Dynamic ScrollPane wont scroll

programming flash
1

I know this is a common problem but I can’t seem to figure out the solution. I have a container movieclip which I am adding other clips to by looping through an array of said clips. I have set the source of the scrollpane set as the container movieclip but the pane wont scroll. I have confirmed this by tracing the height of the container and it’s 0. I’ve tried invalidate() refreshPane() and update() but none of these seem to help. I’m working in 100% AS 3 within Flex Builder.

Simplified from within a class that extends ScrollPane:


this.setSize(490, 440);
storeBG = new MovieClip();
this.source = storeBG;
for (var i=0; i < storeItems.length; i++) {
      var item = storeItems*;
      storeBG.addChild(item);
      this.invalidate();
      this.update();               
}

So the scrollPane is the correct size, and displays the objects correctly, but it just cuts them off at the bottom instead of enabling the scrollbar for vertical scrolling. This can be seen in the picture

Thanks for your help