From 92692c0284c2249e9a5381f7f19ec97f6b76d12f Mon Sep 17 00:00:00 2001
From: George Mount <mount@google.com>
Date: Mon, 1 Dec 2014 16:44:05 -0800
Subject: [PATCH] Keep snapshot order matching the shared elements.

Bug 18578796

When no snapshot was created, we weren't adding anything to
the snapshot list. When a snapshot is not created, we should
add an null snapshot to the snapshot list to keep them in
order.

Change-Id: I522e485163229230037dcdd635b83cff800df28f
---
 core/java/android/app/ActivityTransitionCoordinator.java | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/core/java/android/app/ActivityTransitionCoordinator.java b/core/java/android/app/ActivityTransitionCoordinator.java
index 9062892efde9d..d0d9d7153eaf4 100644
--- a/core/java/android/app/ActivityTransitionCoordinator.java
+++ b/core/java/android/app/ActivityTransitionCoordinator.java
@@ -641,17 +641,18 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         Matrix tempMatrix = new Matrix();
         for (String name: names) {
             Bundle sharedElementBundle = state.getBundle(name);
+            View snapshot = null;
             if (sharedElementBundle != null) {
                 Parcelable parcelable = sharedElementBundle.getParcelable(KEY_SNAPSHOT);
-                View snapshot = null;
                 if (parcelable != null && mListener != null) {
                     snapshot = mListener.onCreateSnapshotView(context, parcelable);
                 }
                 if (snapshot != null) {
                     setSharedElementState(snapshot, name, state, tempMatrix, null, decorLoc);
                 }
-                snapshots.add(snapshot);
             }
+            // Even null snapshots are added so they remain in the same order as shared elements.
+            snapshots.add(snapshot);
         }
         return snapshots;
     }