (sPendingHandler != null && sPendingHandler.mAnchor == view) {
+            setPendingHandler(null);
+        }
         if (TextUtils.isEmpty(tooltipText)) {
             if (sActiveHandler != null && sActiveHandler.mAnchor == view) {
                 sActiveHandler.hide();
@@ -119,8 +132,7 @@
                 if (mAnchor.isEnabled() && mPopup == null) {
                     mAnchorX = (int) event.getX();
                     mAnchorY = (int) event.getY();
-                    mAnchor.removeCallbacks(mShowRunnable);
-                    mAnchor.postDelayed(mShowRunnable, ViewConfiguration.getLongPressTimeout());
+                    setPendingHandler(this);
                 }
                 break;
             case MotionEvent.ACTION_HOVER_EXIT:
@@ -145,6 +157,7 @@
         if (!ViewCompat.isAttachedToWindow(mAnchor)) {
             return;
         }
+        setPendingHandler(null);
         if (sActiveHandler != null) {
             sActiveHandler.hide();
         }
@@ -180,7 +193,27 @@
                 Log.e(TAG, "sActiveHandler.mPopup == null");
             }
         }
-        mAnchor.removeCallbacks(mShowRunnable);
+        if (sPendingHandler == this) {
+            setPendingHandler(null);
+        }
         mAnchor.removeCallbacks(mHideRunnable);
     }
+
+    private static void setPendingHandler(TooltipCompatHandler handler) {
+        if (sPendingHandler != null) {
+            sPendingHandler.cancelPendingShow();
+        }
+        sPendingHandler = handler;
+        if (sPendingHandler != null) {
+            sPendingHandler.scheduleShow();
+        }
+    }
+
+    private void scheduleShow() {
+        mAnchor.postDelayed(mShowRunnable, ViewConfiguration.getLongPressTimeout());
+    }
+
+    private void cancelPendingShow() {
+        mAnchor.removeCallbacks(mShowRunnable);
+    }
 }
diff --git a/v7/appcompat/src/main/java/android/support/v7/widget/WithHint.java b/v7/appcompat/src/main/java/android/support/v7/widget/WithHint.java
new file mode 100644
index 0000000..d14f483
--- /dev/null
+++ b/v7/appcompat/src/main/java/android/support/v7/widget/WithHint.java
@@ -0,0 +1,36 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.support.v7.widget;
+
+import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;
+
+import android.support.annotation.Nullable;
+import android.support.annotation.RestrictTo;
+
+/**
+ * @hide
+ */
+@RestrictTo(LIBRARY_GROUP)
+public interface WithHint {
+    /**
+     * Returns the hint which is displayed in the floating label, if enabled.
+     *
+     * @return the hint, or null if there isn't one set, or the hint is not enabled.
+     */
+    @Nullable
+    CharSequence getHint();
+}
diff --git a/v7/cardview/build.gradle b/v7/cardview/build.gradle
index 76c3bf3..23d8076 100644
--- a/v7/cardview/build.gradle
+++ b/v7/cardview/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -15,8 +20,11 @@
 }
 
 supportLibrary {
-    name 'Android Support CardView v7'
-    publish true
-    inceptionYear '2011'
-    description 'Android Support CardView v7'
+    name = "Android Support CardView v7"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2011"
+    description = "Android Support CardView v7"
+    legacySourceLocation = true
 }
diff --git a/v7/gridlayout/build.gradle b/v7/gridlayout/build.gradle
index d4d467d..052b9db 100644
--- a/v7/gridlayout/build.gradle
+++ b/v7/gridlayout/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -19,8 +24,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Grid Layout'
-    publish true
-    inceptionYear '2013'
-    description 'Android Support Grid Layout'
+    name = "Android Support Grid Layout"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2013"
+    description = "Android Support Grid Layout"
+    legacySourceLocation = true
 }
diff --git a/v7/mediarouter/build.gradle b/v7/mediarouter/build.gradle
index f301324..09e48df 100644
--- a/v7/mediarouter/build.gradle
+++ b/v7/mediarouter/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(":support-media-compat")
@@ -28,8 +33,11 @@
 }
 
 supportLibrary {
-    name 'Android MediaRouter Support Library'
-    publish true
-    inceptionYear '2013'
-    description 'Android MediaRouter Support Library'
+    name = "Android MediaRouter Support Library"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2013"
+    description = "Android MediaRouter Support Library"
+    legacySourceLocation = true
 }
diff --git a/v7/mediarouter/res/values/themes.xml b/v7/mediarouter/res/values/themes.xml
index 586db92..8c6e97a 100644
--- a/v7/mediarouter/res/values/themes.xml
+++ b/v7/mediarouter/res/values/themes.xml
@@ -17,7 +17,6 @@
 <resources>
 
