MessageDialog.ShowModalWithin frequently causes the parent window to blink


“Using MessageDialog.ShowModalWithin often causes the parent window to blink. The content behind the parent seems to play a role, as the IDE does it sometimes but Chrome does it nearly every time. It seems almost as if the windows are cycling.”

The feedback report contains a sample project and demo videos. Posted here to gain awareness, as this is a rather obnoxious bug.

I looked the video, yup pretty strange.

I wonder if when a modal window , in fact any window maybe, is shown a message is sent to the window behind. But that would be carried out by the OS.

What happens if the modal window is completely contained within the parent ?

I have never used MessageDialog.ShowModalWithin, it looks like in Windows should work the same as ShowModal right?

My alerts all go through helper methods, so my workaround strategy is to switch to ShowModal on Windows. But a bug is a bug even if worked around.