Re: return value from expose event / draw signal of GtkDrawingArea

[Luca Bacci <luca bacci982 gmail com>]

All right, I missed that!
Thank you!
Luca

2018-08-14 18:56 GMT+02:00 Emmanuele Bassi <ebassi gmail com>:

> 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]