Don't cause requestLayout when transition changes Visibility.

Bug 21400515

When a Visibility transition temporarily changes a View's
visibility, it should not cause a requestLayout or any other
action, such as focus change. This adds a hidden method to
View to allow it to tweak the visibility without causing
other side-effects.

Change-Id: I5a06149983051319080130e5b5e7cc7edda8dd3e

3 files changed, 22 insertions, 12 deletions

diff --git a/core/java/android/transition/Visibility.java b/core/java/android/transition/Visibility.java
index ed7fd86..684c59e 100644
--- a/core/java/android/transition/Visibility.java
+++ b/core/java/android/transition/Visibility.java
@@ -445,7 +445,7 @@ public abstract class Visibility extends Transition {
                     mForcedEndVisibility != -1;
             if (!isForcedVisibility) {
                 originalVisibility = viewToKeep.getVisibility();
-                viewToKeep.setVisibility(View.VISIBLE);
+                viewToKeep.setTransitionVisibility(View.VISIBLE);
             }
             Animator animator = onDisappear(sceneRoot, viewToKeep, startValues, endValues);
             if (animator != null) {
@@ -454,7 +454,7 @@ public abstract class Visibility extends Transition {
                 animator.addListener(disappearListener);
                 addListener(disappearListener);
             } else if (!isForcedVisibility) {
-                viewToKeep.setVisibility(originalVisibility);
+                viewToKeep.setTransitionVisibility(originalVisibility);
             }
             return animator;
         }
@@ -516,14 +516,14 @@ public abstract class Visibility extends Transition {
         @Override
         public void onAnimationPause(Animator animation) {
             if (!mCanceled && !mIsForcedVisibility) {
-                mView.setVisibility(mFinalVisibility);
+                mView.setTransitionVisibility(mFinalVisibility);
             }
         }
 
         @Override
         public void onAnimationResume(Animator animation) {
             if (!mCanceled && !mIsForcedVisibility) {
-                mView.setVisibility(View.VISIBLE);
+                mView.setTransitionVisibility(View.VISIBLE);
             }
         }
 
@@ -557,7 +557,7 @@ public abstract class Visibility extends Transition {
                 if (mIsForcedVisibility) {
                     mView.setTransitionAlpha(0);
                 } else {
-                    mView.setVisibility(mFinalVisibility);
+                    mView.setTransitionVisibility(mFinalVisibility);
                 }
             }
         }
diff --git a/core/java/android/view/GhostView.java b/core/java/android/view/GhostView.java
index 41502b6..d1b96ba 100644
--- a/core/java/android/view/GhostView.java
+++ b/core/java/android/view/GhostView.java
@@ -39,7 +39,7 @@ public class GhostView extends View {
         mView = view;
         mView.mGhostView = this;
         final ViewGroup parent = (ViewGroup) mView.getParent();
-        setGhostedVisibility(View.INVISIBLE);
+        mView.setTransitionVisibility(View.INVISIBLE);
         parent.invalidate();
     }
 
@@ -66,19 +66,15 @@ public class GhostView extends View {
         super.setVisibility(visibility);
         if (mView.mGhostView == this) {
             int inverseVisibility = (visibility == View.VISIBLE) ? View.INVISIBLE : View.VISIBLE;
-            setGhostedVisibility(inverseVisibility);
+            mView.setTransitionVisibility(inverseVisibility);
         }
     }
 
-    private void setGhostedVisibility(int visibility) {
-        mView.mViewFlags = (mView.mViewFlags & ~View.VISIBILITY_MASK) | visibility;
-    }
-
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
         if (!mBeingMoved) {
-            setGhostedVisibility(View.VISIBLE);
+            mView.setTransitionVisibility(View.VISIBLE);
             mView.mGhostView = null;
             final ViewGroup parent = (ViewGroup) mView.getParent();
             if (parent != null) {
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 126540f..5082b18c 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -8786,6 +8786,20 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
     }
 
     /**
+     * Change the visibility of the View without triggering any other changes. This is
+     * important for transitions, where visibility changes should not adjust focus or
+     * trigger a new layout. This is only used when the visibility has already been changed
+     * and we need a transient value during an animation. When the animation completes,
+     * the original visibility value is always restored.
+     *
+     * @param visibility One of {@link #VISIBLE}, {@link #INVISIBLE}, or {@link #GONE}.
+     * @hide
+     */
+    public void setTransitionVisibility(@Visibility int visibility) {
+        mViewFlags = (mViewFlags & ~View.VISIBILITY_MASK) | visibility;
+    }
+
+    /**
      * Reset the flag indicating the accessibility state of the subtree rooted
      * at this view changed.
      */