Re: Callbacks for windows that return large amounts of data

[Gus Koppel <gtk spamkiller bytechase cx>]

"Luesley, William" wrote:

> If I create a dialog window which obtains a lot of data form the user
> in multiple widgets, what is the best way to get at that data in the
> associated callback function?
>  
> The two thoughts I'd had were either making the widgets required
> global(yuck!),  or using gtk_object_set_data to link all the widgets
> to the parent widget, and then pass the parent widget as data to the
> callback. 
> However, neither of these ideas sounds totally correct to me.

Clarification: I understand your question as asking for a way to obtain
pointers / handles to widgets and not the data / contents / states of
widgets.

For this (the former) purpose Glade provides the lookup_widget ()
function which is only available when the form was created with Glade
and not changed significantly afterwards.

A slightly more generic / independent way is provided by my
widget_find_by_name () function which is available at
http://www.spamkiller.bytechase.cx/democode/widget_find_by_name.c

To use it you just need to pass it a pointer to a suitable container (or
parent window) which can easily be obtained inside any callback function
via (possibly repeated) gtk_widget_get_parent (). No more need for
global variables or other special precautions. However, you should name
your widgets (at least the important ones) comprehensible.

http://developer.gnome.org/doc/API/2.0/gtk/GtkWidget.html#gtk-widget-get-parent
http://developer.gnome.org/doc/API/2.0/gtk/GtkWidget.html#gtk-widget-set-name