     <style name="Theme.MediaRouter" parent="ThemeOverlay.AppCompat.Dark">
-        <item name="android:backgroundDimEnabled">true</item>
         <item name="windowNoTitle">true</item>
         <item name="mediaRouteButtonStyle">@style/Widget.MediaRouter.MediaRouteButton</item>
 
@@ -39,7 +38,6 @@
     </style>
 
     <style name="Theme.MediaRouter.Light" parent="ThemeOverlay.AppCompat.Light">
-        <item name="android:backgroundDimEnabled">true</item>
         <item name="windowNoTitle">true</item>
         <item name="mediaRouteButtonStyle">@style/Widget.MediaRouter.Light.MediaRouteButton</item>
 
diff --git a/v7/mediarouter/src/android/support/v7/app/MediaRouteButton.java b/v7/mediarouter/src/android/support/v7/app/MediaRouteButton.java
index d3f7020..fdbcf9a 100644
--- a/v7/mediarouter/src/android/support/v7/app/MediaRouteButton.java
+++ b/v7/mediarouter/src/android/support/v7/app/MediaRouteButton.java
@@ -121,8 +121,7 @@
     }
 
     public MediaRouteButton(Context context, AttributeSet attrs, int defStyleAttr) {
-        super(MediaRouterThemeHelper.createThemedContext(context, defStyleAttr), attrs,
-                defStyleAttr);
+        super(MediaRouterThemeHelper.createThemedButtonContext(context), attrs, defStyleAttr);
         context = getContext();
 
         mRouter = MediaRouter.getInstance(context);
diff --git a/v7/mediarouter/src/android/support/v7/app/MediaRouteChooserDialog.java b/v7/mediarouter/src/android/support/v7/app/MediaRouteChooserDialog.java
index 0ab2eb1..17364ef 100644
--- a/v7/mediarouter/src/android/support/v7/app/MediaRouteChooserDialog.java
+++ b/v7/mediarouter/src/android/support/v7/app/MediaRouteChooserDialog.java
@@ -92,10 +92,8 @@
     }
 
     public MediaRouteChooserDialog(Context context, int theme) {
-        // If we pass theme ID of 0 to AppCompatDialog, it will apply dialogTheme on the context,
-        // which may override our style settings. Passes our uppermost theme ID to prevent this.
-        super(MediaRouterThemeHelper.createThemedContext(context, theme),
-                theme == 0 ? MediaRouterThemeHelper.createThemeForDialog(context, theme) : theme);
+        super(context = MediaRouterThemeHelper.createThemedDialogContext(context, theme, false),
+                MediaRouterThemeHelper.createThemedDialogStyle(context));
         context = getContext();
 
         mRouter = MediaRouter.getInstance(context);
diff --git a/v7/mediarouter/src/android/support/v7/app/MediaRouteControllerDialog.java b/v7/mediarouter/src/android/support/v7/app/MediaRouteControllerDialog.java
index 4b9a17a..d89bf21 100644
--- a/v7/mediarouter/src/android/support/v7/app/MediaRouteControllerDialog.java
+++ b/v7/mediarouter/src/android/support/v7/app/MediaRouteControllerDialog.java
@@ -201,12 +201,8 @@
     }
 
     public MediaRouteControllerDialog(Context context, int theme) {
-        // If we pass theme ID of 0 to AppCompatDialog, it will apply dialogTheme on the context,
-        // which may override our style settings. Passes our uppermost theme ID to prevent this.
-        super(MediaRouterThemeHelper.createThemedContext(context,
-                MediaRouterThemeHelper.getAlertDialogResolvedTheme(context, theme)), theme == 0
-                ? MediaRouterThemeHelper.createThemeForDialog(context, MediaRouterThemeHelper
-                        .getAlertDialogResolvedTheme(context, theme)) : theme);
+        super(context = MediaRouterThemeHelper.createThemedDialogContext(context, theme, true),
+                MediaRouterThemeHelper.createThemedDialogStyle(context));
         mContext = getContext();
 
         mControllerCallback = new MediaControllerCallback();
diff --git a/v7/mediarouter/src/android/support/v7/app/MediaRouterThemeHelper.java b/v7/mediarouter/src/android/support/v7/app/MediaRouterThemeHelper.java
index 9ef218e..69e40ac 100644
--- a/v7/mediarouter/src/android/support/v7/app/MediaRouterThemeHelper.java
+++ b/v7/mediarouter/src/android/support/v7/app/MediaRouterThemeHelper.java
@@ -42,47 +42,76 @@
     private MediaRouterThemeHelper() {
     }
 
