Delay sending shared element position until after layout.

Bug 15380396

Also updated fade duration to 300ms now that shared element
transition can take place before fade.

Change-Id: I9053615c83b9e0938b015645de0eb6c1534cbb34

3 files changed, 28 insertions, 3 deletions

diff --git a/core/java/android/app/ActivityTransitionCoordinator.java b/core/java/android/app/ActivityTransitionCoordinator.java
index 5e4ddd0..b739387 100644
--- a/core/java/android/app/ActivityTransitionCoordinator.java
+++ b/core/java/android/app/ActivityTransitionCoordinator.java
@@ -129,8 +129,8 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
     protected static final String KEY_SCALE_TYPE = "shared_element:scaleType";
     protected static final String KEY_IMAGE_MATRIX = "shared_element:imageMatrix";
 
-    // The background fade in/out duration. 150ms is pretty quick, but not abrupt.
-    public static final int FADE_BACKGROUND_DURATION_MS = 150;
+    // The background fade in/out duration. TODO: Enable tuning this.
+    public static final int FADE_BACKGROUND_DURATION_MS = 300;
 
     protected static final ImageView.ScaleType[] SCALE_TYPE_VALUES = ImageView.ScaleType.values();
 
@@ -195,6 +195,11 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
      */
     public static final int MSG_SHARED_ELEMENT_DESTINATION = 107;
 
+    /**
+     * Send the shared element positions.
+     */
+    public static final int MSG_SEND_SHARED_ELEMENT_DESTINATION = 108;
+
     final private Window mWindow;
     final protected ArrayList<String> mAllSharedElementNames;
     final protected ArrayList<View> mSharedElements = new ArrayList<View>();
diff --git a/core/java/android/app/EnterTransitionCoordinator.java b/core/java/android/app/EnterTransitionCoordinator.java
index a8617b8..4b052e7 100644
--- a/core/java/android/app/EnterTransitionCoordinator.java
+++ b/core/java/android/app/EnterTransitionCoordinator.java
@@ -29,6 +29,7 @@ import android.transition.TransitionManager;
 import android.util.ArrayMap;
 import android.util.Pair;
 import android.view.View;
+import android.view.ViewGroup;
 import android.view.ViewGroupOverlay;
 import android.view.ViewTreeObserver;
 import android.widget.ImageView;
@@ -72,8 +73,24 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
                 }
             };
             mHandler.sendEmptyMessageDelayed(MSG_CANCEL, MAX_WAIT_MS);
+            send(MSG_SEND_SHARED_ELEMENT_DESTINATION, null);
+        }
+    }
+
+    private void sendSharedElementDestination() {
+        ViewGroup decor = getDecor();
+        if (!decor.isLayoutRequested()) {
             Bundle state = captureSharedElementState();
             mResultReceiver.send(MSG_SHARED_ELEMENT_DESTINATION, state);
+        } else {
+            getDecor().getViewTreeObserver()
+                    .addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                        @Override
+                        public boolean onPreDraw() {
+                            getDecor().getViewTreeObserver().removeOnPreDrawListener(this);
+                            return true;
+                        }
+                    });
         }
     }
 
@@ -105,6 +122,9 @@ class EnterTransitionCoordinator extends ActivityTransitionCoordinator {
             case MSG_CANCEL:
                 cancel();
                 break;
+            case MSG_SEND_SHARED_ELEMENT_DESTINATION:
+                sendSharedElementDestination();
+                break;
         }
     }
 
diff --git a/core/java/android/app/ExitTransitionCoordinator.java b/core/java/android/app/ExitTransitionCoordinator.java
index a71d649..ba1638f 100644
--- a/core/java/android/app/ExitTransitionCoordinator.java
+++ b/core/java/android/app/ExitTransitionCoordinator.java
@@ -294,7 +294,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
     }
 
     private void finishIfNecessary() {
-        if (mIsReturning && mExitNotified && (mSharedElements.isEmpty()
+        if (mIsReturning && mExitNotified && mActivity != null && (mSharedElements.isEmpty()
                 || mSharedElements.get(0).getVisibility() == View.INVISIBLE)) {
             mActivity.finish();
             mActivity.overridePendingTransition(0, 0);