Re: Gdk problem.

[Michael J M Thomson <mjmt internode on net>]

PerBeatus wrote:
> Hi.
>
> Simple question. Why it compiles ok, and at run prints "segmentation 
> fault" ?
>
>     Gtk::Main main(argc, argv);
>
>     Gtk::Window w;
>
>     Gdk::Color c_red;
>     c_red.set_red(65535);
>
>     Glib::RefPtr<Gdk::Window> gdk_w = w.get_frame();
>     gdk_w->set_background(c_red);

I don't think Gtk::Window::get_frame() does what you're expecting. It actually 
only returns a valid Gdk::Window when GTK is providing its own window frames*, 
which on most platforms (X, Windows, etc) isn't the case, given window frames 
are provided by a separate window manager process or the OS, so it isn't really 
useful for GTK to give programs access to them. Instead get_frame() returns a 
Glib::RefPtr<Gdk::Window> containing NULL, hence your segfault.

By the way, not everybody likes red. ;) If you want to draw attention to your 
window, try Gtk::Window::set_urgency_hint(). Or possibly you were just looking for:
  w.modify_bg(Gtk::STATE_NORMAL, Gdk::Color("red"));

[*] I think GTK only does this with DirectFB, which doesn't or didn't always 
provide window management.