New roots UX, async, performance, docs.

Yet another iteration from UX on how roots should be ordered.  Since
we no longer categorize by type, remove from public API.  Updated
asset drop with new dividers.

Update public API docs to be explicit about required columns.  Hide
flags and columns that aren't required for third-party apps.

Move remainder of potentially blocking work to AsyncTasks, including
creating directories, picked root resolution, and creation of new
documents once picked.

Improve performance of layouts by removing baseline alignment and
reduce hierarchy depth.  Set alpha on ImageViews directly to avoid
offscreen rendering hit.

Limit returned recents to 45 days.  Show load in recents when still
waiting for backends.  Show empty message when no recents stacks to
create from.  Use unique key when saving recent stacks.

Bug: 10941423, 10819454, 10964412, 10960718
Change-Id: I08cf589dcda7e203acf67928f4d30322ae36ee94
diff --git a/api/current.txt b/api/current.txt
index fd9c6c2..1ae9ab7 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -20985,7 +20985,6 @@
     field public static final java.lang.String COLUMN_MIME_TYPE = "mime_type";
     field public static final java.lang.String COLUMN_SIZE = "_size";
     field public static final java.lang.String COLUMN_SUMMARY = "summary";
-    field public static final int FLAG_DIR_HIDE_GRID_TITLES = 64; // 0x40
     field public static final int FLAG_DIR_PREFERS_GRID = 16; // 0x10
     field public static final int FLAG_DIR_PREFERS_LAST_MODIFIED = 32; // 0x20
     field public static final int FLAG_DIR_SUPPORTS_CREATE = 8; // 0x8
@@ -21002,18 +21001,12 @@
     field public static final java.lang.String COLUMN_ICON = "icon";
     field public static final java.lang.String COLUMN_MIME_TYPES = "mime_types";
     field public static final java.lang.String COLUMN_ROOT_ID = "root_id";
-    field public static final java.lang.String COLUMN_ROOT_TYPE = "root_type";
     field public static final java.lang.String COLUMN_SUMMARY = "summary";
     field public static final java.lang.String COLUMN_TITLE = "title";
-    field public static final int FLAG_ADVANCED = 4; // 0x4
-    field public static final int FLAG_EMPTY = 32; // 0x20
     field public static final int FLAG_LOCAL_ONLY = 2; // 0x2
     field public static final int FLAG_SUPPORTS_CREATE = 1; // 0x1
-    field public static final int FLAG_SUPPORTS_RECENTS = 8; // 0x8
-    field public static final int FLAG_SUPPORTS_SEARCH = 16; // 0x10
-    field public static final int ROOT_TYPE_DEVICE = 3; // 0x3
-    field public static final int ROOT_TYPE_SERVICE = 1; // 0x1
-    field public static final int ROOT_TYPE_SHORTCUT = 2; // 0x2
+    field public static final int FLAG_SUPPORTS_RECENTS = 4; // 0x4
+    field public static final int FLAG_SUPPORTS_SEARCH = 8; // 0x8
   }
 
   public abstract class DocumentsProvider extends android.content.ContentProvider {
diff --git a/core/java/android/provider/DocumentsContract.java b/core/java/android/provider/DocumentsContract.java
index 4c9af19..85ec803 100644
--- a/core/java/android/provider/DocumentsContract.java
+++ b/core/java/android/provider/DocumentsContract.java
@@ -99,7 +99,7 @@
         /**
          * Unique ID of a document. This ID is both provided by and interpreted
          * by a {@link DocumentsProvider}, and should be treated as an opaque
-         * value by client applications.
+         * value by client applications. This column is required.
          * <p>
          * Each document must have a unique ID within a provider, but that
          * single document may be included as a child of multiple directories.
@@ -117,7 +117,7 @@
          * Concrete MIME type of a document. For example, "image/png" or
          * "application/pdf" for openable files. A document can also be a
          * directory containing additional documents, which is represented with
-         * the {@link #MIME_TYPE_DIR} MIME type.
+         * the {@link #MIME_TYPE_DIR} MIME type. This column is required.
          * <p>
          * Type: STRING
          *
@@ -127,15 +127,15 @@
 
         /**
          * Display name of a document, used as the primary title displayed to a
-         * user.
+         * user. This column is required.
          * <p>
          * Type: STRING
          */
         public static final String COLUMN_DISPLAY_NAME = OpenableColumns.DISPLAY_NAME;
 
         /**
-         * Summary of a document, which may be shown to a user. The summary may
-         * be {@code null}.
+         * Summary of a document, which may be shown to a user. This column is
+         * optional, and may be {@code null}.
          * <p>
          * Type: STRING
          */
@@ -143,9 +143,9 @@
 
         /**
          * Timestamp when a document was last modified, in milliseconds since
-         * January 1, 1970 00:00:00.0 UTC, or {@code null} if unknown. A
-         * {@link DocumentsProvider} can update this field using events from
-         * {@link OnCloseListener} or other reliable
+         * January 1, 1970 00:00:00.0 UTC. This column is required, and may be
+         * {@code null} if unknown. A {@link DocumentsProvider} can update this
+         * field using events from {@link OnCloseListener} or other reliable
          * {@link ParcelFileDescriptor} transports.
          * <p>
          * Type: INTEGER (long)
@@ -155,15 +155,16 @@
         public static final String COLUMN_LAST_MODIFIED = "last_modified";
 
         /**
-         * Specific icon resource ID for a document, or {@code null} to use
-         * platform default icon based on {@link #COLUMN_MIME_TYPE}.
+         * Specific icon resource ID for a document. This column is optional,
+         * and may be {@code null} to use a platform-provided default icon based
+         * on {@link #COLUMN_MIME_TYPE}.
          * <p>
          * Type: INTEGER (int)
          */
         public static final String COLUMN_ICON = "icon";
 
         /**
-         * Flags that apply to a document.
+         * Flags that apply to a document. This column is required.
          * <p>
          * Type: INTEGER (int)
          *
@@ -171,12 +172,13 @@
          * @see #FLAG_SUPPORTS_DELETE
          * @see #FLAG_SUPPORTS_THUMBNAIL
          * @see #FLAG_DIR_PREFERS_GRID
-         * @see #FLAG_DIR_SUPPORTS_CREATE
+         * @see #FLAG_DIR_PREFERS_LAST_MODIFIED
          */
         public static final String COLUMN_FLAGS = "flags";
 
         /**
-         * Size of a document, in bytes, or {@code null} if unknown.
+         * Size of a document, in bytes, or {@code null} if unknown. This column
+         * is required.
          * <p>
          * Type: INTEGER (long)
          */
@@ -211,7 +213,7 @@
          * writability of a document may change over time, for example due to
          * remote access changes. This flag indicates that a document client can
          * expect {@link ContentResolver#openOutputStream(Uri)} to succeed.
-         *
+         * 
          * @see #COLUMN_FLAGS
          */
         public static final int FLAG_SUPPORTS_WRITE = 1 << 1;
@@ -265,8 +267,9 @@
          *
          * @see #COLUMN_FLAGS
          * @see #FLAG_DIR_PREFERS_GRID
+         * @hide
          */
-        public static final int FLAG_DIR_HIDE_GRID_TITLES = 1 << 6;
+        public static final int FLAG_DIR_HIDE_GRID_TITLES = 1 << 16;
     }
 
     /**
@@ -282,31 +285,17 @@
         /**
          * Unique ID of a root. This ID is both provided by and interpreted by a
          * {@link DocumentsProvider}, and should be treated as an opaque value
-         * by client applications.
+         * by client applications. This column is required.
          * <p>
          * Type: STRING
          */
         public static final String COLUMN_ROOT_ID = "root_id";
 
         /**
-         * Type of a root, used for clustering when presenting multiple roots to
-         * a user.
+         * Flags that apply to a root. This column is required.
          * <p>
          * Type: INTEGER (int)
          *
-         * @see #ROOT_TYPE_SERVICE
-         * @see #ROOT_TYPE_SHORTCUT
-         * @see #ROOT_TYPE_DEVICE
-         */
-        public static final String COLUMN_ROOT_TYPE = "root_type";
-
-        /**
-         * Flags that apply to a root.
-         * <p>
-         * Type: INTEGER (int)
-         *
-         * @see #FLAG_ADVANCED
-         * @see #FLAG_EMPTY
          * @see #FLAG_LOCAL_ONLY
          * @see #FLAG_SUPPORTS_CREATE
          * @see #FLAG_SUPPORTS_RECENTS
@@ -315,22 +304,23 @@
         public static final String COLUMN_FLAGS = "flags";
 
         /**
-         * Icon resource ID for a root.
+         * Icon resource ID for a root. This column is required.
          * <p>
          * Type: INTEGER (int)
          */
         public static final String COLUMN_ICON = "icon";
 
         /**
-         * Title for a root, which will be shown to a user.
+         * Title for a root, which will be shown to a user. This column is
+         * required.
          * <p>
          * Type: STRING
          */
         public static final String COLUMN_TITLE = "title";
 
         /**
-         * Summary for this root, which may be shown to a user. The summary may
-         * be {@code null}.
+         * Summary for this root, which may be shown to a user. This column is
+         * optional, and may be {@code null}.
          * <p>
          * Type: STRING
          */
@@ -338,7 +328,7 @@
 
         /**
          * Document which is a directory that represents the top directory of
-         * this root.
+         * this root. This column is required.
          * <p>
          * Type: STRING
          *
@@ -347,20 +337,20 @@
         public static final String COLUMN_DOCUMENT_ID = "document_id";
 
