Dispatch screen state change events to Views

Bug #6120957

Using this new callback, views can interrupt and resume their
animations or other periodic tasks based on the current state
of the display.

Change-Id: I398f4abd421e9c5f207107bf1009a7b92cf45daa

1 files changed, 33 insertions, 0 deletions

diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 94531c8..14e2d6f 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -1994,6 +1994,20 @@ public class View implements Drawable.Callback, Drawable.Callback2, KeyEvent.Cal
     public static final int FIND_VIEWS_WITH_ACCESSIBILITY_NODE_PROVIDERS = 0x00000004;
 
     /**
+     * Indicates that the screen has changed state and is now off.
+     *
+     * @see #onScreenStateChanged(int)
+     */
+    public static final int SCREEN_STATE_OFF = 0x0;
+
+    /**
+     * Indicates that the screen has changed state and is now on.
+     *
+     * @see #onScreenStateChanged(int 
+     */
+    public static final int SCREEN_STATE_ON = 0x1;
+
+    /**
      * Controls the over-scroll mode for this view.
      * See {@link #overScrollBy(int, int, int, int, int, int, int, int, boolean)},
      * {@link #OVER_SCROLL_ALWAYS}, {@link #OVER_SCROLL_IF_CONTENT_SCROLLS},
@@ -9604,6 +9618,25 @@ public class View implements Drawable.Callback, Drawable.Callback2, KeyEvent.Cal
     }
 
     /**
+     * @see #onScreenStateChanged(int)
+     */
+    void dispatchScreenStateChanged(int screenState) {
+        onScreenStateChanged(screenState);
+    }
+
+    /**
+     * This method is called whenever the state of the screen this view is
+     * attached to changes. A state change will usually occurs when the screen
+     * turns on or off (whether it happens automatically or the user does it
+     * manually.)
+     *
+     * @param screenState The new state of the screen. Can be either
+     *                    {@link #SCREEN_STATE_ON} or {@link #SCREEN_STATE_OFF}
+     */
+    public void onScreenStateChanged(int screenState) {
+    }
+
+    /**
      * Resolve and cache the layout direction. LTR is set initially. This is implicitly supposing
      * that the parent directionality can and will be resolved before its children.
      */