Fix animation video render issue when Settings->Moves is resumed from

screen off.

Re-initialize the animation video if necessary when the preference is
visible to the user.

Fixes: 31023261

Test: manual -
1. Go to Settings -> Moves and verify that the animation video are
displayed correctly on load.
2. Press power button to turn screen off, then on again. Verify when
Moves settings resumes, the animation video is displayed correctly.
3. Repeat #2 above but let display time out instead of turning off
screen by power button.

Change-Id: I0ee21d23a4c402b3a8463dca3b36fce67d651993

src/com/android/settings/gestures/GesturePreference.java

@@ -185,6 +185,12 @@ void loadPreview(LoaderManager manager, int id) {
         Loader<Bitmap> loader = manager.initLoader(id, Bundle.EMPTY, this);
     }
 
+    void onViewVisible() {
+        if (mVideoReady && mMediaPlayer != null && !mMediaPlayer.isPlaying()) {
+            mMediaPlayer.seekTo(0);
+        }
+    }
+
     private static final class PreviewRetriever extends AsyncLoader<Bitmap> {
         private Uri mVideoPath;
 

src/com/android/settings/gestures/GestureSettings.java

@@ -118,6 +118,14 @@ public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
         return view;
     }
 
+    @Override
+    public void onStart() {
+        super.onStart();
+        for (GesturePreference preference : mPreferences) {
+            preference.onViewVisible();
+        }
+    }
+
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
         boolean enabled = (boolean) newValue;