Re: how efficient is the canvas

[Lauris Kaplinski <lauris ariman ee>]

Hello

On Wed, 4 Aug 1999, Christopher T. Lansdown wrote:

> Hi,
> 	I'm planning to use the canvas for displaying html.  Needless to
> say, html pages can get quite big, much larger than a scrolled window.
> Now, a number of projects manually attach scrollbars to a drawing area and
> only draw that portion of a large pixmap that is needed, for speed and
> memory reasons.  Does the canvas do the same thing if the viewport is
> smaller than the canvas?

Yes, it does :-)

  Is the canvas still efficient for very large
> canvases (like the 5,000-15,000+ pixel sizes)?
> 	Also, is the canvas efficient with hundreds or even thousands of
> text items?  Obviously they're going to take up RAM and so forth, I'm not
> expecting the canvas to be magic, just is it reasonable to use it for
> situations like that?  Thanks.
> 	-Chris

There are several possible performance bottlenecks in canvas, but as much
as I've looked at it, they are all caused by temporary workarounds in some
methods. General framework is very good.
You can try out, if performance is sufficent. There is canvas-test section
in gnome-test, which you can populate with as much text items as you want.

Lauris Kaplinski