Fix AnimatorSet duration issue

Setting the duration on an AnimatorSet should propagate that value
to its children. This works, but only if all children are added to the set
before setDuration() is called. This fix delays that propagation until
the set is started, making it possible to have a more flexible order of when
the children are added and when the duration is set.

Issue #6324904 AnimatorSet durations too long

Change-Id: I797971c2310eb2e3fe931b4aa35de505f2a519f7

Author: chethaase

core/java/android/animation/AnimatorSet.java

@@ -420,11 +420,7 @@ public AnimatorSet setDuration(long duration) {
         if (duration < 0) {
             throw new IllegalArgumentException("duration must be a value of zero or greater");
         }
-        for (Node node : mNodes) {
-            // TODO: don't set the duration of the timing-only nodes created by AnimatorSet to
-            // insert "play-after" delays
-            node.animation.setDuration(duration);
-        }
+        // Just record the value for now - it will be used later when the AnimatorSet starts
         mDuration = duration;
         return this;
     }
@@ -456,6 +452,14 @@ public void start() {
         mTerminated = false;
         mStarted = true;
 
+        if (mDuration >= 0) {
+            // If the duration was set on this AnimatorSet, pass it along to all child animations
+            for (Node node : mNodes) {
+                // TODO: don't set the duration of the timing-only nodes created by AnimatorSet to
+                // insert "play-after" delays
+                node.animation.setDuration(mDuration);
+            }
+        }
         // First, sort the nodes (if necessary). This will ensure that sortedNodes
         // contains the animation nodes in the correct order.
         sortNodes();