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

Fri May 1 11:45:23 EDT 2009

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
>