Is measure() being called? If explicitWidth/Height get set somehow (like to 0), then measure won't get called and you'll get sized at 0x0
Yes measure() gets called and the measured values are set to the expected values by the time updateDisplayList() gets called. I never set the explicitWidth/Height (or the width/height), so if it's set to 0,0 that would be done by the Flex framework somewhere... which I would have thought it would set it to measuredMinWidth/Height at the least?
You could set breakpoints to see if explicitWidth/Height is getting set in some surprising way. Could maxWidth/maxHeight be set to 0? That could also mess it up.
One more thing is that the component is given its size by its parent. If the parent is 0x0 that could also cause trouble. Or some other part of the layout logic is trumping the measuredWidth/Height. In theory there should be a call to setActualSize or setLayoutBoundsSize. A breakpoint there should help you figure out the logic that determined the size.