Apache – Flex: Testing UI components at the click level

I had a similar issue and I handled it like this.

on the validators I add valid and invalid functions which then changed the background color of the text box or whatever form elements you want. Here is a snippet of code:

<mx:StringValidator valid="handleValid(event)" invalid="handleValid(event)"/>


private function handleValid(event:ValidationResultEvent):void{
  if(event.type== ValidationResultEvent.VALID){
    TextInput(event.target.source).styleName = "validTextStyle";
  }
  else{
    TextInput(event.target.source).styleName = "inValidTextStyle";
  }
}

Then I had styles the turned the background color of the textInput Red for invalid and white for valid

Yes, Flex is not designed to support very large numbers of components, it is well known that you should minimize the number of components and don't use features that you don't need (Eg. DisplayObject instead of Canvas if you don't need the extra functions).

It's unwise to mirror your data exactly with displayed objects. DisplayObjects (and related classes) are relatively heavyweight, and you need to control how many of those you have.

I would say that the scale you're working at, with 1000+ Cells, and an event listener for each one, would definitely reach Flex's limits.

I think you should take a better look at your approach and architecture. I assume you are not displaying all 1000+ items at the same time, perhaps you should use paging and display 100ish with each screen, with previous/next buttons to move on to another page. You could also consider dynamically adding and removing rows using a custom scrollbar, simulating the scroll effect. This is much more complicated to do.