-    /**
-     * Creates a themed context based on the explicit style resource or the parent context's default
-     * theme.
-     * <p>
-     * The theme which will be applied on top of the parent {@code context}'s theme is determined
-     * by the primary color defined in the given {@code style}, or in the parent {@code context}.
+    static Context createThemedButtonContext(Context context) {
+        // Apply base Media Router theme.
+        context = new ContextThemeWrapper(context, getRouterThemeId(context));
+
+        // Apply custom Media Router theme.
+        int style = getThemeResource(context, R.attr.mediaRouteTheme);
+        if (style != 0) {
+            context = new ContextThemeWrapper(context, style);
+        }
+
+        return context;
+    }
+
+    /*
+     * The following two methods are to be used in conjunction. They should be used to prepare
+     * the context and theme for a super class constructor (the latter method relies on the
+     * former method to properly prepare the context):
+     *   super(context = createThemedDialogContext(context, theme),
+     *           createThemedDialogStyle(context));
      *
-     * @param context the parent context
-     * @param style the resource ID of the style against which to inflate this context, or
-     *              {@code 0} to use the parent {@code context}'s default theme.
-     * @return The themed context.
+     * It will apply theme in the following order (style lookups will be done in reverse):
+     *   1) Current theme
+     *   2) Supplied theme
+     *   3) Base Media Router theme
+     *   4) Custom Media Router theme, if provided
      */
-    static Context createThemedContext(Context context, int style) {
-        // First, apply dialog property overlay.
-        Context themedContext =
-                new ContextThemeWrapper(context, getStyledRouterThemeId(context, style));
-        int customizedThemeId = getThemeResource(context, R.attr.mediaRouteTheme);
-        return customizedThemeId == 0 ? themedContext
-                : new ContextThemeWrapper(themedContext, customizedThemeId);
-    }
+    static Context createThemedDialogContext(Context context, int theme, boolean alertDialog) {
+        // 1) Current theme is already applied to the context
 
-    /**
-     * Creates the theme resource ID intended to be used by dialogs.
-     */
-    static int createThemeForDialog(Context context, int style) {
-        int customizedThemeId = getThemeResource(context, R.attr.mediaRouteTheme);
-        return customizedThemeId != 0 ? customizedThemeId : getStyledRouterThemeId(context, style);
-    }
+        // 2) If no theme is supplied, look it up from the context (dialogTheme/alertDialogTheme)
+        if (theme == 0) {
+            theme = getThemeResource(context, !alertDialog
+                    ? android.support.v7.appcompat.R.attr.dialogTheme
+                    : android.support.v7.appcompat.R.attr.alertDialogTheme);
+        }
+        //    Apply it
+        context = new ContextThemeWrapper(context, theme);
 
-    public static int getThemeResource(Context context, int attr) {
+        // 3) If a custom Media Router theme is provided then apply the base theme
+        if (getThemeResource(context, R.attr.mediaRouteTheme) != 0) {
+            context = new ContextThemeWrapper(context, getRouterThemeId(context));
+        }
+
+        return context;
+    }
+    // This method should be used in conjunction with the previous method.
+    static int createThemedDialogStyle(Context context) {
+        // 4) Apply the custom Media Router theme
+        int theme = getThemeResource(context, R.attr.mediaRouteTheme);
+        if (theme == 0) {
+            // 3) No custom MediaRouther theme was provided so apply the base theme instead
+            theme = getRouterThemeId(context);
+        }
+
+        return theme;
+    }
+    // END. Previous two methods should be used in conjunction.
+
+    static int getThemeResource(Context context, int attr) {
         TypedValue value = new TypedValue();
         return context.getTheme().resolveAttribute(attr, value, true) ? value.resourceId : 0;
     }
 
-    public static float getDisabledAlpha(Context context) {
+    static float getDisabledAlpha(Context context) {
         TypedValue value = new TypedValue();
         return context.getTheme().resolveAttribute(android.R.attr.disabledAlpha, value, true)
                 ? value.getFloat() : 0.5f;
     }
 
