From d9e72a7b3409d2a6cb0ceac89b2423e70cc54c7f Mon Sep 17 00:00:00 2001
From: Ben Lin <linben@google.com>
Date: Thu, 20 May 2021 16:35:12 -0700
Subject: [PATCH] PiP: Show the wallpaper as part of the transition.

This is usually taken care by RemoteAnimation, but since PiP takes
control of the entire thing that is no longer the case. So let's just
handle it.

Bug: 165793917
Test: Enter PiP with ENABLE_SHELL_TRANSITIONS flag on
Change-Id: I8f0af4472c20016f856f33f903bd9a431cd5ef3a
---
 .../android/wm/shell/pip/PipTransition.java   | 26 +++++++++++++++----
 1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
index 7581dfaaa1103..9d21e55106c36 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/PipTransition.java
@@ -18,6 +18,7 @@ package com.android.wm.shell.pip;
 
 import static android.app.WindowConfiguration.WINDOWING_MODE_PINNED;
 import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
+import static android.window.TransitionInfo.FLAG_IS_WALLPAPER;
 
 import static com.android.wm.shell.pip.PipAnimationController.ANIM_TYPE_ALPHA;
 import static com.android.wm.shell.pip.PipAnimationController.ANIM_TYPE_BOUNDS;
@@ -90,17 +91,32 @@ public class PipTransition extends PipTransitionController {
             return success;
         }
 
+        // Search for an Enter PiP transition (along with a show wallpaper one)
+        TransitionInfo.Change enterPip = null;
+        TransitionInfo.Change wallpaper = null;
         for (int i = info.getChanges().size() - 1; i >= 0; --i) {
             final TransitionInfo.Change change = info.getChanges().get(i);
             if (change.getTaskInfo() != null
                     && change.getTaskInfo().configuration.windowConfiguration.getWindowingMode()
                     == WINDOWING_MODE_PINNED) {
-                mFinishCallback = finishCallback;
-                return startEnterAnimation(change.getTaskInfo(), change.getLeash(),
-                        startTransaction, finishTransaction);
+                enterPip = change;
+            } else if ((change.getFlags() & FLAG_IS_WALLPAPER) != 0) {
+                wallpaper = change;
             }
         }
-        return false;
+        if (enterPip == null) {
+            return false;
+        }
+
+        // Show the wallpaper if there is a wallpaper change.
+        if (wallpaper != null) {
+            startTransaction.show(wallpaper.getLeash());
+            startTransaction.setAlpha(wallpaper.getLeash(), 1.f);
+        }
+
+        mFinishCallback = finishCallback;
+        return startEnterAnimation(enterPip.getTaskInfo(), enterPip.getLeash(),
+                startTransaction, finishTransaction);
     }
 
     @Nullable
@@ -160,7 +176,6 @@ public class PipTransition extends PipTransitionController {
                     0 /* startingAngle */, Surface.ROTATION_0);
         } else if (mOneShotAnimationType == ANIM_TYPE_ALPHA) {
             startTransaction.setAlpha(leash, 0f);
-            startTransaction.apply();
             animator = mPipAnimationController.getAnimator(taskInfo, leash, destinationBounds,
                     0f, 1f);
             mOneShotAnimationType = ANIM_TYPE_BOUNDS;
@@ -168,6 +183,7 @@ public class PipTransition extends PipTransitionController {
             throw new RuntimeException("Unrecognized animation type: "
                     + mOneShotAnimationType);
         }
+        startTransaction.apply();
         animator.setTransitionDirection(TRANSITION_DIRECTION_TO_PIP)
                 .setPipAnimationCallback(mPipAnimationCallback)
                 .setDuration(mEnterExitAnimationDuration)