Re: Graph widget, assigning actions to signals

[Havoc Pennington <rhp zirx pair com>]

On Wed, 21 Apr 1999, David Hodson wrote:
> Two questions:
>

wrong list probably - gtk-list is better...
 
>   Is anyone (else) working on a graph widget? I'm thinking of something
> useful for drawing flowcharts, data flow diagrams, that sort of thing.
> Basically a drawing area containing widgets connected by links; one or
> more widgets can be selected and dragged around, with the links staying
> connected. (If not, but you have some suggestions or requests for such
> a widget, let me know.)
> 

GnomeCanvas will let you write this in about 10% of the time you'd spend
with drawing area. No, 5% of the time. Much less time. :-)

There is an app called Dia ('dia' in gtk/gnome CVS) which implements
something like this on a drawing area though.

>   Secondly, are there any hints for assigning events to actions in
> complex widgets, or for allowing user customisation? For example, in
> the graph widget above, I would like a left button drag on the
> background to select the enclosed widgets, while a right button press
> pops up a menu. Is there a convenient way to set this up so that users
> can change these assignments if they wish? I've been looking through
> the 1.2 sources, but the only example I could find seemed pretty
> hardwired.
> 

Use Gnome config files to load and save bindings, or write your own config
file parser/writer. You can load/save button numbers pretty easily I'd
think.

Havoc