<Swing Dev> JViewport Performance issues

Alexander Potochkin Alexander.Potochkin at Sun.COM
Tue Jun 3 15:40:19 UTC 2008


Hello Chen

Thanks for the information

I wonder if JViewport in the BACKINGSTORE_SCROLL_MODE
works better in this case?

Could you please give more details about the workaround
from JadeDisplay which you mentioned below ?

Thanks
alexp

> Hello Swing Dev,
> 
>  
> 
> Could we get some visibility on bugs 4478765 and 4486696?
> 
>  
> 
> I noticed there are a lot of flash based applications that use the mouse 
> drag to scroll in all directions.  This is a great user interface 
> device, but it currently cannot be implemented in Swing due to 
> performance bug 4486696.
> 
>  
> 
> The current work around is to do something like what JadeDisplay did 
> using their JViewportImage
> 
> http://downloads.openchannelsoftware.org/JadeDisplay/jade_display_2_0.tar.gz
> 
>  
> 
> If you look at the implementation, you’ll see that bug 4478765 made it 
> very difficult.
> 
>  
> 
> This is one of those bugs that developers run into and just continue to 
> think Java has poor performance, while this is actually just an API 
> performance issue.  I’ve tested JViewportImage, and while it only works 
> for opaque components (but can be implemented to work with all 
> components), it improved perceived performance by an order of magnitude 
> when implementing drag scroll.
> 
>  
> 
> Thanks,
> 
> **Ronald Chen**
> 
>  
> 




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