ScrollBar

package code.utils {
	import flash.display.MovieClip;
	import flash.geom.Rectangle;
	import flash.events.MouseEvent;
	import flash.display.Stage;
	import com.greensock.TweenLite;
 
 
	public class scroll {
 
		static public function addScroll(scrollBar:MovieClip, content:MovieClip, maska:Number, draha:Number = 270, dolnyOkraj:Number = 0, hornyOkraj:Number = 0):void {
			var stage:Stage = scrollBar.stage;
 
			if (content.height > maska){
				scrollBar.scrollBTN.buttonMode = true;
				scrollBar.scrollBTN.addEventListener(MouseEvent.MOUSE_DOWN, scrollDown);
				stage.addEventListener(MouseEvent.MOUSE_UP, scrollUp);
			} else {
				scrollBar.visible = false;
			}
 
			function scrollDown(e:MouseEvent):void {
				scrollBar.scrollBTN.startDrag(false, new Rectangle(0, 0, 0, draha));
				stage.addEventListener(MouseEvent.MOUSE_MOVE, scrollMove);
			}
 
			function scrollUp(e:MouseEvent):void {
				scrollBar.scrollBTN.stopDrag();
				stage.removeEventListener(MouseEvent.MOUSE_MOVE, scrollMove);
			}
 
			function scrollMove(e:MouseEvent):void {
				var okrajDole:Number = dolnyOkraj;
				var okrajHore:Number = hornyOkraj;
				var maskaHeight:Number = maska;
				var drahaPosuvnika:Number = draha;
				var scrollIndex:Number = -((scrollBar.scrollBTN.y / drahaPosuvnika) * ((content.height + okrajDole + okrajHore) - maskaHeight)) + okrajHore;
				TweenLite.to(content, .4, {y: scrollIndex});
			}
		}
 
	}
 
}