         /**
-         * Number of bytes available in this root, or {@code null} if unknown or
-         * unbounded.
+         * Number of bytes available in this root. This column is optional, and
+         * may be {@code null} if unknown or unbounded.
          * <p>
          * Type: INTEGER (long)
          */
         public static final String COLUMN_AVAILABLE_BYTES = "available_bytes";
 
         /**
-         * MIME types supported by this root, or {@code null} if the root
-         * supports all MIME types. Multiple MIME types can be separated by a
-         * newline. For example, a root supporting audio might use
-         * "audio/*\napplication/x-flac".
+         * MIME types supported by this root. This column is optional, and if
+         * {@code null} the root is assumed to support all MIME types. Multiple
+         * MIME types can be separated by a newline. For example, a root
+         * supporting audio might return "audio/*\napplication/x-flac".
          * <p>
-         * Type: String
+         * Type: STRING
          */
         public static final String COLUMN_MIME_TYPES = "mime_types";
 
@@ -368,29 +358,6 @@
         public static final String MIME_TYPE_ITEM = "vnd.android.document/root";
 
         /**
-         * Type of root that represents a storage service, such as a cloud-based
-         * service.
-         *
-         * @see #COLUMN_ROOT_TYPE
-         */
-        public static final int ROOT_TYPE_SERVICE = 1;
-
-        /**
-         * Type of root that represents a shortcut to content that may be
-         * available elsewhere through another storage root.
-         *
-         * @see #COLUMN_ROOT_TYPE
-         */
-        public static final int ROOT_TYPE_SHORTCUT = 2;
-
-        /**
-         * Type of root that represents a physical storage device.
-         *
-         * @see #COLUMN_ROOT_TYPE
-         */
-        public static final int ROOT_TYPE_DEVICE = 3;
-
-        /**
          * Flag indicating that at least one directory under this root supports
          * creating content. Roots with this flag will be shown when an
          * application interacts with {@link Intent#ACTION_CREATE_DOCUMENT}.
@@ -409,21 +376,13 @@
         public static final int FLAG_LOCAL_ONLY = 1 << 1;
 
         /**
-         * Flag indicating that this root should only be visible to advanced
-         * users.
-         *
-         * @see #COLUMN_FLAGS
-         */
-        public static final int FLAG_ADVANCED = 1 << 2;
-
-        /**
          * Flag indicating that this root can report recently modified
          * documents.
          *
          * @see #COLUMN_FLAGS
          * @see DocumentsContract#buildRecentDocumentsUri(String, String)
          */
-        public static final int FLAG_SUPPORTS_RECENTS = 1 << 3;
+        public static final int FLAG_SUPPORTS_RECENTS = 1 << 2;
 
         /**
          * Flag indicating that this root supports search.
@@ -432,19 +391,31 @@
          * @see DocumentsProvider#querySearchDocuments(String, String,
          *      String[])
          */
-        public static final int FLAG_SUPPORTS_SEARCH = 1 << 4;
+        public static final int FLAG_SUPPORTS_SEARCH = 1 << 3;
 
         /**
          * Flag indicating that this root is currently empty. This may be used
          * to hide the root when opening documents, but the root will still be
          * shown when creating documents and {@link #FLAG_SUPPORTS_CREATE} is
-         * also set.
+         * also set. If the value of this flag changes, such as when a root
+         * becomes non-empty, you must send a content changed notification for
+         * {@link DocumentsContract#buildRootsUri(String)}.
          *
          * @see #COLUMN_FLAGS
-         * @see DocumentsProvider#querySearchDocuments(String, String,
-         *      String[])
+         * @see ContentResolver#notifyChange(Uri,
+         *      android.database.ContentObserver, boolean)
+         * @hide
          */
-        public static final int FLAG_EMPTY = 1 << 5;
+        public static final int FLAG_EMPTY = 1 << 16;
+
+        /**
+         * Flag indicating that this root should only be visible to advanced
+         * users.
+         *
+         * @see #COLUMN_FLAGS
+         * @hide
+         */
+        public static final int FLAG_ADVANCED = 1 << 17;
     }
 
     /**
diff --git a/packages/DocumentsUI/res/drawable-hdpi/ic_dir_shadow.9.png b/packages/DocumentsUI/res/drawable-hdpi/ic_dir_shadow.9.png
index 0240874..904d525 100644
--- a/packages/DocumentsUI/res/drawable-hdpi/ic_dir_shadow.9.png
+++ b/packages/DocumentsUI/res/drawable-hdpi/ic_dir_shadow.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_hairline_divider.9.png b/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_hairline_divider.9.png
new file mode 100644
index 0000000..0d75172
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_hairline_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_tall_divider.9.png b/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_tall_divider.9.png
new file mode 100644
index 0000000..403eddb
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-hdpi/ic_drawer_tall_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-mdpi/ic_dir_shadow.9.png b/packages/DocumentsUI/res/drawable-mdpi/ic_dir_shadow.9.png
index 0240874..068619b 100644
--- a/packages/DocumentsUI/res/drawable-mdpi/ic_dir_shadow.9.png
+++ b/packages/DocumentsUI/res/drawable-mdpi/ic_dir_shadow.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_hairline_divider.9.png b/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_hairline_divider.9.png
new file mode 100644
index 0000000..0d75172
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_hairline_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_tall_divider.9.png b/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_tall_divider.9.png
new file mode 100644
index 0000000..9a9cf5e
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-mdpi/ic_drawer_tall_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xhdpi/ic_dir_shadow.9.png b/packages/DocumentsUI/res/drawable-xhdpi/ic_dir_shadow.9.png
index 0240874..e38a868 100644
--- a/packages/DocumentsUI/res/drawable-xhdpi/ic_dir_shadow.9.png
+++ b/packages/DocumentsUI/res/drawable-xhdpi/ic_dir_shadow.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_hairline_divider.9.png b/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_hairline_divider.9.png
new file mode 100644
index 0000000..0d75172
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_hairline_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_tall_divider.9.png b/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_tall_divider.9.png
new file mode 100644
index 0000000..205c34b
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-xhdpi/ic_drawer_tall_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xxhdpi/ic_dir_shadow.9.png b/packages/DocumentsUI/res/drawable-xxhdpi/ic_dir_shadow.9.png
index 0240874..0b332e4 100644
--- a/packages/DocumentsUI/res/drawable-xxhdpi/ic_dir_shadow.9.png
+++ b/packages/DocumentsUI/res/drawable-xxhdpi/ic_dir_shadow.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_hairline_divider.9.png b/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_hairline_divider.9.png
new file mode 100644
index 0000000..32b5f98
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_hairline_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_tall_divider.9.png b/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_tall_divider.9.png
new file mode 100644
index 0000000..f47d50a
--- /dev/null
+++ b/packages/DocumentsUI/res/drawable-xxhdpi/ic_drawer_tall_divider.9.png
Binary files differ
diff --git a/packages/DocumentsUI/res/layout-sw720dp-land/item_doc_list.xml b/packages/DocumentsUI/res/layout-sw720dp-land/item_doc_list.xml
index 3bea166..851061f 100644
--- a/packages/DocumentsUI/res/layout-sw720dp-land/item_doc_list.xml
+++ b/packages/DocumentsUI/res/layout-sw720dp-land/item_doc_list.xml
@@ -21,17 +21,18 @@
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
-    android:paddingTop="8dip"
-    android:paddingBottom="8dip"
-    android:orientation="horizontal">
+    android:paddingTop="8dp"
+    android:paddingBottom="8dp"
+    android:gravity="center_vertical"
+    android:orientation="horizontal"
+    android:baselineAligned="false">
 
     <FrameLayout
         android:id="@android:id/icon"
         android:layout_width="@dimen/icon_size"
         android:layout_height="@dimen/icon_size"
         android:layout_marginStart="12dp"
-        android:layout_marginEnd="20dp"
-        android:layout_gravity="center_vertical">
+        android:layout_marginEnd="20dp">
 
         <ImageView
             android:id="@+id/icon_mime"
@@ -49,11 +50,11 @@
 
     </FrameLayout>
 
+    <!-- This is the one special case where we want baseline alignment! -->
     <LinearLayout
-        android:layout_width="0dip"
+        android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_weight="1"
-        android:layout_gravity="center_vertical"
         android:orientation="horizontal">
 
         <TextView
diff --git a/packages/DocumentsUI/res/layout-sw720dp/activity.xml b/packages/DocumentsUI/res/layout-sw720dp/activity.xml
index 78735fd..9286277 100644
--- a/packages/DocumentsUI/res/layout-sw720dp/activity.xml
+++ b/packages/DocumentsUI/res/layout-sw720dp/activity.xml
@@ -17,7 +17,8 @@
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="horizontal">
+    android:orientation="horizontal"
+    android:baselineAligned="false">
 
     <FrameLayout
         android:layout_width="wrap_content"
@@ -47,7 +48,7 @@
         <com.android.documentsui.DirectoryContainerView
             android:id="@+id/container_directory"
             android:layout_width="match_parent"
-            android:layout_height="0dip"
+            android:layout_height="0dp"
             android:layout_weight="1" />
 
