All app windows randomly flash in global repaint

Question

As with many Swing apps I've used, the windows in my app are possessed with some impulse to convulsively repaint their entire contents at random times. This seems to happen most often when a significant paint task is dispatched in one of the windows. The convulsive repaint occurs in all of the app's visible windows, even where a window's contents have not changed in any way. The worst case is when I drag a scrollbar quickly -- it's as if the paint manager is suddenly bewildered by the mouse activity, and dispatches the insidious "paint gray" event to all windows, followed by the normal paint routine in all windows.
I'm very tired of watching my windows flash gray, then casually roll down their buffered contents. Somebody please help!
1) Is there any way to prevent Swing from painting my window gray before invoking the usual painting of contents? I never ever ever want to see my window turn plain gray. Never!
2) Or, can I control the repaint event, so that it is restricted to invocation on windows whose contents have changed? I see no reason to repaint window A in response to a scroll event somewhere in window B. ...it's times like this I wonder if Swing is secretly the result of a high school outreach program.
Many thanks for your help!
Byron

Answer 1

I'm very tired of watching my windows flash gray,
then casually roll down their buffered contents.Yes. I think we all are.
Part of what causes this is the vast size that even a simple java program takes up in memory due to the size of the JRE.
1) Is there any way to prevent Swing from painting
my window gray before invoking the usual paintingYou could probably change the default background color of windows in your windows display preferences, but that's probably not what you want.
There is no want to prevent this from ever happening, but you can make it occur less often by
1. Doing all of your painting to ImageBuffers and just drawing those in your paint method(s)
2. Setting an upper limit to Java's memory that is conservative and automatically restarting it when you get an OutOfMemoryError
of contents? I never ever ever want to see my window
turn plain gray. Never!
2) Or, can I control the repaint event, so
that it is restricted to invocation on windows whose
contents have changed? I see no reason to repaint
window A in response to a scroll event somewhere in
window B. ...it's times like this I wonder if Swing
is secretly the result of a high school outreach
program.
Many thanks for your help!
Byron