Make Keyguard a library and make StatusBar the new Keyguard.

This change achieves a couple of things:
- Let Keyguard be a library, so we can use it in SystemUI.
- Introduce FLAG_KEYGUARD for windows and deprecate TYPE_KEYGUARD. Make
all the TYPE_KEYGUARD behaviour dependant on the flag.
- Implement a new KeyguardService in SystemUI, and bind that service
from PhoneWindowManager.
- Introduce BaseStatusBar.setKeyguardState and inflate
KeyguardSimpleHostView there and use FLAG_KEYGUARD for the window, such
that the status bar window essentially gets the Keyguard.

Bug: 13635952
Change-Id: I059d80d8b9b9818a778ab685f4672ea2694def63
diff --git a/core/java/android/view/WindowManager.java b/core/java/android/view/WindowManager.java
index 53a4c0d0..0856492 100644
--- a/core/java/android/view/WindowManager.java
+++ b/core/java/android/view/WindowManager.java
@@ -49,7 +49,7 @@
 public interface WindowManager extends ViewManager {
     /**
      * Exception that is thrown when trying to add view whose
-     * {@link WindowManager.LayoutParams} {@link WindowManager.LayoutParams#token}
+     * {@link LayoutParams} {@link LayoutParams#token}
      * is invalid.
      */
     public static class BadTokenException extends RuntimeException {
@@ -173,7 +173,6 @@
          * @see #TYPE_SEARCH_BAR
          * @see #TYPE_PHONE
          * @see #TYPE_SYSTEM_ALERT
-         * @see #TYPE_KEYGUARD
          * @see #TYPE_TOAST
          * @see #TYPE_SYSTEM_OVERLAY
          * @see #TYPE_PRIORITY_PHONE
@@ -197,7 +196,6 @@
             @ViewDebug.IntToString(from = TYPE_SEARCH_BAR, to = "TYPE_SEARCH_BAR"),
             @ViewDebug.IntToString(from = TYPE_PHONE, to = "TYPE_PHONE"),
             @ViewDebug.IntToString(from = TYPE_SYSTEM_ALERT, to = "TYPE_SYSTEM_ALERT"),
-            @ViewDebug.IntToString(from = TYPE_KEYGUARD, to = "TYPE_KEYGUARD"),
             @ViewDebug.IntToString(from = TYPE_TOAST, to = "TYPE_TOAST"),
             @ViewDebug.IntToString(from = TYPE_SYSTEM_OVERLAY, to = "TYPE_SYSTEM_OVERLAY"),
             @ViewDebug.IntToString(from = TYPE_PRIORITY_PHONE, to = "TYPE_PRIORITY_PHONE"),
@@ -341,13 +339,13 @@
          * In multiuser systems shows only on the owning user's window.
          */
         public static final int TYPE_SYSTEM_ALERT       = FIRST_SYSTEM_WINDOW+3;
-        
+
         /**
          * Window type: keyguard window.
          * In multiuser systems shows on all users' windows.
          */
         public static final int TYPE_KEYGUARD           = FIRST_SYSTEM_WINDOW+4;
-        
+
         /**
          * Window type: transient notifications.
          * In multiuser systems shows only on the owning user's window.
@@ -913,7 +911,6 @@
          */
         public static final int FLAG_NEEDS_MENU_KEY = 0x40000000;
 
-
         /**
          * Various behavioral options/flags.  Default is none.
          * 
@@ -1087,6 +1084,14 @@
         public static final int PRIVATE_FLAG_INHERIT_TRANSLUCENT_DECOR = 0x00000200;
 
         /**
+         * Flag whether the current window is a keyguard window, meaning that it will hide all other
+         * windows behind it except for windows with flag {@link #FLAG_SHOW_WHEN_LOCKED} set.
+         * Further, this can only be set by {@link LayoutParams#TYPE_STATUS_BAR}.
+         * {@hide}
+         */
+        public static final int PRIVATE_FLAG_KEYGUARD = 0x00000400;
+
+        /**
          * Control flags that are private to the platform.
          * @hide
          */
diff --git a/core/java/com/android/internal/policy/IKeyguardService.aidl b/core/java/com/android/internal/policy/IKeyguardService.aidl
index 63ff5a0..7fc024d 100644
--- a/core/java/com/android/internal/policy/IKeyguardService.aidl
+++ b/core/java/com/android/internal/policy/IKeyguardService.aidl
@@ -30,7 +30,19 @@
     boolean isDismissable();
     oneway void verifyUnlock(IKeyguardExitCallback callback);
     oneway void keyguardDone(boolean authenticated, boolean wakeup);
-    oneway void setHidden(boolean isHidden);
+
+    /**
+     * Hides the Keyguard when a window comes on top of the Keyguard with flag
+     * FLAG_SHOW_ON_LOCK_SCREEN.
+     *
+     * @param isHidden Whether the Keyguard should be hidden.
+     * @return See IKeyguardServiceConstants.KEYGUARD_SERVICE_HIDE_*. This is needed because
+     *         PhoneWindowManager needs to set these flags immediately and can't wait for the
+     *         Keyguard thread to pick it up. In the hidden case, PhoneWindowManager is solely
+     *         responsible to make sure that the flags are unset.
+     */
+    int setHidden(boolean isHidden);
+
     oneway void dismiss();
     oneway void onDreamingStarted();
     oneway void onDreamingStopped();
diff --git a/core/java/com/android/internal/policy/IKeyguardServiceConstants.java b/core/java/com/android/internal/policy/IKeyguardServiceConstants.java
new file mode 100644
index 0000000..d94cca7
--- /dev/null
+++ b/core/java/com/android/internal/policy/IKeyguardServiceConstants.java
@@ -0,0 +1,41 @@
+/*
+ * 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 com.android.internal.policy;
+
+/**
+ * @hide
+ */
+public class IKeyguardServiceConstants {
+
+    /**
+     * Constant for {@link com.android.internal.policy.IKeyguardService#setHidden(boolean)}:
+     * Don't change the keyguard window flags.
+     */
+    public static final int KEYGUARD_SERVICE_HIDE_RESULT_NONE = 0;
+
+    /**
+     * Constant for {@link com.android.internal.policy.IKeyguardService#setHidden(boolean)}:
+     * Set the keyguard window flags to FLAG_SHOW_WALLPAPER and PRIVATE_FLAG_KEYGUARD.
+     */
+    public static final int KEYGUARD_SERVICE_HIDE_RESULT_SET_FLAGS = 1;
+
+    /**
+     * Constant for {@link com.android.internal.policy.IKeyguardService#setHidden(boolean)}:
+     * Unset the keyguard window flags to FLAG_SHOW_WALLPAPER and PRIVATE_FLAG_KEYGUARD.
+     */
+    public static final int KEYGUARD_SERVICE_HIDE_RESULT_UNSET_FLAGS = 2;
+}