         <FrameLayout
diff --git a/packages/DocumentsUI/res/layout/activity.xml b/packages/DocumentsUI/res/layout/activity.xml
index 9937c39..2ef7e9c 100644
--- a/packages/DocumentsUI/res/layout/activity.xml
+++ b/packages/DocumentsUI/res/layout/activity.xml
@@ -27,7 +27,7 @@
         <com.android.documentsui.DirectoryContainerView
             android:id="@+id/container_directory"
             android:layout_width="match_parent"
-            android:layout_height="0dip"
+            android:layout_height="0dp"
             android:layout_weight="1" />
 
         <FrameLayout
diff --git a/packages/DocumentsUI/res/layout/fragment_roots.xml b/packages/DocumentsUI/res/layout/fragment_roots.xml
index 09782d9..c3a3da0 100644
--- a/packages/DocumentsUI/res/layout/fragment_roots.xml
+++ b/packages/DocumentsUI/res/layout/fragment_roots.xml
@@ -18,4 +18,4 @@
     android:id="@android:id/list"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:divider="@null" />
+    android:divider="@drawable/ic_drawer_hairline_divider" />
diff --git a/packages/DocumentsUI/res/layout/fragment_save.xml b/packages/DocumentsUI/res/layout/fragment_save.xml
index 570b517..891f0a0 100644
--- a/packages/DocumentsUI/res/layout/fragment_save.xml
+++ b/packages/DocumentsUI/res/layout/fragment_save.xml
@@ -29,6 +29,7 @@
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
+        android:baselineAligned="false"
         android:gravity="center_vertical"
         android:background="#ddd"
         android:minHeight="?android:attr/listPreferredItemHeightSmall">
@@ -44,7 +45,7 @@
 
         <EditText
             android:id="@android:id/title"
-            android:layout_width="0dip"
+            android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:layout_weight="1"
             android:singleLine="true"
diff --git a/packages/DocumentsUI/res/layout/item_doc_grid.xml b/packages/DocumentsUI/res/layout/item_doc_grid.xml
index b745bb9..bb5dce1 100644
--- a/packages/DocumentsUI/res/layout/item_doc_grid.xml
+++ b/packages/DocumentsUI/res/layout/item_doc_grid.xml
@@ -28,37 +28,25 @@
 
         <FrameLayout
             android:layout_width="match_parent"
-            android:layout_height="0dip"
+            android:layout_height="0dp"
             android:layout_weight="1"
             android:layout_marginBottom="6dp"
-            android:background="#fff">
-
-            <FrameLayout
-                android:id="@android:id/icon"
-                android:layout_width="match_parent"
-                android:layout_height="match_parent">
-
-                <ImageView
-                    android:id="@+id/icon_mime"
-                    android:layout_width="match_parent"
-                    android:layout_height="match_parent"
-                    android:scaleType="centerInside"
-                    android:contentDescription="@null" />
-
-                <ImageView
-                    android:id="@+id/icon_thumb"
-                    android:layout_width="match_parent"
-                    android:layout_height="match_parent"
-                    android:scaleType="centerCrop"
-                    android:contentDescription="@null" />
-
-            </FrameLayout>
+            android:background="#fff"
+            android:foreground="@drawable/ic_grid_gradient_bg"
+            android:foregroundGravity="fill">
 
             <ImageView
+                android:id="@+id/icon_mime"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
-                android:scaleType="fitXY"
-                android:src="@drawable/ic_grid_gradient_bg"
+                android:scaleType="centerInside"
+                android:contentDescription="@null" />
+
+            <ImageView
+                android:id="@+id/icon_thumb"
+                android:layout_width="match_parent"
+                android:layout_height="match_parent"
+                android:scaleType="centerCrop"
                 android:contentDescription="@null" />
 
         </FrameLayout>
@@ -67,7 +55,9 @@
             android:id="@+id/line1"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:gravity="center_vertical"
             android:orientation="horizontal"
+            android:baselineAligned="false"
             android:paddingStart="?android:attr/listPreferredItemPaddingStart"
             android:paddingEnd="?android:attr/listPreferredItemPaddingEnd">
 
@@ -85,7 +75,7 @@
                 android:id="@android:id/icon1"
                 android:layout_width="@dimen/root_icon_size"
                 android:layout_height="@dimen/root_icon_size"
-                android:layout_marginStart="8dip"
+                android:layout_marginStart="8dp"
                 android:scaleType="centerInside"
                 android:contentDescription="@null" />
 
@@ -95,16 +85,17 @@
             android:id="@+id/line2"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
+            android:gravity="center_vertical"
             android:orientation="horizontal"
+            android:baselineAligned="false"
             android:paddingStart="?android:attr/listPreferredItemPaddingStart"
             android:paddingEnd="?android:attr/listPreferredItemPaddingEnd">
 
             <TextView
                 android:id="@+id/date"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
-                android:layout_gravity="center_vertical"
-                android:minWidth="80dp"
+                android:layout_weight="0.5"
                 android:singleLine="true"
                 android:ellipsize="marquee"
                 android:textAlignment="viewStart"
@@ -112,26 +103,20 @@
 
             <TextView
                 android:id="@+id/size"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
-                android:layout_gravity="center_vertical"
+                android:layout_weight="0.5"
                 android:layout_marginStart="8dp"
-                android:minWidth="80dp"
                 android:singleLine="true"
                 android:ellipsize="marquee"
                 android:textAlignment="viewStart"
                 style="@style/TextAppearance.Small" />
 
-            <Space
-                android:layout_width="0dp"
-                android:layout_height="0dp"
-                android:layout_weight="1" />
-
             <ImageView
                 android:id="@android:id/icon2"
                 android:layout_width="@dimen/root_icon_size"
                 android:layout_height="@dimen/root_icon_size"
-                android:layout_marginStart="8dip"
+                android:layout_marginStart="8dp"
                 android:scaleType="centerInside"
                 android:contentDescription="@null"
                 android:visibility="gone" />
diff --git a/packages/DocumentsUI/res/layout/item_doc_list.xml b/packages/DocumentsUI/res/layout/item_doc_list.xml
index 84fda9d..4c5b2e3 100644
--- a/packages/DocumentsUI/res/layout/item_doc_list.xml
+++ b/packages/DocumentsUI/res/layout/item_doc_list.xml
@@ -21,17 +21,18 @@
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
-    android:paddingTop="8dip"
-    android:paddingBottom="8dip"
-    android:orientation="horizontal">
+    android:paddingTop="8dp"
+    android:paddingBottom="8dp"
+    android:gravity="center_vertical"
+    android:orientation="horizontal"
+    android:baselineAligned="false">
 
     <FrameLayout
         android:id="@android:id/icon"
         android:layout_width="@dimen/icon_size"
         android:layout_height="@dimen/icon_size"
         android:layout_marginStart="12dp"
-        android:layout_marginEnd="20dp"
-        android:layout_gravity="center_vertical">
+        android:layout_marginEnd="20dp">
 
         <ImageView
             android:id="@+id/icon_mime"
@@ -50,20 +51,20 @@
     </FrameLayout>
 
     <LinearLayout
-        android:layout_width="0dip"
+        android:layout_width="0dp"
         android:layout_height="wrap_content"
         android:layout_weight="1"
-        android:layout_gravity="center_vertical"
         android:orientation="vertical">
 
         <LinearLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:orientation="horizontal">
+            android:orientation="horizontal"
+            android:baselineAligned="false">
 
             <TextView
                 android:id="@android:id/title"
-                android:layout_width="0dip"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
                 android:layout_weight="1"
                 android:singleLine="true"
@@ -75,7 +76,7 @@
                 android:id="@android:id/icon1"
                 android:layout_width="@dimen/root_icon_size"
                 android:layout_height="@dimen/root_icon_size"
-                android:layout_marginStart="8dip"
+                android:layout_marginStart="8dp"
                 android:scaleType="centerInside"
                 android:contentDescription="@null" />
 
@@ -85,13 +86,15 @@
             android:id="@+id/line2"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
-            android:orientation="horizontal">
+            android:gravity="center_vertical"
+            android:orientation="horizontal"
+            android:baselineAligned="false">
 
             <TextView
                 android:id="@+id/date"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
-                android:layout_gravity="center_vertical"
+                android:layout_weight="0.25"
                 android:minWidth="70dp"
                 android:singleLine="true"
                 android:ellipsize="marquee"
@@ -100,11 +103,11 @@
 
             <TextView
                 android:id="@+id/size"
-                android:layout_width="wrap_content"
+                android:layout_width="0dp"
                 android:layout_height="wrap_content"
-                android:layout_gravity="center_vertical"
-                android:minWidth="70dp"
+                android:layout_weight="0.25"
                 android:layout_marginStart="8dp"
+                android:minWidth="70dp"
                 android:singleLine="true"
                 android:ellipsize="marquee"
                 android:textAlignment="viewStart"
@@ -114,8 +117,7 @@
                 android:id="@android:id/summary"
                 android:layout_width="0dp"
                 android:layout_height="wrap_content"
-                android:layout_weight="1"
-                android:layout_gravity="center_vertical"
+                android:layout_weight="0.5"
                 android:layout_marginStart="8dp"
                 android:singleLine="true"
                 android:ellipsize="marquee"
diff --git a/packages/DocumentsUI/res/layout/item_loading_grid.xml b/packages/DocumentsUI/res/layout/item_loading_grid.xml
index 21be137..0bf6137 100644
--- a/packages/DocumentsUI/res/layout/item_loading_grid.xml
+++ b/packages/DocumentsUI/res/layout/item_loading_grid.xml
@@ -20,8 +20,8 @@
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
-    android:paddingTop="8dip"
-    android:paddingBottom="8dip"
+    android:paddingTop="8dp"
+    android:paddingBottom="8dp"
     android:orientation="horizontal">
 
