[4650] in java-interest
Re: missing functionality : drawImage != BitBlt/StretchBlt
daemon@ATHENA.MIT.EDU (Pat Niemeyer)
Wed Jan 10 10:30:38 1996
Date: Wed, 10 Jan 1996 07:36:16 -0600 (CST)
From: Pat Niemeyer <pat@icon-stl.net>
To: Jim Graham <flar@bendenweyr.Eng.Sun.COM>
Cc: jonl@sealevelsoftware.com, java-interest@java.Eng.Sun.COM
In-Reply-To: <9601100118.AA26981@bendenweyr.Eng.Sun.COM>
On Tue, 9 Jan 1996, Jim Graham wrote:
>
> If you know that a particular region has new data, but that you might
> get even newer data soon, the timeout argument provides a way to throttle
> the updates by scheduling them in the future. The part of your application
> or applet that is responsible for receiving new data and incorporating it
> into your internal state can then be independent of the part of your code
> that is responsible for redrawing it. The "data integrator" part simply
> uses a timeout in its repaint call that represents the maximum refresh
> rate that you believe is practical to maintain and the system will collapse
> the update callbacks as appropriate. As a result, you will end up repainting
> with the new changes within a specified amount of time after receiving them
> but you won't constantly be redrawing everything for each and every change
> in those situations where they come in faster than is reasonable to do the
> repaints...
What I'm a little confused about is how repaint(time x, y, width, height)
is useful. Are there situations where having AWT set the clipping region
for you "right before" you paint is "good enough"?
The way I've looked at it, if I have a changing data "model" my update()
method has to select a particular (and maybe consistent) "view" of it, set
clipping based on knowledge of the last view that it drew and then let paint()
paint that view.
Is repaint(time,x,y,w,h) just useful if I know that my data model won't be
changing for 'time' milliseconds? Or maybe I don't care if it clips the
wrong area because another repaint() will come along afterwards and clean
up?
Pat
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