I thought flex only rendered what was visible anyway, and to save resources will automatically reuse itemrenderer as they scroll out of view.
Maybe just let flex do its thing and not try to do it manually
also how are the itemrenderes built? I know in mobile projects its recommended that you use AS to build them rather than mxml and not to nest layout containers but lay them out by calculating positions and size with AS.
I've seen Tour de Flex on Android download and render 20,000 lines in seconds. Maybe not the complex itemrenders you use but 20,000 lines on a mobile is pretty impressive.
Thanks for your answer
The reason that we use a custom ItemRenderer is quite complex, but neseccary.
One of the reasons is that ItemRenderers do not handle styling (of skinnable containers f.e.) so well.
Do you have a source for your statement that drawing with AS is quicker than using nested containers?
It sounds interesting. I'm definitely going to preform some tests with it.