Add delay for subsequent animations.

Author: JakeLin

iOSAnimationSample/PositionViewController.swift

@@ -34,13 +34,16 @@ class PositionViewController: UIViewController {
 
         UIView.animateWithDuration(1, animations: {
             self.blueSquare.center.x = self.view.bounds.width - self.blueSquare.center.x
+        })
+        
+        UIView.animateWithDuration(1, delay: 0.5, options: nil, animations: {
             self.redSquare.center.y  = self.view.bounds.height - self.redSquare.center.y
-            
+        }, completion: nil)
+        
+        UIView.animateWithDuration(1, delay: 1, options: nil, animations: {
             self.greenSquare.center.x = self.view.bounds.width - self.greenSquare.center.x
             self.greenSquare.center.y  = self.view.bounds.height - self.greenSquare.center.y
-            // <_UIViewAdditiveAnimationAction: 0x7fe17b70df30>
-            // println(self.view.actionForLayer(self.view.layer, forKey: "position"))
-        })
+        }, completion: nil)
     }
 
     /*