-    public static @ControllerColorType int getControllerColor(Context context, int style) {
+    static @ControllerColorType int getControllerColor(Context context, int style) {
         int primaryColor = getThemeColor(context, style,
                 android.support.v7.appcompat.R.attr.colorPrimary);
         if (ColorUtils.calculateContrast(COLOR_WHITE_ON_DARK_BACKGROUND, primaryColor)
@@ -92,7 +121,7 @@
         return COLOR_DARK_ON_LIGHT_BACKGROUND;
     }
 
-    public static int getButtonTextColor(Context context) {
+    static int getButtonTextColor(Context context) {
         int primaryColor = getThemeColor(context, 0,
                 android.support.v7.appcompat.R.attr.colorPrimary);
         int backgroundColor = getThemeColor(context, 0, android.R.attr.colorBackground);
@@ -104,7 +133,7 @@
         return primaryColor;
     }
 
-    public static void setMediaControlsBackgroundColor(
+    static void setMediaControlsBackgroundColor(
             Context context, View mainControls, View groupControls, boolean hasGroup) {
         int primaryColor = getThemeColor(context, 0,
                 android.support.v7.appcompat.R.attr.colorPrimary);
@@ -124,7 +153,7 @@
         groupControls.setTag(primaryDarkColor);
     }
 
-    public static void setVolumeSliderColor(
+    static void setVolumeSliderColor(
             Context context, MediaRouteVolumeSlider volumeSlider, View backgroundView) {
         int controllerColor = getControllerColor(context, 0);
         if (Color.alpha(controllerColor) != 0xFF) {
@@ -136,23 +165,10 @@
         volumeSlider.setColor(controllerColor);
     }
 
-    // This is copied from {@link AlertDialog#resolveDialogTheme} to pre-evaluate theme in advance.
-    public static int getAlertDialogResolvedTheme(Context context, int themeResId) {
-        if (themeResId >= 0x01000000) {   // start of real resource IDs.
-            return themeResId;
-        } else {
-            TypedValue outValue = new TypedValue();
-            context.getTheme().resolveAttribute(
-                    android.support.v7.appcompat.R.attr.alertDialogTheme, outValue, true);
-            return outValue.resourceId;
-        }
-    }
-
     private static boolean isLightTheme(Context context) {
         TypedValue value = new TypedValue();
-        return context.getTheme().resolveAttribute(
-                android.support.v7.appcompat.R.attr.isLightTheme, value, true)
-                && value.data != 0;
+        return context.getTheme().resolveAttribute(android.support.v7.appcompat.R.attr.isLightTheme,
+                value, true) && value.data != 0;
     }
 
     private static int getThemeColor(Context context, int style, int attr) {
@@ -173,16 +189,16 @@
         return value.data;
     }
 
-    private static int getStyledRouterThemeId(Context context, int style) {
+    private static int getRouterThemeId(Context context) {
         int themeId;
         if (isLightTheme(context)) {
-            if (getControllerColor(context, style) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
+            if (getControllerColor(context, 0) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
                 themeId = R.style.Theme_MediaRouter_Light;
             } else {
                 themeId = R.style.Theme_MediaRouter_Light_DarkControlPanel;
             }
         } else {
-            if (getControllerColor(context, style) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
+            if (getControllerColor(context, 0) == COLOR_DARK_ON_LIGHT_BACKGROUND) {
                 themeId = R.style.Theme_MediaRouter_LightControlPanel;
             } else {
                 themeId = R.style.Theme_MediaRouter;
diff --git a/v7/mediarouter/tests/src/android/support/v7/app/MediaRouteChooserDialogTest.java b/v7/mediarouter/tests/src/android/support/v7/app/MediaRouteChooserDialogTest.java
index 415ec1f..7288968 100644
--- a/v7/mediarouter/tests/src/android/support/v7/app/MediaRouteChooserDialogTest.java
+++ b/v7/mediarouter/tests/src/android/support/v7/app/MediaRouteChooserDialogTest.java
@@ -16,7 +16,6 @@
 
 package android.support.v7.app;
 
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 import android.content.Context;
@@ -66,7 +65,7 @@
         // No base theme, with a customized theme (has window title)
         dialog = new MediaRouteChooserDialog(context, R.style.HasWindowTitle);
         typedArray = dialog.getContext().obtainStyledAttributes(R.styleable.AppCompatTheme);
-        assertFalse(typedArray.getBoolean(R.styleable.AppCompatTheme_windowNoTitle, false));
+        assertTrue(typedArray.getBoolean(R.styleable.AppCompatTheme_windowNoTitle, false));
         typedArray.recycle();
 
