Have wallpaper target itself when dismissing keyguard with wallpaper

We were previous setting the top app window as the wallpaper target
when the keygaurd is animating away with the wallpaper. This causes
a window that doesn't have the flag to show wallpaper behind it to
become the wallpaper target and it remains the target as long as
there are no window movements. Instead we can make the wallpaper
window target itself during this transition.

Bug: 29092234
Change-Id: If4e3972e7012c6605b1f9dfb9234ceda8db8738b
diff --git a/services/core/java/com/android/server/wm/WallpaperController.java b/services/core/java/com/android/server/wm/WallpaperController.java
index 88028be..18f97a7 100644
--- a/services/core/java/com/android/server/wm/WallpaperController.java
+++ b/services/core/java/com/android/server/wm/WallpaperController.java
@@ -479,6 +479,8 @@
         boolean resetTopWallpaper = false;
         boolean inFreeformSpace = false;
         boolean replacing = false;
+        boolean keyguardGoingAwayWithWallpaper = false;
+
         for (int i = windows.size() - 1; i >= 0; i--) {
             w = windows.get(i);
             if ((w.mAttrs.type == TYPE_WALLPAPER)) {
@@ -506,13 +508,11 @@
                 inFreeformSpace = stack != null && stack.mStackId == FREEFORM_WORKSPACE_STACK_ID;
             }
 
-            replacing = replacing || w.mWillReplaceWindow;
+            replacing |= w.mWillReplaceWindow;
+            keyguardGoingAwayWithWallpaper |= (w.mAppToken != null
+                    && w.mWinAnimator.mKeyguardGoingAwayWithWallpaper);
 
-            // If the app is executing an animation because the keyguard is going away (and the
-            // keyguard was showing the wallpaper) keep the wallpaper during the animation so it
-            // doesn't flicker out.
-            final boolean hasWallpaper = (w.mAttrs.flags & FLAG_SHOW_WALLPAPER) != 0
-                    || (w.mAppToken != null && w.mWinAnimator.mKeyguardGoingAwayWithWallpaper);
+            final boolean hasWallpaper = (w.mAttrs.flags & FLAG_SHOW_WALLPAPER) != 0;
             if (hasWallpaper && w.isOnScreen() && (mWallpaperTarget == w || w.isDrawFinishedLw())) {
                 if (DEBUG_WALLPAPER) Slog.v(TAG, "Found wallpaper target: #" + i + "=" + w);
                 result.setWallpaperTarget(w, i);
@@ -529,18 +529,26 @@
             }
         }
 
-        if (result.wallpaperTarget == null && windowDetachedI >= 0) {
+        if (result.wallpaperTarget != null) {
+            return;
+        }
+
+        if (windowDetachedI >= 0) {
             if (DEBUG_WALLPAPER_LIGHT) Slog.v(TAG,
                     "Found animating detached wallpaper activity: #" + windowDetachedI + "=" + w);
             result.setWallpaperTarget(w, windowDetachedI);
-        }
-        if (result.wallpaperTarget == null
-                && (inFreeformSpace || (replacing && mWallpaperTarget != null))) {
+        } else if (inFreeformSpace || (replacing && mWallpaperTarget != null)) {
             // In freeform mode we set the wallpaper as its own target, so we don't need an
             // additional window to make it visible. When we are replacing a window and there was
             // wallpaper before replacement, we want to keep the window until the new windows fully
             // appear and can determine the visibility, to avoid flickering.
             result.setWallpaperTarget(result.topWallpaper, result.topWallpaperIndex);
+
+        } else if (keyguardGoingAwayWithWallpaper) {
+            // If the app is executing an animation because the keyguard is going away (and the
+            // keyguard was showing the wallpaper) keep the wallpaper during the animation so it
+            // doesn't flicker out by having it be its own target.
+            result.setWallpaperTarget(result.topWallpaper, result.topWallpaperIndex);
         }
     }