auto import from //branches/cupcake/...@125939

1 files changed, 47 insertions, 5 deletions

diff --git a/core/java/android/widget/Gallery.java b/core/java/android/widget/Gallery.java
index d886155f3aef..cabca4024d26 100644
--- a/core/java/android/widget/Gallery.java
+++ b/core/java/android/widget/Gallery.java
@@ -56,7 +56,13 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
     private static final String TAG = "Gallery";
 
     private static final boolean localLOGV = Config.LOGV;
-    
+
+    /**
+     * Duration in milliseconds from the start of a scroll during which we're
+     * unsure whether the user is scrolling or flinging.
+     */
+    private static final int SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT = 250;
+
     /**
      * Horizontal spacing between items.
      */
@@ -104,6 +110,17 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
      * Executes the delta scrolls from a fling or scroll movement. 
      */
     private FlingRunnable mFlingRunnable = new FlingRunnable();
+
+    /**
+     * Sets mSuppressSelectionChanged = false. This is used to set it to false
+     * in the future. It will also trigger a selection changed.
+     */
+    private Runnable mDisableSuppressSelectionChangedRunnable = new Runnable() {
+        public void run() {
+            mSuppressSelectionChanged = false;
+            selectionChanged();
+        }
+    };
     
     /**
      * When fling runnable runs, it resets this to false. Any method along the
@@ -142,6 +159,12 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
     private boolean mReceivedInvokeKeyDown;
     
     private AdapterContextMenuInfo mContextMenuInfo;
+
+    /**
+     * If true, this onScroll is the first for this user's drag (remember, a
+     * drag sends many onScrolls).
+     */
+    private boolean mIsFirstScroll;
     
     public Gallery(Context context) {
         this(context, null);
@@ -861,8 +884,13 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
     public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
         
         if (!mShouldCallbackDuringFling) {
+            // We want to suppress selection changes
+            
+            // Remove any future code to set mSuppressSelectionChanged = false
+            removeCallbacks(mDisableSuppressSelectionChangedRunnable);
+
             // This will get reset once we scroll into slots
-            mSuppressSelectionChanged = true;
+            if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true;
         }
         
         // Fling the gallery!
@@ -891,13 +919,24 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
         
         // As the user scrolls, we want to callback selection changes so related-
         // info on the screen is up-to-date with the gallery's selection
-        if (mSuppressSelectionChanged) {
-            mSuppressSelectionChanged = false;
+        if (!mShouldCallbackDuringFling) {
+            if (mIsFirstScroll) {
+                /*
+                 * We're not notifying the client of selection changes during
+                 * the fling, and this scroll could possibly be a fling. Don't
+                 * do selection changes until we're sure it is not a fling.
+                 */
+                if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true;
+                postDelayed(mDisableSuppressSelectionChangedRunnable, SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT);
+            }
+        } else {
+            if (mSuppressSelectionChanged) mSuppressSelectionChanged = false;
         }
         
         // Track the motion
         trackMotionScroll(-1 * (int) distanceX);
-        
+       
+        mIsFirstScroll = false;
         return true;
     }
     
@@ -917,6 +956,9 @@ public class Gallery extends AbsSpinner implements GestureDetector.OnGestureList
             mDownTouchView.setPressed(true);
         }
         
+        // Reset the multiple-scroll tracking state
+        mIsFirstScroll = true;
+        
         // Must return true to get matching events for this down event.
         return true;
     }