From 9407e393f9bd3507df8166af5fbbd16f9319ebb7 Mon Sep 17 00:00:00 2001
From: yingleiw <yingleiw@google.com>
Date: Wed, 29 Jan 2020 11:15:19 -0800
Subject: [PATCH] Fix TYPE_VIEW_SCROLLED event in AsListView and ListView

We should always send TYPE_VIEW_SCROLLED event when scroll. This applies
to ACTION_SHOW_ON_SCREEN. And we also need the scroll event when the
first visible item and last visibile item don't change.

Fix: 147907655, 147282475

Test: tested b/147282475 is fixed (this bug is not related to
ACTION_SHOW_ON_SCREEN, it is the scroll forward action).

Change-Id: I2069dc3ee692042ff87867db9837e85ac1d8dd26
---
 core/java/android/widget/AbsListView.java | 26 ++++-------------------
 core/java/android/widget/ListView.java    |  4 ++++
 2 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index 4752eadfe3852..9f03d956f22c1 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -756,9 +756,6 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
      */
     private ListItemAccessibilityDelegate mAccessibilityDelegate;
 
-    private int mLastAccessibilityScrollEventFromIndex;
-    private int mLastAccessibilityScrollEventToIndex;
-
     /**
      * Track the item count from the last time we handled a data change.
      */
@@ -1520,25 +1517,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         onScrollChanged(0, 0, 0, 0); // dummy values, View's implementation does not use these.
     }
 
-    /** @hide */
-    @Override
-    public void sendAccessibilityEventUnchecked(AccessibilityEvent event) {
-        // Since this class calls onScrollChanged even if the mFirstPosition and the
-        // child count have not changed we will avoid sending duplicate accessibility
-        // events.
-        if (event.getEventType() == AccessibilityEvent.TYPE_VIEW_SCROLLED) {
-            final int firstVisiblePosition = getFirstVisiblePosition();
-            final int lastVisiblePosition = getLastVisiblePosition();
-            if (mLastAccessibilityScrollEventFromIndex == firstVisiblePosition
-                    && mLastAccessibilityScrollEventToIndex == lastVisiblePosition) {
-                return;
-            } else {
-                mLastAccessibilityScrollEventFromIndex = firstVisiblePosition;
-                mLastAccessibilityScrollEventToIndex = lastVisiblePosition;
-            }
-        }
-        super.sendAccessibilityEventUnchecked(event);
-    }
+    /**
+     * A TYPE_VIEW_SCROLLED event should be sent whenever a scroll happens, even if the
+     * mFirstPosition and the child count have not changed.
+     */
 
     @Override
     public CharSequence getAccessibilityClassName() {
diff --git a/core/java/android/widget/ListView.java b/core/java/android/widget/ListView.java
index 79ec680f4c525..3c3daa3c70011 100644
--- a/core/java/android/widget/ListView.java
+++ b/core/java/android/widget/ListView.java
@@ -3255,6 +3255,9 @@ public class ListView extends AbsListView {
      */
     @UnsupportedAppUsage
     private void scrollListItemsBy(int amount) {
+        int oldX = mScrollX;
+        int oldY = mScrollY;
+
         offsetChildrenTopAndBottom(amount);
 
         final int listBottom = getHeight() - mListPadding.bottom;
@@ -3327,6 +3330,7 @@ public class ListView extends AbsListView {
         recycleBin.fullyDetachScrapViews();
         removeUnusedFixedViews(mHeaderViewInfos);
         removeUnusedFixedViews(mFooterViewInfos);
+        onScrollChanged(mScrollX, mScrollY, oldX, oldY);
     }
 
     private View addViewAbove(View theView, int position) {