         // With base theme (has window title), no customized theme
@@ -79,7 +78,7 @@
         // With base theme and a customized theme (both has window title)
         dialog = new MediaRouteChooserDialog(context, R.style.HasWindowTitle);
         typedArray = dialog.getContext().obtainStyledAttributes(R.styleable.AppCompatTheme);
-        assertFalse(typedArray.getBoolean(R.styleable.AppCompatTheme_windowNoTitle, false));
+        assertTrue(typedArray.getBoolean(R.styleable.AppCompatTheme_windowNoTitle, false));
         typedArray.recycle();
 
         context.setTheme(0);
diff --git a/v7/palette/build.gradle b/v7/palette/build.gradle
index 6da6914..2703f2c 100644
--- a/v7/palette/build.gradle
+++ b/v7/palette/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-compat')
@@ -14,8 +19,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Palette v7'
-    publish true
-    inceptionYear '2014'
-    description 'Android Support Palette v7'
+    name = "Android Support Palette v7"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2014"
+    description = "Android Support Palette v7"
+    legacySourceLocation = true
 }
diff --git a/v7/preference/build.gradle b/v7/preference/build.gradle
index 2b1e871..f5bc372 100644
--- a/v7/preference/build.gradle
+++ b/v7/preference/build.gradle
@@ -14,7 +14,12 @@
  * limitations under the License
  */
 
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-v4')
@@ -50,8 +55,11 @@
 }
 
 supportLibrary {
-    name 'Android Support Preference v7'
-    publish true
-    inceptionYear '2015'
-    description 'Android Support Preference v7'
+    name = "Android Support Preference v7"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2015"
+    description = "Android Support Preference v7"
+    legacySourceLocation = true
 }
diff --git a/v7/recyclerview/build.gradle b/v7/recyclerview/build.gradle
index ad1150f..daac4ab 100644
--- a/v7/recyclerview/build.gradle
+++ b/v7/recyclerview/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -26,18 +31,17 @@
         main.res.srcDirs 'res', 'res-public'
     }
 
-    testOptions {
-        unitTests.returnDefaultValues = true
-    }
-
     buildTypes.all {
         consumerProguardFiles 'proguard-rules.pro'
     }
 }
 
 supportLibrary {
-    name 'Android Support RecyclerView v7'
-    publish true
-    inceptionYear '2014'
-    description 'Android Support RecyclerView v7'
+    name = "Android Support RecyclerView v7"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2014"
+    description = "Android Support RecyclerView v7"
+    legacySourceLocation = true
 }
diff --git a/v7/recyclerview/src/main/java/android/support/v7/widget/RecyclerView.java b/v7/recyclerview/src/main/java/android/support/v7/widget/RecyclerView.java
index dea8546..cfa28e8 100644
--- a/v7/recyclerview/src/main/java/android/support/v7/widget/RecyclerView.java
+++ b/v7/recyclerview/src/main/java/android/support/v7/widget/RecyclerView.java
@@ -6339,16 +6339,16 @@
         }
 
         void markKnownViewsInvalid() {
-            if (mAdapter != null && mAdapter.hasStableIds()) {
-                final int cachedCount = mCachedViews.size();
-                for (int i = 0; i < cachedCount; i++) {
-                    final ViewHolder holder = mCachedViews.get(i);
-                    if (holder != null) {
-                        holder.addFlags(ViewHolder.FLAG_UPDATE | ViewHolder.FLAG_INVALID);
-                        holder.addChangePayload(null);
-                    }
+            final int cachedCount = mCachedViews.size();
+            for (int i = 0; i < cachedCount; i++) {
+                final ViewHolder holder = mCachedViews.get(i);
+                if (holder != null) {
+                    holder.addFlags(ViewHolder.FLAG_UPDATE | ViewHolder.FLAG_INVALID);
+                    holder.addChangePayload(null);
                 }
-            } else {
+            }
+
+            if (mAdapter == null || !mAdapter.hasStableIds()) {
                 // we cannot re-use cached views in this case. Recycle them all
                 recycleAndClearCachedViews();
             }
diff --git a/v7/recyclerview/tests/src/android/support/v7/widget/BaseRecyclerViewInstrumentationTest.java b/v7/recyclerview/tests/src/android/support/v7/widget/BaseRecyclerViewInstrumentationTest.java
index d74c36c..157fb12 100644
--- a/v7/recyclerview/tests/src/android/support/v7/widget/BaseRecyclerViewInstrumentationTest.java
+++ b/v7/recyclerview/tests/src/android/support/v7/widget/BaseRecyclerViewInstrumentationTest.java
@@ -1083,13 +1083,18 @@
             });
         }
 
