       self.view.addGestureRecognizer(singleTap)
     }
   }
+  
+  func addPanGesuture() {
+    if self.respondsToSelector(Selector("displayGestureForPanGestureRecognizer:")) {
+      var pan = UIPanGestureRecognizer(
+        target: self, 
+        action: Selector("displayGestureForPanGestureRecognizer:"))
+      self.view.addGestureRecognizer(pan)
+    }
+  }
 }
 
 // MARK: View Handling

  
  func pressedRotationBtn(sender: UIButton) {
    self.isRotate = !self.isRotate
  }
}


    self.initRotationBtn()
    self.onTickTimer()
    self.addTapGesture()
    self.addPanGesuture()
  }
  
  func initBackgroundView() {
