Re: [gtk-list] Should there be a gtk "canvas" widget?

[Tim Janik <timj gimp org>]

On Sun, 15 Feb 1998, Jon Trowbridge wrote:

> If you don't mind extrapolating from two data points, the proper use
> of a the drawing area widget seems to be a FAQ.  (Alois Camenzind
> <camenzind@cyberlink.ch> just asked a question very similar to one I
> sent to this list a week or two ago...)
> 
> For convenience and perhaps just to shave a tiny bit off of the gtk
> learning curve, maybe there should be a "canvas widget" (to borrow a
> name from Tk) that derive from a drawing area and add the tricky bits
> that are frustrating to newbies, namely:
> 
> * Automatically providing an backing pixmap to draw to, handling expose
>   and resize events properly.
> * Allowing all events through.
> * Adding little routines to simplify drawing, setting colors,
>   dealing with GCs, fonts, etc., trading off complete flexibility for
>   some simplicity.
> 
> I'm currently working on a graphing/data visualization program using
> gtk--, and the first thing I did was define a Gtk_Canvas widget that
> did the above.  Then I can derive Gtk_Plot from it and just write code
> like:
> 
> 	plot.set_foreground("red");
> 	plot.draw_line(10,10,plot.width()-10,10);
> 
> This is makes it easy for a novice (like me) to actually write a program
> that does something non-trivial.
> 
> Now I'd be more than happy to clean up this (very simple) code and
> contribute it to gtk--, but it does raise a philosophical question:
> should their be widgets/functionality in gtk-- that doesn't exist in
> gtk+?  Or would it be more proper to add define the canvas object in
> gtk+ and then just make a C++ wrapper for it?  I would think that the
> latter option made more sense --- but that is sufficiently beyond the
> scope of my current understanding gtk+ that I couldn't be much help in
> such an endeavor...

hm, i for one would really like to see this to go into gtk+.
for one thing, this will reduce the questi9ons about GtkDrawingAreas
on this list ;)

> 
> -Jon Trowbridge
>  EMC Capital Management, Inc.
> 

---
ciaoTJ