Fix bug 3362258 - Fastscroll is out of sync with the list

Change-Id: I13282bfed355f5794041e83818ee2e9e97c1b318

2 files changed, 22 insertions, 0 deletions

diff --git a/core/java/android/widget/AbsListView.java b/core/java/android/widget/AbsListView.java
index d8f597207dac..f85772ca898e 100644
--- a/core/java/android/widget/AbsListView.java
+++ b/core/java/android/widget/AbsListView.java
@@ -5315,6 +5315,24 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
         mRecycler.mRecyclerListener = listener;
     }
 
+    class AdapterDataSetObserver extends AdapterView<ListAdapter>.AdapterDataSetObserver {
+        @Override
+        public void onChanged() {
+            super.onChanged();
+            if (mFastScroller != null) {
+                mFastScroller.onSectionsChanged();
+            }
+        }
+
+        @Override
+        public void onInvalidated() {
+            super.onInvalidated();
+            if (mFastScroller != null) {
+                mFastScroller.onSectionsChanged();
+            }
+        }
+    }
+
     /**
      * A MultiChoiceModeListener receives events for {@link AbsListView#CHOICE_MODE_MULTIPLE_MODAL}.
      * It acts as the {@link ActionMode.Callback} for the selection mode and also receives
diff --git a/core/java/android/widget/FastScroller.java b/core/java/android/widget/FastScroller.java
index dfa94c75aaaa..200c870f3790 100644
--- a/core/java/android/widget/FastScroller.java
+++ b/core/java/android/widget/FastScroller.java
@@ -476,6 +476,10 @@ class FastScroller {
         }
     }
 
+    public void onSectionsChanged() {
+        mListAdapter = null;
+    }
+
     private void scrollTo(float position) {
         int count = mList.getCount();
         mScrollCompleted = false;