[Glade-devel] [glade3, patch] load library module before calling *_get_type ()

[bighead@users.sourceforge.net]

Hey

"Joaquin Cuenca Abela" <e98cuenc@free.fr> writes:

> Hi!
> 
> Tommi wrote:
> > 
> > Hi,
> > 
> > Please find attached a patch that moves loading of the 
> > library module before the call to foo_get_type() that's 
> > supposedly in that library. 
> > With the patch I was able to get custom widgets to appear in 
> > glade palette.
> 
> Thank you for the patch, but unfortunately it's not correct (even if you're
> right when you say that without it custom widgets don't work).
> 
> The "library" variable refers to the name of the library that contains the
> special functions that may be needed by glade-3 to handle specially some of
> the widgets contained in the real library.
> 
> Let me explain it with an example.
> 
> Let's say that you want to add support for a library that contains a widget
> named foo.  We will call this library libfoo.so.
> 
> If you're lucky, you should be able to add support for this library just
> adding an entry to glade-palette.xml and gtk-base.xml or gtk-additional.xml
> (or eventually another special xml file, let's say gtk-foo-catalog.xml).
> 
> If you need some light customization of the handling of this widget by
> glade-3, you can do it with an special xml file that will be indicated in
> gtk-foo-catalog.xml. One example will be to ignore some property in
> "edition" mode, like "visibility" (however you don't need to handle
> specially "visibility" as it's already done in gtkwidget.xml, and these
> things inherite).  Another example will be to change the default value of
> some properties, when you can't change it in the widget itself (for example,
> because you want to retain backward compatibility).
> 
> And, in the worst of cases, you will need to add special code to handle your
> widget (usually neccesary, but not limited to, containers, for instance, as
> you have to add programatically some placeholders here and there).  That
> special code should go in a special library, with a name derived from the
> name specified in the "library" attribute of your GladeCatalog (it should be
> named "libglade" + library attribute, and it should go in the MODULES
> directory of glade-3). It our case it may be libgladefoo.so.
> 
> That's the library that it's loaded by g_module_open in the code that you
> move with your patch, and it's unrelated to the library that contains the
> real Foo widget.

Intriguing, knew all that but never bothered to comprehend it all in on gigantic piece. Nice :-)

> 
> As you see, there's a missing piece, and it's the code that loads the
> library that contains the Foo widget, as you need it to call the
> foo_get_type function. That is, AFAIR, the only missing thing to make the
> plugable widgets really work.

That is already done! Why that was infact my first patch to glade-3 (back when
it was still called glade-2) :D. You can take a look in glade-widget-class.c
There is some code like, glade_widget_class_get_get_type_func or something.
Tommi... wanna take a shot at it :D

> 
> If you can cook a patch to load that library, it will be great.
> 
> I was thinking about having a special attribute in GladeCatalog to indicate
> the name of the "main" library (libfoo.so), and not reusing the "library"
> attribute for both libraries.

Cheers!
Archit Baweja