Æliens

  // only visible within file
  
  import flash.display.Sprite;
  import flash.events.Event;
  import flash.geom.Point;
  import flash.geom.Rectangle;
  
  class TossableBall extends Sprite {
          
          private var bounds:Rectangle;
          private var vector:Point = new Point();
          private var friction:Number = .95;
                  
          public function TossableBall(size:Number, throwBounds:Rectangle) {
                  bounds = throwBounds;
                  graphics.lineStyle(1);
                  graphics.beginFill(0xFF8000);
                  graphics.drawCircle(0, 0, size/2);
                  
                  addEventListener(Event.ENTER_FRAME, soar);
          }
          
          public function toss(tossVector:Point):void {
                  vector = tossVector;
          }
          
          private function soar(evt:Event):void {
                  x += vector.x;
                  y += vector.y;
                  var shapeBounds:Rectangle = getBounds(parent);
                  if (shapeBounds.left < bounds.left) {
                          vector.x = Math.abs(vector.x);
                  }else if (shapeBounds.right > bounds.right) {
                          vector.x = -Math.abs(vector.x);
                  }
                  if (shapeBounds.top < bounds.top) {
                          vector.y = Math.abs(vector.y);
                  }else if (shapeBounds.bottom > bounds.bottom) {
                          vector.y = -Math.abs(vector.y);
                  }
                  vector.x *= friction;
                  vector.y *= friction;
          }
  }