Gedit 3 Plugin Sample

Required bindings are for:

Gedit >= 3.0 (gedit.vapi for gedit 3.0+ is automatically generated from upstream and usually distributed with gedit development packages)
GtkSourceView >= 3.0 (gtksourceview-3.0.vapi is automatically generated from upstream and distributed with Vala)
PeasGtk >=1.0 (libpeas-gtk-1.0.vapi is automatically generated from upstream and distributed with Vala)

...and Vala >= 0.11

Source & support files

A Gedit plugin compiled from Vala/Genie source files is composed of just two files: a library (.so) and the plugin file definition (.plugin).

Our example plugin will be contained in just one Vala soure file, so the directory listing at the start will be:

$ ls
gedit-3-example.plugin
gedit-3-example-plugin.vala

In order to make the example really simple we decided to implement a very basic function: the plugin will just close an xml tag upon writing the '>'. Eg. if you write <test> it will add the corresponding </test> close tag.

Source code for the file: gedit-3-example-plugin.vala

using GLib;

namespace GeditPluginExample
{
        /*
         * This class will be instantiated and activated for each Gedit View
         */
        public class View : Gedit.ViewActivatable, Peas.ExtensionBase
        {
                public View ()
                {
                        GLib.Object ();
                }

                public Gedit.View view {
                         owned get; construct;
                }
                
                public void activate ()
                {
                        print ("View: activated\n");
                        view.key_release_event.connect (this.on_key_release);
                }
                
                public void deactivate ()
                {
                        print ("View: deactivated\n");
                        view.key_release_event.disconnect (this.on_key_release);
                }
                
                private bool on_key_release (Gtk.Widget sender, Gdk.EventKey event)
                {
                        if (event.str == ">") {
                                // Close the tag
                                Gedit.View view = (Gedit.View)sender;
                                Gtk.TextBuffer buffer = view.get_buffer ();
                                Gtk.TextIter end, start;

                                buffer.get_iter_at_mark (out end, (Gtk.TextMark) buffer.get_insert ());
                                if (end.backward_char ()) {
                                        start = end;
                                        if (start.backward_word_start ()) {
                                                string tag = "</%s>".printf (buffer.get_text (start, end, false));

                                                // add the closing tag
                                                buffer.begin_user_action ();
                                                buffer.insert_interactive_at_cursor (tag, -1, true);
                                                buffer.end_user_action ();

                                                // move cursor back
                                                buffer.get_iter_at_mark (out end, (Gtk.TextMark) buffer.get_insert ());
                                                end.backward_chars (tag.length);
                                                buffer.place_cursor (end);
                                        }
                                }
                        }
                        return true;
                }
        }

        /*
         * Plugin config dialog
         */
        public class Config : Peas.ExtensionBase, PeasGtk.Configurable
        {
                public Config () 
                {
                        Object ();
                }

                public Gtk.Widget create_configure_widget () 
                {
                        return new Gtk.Label (" Gedit 3.0 Example Vala Plugin ");
                }
        }
}

[ModuleInit]
public void peas_register_types (TypeModule module) 
{
        var objmodule = module as Peas.ObjectModule;

        // Register my plugin extension
        objmodule.register_extension_type (typeof (Gedit.ViewActivatable), typeof (GeditPluginExample.View));
        // Register my config dialog
        objmodule.register_extension_type (typeof (PeasGtk.Configurable), typeof (GeditPluginExample.Config));
}

Contents of the plugin definition file: gedit-3-example.plugin

[Plugin]
Module=gedit-3-example-plugin.so
IAge=2
Name=Vala Example Plugin
Description=A simple Vala Example Plugin
Authors=Andrea Del Signore <sejerpz@tin.it>
Copyright=Copyright © 2011 Andrea Del Signore
Website=http://wiki.gnome.org/Projects/Vala/Gedit3PluginSample

Compiling & Installing

$ valac \
    --pkg gtk+-3.0 \
    --pkg gedit \
    --pkg libpeas-gtk-1.0 \
    --pkg gtksourceview-3.0 \
    gedit-3-example-plugin.vala \
    -X --shared \
    -X -fPIC \
    --library libgedit-3-example-plugin \
    --output libgedit-3-example-plugin.so
$ cp libgedit-3-example-plugin.so gedit-3-example.plugin ~/.local/share/gedit/plugins/

Running

Start gedit 3 and enable the plugin from the edit -> preference menu

Vala/Examples