[news.eclipse.tools] Re: GC.drawImage()

["Patrick Mueller" <pmuellr@xxxxxxxxx>]

Try adding the style bit SWT.NO_BACKGROUND to your canvas.  The canvas won't
be repainted automatically at all, so you need to ensure that YOU do this;
unless your image ALWAYS COMPLETELY fills the canvas (no empty spaces).
Typical bad behaviour on your part would be background windows bleeding
through (transparency effects) ...

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Patrick_Mueller@xxxxxxx
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"Thomas Mäder" <thomas_maeder@xxxxxxx> wrote in message
news:3ADEEC32.67398288@xxxxxxxxxx
> I'm not an SWT hacker, but you could try this:
>
> 1) use GC.copy(int, int, int, int, int, int, int, int) to copy the area of
the
> image that is still visible in the new scroll position
> 2) only draw the part of the image that has become newly visible because
of
> the scrolling.
>
> but perhaps an SWT guy has a better way?
>
> Thomas
>
> Pratik Shah wrote:
>
> > I have a scrollable canvas where I display an image.  But, the image
> > flickers badly when I scroll.  It seems the drawImage() method of GC is
> > pretty slow.  Is that true?  Anybody else have any similar problems?
Know
> > of any solution?
> >
> > Pratik Shah
>