Re: drawing area and button press event

[Yiannis <odysseus lost gmail com>]

On 12/08/05, Yiannis <odysseus lost gmail com> wrote:
> On 12/08/05, Michal Porzuczek <mporzuczek gmail com> wrote:
> > On 8/12/05, Yiannis <odysseus lost gmail com> wrote:
> > > Hi,
> > >
> > > my callback on the button press event seems not to be called... in
> > > fact I am not sure if a button press event occurs. Find below a simple
> > > program (using glade/libglade) that makes a drawing area and a 2
> > > callbacks... The expose event and the button press event callback.
> >
> > Hi,
> >
> > I'm not 100% sure since I've never used Glade before and I'm not sure
> > if it takes care of it, but I know with GTK  you have to include:
> >
> > gtk_widget_set_events (Drawing_Area, GDK_EXPOSURE_MASK
> >                         | GDK_LEAVE_NOTIFY_MASK
> >                         | GDK_BUTTON_PRESS_MASK);
>
> Cheers, this missing bit on my code seems to be the problem, as if you
> take it out from the original scribble tutorial program there are no
> "responses" to button press events. However, firstly I never
> understood what is meant by  the following (taken from the gtk
> tutorial)
>
> "As for other signals, to determine what happens when an event occurs
> we call gtk_signal_connect(). But we also need let GTK know which
> events we want to be notified about. To do this, we call the function:
> gtk_widget_set_events"
>
> Doesn't gtk sends these events??? And what these have to do with the
> button press event?
>
> Anyway including this on my code gives me the following error:
> (md:9727): GLib-GObject-CRITICAL **: g_object_unref: assertion
> `G_IS_OBJECT (object)' failed
>
> which if I recall well it has to do with when you call
> gtk_widget_set_events, I think it has to go before showing the
> toplevel widget.... but in my case the only thing I can do is hide the
> window and gtk_widget_show after setting the events... which I tried
> and still gives the same error.

To kind of close the matter. As it is written in the gtk doc:
"This function (gtk_widget_set_events()) must be called while a widget
is unrealized. Consider gtk_widget_add_events() for widgets that are
already realized"

Upon calling glade_xml_new all widgets maybe are realised. It seems
that  the gtk_widget_add_events() does the job. Although I am still
getting this annoying error message not understanding why:
GLib-GObject-CRITICAL **: g_object_unref: assertion `G_IS_OBJECT
(object)' failed

-- 
-- Yiannis