Hi; On Tue, 14 Aug 2018 at 17:30, Luca Bacci via gtk-app-devel-list < gtk-app-devel-list@gnome.org> wrote:
> Hi, does anyone know what meaning has the return value from expose event > handler (for gtk2) and draw signal (for gtk3) of GtkDrawingArea? > > When one should return TRUE, and when FALSE? > > I can't find any information in the reference manual > The "expose-event" signal in GTK+ 2.x comes from GtkWidget: https://developer.gnome.org/gtk2/stable/GtkWidget.html#GtkWidget-expose-event The "draw" signal in GTK+ 3.x comes from GtkWidget: https://developer.gnome.org/gtk3/stable/GtkWidget.html#GtkWidget-draw They have similar semantics as other signals in GTK+, like the input-related ones: returning TRUE means "I handled this signal emission, so do not propagate it further to other signal handlers"; returning FALSE means "I did not handle this signal emission, so propagate it further to other signal handlers". What "handling" means it depends on what you want to achieve. When using GTK+ 3.x, you're strongly encouraged to use the symbolic constants "GDK_EVENT_PROPAGATE" and "GDK_EVENT_STOP", instead, as they make the code easier to read. Ciao, Emmanuele. -- https://www.bassi.io [@] ebassi [@gmail.com] _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
