Merge "Only bind fast scrollbar when attached if not already bound." into tm-qpr-dev am: f61e7bb4a2

Original change: https://googleplex-android-review.googlesource.com/c/platform/packages/apps/Launcher3/+/19225719

Change-Id: I8d65be04f468cef2fbab6756bcd3b21cd3f5a224
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

src/com/android/launcher3/FastScrollRecyclerView.java

@@ -57,7 +57,9 @@ public abstract class FastScrollRecyclerView extends RecyclerView  {
     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();
-        bindFastScrollbar();
+        if (mScrollbar == null || !mScrollbar.hasRecyclerView()) {
+            bindFastScrollbar();
+        }
     }
 
     public void bindFastScrollbar() {

src/com/android/launcher3/views/RecyclerViewFastScroller.java

@@ -174,6 +174,11 @@ public class RecyclerViewFastScroller extends View {
         ta.recycle();
     }
 
+    /** @return whether there is a RecyclerView bound to this scroller. */
+    public boolean hasRecyclerView() {
+        return mRv != null;
+    }
+
     public void setRecyclerView(FastScrollRecyclerView rv, TextView popupView) {
         if (mRv != null && mOnScrollListener != null) {
             mRv.removeOnScrollListener(mOnScrollListener);