     <ProgressBar
diff --git a/packages/DocumentsUI/res/layout/item_loading_list.xml b/packages/DocumentsUI/res/layout/item_loading_list.xml
index 7da71e3..cdcd01d 100644
--- a/packages/DocumentsUI/res/layout/item_loading_list.xml
+++ b/packages/DocumentsUI/res/layout/item_loading_list.xml
@@ -20,9 +20,8 @@
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
-    android:paddingTop="8dip"
-    android:paddingBottom="8dip"
-    android:orientation="horizontal">
+    android:paddingTop="8dp"
+    android:paddingBottom="8dp">
 
     <ProgressBar
         android:layout_width="wrap_content"
diff --git a/packages/DocumentsUI/res/layout/item_message_list.xml b/packages/DocumentsUI/res/layout/item_message_list.xml
index ffda98c..2bcbc2d 100644
--- a/packages/DocumentsUI/res/layout/item_message_list.xml
+++ b/packages/DocumentsUI/res/layout/item_message_list.xml
@@ -21,15 +21,16 @@
     android:minHeight="?android:attr/listPreferredItemHeight"
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
-    android:paddingTop="8dip"
-    android:paddingBottom="8dip"
-    android:orientation="horizontal">
+    android:paddingTop="8dp"
+    android:paddingBottom="8dp"
+    android:orientation="horizontal"
+    android:baselineAligned="false">
 
     <ImageView
         android:id="@android:id/icon"
         android:layout_width="@android:dimen/app_icon_size"
         android:layout_height="@android:dimen/app_icon_size"
-        android:layout_marginEnd="8dip"
+        android:layout_marginEnd="8dp"
         android:layout_gravity="center_vertical"
         android:scaleType="centerInside"
         android:contentDescription="@null" />
diff --git a/packages/DocumentsUI/res/layout/item_root.xml b/packages/DocumentsUI/res/layout/item_root.xml
index 98d78da..9b52d85 100644
--- a/packages/DocumentsUI/res/layout/item_root.xml
+++ b/packages/DocumentsUI/res/layout/item_root.xml
@@ -22,13 +22,14 @@
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
     android:gravity="center_vertical"
     android:orientation="horizontal"
+    android:baselineAligned="false"
     android:background="@drawable/item_root">
 
     <ImageView
         android:id="@android:id/icon"
         android:layout_width="@dimen/icon_size"
         android:layout_height="@dimen/icon_size"
-        android:layout_marginEnd="8dip"
+        android:layout_marginEnd="8dp"
         android:scaleType="centerInside"
         android:contentDescription="@null" />
 
diff --git a/packages/DocumentsUI/res/layout/item_root_spacer.xml b/packages/DocumentsUI/res/layout/item_root_spacer.xml
new file mode 100644
index 0000000..7d96ac8
--- /dev/null
+++ b/packages/DocumentsUI/res/layout/item_root_spacer.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 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.
+-->
+
+<View xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="@drawable/ic_drawer_tall_divider" />
diff --git a/packages/DocumentsUI/res/layout/item_title.xml b/packages/DocumentsUI/res/layout/item_title.xml
index 7eb100a..58016f1 100644
--- a/packages/DocumentsUI/res/layout/item_title.xml
+++ b/packages/DocumentsUI/res/layout/item_title.xml
@@ -21,7 +21,8 @@
     android:paddingStart="?android:attr/listPreferredItemPaddingStart"
     android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
     android:gravity="center_vertical"
-    android:orientation="horizontal">
+    android:orientation="horizontal"
+    android:baselineAligned="false">
 
     <ImageView
         android:id="@+id/subdir"
diff --git a/packages/DocumentsUI/src/com/android/documentsui/CreateDirectoryFragment.java b/packages/DocumentsUI/src/com/android/documentsui/CreateDirectoryFragment.java
index 9d92cd8..48bfaf0 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/CreateDirectoryFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/CreateDirectoryFragment.java
@@ -25,6 +25,7 @@
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
 import android.net.Uri;
+import android.os.AsyncTask;
 import android.os.Bundle;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
@@ -35,6 +36,8 @@
 
 import com.android.documentsui.model.DocumentInfo;
 
+import java.io.FileNotFoundException;
+
 /**
  * Dialog to create a new directory.
  */
@@ -64,24 +67,45 @@
             @Override
             public void onClick(DialogInterface dialog, int which) {
                 final String displayName = text1.getText().toString();
-
-                final DocumentsActivity activity = (DocumentsActivity) getActivity();
-                final DocumentInfo cwd = activity.getCurrentDirectory();
-
-                try {
-                    final Uri childUri = DocumentsContract.createDocument(
-                            resolver, cwd.derivedUri, Document.MIME_TYPE_DIR, displayName);
-
-                    // Navigate into newly created child
-                    final DocumentInfo childDoc = DocumentInfo.fromUri(resolver, childUri);
-                    activity.onDocumentPicked(childDoc);
-                } catch (Exception e) {
-                    Toast.makeText(context, R.string.create_error, Toast.LENGTH_SHORT).show();
-                }
+                new CreateDirectoryTask(displayName).execute();
             }
         });
         builder.setNegativeButton(android.R.string.cancel, null);
 
         return builder.create();
     }
+
+    private class CreateDirectoryTask extends AsyncTask<Void, Void, DocumentInfo> {
+        private final String mDisplayName;
+
+        public CreateDirectoryTask(String displayName) {
+            mDisplayName = displayName;
+        }
+
+        @Override
+        protected DocumentInfo doInBackground(Void... params) {
+            final DocumentsActivity activity = (DocumentsActivity) getActivity();
+            final ContentResolver resolver = activity.getContentResolver();
+
+            final DocumentInfo cwd = activity.getCurrentDirectory();
+            final Uri childUri = DocumentsContract.createDocument(
+                    resolver, cwd.derivedUri, Document.MIME_TYPE_DIR, mDisplayName);
+            try {
+                return DocumentInfo.fromUri(resolver, childUri);
+            } catch (FileNotFoundException e) {
+                return null;
+            }
+        }
+
+        @Override
+        protected void onPostExecute(DocumentInfo result) {
+            final DocumentsActivity activity = (DocumentsActivity) getActivity();
+            if (result != null) {
+                // Navigate into newly created child
+                activity.onDocumentPicked(result);
+            } else {
+                Toast.makeText(activity, R.string.create_error, Toast.LENGTH_SHORT).show();
+            }
+        }
+    }
 }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java b/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
index c46dfb2..1f11aed 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DirectoryFragment.java
@@ -742,7 +742,6 @@
             final View line1 = convertView.findViewById(R.id.line1);
             final View line2 = convertView.findViewById(R.id.line2);
 
-            final View icon = convertView.findViewById(android.R.id.icon);
             final ImageView iconMime = (ImageView) convertView.findViewById(R.id.icon_mime);
             final ImageView iconThumb = (ImageView) convertView.findViewById(R.id.icon_thumb);
             final TextView title = (TextView) convertView.findViewById(android.R.id.title);
@@ -786,10 +785,12 @@
             // loaded in background.
             if (cacheHit) {
                 iconMime.setAlpha(0f);
+                iconMime.setImageDrawable(null);
                 iconThumb.setAlpha(1f);
             } else {
                 iconMime.setAlpha(1f);
                 iconThumb.setAlpha(0f);
+                iconThumb.setImageDrawable(null);
                 if (docIcon != 0) {
                     iconMime.setImageDrawable(
                             IconUtils.loadPackageIcon(context, docAuthority, docIcon));
@@ -895,12 +896,14 @@
             final boolean enabled = isDocumentEnabled(docMimeType, docFlags);
             if (enabled) {
                 setEnabledRecursive(convertView, true);
-                icon.setAlpha(1f);
+                iconMime.setAlpha(1f);
+                iconThumb.setAlpha(1f);
                 if (icon1 != null) icon1.setAlpha(1f);
                 if (icon2 != null) icon2.setAlpha(1f);
             } else {
                 setEnabledRecursive(convertView, false);
-                icon.setAlpha(0.5f);
+                iconMime.setAlpha(0.5f);
+                iconThumb.setAlpha(0.5f);
                 if (icon1 != null) icon1.setAlpha(0.5f);
                 if (icon2 != null) icon2.setAlpha(0.5f);
             }
@@ -991,10 +994,11 @@
                 mIconThumb.setTag(null);
                 mIconThumb.setImageBitmap(result);
 
