Re: colormap assertion errors

[Murray Cumming <murrayc murrayc com>]

On Mon, 2004-11-29 at 21:54 -0600, Rob Benton wrote:
> I've narrowed down the error to one variable, the Gdk::Colormap.  That's 
> what's failing the assertion with:
> 
> -ERRORS---------------------------------------------------------
> (chip:3201): GLib-GObject-CRITICAL **: file gobject.c: line 1579 
> (g_object_unref): assertion `G_IS_OBJECT (object)' failed
> (chip:3201): Gdk-CRITICAL **: file gdkcolor-x11.c: line 690 
> (gdk_colormap_free_colors): assertion `GDK_IS_COLORMAP (colormap)' failed
> ----------------------------------------------------------------
> 
> I'm declaring a Gtk::DrawingArea member variable on the stack and a 
> Glib::RefPtr<Gdk::Colormap> member variable.  Then I'm using this line 
> inside the class' constructor:
> 
> -CODE-----------------------------------------------------------
> _colormap = _drawarea.get_default_colormap();
> ----------------------------------------------------------------

I have discovered a bug in Gtk::Widget::get_default_colormap(). It needs
a "refreturn" in the .hg file. I'll fix that.

As a workaround for now, you should be able to using
Gdk::Screen::get_default()->get_default_colormap(). However, you need at
least gtkmm 2.4.6, because Screen::get_default() used to have the same
problem.

By the way, Gtk::Widget::get_default_colormap() is a static function, so
you don't need the _drawarea instance in order to call it.
 
-- 
Murray Cumming
murrayc murrayc com
www.murrayc.com
www.openismus.com