Re: [ruby-gnome2-devel-en] How-To Interfaces

[Kouhei S. <ko...@co...>]

Hi,

In <453...@ro...>
  "Re: [ruby-gnome2-devel-en] How-To Interfaces" on Sat, 23 Jul 2016 17:16:33 +0200,
  Thomas Martitz <ku...@ro...> wrote:

>>Ruby-GNOME2 doesn't support implementing interface in
>>Ruby. Because it needs interface specific C code.
>>
> 
> What do you mean with interface specific c code? From my
> current observations it should be possible to extend rbg
> (seems to be the general shorthand for ruby-gnome2 in the
> code so I'll use that) such that you can create classes
> (inheriting gobject) that implement gobject interfaces
> purely in ruby.

Do you know how to implement GObject interface in C?

Here are codes that GtkSizeGroup implements GtkBuildable:

  https://git.gnome.org/browse/gtk+/tree/gtk/gtksizegroup.c#n150
  https://git.gnome.org/browse/gtk+/tree/gtk/gtksizegroup.c#n273

You need to assign pointers of GObject interface functions
like:

  iface->custom_tag_start = gtk_size_group_buildable_custom_tag_start;
  iface->custom_finished = gtk_size_group_buildable_custom_finished;

https://git.gnome.org/browse/gtk+/tree/gtk/gtksizegroup.c#n276

The function type is GObject interface specific. So we need
to create function for each GObject interface functions.

How did you implement GObject interfaces purely in Ruby?

> pygobject can do it after all.

Could you show us how PyGObject do it?

> That's clear. Before I implement a loader I need rbg to
> meet the requirements for libpeas. That's mainly
> supporting interfaces. The libpeas loader would look for
> ruby classes that implement certain interfaces, and
> instantiate them.

You can use Ruby-GNOME2 when you implement the Ruby loader.

> PS: I'm currently having a problem with "rgbobjects" being
> initialized twice if I call g_type_interface_static() for
> it

g_type_register_static()?
I don't know about the details of what you're doing but you
should not call XXX_static() dynamically.


Thanks,
--
kou