-        public void clearOnUIThread() {
+        void changeAllItemsAndNotifyDataSetChanged(int count) {
             assertEquals("clearOnUIThread called from a wrong thread",
                     Looper.getMainLooper(), Looper.myLooper());
-            mItems = new ArrayList<Item>();
+            mItems = new ArrayList<>();
+            addItems(0, count, DEFAULT_ITEM_PREFIX);
             notifyDataSetChanged();
         }
 
+        public void clearOnUIThread() {
+            changeAllItemsAndNotifyDataSetChanged(0);
+        }
+
         protected void moveInUIThread(int from, int to) {
             Item item = mItems.remove(from);
             offsetOriginalIndices(from, -1);
diff --git a/v7/recyclerview/tests/src/android/support/v7/widget/RecyclerViewLayoutTest.java b/v7/recyclerview/tests/src/android/support/v7/widget/RecyclerViewLayoutTest.java
index 42fde85..bdc450b 100644
--- a/v7/recyclerview/tests/src/android/support/v7/widget/RecyclerViewLayoutTest.java
+++ b/v7/recyclerview/tests/src/android/support/v7/widget/RecyclerViewLayoutTest.java
@@ -24,6 +24,7 @@
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.CoreMatchers.notNullValue;
 import static org.hamcrest.CoreMatchers.sameInstance;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
@@ -298,6 +299,201 @@
     }
 
