Re: Future of Canvas on GTK+ (and probably GNOME)

[Havoc Pennington <hp redhat com>]

On Thu, 2005-02-10 at 19:12 +0100, Jost Boekemeier wrote:
> 
> Since cairo can now be used by gtk apps, writing a gtk
> canvas shouldn't be difficult.  However, it would be
> good if someone could post the issues that the current
> gnome canvas has.  What should be in the gtk canvas,
> what not?
> 

An important question is what a canvas widget is for. In the GNOME 1.x
days, GnomeCanvas was used to implement a lot of custom widgets.
However, in GNOME 2.x that is very uncommon; because of accessibility
concerns and because GTK+ itself provides anti-flicker capabilities.

So it would be interesting to map where the canvas is still used. I'd
assume gnome-games and nautilus for example.

On some level a canvas widget is a kind of alternate widget system
inside GTK+, provided to work around some of the limitations of GTK+
core. Certainly in GNOME 1.x that was one of the main reasons it was
used.

In XUL you can imagine that there's no need for a canvas since you can
use SVG and HTML and so forth; in Microsoft's Longhorn stuff I'm not as
sure how it plays out but the "canvas" type functionality does seem to
be more designed in to the overall toolkit.

Have to get a handle on the target use cases of the canvas I think in
order to design it correctly.

Havoc