-                mIconMime.setAlpha(1f);
+                final float targetAlpha = mIconMime.isEnabled() ? 1f : 0.5f;
+                mIconMime.setAlpha(targetAlpha);
                 mIconMime.animate().alpha(0f).start();
                 mIconThumb.setAlpha(0f);
-                mIconThumb.animate().alpha(1f).start();
+                mIconThumb.animate().alpha(targetAlpha).start();
             }
         }
     }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DirectoryLoader.java b/packages/DocumentsUI/src/com/android/documentsui/DirectoryLoader.java
index 8627ecf..0b3ecf8 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DirectoryLoader.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DirectoryLoader.java
@@ -63,6 +63,9 @@
 }
 
 public class DirectoryLoader extends AsyncTaskLoader<DirectoryResult> {
+
+    private static final String[] SEARCH_REJECT_MIMES = new String[] { Document.MIME_TYPE_DIR };
+
     private final ForceLoadContentObserver mObserver = new ForceLoadContentObserver();
 
     private final int mType;
@@ -164,8 +167,7 @@
 
             if (mType == DirectoryFragment.TYPE_SEARCH) {
                 // Filter directories out of search results, for now
-                cursor = new FilteringCursorWrapper(cursor, null, new String[] {
-                        Document.MIME_TYPE_DIR });
+                cursor = new FilteringCursorWrapper(cursor, null, SEARCH_REJECT_MIMES);
             } else {
                 // Normal directories should have sorting applied
                 cursor = new SortingCursorWrapper(cursor, result.sortOrder);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
index 72fdc57..4caec8f 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/DocumentsActivity.java
@@ -854,14 +854,7 @@
         mState.stackTouched = true;
 
         if (!mRoots.isRecentsRoot(root)) {
-            try {
-                final Uri uri = DocumentsContract.buildDocumentUri(root.authority, root.documentId);
-                final DocumentInfo doc = DocumentInfo.fromUri(getContentResolver(), uri);
-                mState.stack.push(doc);
-                mState.stackTouched = true;
-                onCurrentDirectoryChanged(ANIM_SIDE);
-            } catch (FileNotFoundException e) {
-            }
+            new PickRootTask(root).execute();
         } else {
             onCurrentDirectoryChanged(ANIM_SIDE);
         }
@@ -871,6 +864,34 @@
         }
     }
 
+    private class PickRootTask extends AsyncTask<Void, Void, DocumentInfo> {
+        private RootInfo mRoot;
+
+        public PickRootTask(RootInfo root) {
+            mRoot = root;
+        }
+
+        @Override
+        protected DocumentInfo doInBackground(Void... params) {
+            try {
+                final Uri uri = DocumentsContract.buildDocumentUri(
+                        mRoot.authority, mRoot.documentId);
+                return DocumentInfo.fromUri(getContentResolver(), uri);
+            } catch (FileNotFoundException e) {
+                return null;
+            }
+        }
+
+        @Override
+        protected void onPostExecute(DocumentInfo result) {
+            if (result != null) {
+                mState.stack.push(result);
+                mState.stackTouched = true;
+                onCurrentDirectoryChanged(ANIM_SIDE);
+            }
+        }
+    }
+
     public void onAppPicked(ResolveInfo info) {
         final Intent intent = new Intent(getIntent());
         intent.setFlags(intent.getFlags() & ~Intent.FLAG_ACTIVITY_FORWARD_RESULT);
@@ -909,7 +930,7 @@
             onCurrentDirectoryChanged(ANIM_DOWN);
         } else if (mState.action == ACTION_OPEN || mState.action == ACTION_GET_CONTENT) {
             // Explicit file picked, return
-            onFinished(doc.derivedUri);
+            new ExistingFinishTask(doc.derivedUri).execute();
         } else if (mState.action == ACTION_CREATE) {
             // Replace selected file
             SaveFragment.get(fm).setReplaceTarget(doc);
@@ -943,29 +964,19 @@
             for (int i = 0; i < size; i++) {
                 uris[i] = docs.get(i).derivedUri;
             }
-            onFinished(uris);
+            new ExistingFinishTask(uris).execute();
         }
     }
 
     public void onSaveRequested(DocumentInfo replaceTarget) {
-        onFinished(replaceTarget.derivedUri);
+        new ExistingFinishTask(replaceTarget.derivedUri).execute();
     }
 
     public void onSaveRequested(String mimeType, String displayName) {
-        final DocumentInfo cwd = getCurrentDirectory();
-
-        final Uri childUri = DocumentsContract.createDocument(
-                getContentResolver(), cwd.derivedUri, mimeType, displayName);
-        if (childUri != null) {
-            onFinished(childUri);
-        } else {
-            Toast.makeText(this, R.string.save_error, Toast.LENGTH_SHORT).show();
-        }
+        new CreateFinishTask(mimeType, displayName).execute();
     }
 
-    private void onFinished(Uri... uris) {
-        Log.d(TAG, "onFinished() " + Arrays.toString(uris));
-
+    private void saveStackBlocking() {
         final ContentResolver resolver = getContentResolver();
         final ContentValues values = new ContentValues();
 
@@ -973,6 +984,7 @@
         if (mState.action == ACTION_CREATE) {
             // Remember stack for last create
             values.clear();
+            values.put(RecentColumns.KEY, mState.stack.buildKey());
             values.put(RecentColumns.STACK, rawStack);
             resolver.insert(RecentsProvider.buildRecent(), values);
         }
@@ -983,6 +995,10 @@
         values.put(ResumeColumns.STACK, rawStack);
         values.put(ResumeColumns.EXTERNAL, 0);
         resolver.insert(RecentsProvider.buildResume(packageName), values);
+    }
+
+    private void onFinished(Uri... uris) {
+        Log.d(TAG, "onFinished() " + Arrays.toString(uris));
 
         final Intent intent = new Intent();
         if (uris.length == 1) {
@@ -1008,6 +1024,56 @@
         finish();
     }
 
+    private class CreateFinishTask extends AsyncTask<Void, Void, Uri> {
+        private final String mMimeType;
+        private final String mDisplayName;
+
+        public CreateFinishTask(String mimeType, String displayName) {
+            mMimeType = mimeType;
+            mDisplayName = displayName;
+        }
+
+        @Override
+        protected Uri doInBackground(Void... params) {
+            final DocumentInfo cwd = getCurrentDirectory();
+            final Uri childUri = DocumentsContract.createDocument(
+                    getContentResolver(), cwd.derivedUri, mMimeType, mDisplayName);
+            if (childUri != null) {
+                saveStackBlocking();
+            }
+            return childUri;
+        }
+
+        @Override
+        protected void onPostExecute(Uri result) {
+            if (result != null) {
+                onFinished(result);
+            } else {
+                Toast.makeText(DocumentsActivity.this, R.string.save_error, Toast.LENGTH_SHORT)
+                        .show();
+            }
+        }
+    }
+
+    private class ExistingFinishTask extends AsyncTask<Void, Void, Void> {
+        private final Uri[] mUris;
+
+        public ExistingFinishTask(Uri... uris) {
+            mUris = uris;
+        }
+
+        @Override
+        protected Void doInBackground(Void... params) {
+            saveStackBlocking();
+            return null;
+        }
+
+        @Override
+        protected void onPostExecute(Void result) {
+            onFinished(mUris);
+        }
+    }
+
     public static class State implements android.os.Parcelable {
         public int action;
         public String[] acceptMimes;
diff --git a/packages/DocumentsUI/src/com/android/documentsui/FilteringCursorWrapper.java b/packages/DocumentsUI/src/com/android/documentsui/FilteringCursorWrapper.java
index 5f56963..52d816f 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/FilteringCursorWrapper.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/FilteringCursorWrapper.java
@@ -34,10 +34,15 @@
     private int mCount;
 
     public FilteringCursorWrapper(Cursor cursor, String[] acceptMimes) {
-        this(cursor, acceptMimes, null);
+        this(cursor, acceptMimes, null, Long.MIN_VALUE);
     }
 
     public FilteringCursorWrapper(Cursor cursor, String[] acceptMimes, String[] rejectMimes) {
+        this(cursor, acceptMimes, rejectMimes, Long.MIN_VALUE);
+    }
+
+    public FilteringCursorWrapper(
+            Cursor cursor, String[] acceptMimes, String[] rejectMimes, long rejectBefore) {
         mCursor = cursor;
 
         final int count = cursor.getCount();
@@ -47,9 +52,14 @@
         while (cursor.moveToNext()) {
             final String mimeType = cursor.getString(
                     cursor.getColumnIndex(Document.COLUMN_MIME_TYPE));
+            final long lastModified = cursor.getLong(
+                    cursor.getColumnIndex(Document.COLUMN_LAST_MODIFIED));
             if (rejectMimes != null && MimePredicate.mimeMatches(rejectMimes, mimeType)) {
                 continue;
             }
+            if (lastModified < rejectBefore) {
+                continue;
+            }
             if (MimePredicate.mimeMatches(acceptMimes, mimeType)) {
                 mPosition[mCount++] = cursor.getPosition();
             }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RecentLoader.java b/packages/DocumentsUI/src/com/android/documentsui/RecentLoader.java
index e390456..9a4fb7d 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RecentLoader.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RecentLoader.java
@@ -26,9 +26,11 @@
 import android.database.Cursor;
 import android.database.MergeCursor;
 import android.net.Uri;
+import android.os.Bundle;
 import android.provider.DocumentsContract;
 import android.provider.DocumentsContract.Document;
 import android.provider.DocumentsContract.Root;
+import android.text.format.DateUtils;
 import android.util.Log;
 
 import com.android.documentsui.DocumentsActivity.State;
@@ -54,17 +56,23 @@
 public class RecentLoader extends AsyncTaskLoader<DirectoryResult> {
     private static final boolean LOGD = true;
 
-    public static final int MAX_OUTSTANDING_RECENTS = 2;
+    // TODO: adjust for svelte devices
+    // TODO: add support for oneway queries to avoid wedging loader
+    private static final int MAX_OUTSTANDING_RECENTS = 2;
 
     /**
      * Time to wait for first pass to complete before returning partial results.
      */
-    public static final int MAX_FIRST_PASS_WAIT_MILLIS = 500;
+    private static final int MAX_FIRST_PASS_WAIT_MILLIS = 500;
 
