Re: User defined signals for GtkWidget

[Owen Taylor <otaylor redhat com>]

On Sun, 2003-10-26 at 08:50, Matthias Mann wrote:
> In an older documentation of Gtk+ i saw this function:
>     
> gtk_object_class_user_signal_new()
>     
> This could be a good solution for adding a special needed
> signal to an existing GtkWidget without creating a new
> object based on the needed widget class. But this feature
> seems to be removed from Gtk2.x. Had nothing found about in
> API. Is there a similar possibility to add a user defined
> signal to a widget?

Simply pass 0 for the struct_offset field in g_signal_new()
and you'll get the same effect.

But doing this on someone else's class is not a good idea for
the same reason gtk_object_class_user_signal_new() was not 
a good idea ... you are adding that signal to *all* instances
of that widget class, globally in your entire process.

(If you proceed anyways, make sure you use a namespaced
signal name ... e.g., "myprog-something-happened" rather than
"something-happened")

Regards,
                                        Owen