Re: Cannot get realize() events on GtkViewport created by libglade

[Tristan Van Berkom <tvb gnome org>]

On Mon, 2007-07-23 at 10:41 -0500, david hagood gmail com wrote:
[...]
> So, my thought was to hook into some "constructor-like" event for some
> container widget, and then create my custom widgets in that event
> callback. That way I could at least begin to make progress.

If you want a temporary way to get started before integrating your
widgets into glade/gazpacho, simply do this:

   - Add a widget to your project that your custom widget derives from,
     for example, GtkLabel for MyCustomLabel
   - search/replace occurences of <widget class="GtkLabel".. for
     <widget class="MyCustomLabel".. in the glade file
   - use glade_xml_register_widget() to tell libglade about
     MyCustomLabel (look at glade-gtk.c from libglade for examples
     of glade_xml_register_widget() & register_custom_prop() funcs).

What kind of widget are you trying to add ? is it a container type ?

See below, I'm including an example glade catalog file that should
get your widget recognized in no time...

> It *looked* like the realize/unrealize events were what I needed, however,
> when I hook them they don't get called. If I change the .glade file to
> hook, say, a button press, my event callbacks happen, so I know that at
> that level my code is working.

I would say that "realize" time is a bad time for rebuilding/reparenting
your widget hierarchy, "realize" is when objects allocate thier gdk
backend resources.

> I am hooking the events as "after" events, so that they should be called
> in addition to any other events.
>
> OK, so - what am I doing wrong here?

If your toplevel widget is visible=True in the glade file then
it will be shown by the time glade_xml_new() returns, so all
the realize handlers have already run before ever connecting
to the signal... if you hide the toplevel and do gtk_window_present()
yourself then you'll be able to get the signal.

Cheers,
                -Tristan

Ok so here is your custom widget catalog for glade 
(goes in /usr/share/glade3/catalogs) :
===================================================
<glade-catalog name="mywidgets" library="mywidgets" depends="gtk+">
  <glade-widget-classes>
    <glade-widget-class name="MyCustomWidget" generic-name="custom"
title="Custom"/>
  </glade-widget-classes>

  <glade-widget-group name="mywidgets" title="My Widgets">
    <glade-widget-class-ref name="MyCustom"/>
  </glade-widget-group>
</glade-catalog>
===================================================

Notes:
   - MyCustomWidget will be used in the glade and also used
     to derive the function name "my_custom_widget_get_type()"
     that nameing scheme must work for libglade to work (and
     also for glade to instantiate your type inside the glade runtime).

   - Currently the "library" xml element is assumed to point to a 
     support module that you can optionally add to
     /usr/share/glade3/modules, we should be also searching standard
     library paths but for now you can simply symlink your library
     to /usr/share/glade3/modules/libmywidgets.so (i.e. we dont need
     support code, but at least we need to open the library that
     contains your actual widget).

   - Using your widget in glade will have the side effect of adding a
     <requires lib="mywidgets"/> element to your glade file, libglade
     will be expecting a module for it, you can cheat around writing a
     module by just calling glade_xml_register_widget() &
     glade_provides() (i.e. funcs that would have been called by the
     module).

That should be enough to get you up and running :)