-    /**
-     * Maximum documents from a single root.
-     */
-    public static final int MAX_DOCS_FROM_ROOT = 64;
+    /** Maximum documents from a single root. */
+    private static final int MAX_DOCS_FROM_ROOT = 64;
+
+    /** Ignore documents older than this age. */
+    private static final long REJECT_OLDER_THAN = 45 * DateUtils.DAY_IN_MILLIS;
+
+    /** MIME types that should always be excluded from recents. */
+    private static final String[] RECENT_REJECT_MIMES = new String[] { Document.MIME_TYPE_DIR };
 
     private static final ExecutorService sExecutor = buildExecutor();
 
@@ -173,6 +181,8 @@
             }
         }
 
+        final long rejectBefore = System.currentTimeMillis() - REJECT_OLDER_THAN;
+
         // Collect all finished tasks
         List<Cursor> cursors = Lists.newArrayList();
         for (RecentTask task : mTasks.values()) {
@@ -180,7 +190,7 @@
                 try {
                     final Cursor cursor = task.get();
                     final FilteringCursorWrapper filtered = new FilteringCursorWrapper(
-                            cursor, mState.acceptMimes, new String[] { Document.MIME_TYPE_DIR }) {
+                            cursor, mState.acceptMimes, RECENT_REJECT_MIMES, rejectBefore) {
                         @Override
                         public void close() {
                             // Ignored, since we manage cursor lifecycle internally
@@ -203,11 +213,22 @@
         final DirectoryResult result = new DirectoryResult();
         result.sortOrder = SORT_ORDER_LAST_MODIFIED;
 
-        if (cursors.size() > 0) {
-            final MergeCursor merged = new MergeCursor(cursors.toArray(new Cursor[cursors.size()]));
-            final SortingCursorWrapper sorted = new SortingCursorWrapper(merged, result.sortOrder);
-            result.cursor = sorted;
+        // Hint to UI if we're still loading
+        final Bundle extras = new Bundle();
+        if (cursors.size() != mTasks.size()) {
+            extras.putBoolean(DocumentsContract.EXTRA_LOADING, true);
         }
+
+        final MergeCursor merged = new MergeCursor(cursors.toArray(new Cursor[cursors.size()]));
+        final SortingCursorWrapper sorted = new SortingCursorWrapper(merged, result.sortOrder) {
+            @Override
+            public Bundle getExtras() {
+                return extras;
+            }
+        };
+
+        result.cursor = sorted;
+
         return result;
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RecentsCreateFragment.java b/packages/DocumentsUI/src/com/android/documentsui/RecentsCreateFragment.java
index c975382..3954173 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RecentsCreateFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RecentsCreateFragment.java
@@ -66,6 +66,7 @@
  */
 public class RecentsCreateFragment extends Fragment {
 
+    private View mEmptyView;
     private ListView mListView;
 
     private DocumentStackAdapter mAdapter;
@@ -87,6 +88,8 @@
 
         final View view = inflater.inflate(R.layout.fragment_directory, container, false);
 
+        mEmptyView = view.findViewById(android.R.id.empty);
+
         mListView = (ListView) view.findViewById(R.id.list);
         mListView.setOnItemClickListener(mItemListener);
 
@@ -189,6 +192,13 @@
 
         public void swapStacks(List<DocumentStack> stacks) {
             mStacks = stacks;
+
+            if (isEmpty()) {
+                mEmptyView.setVisibility(View.VISIBLE);
+            } else {
+                mEmptyView.setVisibility(View.GONE);
+            }
+
             notifyDataSetChanged();
         }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RecentsProvider.java b/packages/DocumentsUI/src/com/android/documentsui/RecentsProvider.java
index 7386cae..4313fa7 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RecentsProvider.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RecentsProvider.java
@@ -33,7 +33,7 @@
 public class RecentsProvider extends ContentProvider {
     private static final String TAG = "RecentsProvider";
 
-    public static final long MAX_HISTORY_IN_MILLIS = DateUtils.DAY_IN_MILLIS * 45;
+    public static final long MAX_HISTORY_IN_MILLIS = 45 * DateUtils.DAY_IN_MILLIS;
 
     private static final String AUTHORITY = "com.android.documentsui.recents";
 
@@ -56,6 +56,7 @@
     public static final String TABLE_RESUME = "resume";
 
     public static class RecentColumns {
+        public static final String KEY = "key";
         public static final String STACK = "stack";
         public static final String TIMESTAMP = "timestamp";
     }
@@ -99,16 +100,18 @@
         private static final int VERSION_INIT = 1;
         private static final int VERSION_AS_BLOB = 3;
         private static final int VERSION_ADD_EXTERNAL = 4;
+        private static final int VERSION_ADD_RECENT_KEY = 5;
 
         public DatabaseHelper(Context context) {
-            super(context, DB_NAME, null, VERSION_ADD_EXTERNAL);
+            super(context, DB_NAME, null, VERSION_ADD_RECENT_KEY);
         }
 
         @Override
         public void onCreate(SQLiteDatabase db) {
 
             db.execSQL("CREATE TABLE " + TABLE_RECENT + " (" +
-                    RecentColumns.STACK + " BLOB PRIMARY KEY ON CONFLICT REPLACE," +
+                    RecentColumns.KEY + " TEXT PRIMARY KEY ON CONFLICT REPLACE," +
+                    RecentColumns.STACK + " BLOB DEFAULT NULL," +
                     RecentColumns.TIMESTAMP + " INTEGER" +
                     ")");
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java b/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
index 15af8aa..e3908e9 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RootsCache.java
@@ -99,7 +99,8 @@
      */
     public void updateAsync() {
         // Special root for recents
-        mRecentsRoot.rootType = Root.ROOT_TYPE_SHORTCUT;
+        mRecentsRoot.authority = null;
+        mRecentsRoot.rootId = null;
         mRecentsRoot.icon = R.drawable.ic_root_recent;
         mRecentsRoot.flags = Root.FLAG_LOCAL_ONLY | Root.FLAG_SUPPORTS_CREATE;
         mRecentsRoot.title = mContext.getString(R.string.root_recent);
diff --git a/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java b/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
index d602622..2fb12bb 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/RootsFragment.java
@@ -26,7 +26,6 @@
 import android.content.pm.PackageManager;
 import android.content.pm.ResolveInfo;
 import android.os.Bundle;
-import android.provider.DocumentsContract.Root;
 import android.text.TextUtils;
 import android.text.format.Formatter;
 import android.view.LayoutInflater;
@@ -37,16 +36,16 @@
 import android.widget.ArrayAdapter;
 import android.widget.ImageView;
 import android.widget.ListView;
-import android.widget.Space;
 import android.widget.TextView;
 
 import com.android.documentsui.DocumentsActivity.State;
-import com.android.documentsui.SectionedListAdapter.SectionAdapter;
 import com.android.documentsui.model.DocumentInfo;
 import com.android.documentsui.model.RootInfo;
 import com.android.internal.util.Objects;
+import com.google.common.collect.Lists;
 
 import java.util.Collection;
+import java.util.Collections;
 import java.util.Comparator;
 import java.util.List;
 
@@ -56,7 +55,7 @@
 public class RootsFragment extends Fragment {
 
     private ListView mList;
-    private SectionedRootsAdapter mAdapter;
+    private RootsAdapter mAdapter;
 
     private LoaderCallbacks<Collection<RootInfo>> mCallbacks;
 
@@ -112,7 +111,7 @@
 
                 final Intent includeApps = getArguments().getParcelable(EXTRA_INCLUDE_APPS);
 
-                mAdapter = new SectionedRootsAdapter(context, result, includeApps);
+                mAdapter = new RootsAdapter(context, result, includeApps);
                 mList.setAdapter(mAdapter);
 
                 onCurrentRootChanged();
@@ -154,136 +153,148 @@
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
             final DocumentsActivity activity = DocumentsActivity.get(RootsFragment.this);
-            final Object item = mAdapter.getItem(position);
-            if (item instanceof RootInfo) {
-                activity.onRootPicked((RootInfo) item, true);
-            } else if (item instanceof ResolveInfo) {
-                activity.onAppPicked((ResolveInfo) item);
+            final Item item = mAdapter.getItem(position);
+            if (item instanceof RootItem) {
+                activity.onRootPicked(((RootItem) item).root, true);
+            } else if (item instanceof AppItem) {
+                activity.onAppPicked(((AppItem) item).info);
             } else {
                 throw new IllegalStateException("Unknown root: " + item);
             }
         }
     };
 
-    private static class RootsAdapter extends ArrayAdapter<RootInfo> implements SectionAdapter {
-        public RootsAdapter(Context context) {
-            super(context, 0);
+    private static abstract class Item {
+        private final int mLayoutId;
+
+        public Item(int layoutId) {
+            mLayoutId = layoutId;
+        }
+
+        public View getView(View convertView, ViewGroup parent) {
+            if (convertView == null) {
+                convertView = LayoutInflater.from(parent.getContext())
+                        .inflate(mLayoutId, parent, false);
+            }
+            bindView(convertView);
+            return convertView;
+        }
+
+        public abstract void bindView(View convertView);
+    }
+
+    private static class RootItem extends Item {
+        public final RootInfo root;
+
+        public RootItem(RootInfo root) {
+            super(R.layout.item_root);
+            this.root = root;
         }
 
