GObject Introspection provides a way for language bindings to access GObject-based libraries without needing separate bindings libraries. It uses annotations in library source code to generate metadata about APIs. When an API changes, only the library needs to be recompiled rather than each language binding. This metadata allows languages to access the libraries directly through a common C-based introspection mechanism.

1. Introduce GObject
Introspection
HanIRC #gnome
gana코코아

2. Typical GObject Application
Development Layer
GLib/GObject
ATK Pango
GTK+
Clutter Gstreamer
Ext Libraries
PyGTK Gtk#
java-
gnome
Gtk2-
Perl
Ruby-
Gnome2
C
Apps
Python
Apps
Mono
Apps
Java
Apps
Perl
Apps
Ruby
Apps

3. If Library apis are changed...
●Library bump version
●PyGtk bump version
●gtk-sharp bump version
●java-gnome bump version
●Gtk2-Perl bump version
●Ruby-Gnome2 bump version
●듣보잡 language binding bump version

5. GI Enabled Development Layer
GLib/GObject
ATK Pango
GTK+
Clutter Gstreamer
Ext Libraries
libffi/libgirepository
C
Apps
Python
Apps
Mono
Apps
Java
Apps
Perl
Apps
Ruby
Apps
Typelib
Typelib
Typelib
Typelib
TypelibTypelib
Typelib
Typelib

6. If Library apis are changed...
●Library bump version (with TypeLib)
●don't need to change each language binding.

7. Overview of GI's Architecture
●http://live.gnome.org/GObjectIntrospection/Architecture
●Annotations in library source codes
ogtk_window_resize()
 http://goo.gl/8i7dx
ogtk_window_get_size()
 http://goo.gl/MOr8a

8. The Difference between GI and CLI
●TypeLib are not bytecodes
but metadata.
●Each Language Host are
just using each C libraries
with libgirepository.
●Each Libraries are CIL
bytecodes.
●Each Language Host must
build/run on CLR.

9. Example 1 for python binding
# using pygtk
import gtk
w = gtk.Window()
w.show_all()
gtk.main()
# using gir
import gi
gi.require_version("Gtk", "2.0")
from gi.repository import Gtk
w = Gtk.Window()
w.show_all()
Gtk.main()

10. Example 2 for js binding (gjs, seed)
imports.gi.versions.Gtk = '3.0'
const Gtk = imports.gi.Gtk;
Gtk.init(null, 0)
w = new Gtk.Window({ type: Gtk.WindowType.TOPLEVEL })
w.show_all()
Gtk.main()

11. Example 3
●WebPreview
ojs version
 http://goo.gl/W4wt3
opython version
 http://goo.gl/lHspm

12. References
●http://live.gnome.org/GObjectIntrospection and subpages
●http://git.gnome.org/browse/