I don't know if you noticed it in another thread, but I created a working example of the approach that I described in my earlier email. See:
http://github.com/dov/dovtk-lasso See the program test-dovtk-lasso.c for an example of how to use it. Please let me know if you need more explanations. The source code isn't very well documented yet. Regards, Dov On Wed, Aug 11, 2010 at 20:12, Allin Cottrell <cottr...@wfu.edu> wrote: > On Wed, 11 Aug 2010 jcup...@gmail.com wrote: > > > > > On 11 August 2010 02:14, Allin Cottrell <cottr...@wfu.edu> wrote: > > > rid of GdkGC. I'd imagine that the effect I'm after is something > > > that many GTP apps have need of, and it's trivial to achieve with > > > the GDK API. > > > > I've found that XOR rubber banding is quite hard to do reliably in > > gdk. The problem I think is that you are using the screen pixels to > > store part of the state, and that gets hard to coordinate between the > > various things that can affect the display. > > > > I had mouse movements triggering rect moves, mouse moves with a button > > held down causing background scrolling of the canvas, and mouse moves > > over other screen objects triggering highlight effects. With all these > > things going on at once it became very difficult to get XOR rubber > > bands to not leave annoying trails as they moved. > > > > I switched to an update-model / invalidate-widget / redraw-on-idle > > scheme as Dov suggests and I got prettier updates with less > > complication. Since input and output are decoupled, it'll scale more > > gracefully between slower and faster machines as well, which is nice. > > My drawing case may be simpler than yours -- there's nothing > scrollable in the vicinity -- but I've found that rubber-banding > using GDK_INVERT to "undraw" the last box works flawlessly at > low programming cost. > > But can you suggest a good example to look at for the alternative > approach? Thanks. > > Allin Cottrell > _______________________________________________ > gtk-app-devel-list mailing list > gtk-app-devel-list@gnome.org > http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list > _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