         @Override
-        public View getView(int position, View convertView, ViewGroup parent) {
-            final Context context = parent.getContext();
-            if (convertView == null) {
-                convertView = LayoutInflater.from(context)
-                        .inflate(R.layout.item_root, parent, false);
-            }
-
+        public void bindView(View convertView) {
             final ImageView icon = (ImageView) convertView.findViewById(android.R.id.icon);
             final TextView title = (TextView) convertView.findViewById(android.R.id.title);
             final TextView summary = (TextView) convertView.findViewById(android.R.id.summary);
 
-            final RootInfo root = getItem(position);
+            final Context context = convertView.getContext();
             icon.setImageDrawable(root.loadIcon(context));
             title.setText(root.title);
 
-            // Device summary is always available space
-            final String summaryText;
-            if (root.rootType == Root.ROOT_TYPE_DEVICE && root.availableBytes >= 0) {
+            // Show available space if no summary
+            String summaryText = root.summary;
+            if (TextUtils.isEmpty(summaryText) && root.availableBytes >= 0) {
                 summaryText = context.getString(R.string.root_available_bytes,
                         Formatter.formatFileSize(context, root.availableBytes));
-            } else {
-                summaryText = root.summary;
             }
 
             summary.setText(summaryText);
             summary.setVisibility(TextUtils.isEmpty(summaryText) ? View.GONE : View.VISIBLE);
-
-            return convertView;
-        }
-
-        @Override
-        public View getHeaderView(View convertView, ViewGroup parent) {
-            if (convertView == null) {
-                convertView = new Space(parent.getContext());
-            }
-            return convertView;
         }
     }
 
-    private static class AppsAdapter extends ArrayAdapter<ResolveInfo> implements SectionAdapter {
-        public AppsAdapter(Context context) {
-            super(context, 0);
+    private static class SpacerItem extends Item {
+        public SpacerItem() {
+            super(R.layout.item_root_spacer);
         }
 
         @Override
-        public View getView(int position, View convertView, ViewGroup parent) {
-            final Context context = parent.getContext();
-            final PackageManager pm = context.getPackageManager();
-            if (convertView == null) {
-                convertView = LayoutInflater.from(context)
-                        .inflate(R.layout.item_root, parent, false);
-            }
+        public void bindView(View convertView) {
+            // Nothing to bind
+        }
+    }
 
+    private static class AppItem extends Item {
+        public final ResolveInfo info;
+
+        public AppItem(ResolveInfo info) {
+            super(R.layout.item_root);
+            this.info = info;
+        }
+
+        @Override
+        public void bindView(View convertView) {
             final ImageView icon = (ImageView) convertView.findViewById(android.R.id.icon);
             final TextView title = (TextView) convertView.findViewById(android.R.id.title);
             final TextView summary = (TextView) convertView.findViewById(android.R.id.summary);
 
-            final ResolveInfo info = getItem(position);
+            final PackageManager pm = convertView.getContext().getPackageManager();
             icon.setImageDrawable(info.loadIcon(pm));
             title.setText(info.loadLabel(pm));
 
             // TODO: match existing summary behavior from disambig dialog
             summary.setVisibility(View.GONE);
-
-            return convertView;
-        }
-
-        @Override
-        public View getHeaderView(View convertView, ViewGroup parent) {
-            if (convertView == null) {
-                convertView = LayoutInflater.from(parent.getContext())
-                        .inflate(R.layout.item_root_header, parent, false);
-            }
-
-            final TextView title = (TextView) convertView.findViewById(android.R.id.title);
-            title.setText(R.string.root_type_apps);
-
-            return convertView;
         }
     }
 
-    private static class SectionedRootsAdapter extends SectionedListAdapter {
-        private final RootsAdapter mRecent;
-        private final RootsAdapter mServices;
-        private final RootsAdapter mShortcuts;
-        private final RootsAdapter mDevices;
-        private final AppsAdapter mApps;
+    private static class RootsAdapter extends ArrayAdapter<Item> {
+        public RootsAdapter(Context context, Collection<RootInfo> roots, Intent includeApps) {
+            super(context, 0);
 
-        public SectionedRootsAdapter(
-                Context context, Collection<RootInfo> roots, Intent includeApps) {
-            mRecent = new RootsAdapter(context);
-            mServices = new RootsAdapter(context);
-            mShortcuts = new RootsAdapter(context);
-            mDevices = new RootsAdapter(context);
-            mApps = new AppsAdapter(context);
+            RootItem recents = null;
+            RootItem images = null;
+            RootItem videos = null;
+            RootItem audio = null;
+            RootItem downloads = null;
+
+            final List<RootInfo> clouds = Lists.newArrayList();
+            final List<RootInfo> locals = Lists.newArrayList();
 
             for (RootInfo root : roots) {
-                if (root.authority == null) {
-                    mRecent.add(root);
-                    continue;
+                if (root.isRecents()) {
+                    recents = new RootItem(root);
+                } else if (root.isExternalStorage()) {
+                    locals.add(root);
+                } else if (root.isDownloads()) {
+                    downloads = new RootItem(root);
+                } else if (root.isImages()) {
+                    images = new RootItem(root);
+                } else if (root.isVideos()) {
+                    videos = new RootItem(root);
+                } else if (root.isAudio()) {
+                    audio = new RootItem(root);
+                } else {
+                    clouds.add(root);
                 }
+            }
 
-                switch (root.rootType) {
-                    case Root.ROOT_TYPE_SERVICE:
-                        mServices.add(root);
-                        break;
-                    case Root.ROOT_TYPE_SHORTCUT:
-                        mShortcuts.add(root);
-                        break;
-                    case Root.ROOT_TYPE_DEVICE:
-                        mDevices.add(root);
-                        break;
-                }
+            final RootComparator comp = new RootComparator();
+            Collections.sort(clouds, comp);
+            Collections.sort(locals, comp);
+
+            if (recents != null) add(recents);
+
+            for (RootInfo cloud : clouds) {
+                add(new RootItem(cloud));
+            }
+
+            if (images != null) add(images);
+            if (videos != null) add(videos);
+            if (audio != null) add(audio);
+            if (downloads != null) add(downloads);
+
+            for (RootInfo local : locals) {
+                add(new RootItem(local));
             }
 
             if (includeApps != null) {
@@ -291,34 +302,53 @@
                 final List<ResolveInfo> infos = pm.queryIntentActivities(
                         includeApps, PackageManager.MATCH_DEFAULT_ONLY);
 
+                final List<AppItem> apps = Lists.newArrayList();
+
                 // Omit ourselves from the list
                 for (ResolveInfo info : infos) {
                     if (!context.getPackageName().equals(info.activityInfo.packageName)) {
-                        mApps.add(info);
+                        apps.add(new AppItem(info));
+                    }
+                }
+
+                if (apps.size() > 0) {
+                    add(new SpacerItem());
+                    for (Item item : apps) {
+                        add(item);
                     }
                 }
             }
+        }
 
-            final RootComparator comp = new RootComparator();
-            mServices.sort(comp);
-            mShortcuts.sort(comp);
-            mDevices.sort(comp);
+        @Override
+        public View getView(int position, View convertView, ViewGroup parent) {
+            final Item item = getItem(position);
+            return item.getView(convertView, parent);
+        }
 
-            if (mRecent.getCount() > 0) {
-                addSection(mRecent);
+        @Override
+        public boolean areAllItemsEnabled() {
+            return false;
+        }
+
+        @Override
+        public boolean isEnabled(int position) {
+            return getItemViewType(position) != 1;
+        }
+
+        @Override
+        public int getItemViewType(int position) {
+            final Item item = getItem(position);
+            if (item instanceof RootItem || item instanceof AppItem) {
+                return 0;
+            } else {
+                return 1;
             }
-            if (mServices.getCount() > 0) {
-                addSection(mServices);
-            }
-            if (mShortcuts.getCount() > 0) {
-                addSection(mShortcuts);
-            }
-            if (mDevices.getCount() > 0) {
-                addSection(mDevices);
-            }
-            if (mApps.getCount() > 0) {
-                addSection(mApps);
-            }
+        }
+
+        @Override
+        public int getViewTypeCount() {
+            return 2;
         }
     }
 
diff --git a/packages/DocumentsUI/src/com/android/documentsui/TestActivity.java b/packages/DocumentsUI/src/com/android/documentsui/TestActivity.java
index 57fc7e4..1a47308 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/TestActivity.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/TestActivity.java
@@ -213,8 +213,13 @@
                 if (DocumentsContract.isDocumentUri(this, uri)) {
                     result += "; DOC_ID";
                 }
-                getContentResolver()
-                        .takePersistableUriPermission(uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
+                try {
+                    getContentResolver().takePersistableUriPermission(
+                            uri, Intent.FLAG_GRANT_READ_URI_PERMISSION);
+                } catch (SecurityException e) {
+                    result += "; FAILED TO TAKE";
+                    Log.e(TAG, "Failed to take", e);
+                }
                 InputStream is = null;
                 try {
                     is = getContentResolver().openInputStream(uri);
@@ -222,7 +227,7 @@
                     result += "; read length=" + length;
                 } catch (Exception e) {
                     result += "; ERROR";
-                    Log.w(TAG, "Failed to read " + uri, e);
+                    Log.e(TAG, "Failed to read " + uri, e);
                 } finally {
                     IoUtils.closeQuietly(is);
                 }
@@ -235,15 +240,20 @@
                 if (DocumentsContract.isDocumentUri(this, uri)) {
                     result += "; DOC_ID";
                 }
-                getContentResolver()
-                        .takePersistableUriPermission(uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
+                try {
+                    getContentResolver().takePersistableUriPermission(
+                            uri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
+                } catch (SecurityException e) {
+                    result += "; FAILED TO TAKE";
+                    Log.e(TAG, "Failed to take", e);
+                }
                 OutputStream os = null;
                 try {
                     os = getContentResolver().openOutputStream(uri);
                     os.write("THE COMPLETE WORKS OF SHAKESPEARE".getBytes());
                 } catch (Exception e) {
                     result += "; ERROR";
-                    Log.w(TAG, "Failed to write " + uri, e);
+                    Log.e(TAG, "Failed to write " + uri, e);
                 } finally {
                     IoUtils.closeQuietly(os);
                 }
diff --git a/packages/DocumentsUI/src/com/android/documentsui/model/DocumentStack.java b/packages/DocumentsUI/src/com/android/documentsui/model/DocumentStack.java
index 0a378c0..28bab6c 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/model/DocumentStack.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/model/DocumentStack.java
@@ -71,6 +71,25 @@
         }
     }
 
