Avoid running layout transitions on unattached views and windows

LayoutTransition causes artifacts in some situations where a window is just
becoming visible or a container is just being added to the view tree when animations
are kicked off in LayoutTransition due to the normal automatic mechanism of running
animations when views are added/removed/etc. The problem is that containers in these
situations may have children with positions and sizes of (0, 0), causing the animation to
animate from this default/nonsense value to whatever is appropriate for the views when
they are first laid out and drawn. The end result is correct, but the animation is
superfluous and silly.

The fix is to avoid running any kind of transition animation on windows that are not
currently visible or containers that are not currently atached to the view hierarchy.
This should avoid the situation by only allowing the animations to run after the containers
and windows are visible and set up correctly.

Issue #6544410 issue with layout transition when first showing the activity

Change-Id: I737b2598887ef806dec3b02a483a8e8ff2c3d4e2

1 files changed, 9 insertions, 0 deletions

diff --git a/core/java/android/animation/LayoutTransition.java b/core/java/android/animation/LayoutTransition.java
index c643137..bdcb2af 100644
--- a/core/java/android/animation/LayoutTransition.java
+++ b/core/java/android/animation/LayoutTransition.java
@@ -1208,6 +1208,9 @@ public class LayoutTransition {
      * affect CHANGE_APPEARING or CHANGE_DISAPPEARING animations.
      */
     private void addChild(ViewGroup parent, View child, boolean changesLayout) {
+        if (parent.getWindowVisibility() != View.VISIBLE) {
+            return;
+        }
         if ((mTransitionTypes & FLAG_APPEARING) == FLAG_APPEARING) {
             // Want disappearing animations to finish up before proceeding
             cancel(DISAPPEARING);
@@ -1243,6 +1246,9 @@ public class LayoutTransition {
      * @hide
      */
     public void layoutChange(ViewGroup parent) {
+        if (parent.getWindowVisibility() != View.VISIBLE) {
+            return;
+        }
         if ((mTransitionTypes & FLAG_CHANGING) == FLAG_CHANGING  && !isRunning()) {
             // This method is called for all calls to layout() in the container, including
             // those caused by add/remove/hide/show events, which will already have set up
@@ -1301,6 +1307,9 @@ public class LayoutTransition {
      * affect CHANGE_APPEARING or CHANGE_DISAPPEARING animations.
      */
     private void removeChild(ViewGroup parent, View child, boolean changesLayout) {
+        if (parent.getWindowVisibility() != View.VISIBLE) {
+            return;
+        }
         if ((mTransitionTypes & FLAG_DISAPPEARING) == FLAG_DISAPPEARING) {
             // Want appearing animations to finish up before proceeding
             cancel(APPEARING);