ScrollPane doesn't work with dynamic content in as3

Question

scrollPane.setSize(400,400);
scrollPane.source=emptyc;

Where emptyc is a container in which I add content dynamically (i.e. by addChild method) doesn't work. It simply doesn't scroll at all.

Neither does work if I add content using scrollPane as a container itself (i.e.:

scrollPane.addChild(myChild);

Answer 1

The problem is the ScollPane instance has no clue you've updated it's content (added a child to emptyc/etc.) so you need to tell it to update().

Here's a basic example:

var b:BitmapData = new BitmapData(2,2,false,0xFFFFFF);
b.setPixel(0,0,0);b.setPixel(1,1,0);
var s:Shape = new Shape();

var sp:ScrollPane = new ScrollPane();
sp.scrollDrag = true;
sp.source = s;
addChild(sp);


s.graphics.beginBitmapFill(b);
s.graphics.drawRect(0,0,1000,1000);
s.graphics.endFill();
sp.update();

Notice that you get the same behaviour you mention if you comment out sp.update();. Also, there's an example in the documentation.