commit 615c9ee4d46a208feffb7a74d3011ebc83a49796
author Zhen Zhang <zzhen@google.com> Mon Jan 13 18:48:10 2020 +0000
committer Android (Google) Code Review <android-gerrit@google.com> Mon Jan 13 18:48:10 2020 +0000
tree 1c3d2092225c7f70b1b78f046043244cb407f0a6
parent 238c857815c22f53a9dc0ecc039045b4f0137bb9
parent a7cb697874b9afc8c8323d6325df52f24f997e9d

Merge "Don't let RecyclerView consume fling action when there is no further space."

core/java/com/android/internal/widget/RecyclerView.java

diff --git a/core/java/com/android/internal/widget/RecyclerView.java b/core/java/com/android/internal/widget/RecyclerView.java
index 43a227a..d7a01c4 100644
--- a/core/java/com/android/internal/widget/RecyclerView.java
+++ b/core/java/com/android/internal/widget/RecyclerView.java
@@ -2011,13 +2011,27 @@
         }
 
         if (!dispatchNestedPreFling(velocityX, velocityY)) {
-            final boolean canScroll = canScrollHorizontal || canScrollVertical;
-            dispatchNestedFling(velocityX, velocityY, canScroll);
+            final View firstChild = mLayout.getChildAt(0);
+            final View lastChild = mLayout.getChildAt(mLayout.getChildCount() - 1);
+            boolean consumed = false;
+            if (velocityY < 0) {
+                consumed = getChildAdapterPosition(firstChild) > 0
+                        || firstChild.getTop() < getPaddingTop();
+            }
+
+            if (velocityY > 0) {
+                consumed = getChildAdapterPosition(lastChild) < mAdapter.getItemCount() - 1
+                        || lastChild.getBottom() > getHeight() - getPaddingBottom();
+            }
+
+            dispatchNestedFling(velocityX, velocityY, consumed);
 
             if (mOnFlingListener != null && mOnFlingListener.onFling(velocityX, velocityY)) {
                 return true;
             }
 
+            final boolean canScroll = canScrollHorizontal || canScrollVertical;
+
             if (canScroll) {
                 velocityX = Math.max(-mMaxFlingVelocity, Math.min(velocityX, mMaxFlingVelocity));
                 velocityY = Math.max(-mMaxFlingVelocity, Math.min(velocityY, mMaxFlingVelocity));