commit c2a47a2eedbaf21e1a98ae7ea988a5e2212627ce
author Aga Madurska <amad@google.com> Wed Sep 07 12:54:53 2016 +0100
committer Yigit Boyar <yboyar@google.com> Tue Sep 13 19:41:34 2016 +0000
tree 00b0e6e733337ddeea9751d6b59414f8f8eef7a3
parent 504771a81d16019eb518e8186fab240f04a8d967

Don't snap to center if the scroll position doesn't change.

The underlying casue of the issue is that the RecyclerView
changes the scroll state to settling before it figures out
whether it will actually scroll by any distance.

Bug:31304796

Change-Id: I606a714de6e308bd4958ab17dc607602b88d0c4d
(cherry picked from commit 6004bb47ebf40a36ab049c79b27a7b8065db4970)

v7/recyclerview/src/android/support/v7/widget/SnapHelper.java

diff --git a/v7/recyclerview/src/android/support/v7/widget/SnapHelper.java b/v7/recyclerview/src/android/support/v7/widget/SnapHelper.java
index 27047a2..915556e 100644
--- a/v7/recyclerview/src/android/support/v7/widget/SnapHelper.java
+++ b/v7/recyclerview/src/android/support/v7/widget/SnapHelper.java
@@ -42,13 +42,22 @@
     // Handles the snap on scroll case.
     private final RecyclerView.OnScrollListener mScrollListener =
             new RecyclerView.OnScrollListener() {
+                boolean mScrolled = false;
+
                 @Override
                 public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                     super.onScrollStateChanged(recyclerView, newState);
-                    if (newState == RecyclerView.SCROLL_STATE_IDLE) {
+                    if (newState == RecyclerView.SCROLL_STATE_IDLE && mScrolled) {
+                        mScrolled = false;
                         snapToTargetExistingView();
                     }
                 }
+
+                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
+                    if (dx != 0 || dy != 0) {
+                        mScrolled = true;
+                    }
+                }
             };
 
     @Override