package
{
	import flash.display.Sprite;
	import flash.display.StageAlign;
	import flash.display.StageScaleMode;
	import flash.events.Event;
	import flash.events.MouseEvent;
	
	public class animation_ch07_DragAndMove2 extends Sprite
	{
		private var ball:animation_ch07_Ball;
		private var vx:Number;
		private var vy:Number;
		private var bounce:Number = -0.7;
		private var gravity:Number = .5;
		
		public function animation_ch07_DragAndMove2()
		{
			init();
		}
		
		private function init():void
		{
			stage.scaleMode = StageScaleMode.NO_SCALE;
			stage.align=StageAlign.TOP_LEFT;

			ball = new animation_ch07_Ball();
			ball.x = stage.stageWidth / 2;
			ball.y = stage.stageHeight / 2;
			vx = Math.random() * 10 - 5;
			vy = -10;
			addChild(ball);
			ball.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
		
		private function onEnterFrame(event:Event):void
		{
			vy += gravity;
			ball.x += vx;
			ball.y += vy;
			var left:Number = 0;
			var right:Number = stage.stageWidth;
			var top:Number = 0;
			var bottom:Number = stage.stageHeight;
			
			if(ball.x + ball.radius > right)
			{
				ball.x = right - ball.radius;
				vx *= bounce;
			}
			else if(ball.x - ball.radius < left)
			{
				ball.x = left + ball.radius;
				vx *= bounce;
			}
			if(ball.y + ball.radius > bottom)
			{
				ball.y = bottom - ball.radius;
				vy *= bounce;
			}
			else if(ball.y - ball.radius < top)
			{
				ball.y = top + ball.radius;
				vy *= bounce;
			}
		}
		
		private function onMouseDown(event:MouseEvent):void
		{
			//vx = 0;
			//vy = 0;
			stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
			ball.startDrag();
			removeEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
		
		private function onMouseUp(event:MouseEvent):void
		{
			stage.removeEventListener(MouseEvent.MOUSE_UP, onMouseUp);
			ball.stopDrag();
			addEventListener(Event.ENTER_FRAME, onEnterFrame);
		}
	}
}