Re: GTK+ canvas?

[Tristan Van Berkom <tristan van berkom gmail com>]

Havoc Pennington wrote:

> Gustavo J. A. M. Carneiro wrote:
>  
[...]

Thanks Havoc for sharing that wealth of notes with us !

I didnt really look  deeply into any of these implementations and I'm 
not commenting
on them per se, but will happily share my thoughts with you :-)

 < Havoc >
 I think an important thing to keep in mind is that a canvas is just an 
alternate
 widget system. You can think of it as a GUI toolkit with different 
tradeoffs from
 GtkWidget, or a GUI toolkit with some of the misfeatures/limitations 
of GtkWidget
 corrected. But in any case it is basically defining the same thing as 
gtkwidget.c,
 gtkcontainer.c and other core GTK classes.

Yes, I think having it all mixable is also a big priority, a notable 
advantage of
GnomeCanvas is the fact that it can easily blend with normal widgets, it 
derives from
GtkContainer - allowing you to add widgets and canvas items.

 < Havoc >
 My opinion is that the canvas should "replace" the GTK core in a way, 
i.e. GtkWidget
 becomes a specialized thing you can embed in a canvas.
 This obviously makes the canvas into a pretty big project.

Kindof disagree here - I think that in most cases a canvas is needed 
when one
leaves the boundries of a simple UI. Core GTK widgets offer standard 
tools for
standard proceedures, stock icons, hig complient dialogs and everything is
supposed to be theme friendly. On the other hand, when you want to plot 
out an accel
sheet or draw a map with clickable "city" items, or anything at all visually
specialized - then you are looking at canvas work.

     < Havoc >
     so having a markup language
     as an integral part of a canvas design is of interest.

   < Gustavo >
   Markup in the text item sounds fine.  Anything else sounds like
   reinventing HTML.

 < Havoc >
 Is Glade reinventing HTML? ;-)

Luckily; since markup language is already an integral part of gtk+ 
design, it wouldnt
have to be part of the canvas design at all - canvases and canvas items 
should simply
be buildable from thier properties and the GtkBuilder should take care 
of it natively.

/me actively discourages yet another seperate builder mechanism in gtk+

Cheers,
                            -Tristan