Re: easy newbie question (I think)

[Iago Rubio <iago rubio hispalinux es>]

On Mon, 2004-09-13 at 07:50, Brian Clark wrote:
> Yep.  That seems to be the general consensus, and that's what I'll do.
> I'm just surprised there's not a built in way.

There're some code used by Glade, that can achieve the goal you're
looking for.

It deals with the GObject data, storing pointers to all widgets there,
and using a single function to search the Widgets by name.


// glade generated code, paste it in your project

#define GLADE_HOOKUP_OBJECT(component,widget,name) \
  g_object_set_data_full (G_OBJECT (component), name, \
    gtk_widget_ref (widget), (GDestroyNotify) gtk_widget_unref)

#define GLADE_HOOKUP_OBJECT_NO_REF(component,widget,name) \
  g_object_set_data (G_OBJECT (component), name, widget)


GtkWidget*
lookup_widget                          (GtkWidget       *widget,
                                        const gchar     *widget_name)
{
  GtkWidget *parent, *found_widget;

  for (;;)
    {
      if (GTK_IS_MENU (widget))
        parent = gtk_menu_get_attach_widget (GTK_MENU (widget));
      else
        parent = widget->parent;
      if (!parent)
        parent = (GtkWidget*) g_object_get_data (G_OBJECT (widget),
"GladeParentKey");
      if (parent == NULL)
        break;
      widget = parent;
    }

  found_widget = (GtkWidget*) g_object_get_data (G_OBJECT (widget),
                                                 widget_name);
  if (!found_widget)
    g_warning ("Widget not found: %s", widget_name);
  return found_widget;
}

// end Glade's code


// EXAMPLE 

GtkWidget*
create_dialog (void)
{
        GtkWidget *dialog;
        GtkWidget *dialog_vbox;
        GtkWidget *hbox;
        GtkWidget *label_1;
        GtkWidget *label_2;
        GtkWidget *dialog_action_area;
        GtkWidget *okbutton;
        
        dialog = gtk_dialog_new ();
        gtk_window_set_title (GTK_WINDOW (dialog), _("Miter limit"));
        
        dialog_vbox = GTK_DIALOG (dialog)->vbox;
        gtk_widget_show (dialog_vbox);
        
        hbox = gtk_hbox_new (TRUE, 0);
        gtk_widget_show (hbox);
        gtk_box_pack_start (GTK_BOX (dialog_vbox), hbox, TRUE, TRUE, 0);
        
        label_1 = gtk_label_new (_("Label1"));
        gtk_widget_show (label_1);
        gtk_box_pack_start (GTK_BOX (hbox), label_1, TRUE, TRUE, 0);

        label_2 = gtk_label_new (_("Label2"));
        gtk_widget_show (label_2);
        gtk_box_pack_start (GTK_BOX (hbox), label_2, TRUE, TRUE, 0);

        dialog_action_area = GTK_DIALOG (dialog)->action_area;
        gtk_widget_show (dialog_action_area);
        gtk_button_box_set_layout (GTK_BUTTON_BOX (dialog), GTK_BUTTONBOX_END);

        okbutton = gtk_button_new_from_stock ("gtk-ok");
        gtk_widget_show (okbutton);
        gtk_dialog_add_action_widget (GTK_DIALOG (dialog), okbutton,
GTK_RESPONSE_OK);
        GTK_WIDGET_SET_FLAGS (okbutton, GTK_CAN_DEFAULT);


        g_signal_connect ((gpointer) okbutton, "clicked",
                                        G_CALLBACK (on_okbutton_clicked),
                                        NULL);


        // store pointers to use by lookup widget
        GLADE_HOOKUP_OBJECT_NO_REF (dialog, dialog, "dialog");
        GLADE_HOOKUP_OBJECT (dialog, label_1, "label_1");
        GLADE_HOOKUP_OBJECT (dialog, label_2, "label_2");
        GLADE_HOOKUP_OBJECT (dialog, okbutton, "okbutton");
        
        return dialog;
}

// Examples catching the widgets
void
do_something()
{
        GtkWidget* dialog;
        GtkWidget* label_1;
        GtkWidget* label_2;

        dialog = create_dialog();
        label_1 = lookup_widget(dialog, "label_1");
        label_2 = lookup_widget(dialog, "label_2");

        if( label_1 != NULL && label_2 != NULL ){
                // ......
        }
}

// callback example
void
on_okbutton_clicked(GtkButton* button, gpointer data)
{
        GtkWidget* label_1;
        GtkWidget* label_2;
        
        // you can catch the widget from any widget
        // in the hierarchy, not just from the top level widget

        label_1 = lookup_widget(GTK_WIDGET(button), "label_1");
        label_2 = lookup_widget(GTK_WIDGET(button), "label_2");

        if( label_1 != NULL && label_2 != NULL ){
                // ......
        }       

}
// EXAMPLE end

This code is generated in each Glade's project and works fine.

More on this:
http://developer.gnome.org/doc/API/2.0/gobject/gobject-The-Base-Object-Type.html
http://developer.gnome.org/doc/API/2.0/gobject/gobject-The-Base-Object-Type.html#g-object-set-data
http://developer.gnome.org/doc/API/2.0/gobject/gobject-The-Base-Object-Type.html#g-object-set-data-full
http://developer.gnome.org/doc/API/2.0/gobject/gobject-The-Base-Object-Type.html#g-object-get-data

-- 
Iago Rubio         
- GPG Keyserv  * pgp.rediris.es id=0x909BD4DD