Re: GTK+ canvas?

[Damon Chaplin <damon karuna uklinux net>]

On Tue, 2006-09-19 at 11:20 -0400, Havoc Pennington wrote:
> Hi,
> 
> Damon Chaplin wrote:
> > So how are we going to decide on a list of requirements for a canvas?
> > 
> > I think there seem to be two main use cases:
> > 
> >  A) DTP/Graphics apps that want a canvas for the main document.
> >     (A model/view split, device-independent layout, zooming & printing
> >     are important here.)
> > 
> >  B) Flashy user interfaces.
> >     (Support for embedded widgets is useful here.)
> 
> My basic feeling is that a) should be a separate lib and b) should be in 
> gtk, but both are potentially useful. a) might or could be a little 
> different api as Soeren was talking about, I don't know. b) is the one I 
> have the most experience with.
> 
> > Can we even agree on 2 fundamental requirements:
> > 
> >  1) Should the canvas & items have a model/view split?
> >     - It is very useful for (A) above but makes (B) awkward.
> 
> For b) I don't think it's very important.

I think it may actually be possible to make the model optional. (For a
simple canvas you would add items & groups yourself, but if you set a
model the canvas connects to the model's "item-added/moved/removed"
signals and creates/updates the canvas items automatically.)

The only downside is that canvas items would have to be either simple
items or model/view items. (I'd turn the basic items into simple canvas
items, since they probably aren't that useful for large model/view apps
anyway.)

Is it worth trying that?



> missing (from your list anyway), some important, some nice:
> o Widget embedding
> o Layout

I'd be willing to try to support these as well (though someone else can
sort out the widget embedding limitations if they want to).


Damon