Fix bug 2587373 - awaken scrollbars when a scrolling view becomes visible.
Change-Id: I7eb38c53c3a03b23786b8b0c2d16139acd0eb38e
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index d99ebc9..11e5ad1 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -1512,6 +1512,13 @@
* @hide
*/
static final int CANCEL_NEXT_UP_EVENT = 0x04000000;
+
+ /**
+ * Indicates that we should awaken scroll bars once attached
+ *
+ * @hide
+ */
+ private static final int AWAKEN_SCROLL_BARS_ON_ATTACH = 0x08000000;
/**
* The parent this view is attached to.
@@ -3838,6 +3845,13 @@
* {@link #INVISIBLE} or {@link #GONE}.
*/
protected void onVisibilityChanged(View changedView, int visibility) {
+ if (visibility == VISIBLE) {
+ if (mAttachInfo != null) {
+ initialAwakenScrollBars();
+ } else {
+ mPrivateFlags |= AWAKEN_SCROLL_BARS_ON_ATTACH;
+ }
+ }
}
/**
@@ -3888,6 +3902,9 @@
* @param visibility The new visibility of the window.
*/
protected void onWindowVisibilityChanged(int visibility) {
+ if (visibility == VISIBLE) {
+ initialAwakenScrollBars();
+ }
}
/**
@@ -4909,6 +4926,19 @@
}
/**
+ * Trigger the scrollbars to draw.
+ * This method differs from awakenScrollBars() only in its default duration.
+ * initialAwakenScrollBars() will show the scroll bars for longer than
+ * usual to give the user more of a chance to notice them.
+ *
+ * @return true if the animation is played, false otherwise.
+ */
+ private boolean initialAwakenScrollBars() {
+ return mScrollCache != null &&
+ awakenScrollBars(mScrollCache.scrollBarDefaultDelayBeforeFade * 4, true);
+ }
+
+ /**
* <p>
* Trigger the scrollbars to draw. When invoked this method starts an
* animation to fade the scrollbars out after a fixed delay. If a subclass
@@ -5900,6 +5930,10 @@
if ((mPrivateFlags & REQUEST_TRANSPARENT_REGIONS) != 0) {
mParent.requestTransparentRegion(this);
}
+ if ((mPrivateFlags & AWAKEN_SCROLL_BARS_ON_ATTACH) != 0) {
+ initialAwakenScrollBars();
+ mPrivateFlags &= ~AWAKEN_SCROLL_BARS_ON_ATTACH;
+ }
}
/**
