Re: unref-erencing a GtkWindow

[James Henstridge <james daa com au>]

Emmanuel Briot wrote:

> Hello all,
>
> While writting an MDI widget with GtkAda, in which, among other features, the
> user can insert any kind of widget, including a toplevel GtkWindow), I
> encountered the following problem:
>
> It seems that one can not do a gtk_widget_unref() on a GtkWindow.
> The following program results in a segmentation fault.
>
> #include <gtk/gtk.h>
>
> int main (int argc, char** argv) {
>  GtkWidget* win;
>  
>  gtk_init (&argc, &argv);
>  win = gtk_window_new (GTK_WINDOW_TOPLEVEL);
>  gtk_widget_show_all (win);
>
>  gtk_widget_unref (win);
>  //    gtk_widget_destroy (win);
>
>  gtk_main ();
> }
>
>
>
> Whereas if you replace the gtk_widget_unref() by the call to
> gtk_widget_destroy(), the main loop is properly started.
>
> Is this expected ?
>
>
> What I am trying to achieve is that if the user as gtk_widget_ref()-ed the
> widget before putting it in the MDI, then this widget is never destroyed, even
> when removed from the MDI. This can be used for instance to always reuse the
> same instance of the widget when the user wants to open a search dialog in an
> IDE.
> Therefore, I believe I shouldn't call gtk_widget_destroy() explicitely. Am I right ?
>
> Any suggestion would be most welcome.
>
> thanks in advance
>  
You don't own the reference to the GtkWindow, so calling 
g_object_unref()  (or whatever) on it is an error.  However, calling 
gtk_object_destroy() on a GtkWindow is not an error (it is the correct 
way to destroy a toplevel window and all its children).  The GtkWindow 
is then responsible for destroying its children.

James.

--
Email: james daa com au              | Linux.conf.au 2003 Call for Papers out
WWW:   http://www.daa.com.au/~james/ |   http://conf.linux.org.au/cfp.html