     @Test
+    public void onDataSetChanged_doesntHaveStableIds_cachedViewHasNoPosition() throws Throwable {
+        onDataSetChanged_handleCachedViews(false);
+    }
+
+    @Test
+    public void onDataSetChanged_hasStableIds_noCachedViewsAreRecycled() throws Throwable {
+        onDataSetChanged_handleCachedViews(true);
+    }
+
+    /**
+     * If Adapter#setHasStableIds(boolean) is false, cached ViewHolders should be recycled in
+     * response to RecyclerView.Adapter#notifyDataSetChanged() and should report a position of
+     * RecyclerView#NO_POSITION inside of
+     * RecyclerView.Adapter#onViewRecycled(RecyclerView.ViewHolder).
+     *
+     * If Adapter#setHasStableIds(boolean) is true, cached Views/ViewHolders should not be recycled.
+     */
+    public void onDataSetChanged_handleCachedViews(boolean hasStableIds) throws Throwable {
+        final AtomicInteger cachedRecycleCount = new AtomicInteger(0);
+
+        final RecyclerView recyclerView = new RecyclerView(getActivity());
+        recyclerView.setItemViewCacheSize(1);
+
+        final TestAdapter adapter = new TestAdapter(2) {
+            @Override
+            public void onViewRecycled(TestViewHolder holder) {
+                // If the recycled holder is currently in the cache, then it's position in the
+                // adapter should be RecyclerView.NO_POSITION.
+                if (mRecyclerView.mRecycler.mCachedViews.contains(holder)) {
+                    assertThat("ViewHolder's getAdapterPosition should be "
+                                    + "RecyclerView.NO_POSITION",
+                            holder.getAdapterPosition(),
+                            is(RecyclerView.NO_POSITION));
+                    cachedRecycleCount.incrementAndGet();
+                }
+                super.onViewRecycled(holder);
+            }
+        };
+        adapter.setHasStableIds(hasStableIds);
+        recyclerView.setAdapter(adapter);
+
+        final AtomicInteger numItemsToLayout = new AtomicInteger(2);
+
+        TestLayoutManager layoutManager = new TestLayoutManager() {
+            @Override
+            public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
+                try {
+                    detachAndScrapAttachedViews(recycler);
+                    layoutRange(recycler, 0, numItemsToLayout.get());
+                } catch (Throwable t) {
+                    postExceptionToInstrumentation(t);
+                } finally {
+                    this.layoutLatch.countDown();
+                }
+            }
+
+            @Override
+            public boolean supportsPredictiveItemAnimations() {
+                return false;
+            }
+        };
+        recyclerView.setLayoutManager(layoutManager);
+
+        // Layout 2 items and sanity check that no items are in the recycler's cache.
+        numItemsToLayout.set(2);
+        layoutManager.expectLayouts(1);
+        setRecyclerView(recyclerView, true, false);
+        layoutManager.waitForLayout(2);
+        checkForMainThreadException();
+        assertThat("Sanity check, no views should be cached at this time",
+                mRecyclerView.mRecycler.mCachedViews.size(),
+                is(0));
+
+        // Now only layout 1 item and assert that 1 item is cached.
+        numItemsToLayout.set(1);
+        layoutManager.expectLayouts(1);
+        requestLayoutOnUIThread(mRecyclerView);
+        layoutManager.waitForLayout(1);
+        checkForMainThreadException();
+        assertThat("One view should be cached.",
+                mRecyclerView.mRecycler.mCachedViews.size(),
+                is(1));
+
+        // Notify data set has changed then final assert.
+        layoutManager.expectLayouts(1);
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                adapter.notifyDataSetChanged();
+            }
+        });
+        layoutManager.waitForLayout(1);
+        checkForMainThreadException();
+        // If hasStableIds, then no cached views should be recycled, otherwise just 1 should have
+        // been recycled.
+        assertThat(cachedRecycleCount.get(), is(hasStableIds ? 0 : 1));
+    }
+
+    @Test
+    public void notifyDataSetChanged_hasStableIds_cachedViewsAreReusedForSamePositions()
+            throws Throwable {
+        final Map<Integer, TestViewHolder> positionToViewHolderMap = new HashMap<>();
+        final AtomicInteger layoutItemCount = new AtomicInteger();
+        final AtomicBoolean inFirstBindViewHolderPass = new AtomicBoolean();
+
+        final RecyclerView recyclerView = new RecyclerView(getActivity());
+        recyclerView.setItemViewCacheSize(5);
+
+        final TestAdapter adapter = new TestAdapter(10) {
+            @Override
+            public void onBindViewHolder(TestViewHolder holder, int position) {
+                // Only track the top 5 positions that are going to be cached and then reused.
+                if (position >= 5) {
+                    // If we are in the first phase, put the items in the map, if we are in the
+                    // second phase, remove each one at the position and verify that it matches the
+                    // provided ViewHolder.
+                    if (inFirstBindViewHolderPass.get()) {
+                        positionToViewHolderMap.put(position, holder);
+                    } else {
+                        TestViewHolder testViewHolder = positionToViewHolderMap.get(position);
+                        assertThat(holder, is(testViewHolder));
+                        positionToViewHolderMap.remove(position);
+                    }
+                }
+                super.onBindViewHolder(holder, position);
+            }
+        };
+        adapter.setHasStableIds(true);
+        recyclerView.setAdapter(adapter);
+
+        TestLayoutManager testLayoutManager = new TestLayoutManager() {
+            @Override
+            public void onLayoutChildren(RecyclerView.Recycler recycler, RecyclerView.State state) {
+                try {
+                    detachAndScrapAttachedViews(recycler);
+                    layoutRange(recycler, 0, layoutItemCount.get());
+                } catch (Throwable t) {
+                    postExceptionToInstrumentation(t);
+                } finally {
+                    layoutLatch.countDown();
+                }
+            }
+
+            @Override
+            public boolean supportsPredictiveItemAnimations() {
+                return false;
+            }
+        };
+        recyclerView.setLayoutManager(testLayoutManager);
+
+        // First layout 10 items, then verify that the map has all 5 ViewHolders in it that will
+        // be cached, and sanity check that the cache is empty.
+        inFirstBindViewHolderPass.set(true);
+        layoutItemCount.set(10);
+        testLayoutManager.expectLayouts(1);
+        setRecyclerView(recyclerView, true, false);
+        testLayoutManager.waitForLayout(2);
+        checkForMainThreadException();
+        for (int i = 5; i < 10; i++) {
+            assertThat(positionToViewHolderMap.get(i), notNullValue());
+        }
+        assertThat(mRecyclerView.mRecycler.mCachedViews.size(), is(0));
+
+        // Now only layout the first 5 items and verify that the cache has 5 items in it.
+        layoutItemCount.set(5);
+        testLayoutManager.expectLayouts(1);
+        requestLayoutOnUIThread(mRecyclerView);
+        testLayoutManager.waitForLayout(1);
+        checkForMainThreadException();
+        assertThat(mRecyclerView.mRecycler.mCachedViews.size(), is(5));
+
+        // Trigger notifyDataSetChanged and wait for layout.
+        testLayoutManager.expectLayouts(1);
+        mActivityRule.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                adapter.notifyDataSetChanged();
+            }
+        });
+        testLayoutManager.waitForLayout(1);
+        checkForMainThreadException();
+
+        // Layout 10 items again, via the onBindViewholder method, check that each one of the views
+        // returned from the recycler for positions >= 5 was in our cache of views, and verify that
+        // all 5 cached views were returned.
+        inFirstBindViewHolderPass.set(false);
+        layoutItemCount.set(10);
+        testLayoutManager.expectLayouts(1);
+        requestLayoutOnUIThread(mRecyclerView);
+        testLayoutManager.waitForLayout(1);
+        checkForMainThreadException();
+        assertThat(positionToViewHolderMap.size(), is(0));
+    }
+
+    @Test
     public void predictiveMeasuredCrashTest() throws Throwable {
         final RecyclerView rv = new RecyclerView(getActivity());
         final LayoutAllLayoutManager lm = new LayoutAllLayoutManager(true) {
@@ -4654,7 +4850,7 @@
 
