Fix 6399813: tapping on a photo that isn't in the middle of the screen doesn't select it.

Also make tapping while flinging stop the scroll instead of opening the item.

Change-Id: Iefef4738d7d74b29e4594ea3ae2cb1c91e0e17ab
diff --git a/src/com/android/gallery3d/ui/PositionController.java b/src/com/android/gallery3d/ui/PositionController.java
index 03fe65b..c09ffea 100644
--- a/src/com/android/gallery3d/ui/PositionController.java
+++ b/src/com/android/gallery3d/ui/PositionController.java
@@ -1003,6 +1003,16 @@
         return edges;
     }
 
+    public boolean isScrolling() {
+        return mPlatform.mAnimationStartTime != NO_ANIMATION
+                && mPlatform.mCurrentX != mPlatform.mToX;
+    }
+
+    public void stopScrolling() {
+        if (mPlatform.mAnimationStartTime == NO_ANIMATION) return;
+        mPlatform.mFromX = mPlatform.mToX = mPlatform.mCurrentX;
+    }
+
     ////////////////////////////////////////////////////////////////////////////
     //  Private utilities
     ////////////////////////////////////////////////////////////////////////////