Multi-button instance problem

programming flash
1

Hi there kirupees…

I’ve got this problem with an app that I’m writing - probably because I’m new to OOP & AS3 so forgive me if it’s just school boy stuff!

I’m trying to show 9 instances of a “BkgMatch” movie which each contain three buttons, A, B & C which will trigger various new “pages” to load. I’ve got the movie to animate onto the stage & each instance contains the 3 buttons, all created by a simpleBtn class, but when the buttons are clicked I get a runtime error;

ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
at flash.display::DisplayObjectContainer/getChildIndex()
at formGuide/::mouseDownHandler()

Here’s some of the code…


package
{
    // assume we import all the stuff we need here, and probably loads we don't!
    // ...
    //
    public class formGuide extends MovieClip
    {
        showMatches()
    }
    private function showMatches():void
    {
        // create 9 instances of movie BkgMatch
        var i:Number;
        for (i = 0; i < 9; i++) {
            var y:Number;
            y = 300 + (i * 110);
            var newMatch:BkgMatch = new BkgMatch();
            // set constant for initial y offset for tween start
            var start_y:Number= 300;
            // Setting the match's X and Y position
            newMatch.x = 48;
            newMatch.y = start_y;
            newMatch.name = "MatchID_" + i;
            newMatch.MatchID.text = newMatch.name;
            this.addChildAt(newMatch,10);

            // add 3 btns to the MC instance
            for (var n:Number=1; n <=3; n++)
            {
                var mName:String = new String();
                var xOffSet:Number = new Number();
                if (n == 1) {
                    mName = "A_" + i;
                    xOffSet = 50;
                } else if (n == 2){
                    mName = "B_" + i;
                    xOffSet = 250;
                } else if (n == 3){
                    mName = "C_" + i;                  
                    xOffSet = 450;
                }
                // calling the simpleBtn class to draw the btns
                var btn:simpleBtn = new simpleBtn();
                btn.makeBtns (mName);
                // arrange the buttons in the movie
                   btn.x = xOffSet;
                   btn.y = 70;
                   // add the buttons to the Match MC instance
                   newMatch.addChild (btn);
                // add an eventhandler to the button
                // I think my problems start here...
                btn.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
            }
            // move the matches on in an orderly fashion
            var myPositionTween:Tween;
            myPositionTween = new Tween(newMatch, "y", Regular.easeOut, start_y, y, 20, false);
        }
    }
    // main eventhandler
    private function mouseDownHandler(event:Object):void
    {
       // HERE'S THE PROBLEM!!!!
       var i:uint = getChildIndex(event.target);          
       trace (i);
       // etc...
    }
}

Many thanks…

Ben