From a2bbbb3bac464c3a52e33008401fed4a7542744c Mon Sep 17 00:00:00 2001
From: George Mount <mount@google.com>
Date: Tue, 12 Aug 2014 10:16:20 -0700
Subject: [PATCH] Don't blink in views that haven't transitioned yet.

Bug 16959262

Views that hadn't animated in during the enter transition were
being stripped from the exit transition. This caused them to
blink in as the enter transition was canceled.

This pauses the entering transition so that the view positions
are properly captured for the exit transition and aren't stripped.

Change-Id: I39cc94ed3bf92a51f8c5fe741f0aa5456b704bf0
---
 .../android/app/ActivityTransitionCoordinator.java |  2 +-
 core/java/android/app/ActivityTransitionState.java | 12 ++++++++++++
 .../android/app/EnterTransitionCoordinator.java    | 14 +++++++++++++-
 3 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/core/java/android/app/ActivityTransitionCoordinator.java b/core/java/android/app/ActivityTransitionCoordinator.java
index f7c0d23f94943..7d2f677dbcc82 100644
--- a/core/java/android/app/ActivityTransitionCoordinator.java
+++ b/core/java/android/app/ActivityTransitionCoordinator.java
@@ -239,7 +239,7 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         return mWindow;
     }
 
-    protected ViewGroup getDecor() {
+    public ViewGroup getDecor() {
         return (mWindow == null) ? null : (ViewGroup) mWindow.getDecorView();
     }
 
diff --git a/core/java/android/app/ActivityTransitionState.java b/core/java/android/app/ActivityTransitionState.java
index 4f3b02c0a86e5..613e24854dbd3 100644
--- a/core/java/android/app/ActivityTransitionState.java
+++ b/core/java/android/app/ActivityTransitionState.java
@@ -17,9 +17,11 @@ package android.app;
 
 import android.os.Bundle;
 import android.os.ResultReceiver;
+import android.transition.Transition;
 import android.util.ArrayMap;
 import android.util.SparseArray;
 import android.view.View;
+import android.view.ViewGroup;
 import android.view.Window;
 
 import java.lang.ref.WeakReference;
@@ -245,13 +247,23 @@ class ActivityTransitionState {
         } else {
             if (!mHasExited) {
                 mHasExited = true;
+                Transition enterViewsTransition = null;
+                ViewGroup decor = null;
                 if (mEnterTransitionCoordinator != null) {
+                    enterViewsTransition = mEnterTransitionCoordinator.getEnterViewsTransition();
+                    decor = mEnterTransitionCoordinator.getDecor();
                     mEnterTransitionCoordinator.cancelEnter();
                     mEnterTransitionCoordinator = null;
+                    if (enterViewsTransition != null && decor != null) {
+                        enterViewsTransition.pause(decor);
+                    }
                 }
 
                 ExitTransitionCoordinator exitCoordinator =
                         new ExitTransitionCoordinator(activity, mEnteringNames, null, null, true);
+                if (enterViewsTransition != null && decor != null) {
+                    enterViewsTransition.resume(decor);
+                }
                 exitCoordinator.startExit(activity.mResultCode, activity.mResultData);
             }
             return true;
diff --git a/core/java/android/app/EnterTransitionCoordinator.java b/core/java/android/app/EnterTransitionCoordinator.java
index 54c5bc441ef54..75ecbd931b5d1 100644
--- a/core/java/android/app/EnterTransitionCoordinator.java
+++ b/core/java/android/app/EnterTransitionCoordinator.java
@@ -59,6 +59,7 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
     private boolean mIsViewsTransitionComplete;
     private boolean mIsSharedElementTransitionComplete;
     private ArrayList<Matrix> mSharedElementParentMatrices;
+    private Transition mEnterViewsTransition;
 
     public EnterTransitionCoordinator(Activity activity, ResultReceiver resultReceiver,
             ArrayList<String> sharedElementNames, boolean isReturning) {
@@ -104,6 +105,10 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
         triggerViewsReady(mapNamedElements(accepted, localNames));
     }
 
+    public Transition getEnterViewsTransition() {
+        return mEnterViewsTransition;
+    }
+
     @Override
     protected void viewsReady(ArrayMap<String, View> sharedElements) {
         super.viewsReady(sharedElements);
@@ -399,10 +404,17 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
                 viewTransitionComplete();
             } else {
                 viewsTransition.forceVisibility(View.INVISIBLE, true);
-                setTransitionAlpha(mTransitioningViews, 1);
                 viewsTransition.addListener(new ContinueTransitionListener() {
+                    @Override
+                    public void onTransitionStart(Transition transition) {
+                        mEnterViewsTransition = transition;
+                        setTransitionAlpha(mTransitioningViews, 1);
+                        super.onTransitionStart(transition);
+                    }
+
                     @Override
                     public void onTransitionEnd(Transition transition) {
+                        mEnterViewsTransition = null;
                         transition.removeListener(this);
                         viewTransitionComplete();
                         super.onTransitionEnd(transition);