[Glade-users] custom handlers in libglade and gtk builder

[tristan.van.berkom at gmail.com (Tristan Van Berkom)]

Oh sorry, sometimes the question is so simple that is escapes you :)

If I'm not mistaken, you are talking about set_custom_handler()
from libglade to handle custom properties in the xml... now that
you have a real type - all you need is to support object properties
in the standard way (in C that would be g_object_class_install_property()
from the class initializer).

Cheers,
       -Tristan


On Fri, May 1, 2009 at 11:37 AM, Gerald Britton
<gerald.britton at gmail.com> wrote:
> OK. ?Thanks to your help before, I've been able to define custom
> objects and use them in both glade-3 and GtkBuilder. ?Now, I'm working
> on using these new types to replace the old custom widgets. ?These old
> widgets make us of the set_custom_handler function. ?The custom
> handler that is set by that function, in the current code, on the
> value of the field "Creation Function:" in the definition of the
> custom object in glade. ?So today, I have something like:
>
> ? ? ? ?<widget class="Custom" id="lon_entry">
> ? ? ? ? ?<property name="visible">True</property>
> ? ? ? ? ?<property name="creation_function">ValidatableMaskedEntry</property>
> ? ? ? ? ?<property name="int1">0</property>
> ? ? ? ? ?<property name="int2">0</property>
> ? ? ? ? ?<property name="last_modification_time">Fri, 23 Mar 2007
> 20:18:43 GMT</property>
> ? ? ? ?</widget>
>
> Then, I have this code:
>
> from gtk.glade import set_custom_handler
>
> def get_custom_handler(glade, function_name, widget_name,
> ? ? ? ? ? ? ? ? ? ? ? str1, str2, int1, int2):
> ? ?if function_name == 'ValidatableMaskedEntry':
> ? ? ? ?return ValidatableMaskedEntry()
> ? ?if function_name == 'StyledTextEditor':
> ? ? ? ?return StyledTextEditor()
>
> set_custom_handler(get_custom_handler)
>
> Which, as you can see, returns one of two possible "handlers"
> depending on the value of the "creation function" field.
>
> In my progress so far towards converting these to GtkBuilder, I've
> constructed a custom widget like this:
>
> ? ? ? ? ?<object class="ValidatableMaskedEntry" id="val_mask1">
> ? ? ? ? ? ?<property name="visible">True</property>
> ? ? ? ? ? ?<property name="can_focus">True</property>
> ? ? ? ? ? ?<property name="invisible_char">&#x25CF;</property>
> ? ? ? ? ? ?<property name="text" translatable="yes">valmask</property>
> ? ? ? ? ?</object>
>
> and built a python class to handle it:
>
> import gobject
> import gtk
>
> class ValidatableMaskedEntry(gtk.Entry):
> ? ? ? __gtype_name__ = 'ValidatableMaskedEntry'
>
> ? ? ? def __init__(self):
> ? ? ? ? ? ? ? gtk.Entry.__init__(self)
>
> After setting up the proper env vars and starting glade-3, I can use
> my new custom object. ?Similarly, at run time, I include the class
> definition before calling the add_from_file method on my new glade
> file. ?At this point, all is well.
>
> So, what I need to grasp is what the set_custom_handler function does
> in the old gtk,glade world how to accomplish the same thing in the
> GtkBuilder world, while reusing as much existing code as I can.
> Unfortunately, I found the docs on set_custom_handler a little on the
> terse side. ?They state:
>
> "This gtk.glade.set_custom_handler() function allows you to override
> the default behaviour when a Custom widget is found in an interface. "
>
> which is great but where is the default behavior defined?
>
> On Fri, May 1, 2009 at 11:07 AM, Tristan Van Berkom
> <tristan.van.berkom at gmail.com> wrote:
> > Hi,
> > ? GtkBuilder does not support this method of inserting custom objects
> > in the interface, instead GTK+ now allows all widgets to be loadable
> > with builder and the way GtkBuilder builds your objects can be customized
> > using the GtkBuilder interface.
> >
> > We assume here that if you are not introducing a real type, if you only
> > had a function that created stock widgets manually and returned that;
> > you can easily replace that by adding manually built widgets to a known
> > container in the project.
> >
> > With Glade, we have for a long time supported getting your widget
> > types into the palette and thats been improving over the years,
> > the documentation is pretty up to date but its a little terse (its not
> > a tutorial):
> > ?http://glade.gnome.org/docs/
> >
> > Keep in mind that its possible to mimic your widget type completely
> > by just writing up a few lines of xml, while the docs describe lots of
> > things you can do with a plugin library, usually most of that is unneeded.
> > Also remember that if you provide the actual type at runtime to Glade
> > in the form of a library, Glade will introspect your custom widgets properties
> > and signals etc - if you fake the type in the catalog you'll have to define
> > properties for it manually in the Glade catalog.
> >
> > Cheers,
> > ? ? ? ? ?-Tristan
> >
> > On Fri, May 1, 2009 at 10:36 AM, Gerald Britton
> > <gerald.britton at gmail.com> wrote:
> > > Hi -- I'm converting a project from libglade to gtkbuilder and I've
> > > run into a snag with custom objects. ?In the code I'm working on there
> > > is the line:
> > >
> > > ? ?from gtk.glade import set_custom_handler
> > >
> > > followed by a function definition:
> > >
> > > ? ?def get_custom_handler(glade, function_name, widget_name,
> > > ? ? ? ? ? ? ? ? ? ? ? str1, str2, int1, int2)
> > >
> > > ? ?...
> > >
> > > and
> > >
> > > ? ?set_custom_handler(get_custom_handler)
> > >
> > > I need to know how to do the same sort of thing in the gtkbuilder
> > > world. ?So, how does one set up custom handlers in the gtk.builder
> > > world?
> > >
> > > --
> > > Gerald Britton
> > > _______________________________________________
> > > Glade-users maillist ?- ?Glade-users at lists.ximian.com
> > > http://lists.ximian.com/mailman/listinfo/glade-users
>
>
>
> --
> Gerald Britton