         @Override
         public void onNestedPreScroll(@NonNull View target, int dx, int dy,
-                @Nullable int[] consumed, @ViewCompat.NestedScrollType int type) {
+                @NonNull int[] consumed, @ViewCompat.NestedScrollType int type) {
             // Consume everything!
             consumed[0] = dx;
             consumed[1] = dy;
diff --git a/v7/recyclerview/tests/src/android/support/v7/widget/TestedFrameLayout.java b/v7/recyclerview/tests/src/android/support/v7/widget/TestedFrameLayout.java
index cd5fa22..2d73fd0 100644
--- a/v7/recyclerview/tests/src/android/support/v7/widget/TestedFrameLayout.java
+++ b/v7/recyclerview/tests/src/android/support/v7/widget/TestedFrameLayout.java
@@ -18,7 +18,6 @@
 
 import android.content.Context;
 import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 import android.support.v4.view.NestedScrollingParent2;
 import android.support.v4.view.ViewCompat;
 import android.util.AttributeSet;
@@ -201,7 +200,7 @@
     }
 
     @Override
-    public void onNestedPreScroll(@NonNull View target, int dx, int dy, @Nullable int[] consumed,
+    public void onNestedPreScroll(@NonNull View target, int dx, int dy, @NonNull int[] consumed,
             @ViewCompat.NestedScrollType int type) {
         if (mNestedScrollingDelegate != null) {
             mNestedScrollingDelegate.onNestedPreScroll(target, dx, dy, consumed, type);
diff --git a/v7/recyclerview/tests/src/android/support/v7/widget/test/NestedScrollingParent2Adapter.java b/v7/recyclerview/tests/src/android/support/v7/widget/test/NestedScrollingParent2Adapter.java
index da0d86f..356cffa 100644
--- a/v7/recyclerview/tests/src/android/support/v7/widget/test/NestedScrollingParent2Adapter.java
+++ b/v7/recyclerview/tests/src/android/support/v7/widget/test/NestedScrollingParent2Adapter.java
@@ -17,7 +17,6 @@
 package android.support.v7.widget.test;
 
 import android.support.annotation.NonNull;
-import android.support.annotation.Nullable;
 import android.support.v4.view.NestedScrollingParent2;
 import android.support.v4.view.ViewCompat;
 import android.view.View;
@@ -46,7 +45,7 @@
 
     @Override
     public void onNestedPreScroll(@NonNull View target, int dx, int dy,
-            @Nullable int[] consumed, @ViewCompat.NestedScrollType int type) {
+            @NonNull int[] consumed, @ViewCompat.NestedScrollType int type) {
     }
 
     @Override
diff --git a/wear/build.gradle b/wear/build.gradle
index 814f5cf..458f722 100644
--- a/wear/build.gradle
+++ b/wear/build.gradle
@@ -1,4 +1,9 @@
-apply plugin: android.support.SupportAndroidLibraryPlugin
+import android.support.LibraryGroups
+import android.support.LibraryVersions
+
+plugins {
+    id("SupportAndroidLibraryPlugin")
+}
 
 dependencies {
     api project(':support-annotations')
@@ -33,13 +38,11 @@
 }
 
 supportLibrary {
-    name 'Android Wear Support UI'
-    publish true
-    inceptionYear '2016'
-    description 'Android Wear Support UI'
-
-    license {
-        name 'The Apache Software License, Version 2.0'
-        url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-    }
+    name = "Android Wear Support UI"
+    publish = true
+    mavenVersion = LibraryVersions.SUPPORT_LIBRARY
+    mavenGroup = LibraryGroups.SUPPORT
+    inceptionYear = "2016"
+    description = "Android Wear Support UI"
+    legacySourceLocation = true
 }