Gallery2: ensure seek gesture happens in allowed area

mFullRect is the rect where seek gesture is allowed.

Change-Id: Ic59f06c6e35c41da3202e129ab0fb179b6c95db2
diff --git a/src/com/android/gallery3d/app/GestureController.java b/src/com/android/gallery3d/app/GestureController.java
index 7a549ee..ca9dd63 100644
--- a/src/com/android/gallery3d/app/GestureController.java
+++ b/src/com/android/gallery3d/app/GestureController.java
@@ -190,7 +190,9 @@
         float currentX = currentEvent.getX();
         float currentY = currentEvent.getY();
         if (Math.abs(currentX - startX) >= GESTURE_THRESHOLD) {
-            return Type.SEEK;
+            if (mFullRect.contains((int) startX, (int) startY)) {
+                return Type.SEEK;
+            }
         } else if (Math.abs(currentY - startY) >= GESTURE_THRESHOLD) {
             if (mBrightnessRect.contains((int) startX, (int) startY)) {
                 return Type.BRIGHTNESS;