DO NOT MERGE: Fix temporary black after setting a new image wallpaper

Sometimes see temporary black wallpaper after setting a new image
wallpaper because of:
- decode bitmap twice, results in long latency until drawing.
- the set wallpaper apis didn't sync with wallpaper rendering well.
Solutions:
- Only decode bitmap when necessary.
- Make set wallpaper apis wait for image wallpaper rendering finished.

Bug: 194080642
Test: see b/194080642#comment3
Test: atest WallpaperManagerServiceTests --iterations 50
Test: atest SystemUITests
Change-Id: I369eff5195571161cf286b3ec97175481b02eed7

1 files changed, 58 insertions, 0 deletions

diff --git a/core/java/android/app/WallpaperManager.java b/core/java/android/app/WallpaperManager.java
index 8d332ab1d58b..6cfa39cd2337 100644
--- a/core/java/android/app/WallpaperManager.java
+++ b/core/java/android/app/WallpaperManager.java
@@ -559,6 +559,53 @@ public class WallpaperManager {
             return null;
         }
 
+        public Rect peekWallpaperDimensions(Context context, boolean returnDefault, int userId) {
+            if (mService != null) {
+                try {
+                    if (!mService.isWallpaperSupported(context.getOpPackageName())) {
+                        return new Rect();
+                    }
+                } catch (RemoteException e) {
+                    throw e.rethrowFromSystemServer();
+                }
+            }
+
+            Rect dimensions = null;
+            synchronized (this) {
+                try {
+                    Bundle params = new Bundle();
+                    // Let's peek user wallpaper first.
+                    ParcelFileDescriptor pfd = mService.getWallpaperWithFeature(
+                            context.getOpPackageName(), context.getAttributionTag(), this,
+                            FLAG_SYSTEM, params, userId);
+                    if (pfd != null) {
+                        BitmapFactory.Options options = new BitmapFactory.Options();
+                        options.inJustDecodeBounds = true;
+                        BitmapFactory.decodeFileDescriptor(pfd.getFileDescriptor(), null, options);
+                        dimensions = new Rect(0, 0, options.outWidth, options.outHeight);
+                    }
+                } catch (RemoteException ex) {
+                    Log.w(TAG, "peek wallpaper dimensions failed", ex);
+                }
+            }
+            // If user wallpaper is unavailable, may be the default one instead.
+            if ((dimensions == null || dimensions.width() == 0 || dimensions.height() == 0)
+                    && returnDefault) {
+                InputStream is = openDefaultWallpaper(context, FLAG_SYSTEM);
+                if (is != null) {
+                    try {
+                        BitmapFactory.Options options = new BitmapFactory.Options();
+                        options.inJustDecodeBounds = true;
+                        BitmapFactory.decodeStream(is, null, options);
+                        dimensions = new Rect(0, 0, options.outWidth, options.outHeight);
+                    } finally {
+                        IoUtils.closeQuietly(is);
+                    }
+                }
+            }
+            return dimensions;
+        }
+
         void forgetLoadedWallpaper() {
             synchronized (this) {
                 mCachedWallpaper = null;
@@ -1039,6 +1086,17 @@ public class WallpaperManager {
     }
 
     /**
+     * Peek the dimensions of system wallpaper of the user without decoding it.
+     *
+     * @return the dimensions of system wallpaper
+     * @hide
+     */
+    public Rect peekBitmapDimensions() {
+        return sGlobals.peekWallpaperDimensions(
+                mContext, true /* returnDefault */, mContext.getUserId());
+    }
+
+    /**
      * Get an open, readable file descriptor to the given wallpaper image file.
      * The caller is responsible for closing the file descriptor when done ingesting the file.
      *