[maemo-developers] Gtkmm's DrawingArea problem

[From: Dinh Khac Thanh]

Hi,

Thank you for your advice. Everything works fine now.

Regards


On Sat, May 31, 2008 at 4:03 PM, Murray Cumming <murrayc at murrayc.com> wrote:

> On Fri, 2008-05-30 at 14:19 +0800, Dinh Khac Thanh wrote:
> > Hi all,
> >
> > I wrote a simple program using gtkmm's DrawingArea widget. It turns
> > out fine (no error) but does not show up in Xephys window. After
> > searching Google I got this:
> [snip]
> > > > Yes, the version of gtkmm that is in the maemo repository uses some
> >
> > > > special optimizations. The most obvious change is that there are no
> > > > default signal handlers, so you must connect a signal handler instead
> of
> > > > just overriding the default one.
> > which I think is my problem (I check on_expose_event and it is not
> > called). But I couldn't find the solution from that link.
> > Could anyone tell me how to solve this? Thnx in advance.
>
> You just need to add this code in your constructor:
>
> #ifndef GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED
> //Connect the signal handler if it isn't already a virtual method
> override:
> signal_expose_event().connect(sigc::mem_fun(*this,
> &Clock::on_expose_event), false);
> #endif //GLIBMM_DEFAULT_SIGNAL_HANDLERS_ENABLED
>
> I am adding that to the clock example in the gtkmm book (in the
> gtkmm-documentation module):
>
> http://www.gtkmm.org/docs/gtkmm-2.4/docs/tutorial/html/sec-drawing-clock-example.html
>
> > Btw, anyone has experiences on using Gnome Canvas in maemo? I am
> > thinking of switching to Gnome Canvas since using Drawing Area/Gdk's
> > Pixmap is a pain to me.
>
> I recommend that you use goocanvas. libgnomecanvas is not really
> maintained now, and people generally avoid using it. goocanvamm exists,
> though I haven't yet used it on Maemo.
>
>
> Do try to use the gtkmm-list mailing list for questions about gtkmm. You
> were lucky that I saw your message on maemo-developers.
>
> --
> Murray Cumming
> murrayc at murrayc.com
> www.murrayc.com
> www.openismus.com
>
>


-- 
Dinh Khac Thanh
Computer Engineering student
National University of Singapore
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