Re: retain image among multiple draw events
Stefan Salewski <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
On Tue, 2015-06-16 at 13:53 +0530, Lokesh Chakka wrote: > hello, > > I am using GtkDrawingArea for drawing images using cairo graphics. I > connected one call back function for draw event. > This call back will be executed multiple times. I am observing that, what > ever drawing happened in the previous call, is disappearing when the same > call back function is called next time. > > I want to know how to retain the previously drawn image. If it is a sample > program, it will be more helpful to me. > Can some body please help me in this ? > Your observation seems to be wrong. When you investigate the GTK3 drawing area example from https://developer.gnome.org/gtk3/3.0/gtk-getting-started.html you will see, that motion_notify_event_cb in called when mouse is moved, and that function calls draw_brush() only for current coordinate -- earlier drawing is conserved. You may investigate your code, maybe there is a background clear operation involved. Or your logic of processing events is wrong. Try to follow that example. -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo