Make ViewPropertyAnimator ListView-animation-capable
ViewPropertyAnimator now sets the hasTransientState flag in View to tell
it when an animation has started (and unsets it when the animation ends).
This allows ListView to retain views with transient state without recycling them,
which makes ListView item animation possible (because you can't animate a View
if it's being recycled and reused elsewhere as it moves into and out of view).
Change-Id: I75c26a7a56474a76428500afef03a80bb46e04e0
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index 7e5fe63..537c474 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -2472,6 +2472,12 @@
int mSystemUiVisibility;
/**
+ * Reference count for transient state.
+ * @see #setHasTransientState(boolean)
+ */
+ int mTransientStateCount = 0;
+
+ /**
* Count of how many windows this view has been attached to.
*/
int mWindowAttachCount;
@@ -5400,21 +5406,32 @@
/**
* Set whether this view is currently tracking transient state that the
- * framework should attempt to preserve when possible.
+ * framework should attempt to preserve when possible. This flag is reference counted,
+ * so every call to setHasTransientState(true) should be paired with a later call
+ * to setHasTransientState(false).
*
* @param hasTransientState true if this view has transient state
*/
public void setHasTransientState(boolean hasTransientState) {
- if (hasTransientState() == hasTransientState) return;
-
- mPrivateFlags2 = (mPrivateFlags2 & ~HAS_TRANSIENT_STATE) |
- (hasTransientState ? HAS_TRANSIENT_STATE : 0);
- if (mParent != null) {
- try {
- mParent.childHasTransientStateChanged(this, hasTransientState);
- } catch (AbstractMethodError e) {
- Log.e(VIEW_LOG_TAG, mParent.getClass().getSimpleName() +
- " does not fully implement ViewParent", e);
+ mTransientStateCount = hasTransientState ? mTransientStateCount + 1 :
+ mTransientStateCount - 1;
+ if (mTransientStateCount < 0) {
+ mTransientStateCount = 0;
+ Log.e(VIEW_LOG_TAG, "hasTransientState decremented below 0: " +
+ "unmatched pair of setHasTransientState calls");
+ }
+ if ((hasTransientState && mTransientStateCount == 1) ||
+ (hasTransientState && mTransientStateCount == 0)) {
+ // update flag if we've just incremented up from 0 or decremented down to 0
+ mPrivateFlags2 = (mPrivateFlags2 & ~HAS_TRANSIENT_STATE) |
+ (hasTransientState ? HAS_TRANSIENT_STATE : 0);
+ if (mParent != null) {
+ try {
+ mParent.childHasTransientStateChanged(this, hasTransientState);
+ } catch (AbstractMethodError e) {
+ Log.e(VIEW_LOG_TAG, mParent.getClass().getSimpleName() +
+ " does not fully implement ViewParent", e);
+ }
}
}
}