package {
    import flash.display.*;
    import flash.events.*;
    import flash.utils.*;  
  
    public class @ax-actionscript-animation-Animation extends Sprite {
      private var distancePerSecond:int = 50;  // Pixels to move per second
      private var now:int;                     // The current time
      private var then:int;                    // The last screen-update time
      private var circle:Shape;                // The object to animate
      
      public function @ax-actionscript-animation-Animation () {
        // Create the object to animate
        circle = new Shape();
        circle.graphics.beginFill(0x0000FF, 1);
        circle.graphics.lineStyle(1);
        circle.graphics.drawEllipse(0, 0, 25, 25);
        addChild(circle);
  
        // Initialize timestamps
        then = getTimer();
        now  = then;
        
        // Register for notification of scheduled screen-update checks
        addEventListener(Event.ENTER_FRAME, enterFrameListener);
      }
  
      //  Handles Event.ENTER_FRAME events
      private function enterFrameListener (e:Event):void {
        // Calculate how much time has passed since the last move
        then = now;
        now = getTimer();
        var elapsed:int = now - then;
        var numSeconds:Number = elapsed / 1000;
        
        // Calculate the amount move based on the amount of time that
        // has passed since the last move
        var moveAmount:Number = distancePerSecond * numSeconds;
        
        // Move the object
        circle.x += moveAmount;
      }
    }
  }