Allow delay of showing/hiding shared element when transferring.

Bug 18932344

Change-Id: Ic967551a4dd27967d2312a6c6c8a83b34c220031

1 files changed, 38 insertions, 0 deletions

diff --git a/core/java/android/app/SharedElementCallback.java b/core/java/android/app/SharedElementCallback.java
index 6ac2401..9c70f1d 100644
--- a/core/java/android/app/SharedElementCallback.java
+++ b/core/java/android/app/SharedElementCallback.java
@@ -221,4 +221,42 @@ public abstract class SharedElementCallback {
         }
         return view;
     }
+
+    /**
+     * Called during an Activity Transition when the shared elements have arrived at the
+     * final location and are ready to be transferred. This method is called for both the
+     * source and destination Activities.
+     * <p>
+     * When the shared elements are ready to be transferred,
+     * {@link OnSharedElementsReadyListener#onSharedElementsReady()}
+     * must be called to trigger the transfer.
+     * <p>
+     * The default behavior is to trigger the transfer immediately.
+     *
+     * @param sharedElementNames The names of the shared elements that are being transferred..
+     * @param sharedElements The shared elements that are part of the View hierarchy.
+     * @param listener The listener to call when the shared elements are ready to be hidden
+     *                 in the source Activity or shown in the destination Activity.
+     */
+    public void onSharedElementsArrived(List<String> sharedElementNames,
+            List<View> sharedElements, OnSharedElementsReadyListener listener) {
+        listener.onSharedElementsReady();
+    }
+
+    /**
+     * Listener to be called after {@link
+     * SharedElementCallback#onSharedElementsArrived(OnSharedElementsReadyListener)}
+     * when the shared elements are ready to be hidden in the source Activity and shown in the
+     * destination Activity.
+     */
+    public interface OnSharedElementsReadyListener {
+
+        /**
+         * Call this method during or after the OnSharedElementsReadyListener has been received
+         * in {@link SharedElementCallback#onSharedElementsArrived(OnSharedElementsReadyListener)}
+         * to indicate that the shared elements are ready to be hidden in the source and shown
+         * in the destination Activity.
+         */
+        void onSharedElementsReady();
+    }
 }