>From: Sven Neumann <sven@xxxxxxxx> > >> I checked drawing area widget page in the tutorial but it is empty. >> The drawing area widget is at the top among widgets where I start >> wishing better documentation and tools. It is the place where GTK+ >> ends too soon. > >There are the two scribble examples in the GTK+ tutorial that explain >GTK+/GDK drawing pretty well. I find it difficult to keep up various states of the tools which I want code. I have a modification of the original scribble which has a small rectangle drawing area by default, and more drawing areas can be added by pressing a button. All drawing areas can be grabbed and moved, in wich case they raise at front and follow the pointer. It has a couple of states and tmp variables used when dragging, but the code looks messy. Some kind of state graph routines with state variables would be nice. I have gathered papers on these topics and people have written some kind of state graph systems. Perhaps similar could be provided by GTK. My modified scribble has evolved to software which with I can paint on large float RGB images. Again the images can be grabbed and dragged. Now the problem is that I don't anymore have multiple drawing areas which naturally isolates the events -- now I have to provide my own routines to maintain the multiple images (because all events go to one place only: to drawing area). If the GTK widget system would be extended inside the OpenGL (see my Widget Portal mail in gtk-app-devel), then I could create one polygon per image, receive events to polygons, have callbacks for each polygon. Image rotations and zooms would be easy now, and they could be painted on. As said, it all stops to drawing area. Beyond that I have to start from scratch. BTW, I'm still looking toward the GIMP rectangle selection tool. It may take while because I yet again started doing a perfect job: first a constraint based system, then any vector manipulations are easier to do. When I grab a selection tool edge or vertex, I just set up a constraint which forces the rectangle (or part of it) to follow pointer implicitly. The rectangle tool is simple but I want save the trouble when I want a more complex tool. That kind of systems could be part of GTK. Regards, Juhana _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
