package
  {
          import flash.display.Sprite;
          import flash.events.Event;
          import flash.events.MouseEvent;
          
          public class @ax-animation-ch08-Easing2 extends Sprite
          {
                  private var ball:animation_ch08_Ball;
                  private var easing:Number = 0.2;
                  private var targetX:Number = stage.stageWidth / 2;
                  private var targetY:Number = stage.stageHeight / 2;
                  
                  public function @ax-animation-ch08-Easing2()
                  {
                          init();
                  }
                  
                  private function init():void
                  {
                          ball = new animation_ch08_Ball();
                          addChild(ball);
                          ball.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
                          addEventListener(Event.ENTER_FRAME, onEnterFrame);
                  }
                  
                  private function onMouseDown(event:MouseEvent):void
                  {
                          ball.startDrag();
                          removeEventListener(Event.ENTER_FRAME, onEnterFrame);
                          stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
                  }
                  
                  private function onMouseUp(event:MouseEvent):void
                  {
                          ball.stopDrag();
                          addEventListener(Event.ENTER_FRAME, onEnterFrame);
                          stage.removeEventListener(MouseEvent.MOUSE_UP, onMouseUp);
                  }
                  
                  private function onEnterFrame(event:Event):void
                  {
                          var vx:Number = (targetX - ball.x) * easing;
                          var vy:Number = (targetY - ball.y) * easing;
                          ball.x += vx;
                          ball.y += vy;
                  }
          }
  }