actionscript 3 - Check when a part of the MovieClip leaves the Stage -

i'm creating drag , drop game using as3, want check when apart of movieclip outside screen move view behind , let user choose drop it.

i cant' test if movieclip credentials bigger stage (scalemode = no_scale) width/height, because there part of stage it's hidden behind browser window.

it's same aspect mouse_leave time has movieclips, tried see code behind mouse_leave couldn't reach it.

thank you.

main class

[swf(width='800', height='800',backgroundcolor='#cc99ff', framerate='60')] public class dragtest extends sprite {     public function dragtest()     {         addchild(new world(this));          this.stage.scalemode = "noscale";         this.stage.align = "tl";          this.graphics.linestyle(5,0x555555,0.5);         this.graphics.drawrect(0,0,800,800);     } } 

world class

public class world extends container // container swc {     private var _display:sprite;     private var _dragpt:point;     private var _dragedobject:movieclip;      public function world(display:sprite)     {         super();          _display = display;          mymc.addeventlistener(mouseevent.mouse_down, onpickup, false, 0, true );           display.stage.addeventlistener(mouseevent.mouse_up, ondrop, false, 0, true );          display.stage.addeventlistener(event.mouse_leave, onmouseleave, false, 0, true );      }      protected function onmouseleave(event:event):void     {         trace("mouse leaving stage");      }      protected function ondrop(e:mouseevent):void     {         _display.stage.removeeventlistener(mouseevent.mouse_move, onmoveobject);      }         private function onpickup(e:mouseevent)     {         _dragedobject = e.currenttarget movieclip;          _display.stage.addeventlistener(mouseevent.mouse_move, onmoveobject, false, 0, true);     }      protected function onmoveobject(e:mouseevent):void     {         var point:point = new point(_display.stage.mousex, _display.stage.mousey);              (_dragedobject movieclip).x = point.x;             (_dragedobject movieclip).y = point.y;                } } 

here example : simple code

the easiest approach use getbounds(stage) , compare stagewidth , stageheight:

var bounds:rectangle = _draggedobject.getbounds(stage); if (bounds.left < 0) {     // left part of object off-screen } else if (bounds.right > stage.stagewidth) {     // right part of object off-screen } if (bounds.top < 0) {     // top part of object offscreen } else if (bounds.bottom > stage.stageheight) {     // bottom part of object off-screen } 

you move display in each of these cases.