Astan Chee wrote:
> I've used ScrollCanvas before and it was awfully slow. My attempt at 
> doing it manually (sticking scrollbars to a frame) was even slower.

That's one of the reasons I didn't do it in the first place! The problem 
with using scroll bars is that they ask the window to re-draw itself 
constantly as you scroll.

I think things could be sped up a lot if you used a method similar to 
what is in place for re-sizing events -- set a up a timer, so that the 
re-draw only happens after a small delay -- that way if the user scrolls 
lot, they will only get the re-draw when they are done, rather than a 
whole bunch of re-draws. Ideally you'd re-blit hte image in the right 
location as you scrolled, so you'd see it move up and down, leaving a 
blank spot, then the blank spot would fill in when the scrolling 
stopped, much like how panning works now.

> So its basically changing the BoundingBox size/limit whenever a 
> scrollbar event is triggered?

No, the other way around -- when the Bounding Box changes, the scroll 
limits would have to change -- that only happens when objects are added 
to or removed from the canvas.

-Chris



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Christopher Barker, Ph.D.
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