Wait for visible wallpaper drawn before starting app transitions

If the opening app has wallpaper, when the closing app starts hiding,
the wallpaper would be revealed. It would be nice if we play the app
transitions while opening apps, closing apps, and visible wallpapers
are all drawn.

https://code.google.com/p/android/issues/detail?id=150811

Change-Id: I3c7d140f6f6e43e18119e48f9cab441ee96b17e5

1 files changed, 52 insertions, 0 deletions

diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 4dd4e1e..a25a84c 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -613,6 +613,13 @@ public class WindowManagerService extends IWindowManager.Stub
     static final long WALLPAPER_TIMEOUT_RECOVERY = 10000;
     boolean mAnimateWallpaperWithTarget;
 
+    // We give a wallpaper up to 1000ms to finish drawing before playing app transitions.
+    static final long WALLPAPER_DRAW_PENDING_TIMEOUT_DURATION = 1000;
+    static final int WALLPAPER_DRAW_NORMAL = 0;
+    static final int WALLPAPER_DRAW_PENDING = 1;
+    static final int WALLPAPER_DRAW_TIMEOUT = 2;
+    int mWallpaperDrawState = WALLPAPER_DRAW_NORMAL;
+
     AppWindowToken mFocusedApp = null;
 
     PowerManager mPowerManager;
@@ -7644,6 +7651,7 @@ public class WindowManagerService extends IWindowManager.Stub
 
         public static final int CHECK_IF_BOOT_ANIMATION_FINISHED = 37;
         public static final int RESET_ANR_MESSAGE = 38;
+        public static final int WALLPAPER_DRAW_PENDING_TIMEOUT = 39;
 
         @Override
         public void handleMessage(Message msg) {
@@ -8160,6 +8168,17 @@ public class WindowManagerService extends IWindowManager.Stub
                     }
                 }
                 break;
+                case WALLPAPER_DRAW_PENDING_TIMEOUT: {
+                    synchronized (mWindowMap) {
+                        if (mWallpaperDrawState == WALLPAPER_DRAW_PENDING) {
+                            mWallpaperDrawState = WALLPAPER_DRAW_TIMEOUT;
+                            if (DEBUG_APP_TRANSITIONS || DEBUG_WALLPAPER) Slog.v(TAG,
+                                    "*** WALLPAPER DRAW TIMEOUT");
+                            performLayoutAndPlaceSurfacesLocked();
+                        }
+                    }
+                }
+                break;
             }
             if (DEBUG_WINDOW_TRACE) {
                 Slog.v(TAG, "handleMessage: exit");
@@ -9066,6 +9085,39 @@ public class WindowManagerService extends IWindowManager.Stub
                     goodToGo = false;
                 }
             }
+            if (goodToGo && isWallpaperVisible(mWallpaperTarget)) {
+                boolean wallpaperGoodToGo = true;
+                for (int curTokenIndex = mWallpaperTokens.size() - 1;
+                        curTokenIndex >= 0 && wallpaperGoodToGo; curTokenIndex--) {
+                    WindowToken token = mWallpaperTokens.get(curTokenIndex);
+                    for (int curWallpaperIndex = token.windows.size() - 1; curWallpaperIndex >= 0;
+                            curWallpaperIndex--) {
+                        WindowState wallpaper = token.windows.get(curWallpaperIndex);
+                        if (wallpaper.mWallpaperVisible && !wallpaper.isDrawnLw()) {
+                            // We've told this wallpaper to be visible, but it is not drawn yet
+                            wallpaperGoodToGo = false;
+                            if (mWallpaperDrawState != WALLPAPER_DRAW_TIMEOUT) {
+                                // wait for this wallpaper until it is drawn or timeout
+                                goodToGo = false;
+                            }
+                            if (mWallpaperDrawState == WALLPAPER_DRAW_NORMAL) {
+                                mWallpaperDrawState = WALLPAPER_DRAW_PENDING;
+                                mH.removeMessages(H.WALLPAPER_DRAW_PENDING_TIMEOUT);
+                                mH.sendEmptyMessageDelayed(H.WALLPAPER_DRAW_PENDING_TIMEOUT,
+                                        WALLPAPER_DRAW_PENDING_TIMEOUT_DURATION);
+                            }
+                            if (DEBUG_APP_TRANSITIONS || DEBUG_WALLPAPER) Slog.v(TAG,
+                                    "Wallpaper should be visible but has not been drawn yet. " +
+                                    "mWallpaperDrawState=" + mWallpaperDrawState);
+                            break;
+                        }
+                    }
+                }
+                if (wallpaperGoodToGo) {
+                    mWallpaperDrawState = WALLPAPER_DRAW_NORMAL;
+                    mH.removeMessages(H.WALLPAPER_DRAW_PENDING_TIMEOUT);
+                }
+            }
         }
         if (goodToGo) {
             if (DEBUG_APP_TRANSITIONS) Slog.v(TAG, "**** GOOD TO GO");