Re: Dialog hide/destroy

[muppet <scott asofyet org>]

On Jul 4, 2005, at 10:40 AM, Juan José 'Peco' San Martín wrote:

> Now, I'm trying to do the same but using a main window with Menu  
> widget
> that calls a new "dialog" window. All seems to be ok, but if I close
> dialog window (delete_event) and try to re-open again (clicking on the
> menu of the main one) I get:
>
> Gtk-CRITICAL **: gtk_container_foreach: assertion `GTK_IS_CONTAINER
> (container)' failed at ...
>
> when I try to show the dialog again.

This typically means that you're trying to call ->show on a dead  
widget.  In your delete-event handler, what are you doing?  If your  
handler returns FALSE, the default handler will destroy the window;  
to hide from delete event, you must set up your handler like this:

  $window->signal_connect (delete_event => sub {
        $_[0]->hide;  # hide the window
        return TRUE;  # tell gtk+ that we handled this event, and
                       # that it should *not* destroy the window.
  });



> BTW, what it's the different between of using "hide"/"show" or  
> directly
> "destroy" to control de windows behaviour?. It is always  
> recommended one
> way to do it?. Is it faster vs memory-lesser?

gtk_widget_hide() unrealizes the widget, which takes it off of the  
screen, but does not kill it.  gtk_widget_destroy() hides and then  
renders unusable the widget; the destroy is explicit in order to  
break reference count cycles.

Whether you reuse or recreate widgets is entirely up to you and the  
architecture of your application.  If it takes a lot of work to  
create a widget, or it should retain state between showings, then  
it's likely a good idea to use hide instead of destroy.  Destroying  
the widget will obviously be the more memory-friendly approach.   
There is no "best" way,  in my experience; the answer is, "try both  
and see which better satisfies your goals".



--
To me, "hajime" means "the man standing opposite you is about to hit  
you with a stick".
  -- Ian Malpass, speaking of the Japanese word for "the beginning"