+    /**
+     * Build key that uniquely identifies this stack. It omits most of the raw
+     * details included in {@link #write(DataOutputStream)}, since they change
+     * too regularly to be used as a key.
+     */
+    public String buildKey() {
+        final StringBuilder builder = new StringBuilder();
+        if (root != null) {
+            builder.append(root.authority).append('#');
+            builder.append(root.rootId).append('#');
+        } else {
+            builder.append("[null]").append('#');
+        }
+        for (DocumentInfo doc : this) {
+            builder.append(doc.documentId).append('#');
+        }
+        return builder.toString();
+    }
+
     @Override
     public void reset() {
         clear();
diff --git a/packages/DocumentsUI/src/com/android/documentsui/model/RootInfo.java b/packages/DocumentsUI/src/com/android/documentsui/model/RootInfo.java
index 014901a..e220c9e 100644
--- a/packages/DocumentsUI/src/com/android/documentsui/model/RootInfo.java
+++ b/packages/DocumentsUI/src/com/android/documentsui/model/RootInfo.java
@@ -42,10 +42,10 @@
  */
 public class RootInfo implements Durable, Parcelable {
     private static final int VERSION_INIT = 1;
+    private static final int VERSION_DROP_TYPE = 2;
 
     public String authority;
     public String rootId;
-    public int rootType;
     public int flags;
     public int icon;
     public String title;
@@ -67,7 +67,6 @@
     public void reset() {
         authority = null;
         rootId = null;
-        rootType = 0;
         flags = 0;
         icon = 0;
         title = null;
@@ -85,10 +84,9 @@
     public void read(DataInputStream in) throws IOException {
         final int version = in.readInt();
         switch (version) {
-            case VERSION_INIT:
+            case VERSION_DROP_TYPE:
                 authority = DurableUtils.readNullableString(in);
                 rootId = DurableUtils.readNullableString(in);
-                rootType = in.readInt();
                 flags = in.readInt();
                 icon = in.readInt();
                 title = DurableUtils.readNullableString(in);
@@ -105,10 +103,9 @@
 
     @Override
     public void write(DataOutputStream out) throws IOException {
-        out.writeInt(VERSION_INIT);
+        out.writeInt(VERSION_DROP_TYPE);
         DurableUtils.writeNullableString(out, authority);
         DurableUtils.writeNullableString(out, rootId);
-        out.writeInt(rootType);
         out.writeInt(flags);
         out.writeInt(icon);
         DurableUtils.writeNullableString(out, title);
@@ -146,7 +143,6 @@
         final RootInfo root = new RootInfo();
         root.authority = authority;
         root.rootId = getCursorString(cursor, Root.COLUMN_ROOT_ID);
-        root.rootType = getCursorInt(cursor, Root.COLUMN_ROOT_TYPE);
         root.flags = getCursorInt(cursor, Root.COLUMN_FLAGS);
         root.icon = getCursorInt(cursor, Root.COLUMN_ICON);
         root.title = getCursorString(cursor, Root.COLUMN_TITLE);
@@ -162,25 +158,44 @@
         derivedMimeTypes = (mimeTypes != null) ? mimeTypes.split("\n") : null;
 
         // TODO: remove these special case icons
-        if ("com.android.externalstorage.documents".equals(authority)) {
-            if ("documents".equals(rootId)) {
-                derivedIcon = R.drawable.ic_doc_text;
-            } else {
-                derivedIcon = R.drawable.ic_root_sdcard;
-            }
-        }
-        if ("com.android.providers.downloads.documents".equals(authority)) {
+        if (isExternalStorage()) {
+            derivedIcon = R.drawable.ic_root_sdcard;
+        } else if (isDownloads()) {
             derivedIcon = R.drawable.ic_root_download;
+        } else if (isImages()) {
+            derivedIcon = R.drawable.ic_doc_image;
+        } else if (isVideos()) {
+            derivedIcon = R.drawable.ic_doc_video;
+        } else if (isAudio()) {
+            derivedIcon = R.drawable.ic_doc_audio;
         }
-        if ("com.android.providers.media.documents".equals(authority)) {
-            if ("images_root".equals(rootId)) {
-                derivedIcon = R.drawable.ic_doc_image;
-            } else if ("videos_root".equals(rootId)) {
-                derivedIcon = R.drawable.ic_doc_video;
-            } else if ("audio_root".equals(rootId)) {
-                derivedIcon = R.drawable.ic_doc_audio;
-            }
-        }
+    }
+
+    public boolean isRecents() {
+        return authority == null && rootId == null;
+    }
+
+    public boolean isExternalStorage() {
+        return "com.android.externalstorage.documents".equals(authority);
+    }
+
+    public boolean isDownloads() {
+        return "com.android.providers.downloads.documents".equals(authority);
+    }
+
+    public boolean isImages() {
+        return "com.android.providers.media.documents".equals(authority)
+                && "images_root".equals(rootId);
+    }
+
+    public boolean isVideos() {
+        return "com.android.providers.media.documents".equals(authority)
+                && "videos_root".equals(rootId);
+    }
+
+    public boolean isAudio() {
+        return "com.android.providers.media.documents".equals(authority)
+                && "audio_root".equals(rootId);
     }
 
     @Override
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index ed28da5..9328b33 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -47,9 +47,8 @@
     // docId format: root:path/to/file
 
     private static final String[] DEFAULT_ROOT_PROJECTION = new String[] {
-            Root.COLUMN_ROOT_ID, Root.COLUMN_ROOT_TYPE, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
-            Root.COLUMN_TITLE, Root.COLUMN_SUMMARY, Root.COLUMN_DOCUMENT_ID,
-            Root.COLUMN_AVAILABLE_BYTES,
+            Root.COLUMN_ROOT_ID, Root.COLUMN_FLAGS, Root.COLUMN_ICON, Root.COLUMN_TITLE,
+            Root.COLUMN_DOCUMENT_ID, Root.COLUMN_AVAILABLE_BYTES,
     };
 
     private static final String[] DEFAULT_DOCUMENT_PROJECTION = new String[] {
@@ -59,7 +58,6 @@
 
     private static class RootInfo {
         public String rootId;
-        public int rootType;
         public int flags;
         public String title;
         public String docId;
@@ -84,7 +82,6 @@
 
             final RootInfo root = new RootInfo();
             root.rootId = rootId;
-            root.rootType = Root.ROOT_TYPE_DEVICE;
             root.flags = Root.FLAG_SUPPORTS_CREATE | Root.FLAG_LOCAL_ONLY | Root.FLAG_ADVANCED
                     | Root.FLAG_SUPPORTS_SEARCH;
             root.title = getContext().getString(R.string.root_internal_storage);
@@ -198,7 +195,6 @@
 
             final RowBuilder row = result.newRow();
             row.add(Root.COLUMN_ROOT_ID, root.rootId);
-            row.add(Root.COLUMN_ROOT_TYPE, root.rootType);
             row.add(Root.COLUMN_FLAGS, root.flags);
             row.add(Root.COLUMN_TITLE, root.title);
             row.add(Root.COLUMN_DOCUMENT_ID, root.docId);
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
index e6fbb1b..5a15cd2 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/TestDocumentsProvider.java
@@ -65,7 +65,7 @@
     private static final String MY_DOC_NULL = "myNull";
 
     private static final String[] DEFAULT_ROOT_PROJECTION = new String[] {
-            Root.COLUMN_ROOT_ID, Root.COLUMN_ROOT_TYPE, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
+            Root.COLUMN_ROOT_ID, Root.COLUMN_FLAGS, Root.COLUMN_ICON,
             Root.COLUMN_TITLE, Root.COLUMN_SUMMARY, Root.COLUMN_DOCUMENT_ID,
             Root.COLUMN_AVAILABLE_BYTES,
     };
@@ -114,7 +114,6 @@
         final MatrixCursor result = new MatrixCursor(resolveRootProjection(projection));
         final RowBuilder row = result.newRow();
         row.add(Root.COLUMN_ROOT_ID, MY_ROOT_ID);
-        row.add(Root.COLUMN_ROOT_TYPE, Root.ROOT_TYPE_SERVICE);
         row.add(Root.COLUMN_FLAGS, Root.FLAG_SUPPORTS_RECENTS);
         row.add(Root.COLUMN_TITLE, "_Test title which is really long");
         row.add(Root.COLUMN_SUMMARY,