Improve previews display and allow to jump directly to any screen.

Change-Id: I87e7a6a53f286ab7a04657e1598a947f9302e2a1
diff --git a/src/com/android/launcher2/CellLayout.java b/src/com/android/launcher2/CellLayout.java
index 05fc20c..6970875 100644
--- a/src/com/android/launcher2/CellLayout.java
+++ b/src/com/android/launcher2/CellLayout.java
@@ -21,6 +21,7 @@
 import android.content.res.Resources;
 import android.graphics.Rect;
 import android.graphics.RectF;
+import android.graphics.Canvas;
 import android.util.AttributeSet;
 import android.view.ContextMenu;
 import android.view.MotionEvent;
@@ -105,6 +106,11 @@
     }
 
     @Override
+    public void dispatchDraw(Canvas canvas) {
+        super.dispatchDraw(canvas);
+    }
+
+    @Override
     public void cancelLongPress() {
         super.cancelLongPress();