example of using ruby and gtkbuilder together

test.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'gtk2'

def gtk_main_quit
    puts "Called quit"
    Gtk.main_quit()
end

def something
    puts "I made something happen!"
end

def zzz
    Thread.new{
        puts "Going to sleep..."
        sleep 3
        puts "Done sleeping!"
    }
end



TheGUI = 'test.ui'

builder = Gtk::Builder.new
builder.add_from_file(TheGUI)
builder.connect_signals{|handler| method(handler)}

Gtk.main

test.ui

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <!-- interface-requires gtk+ 3.0 -->
  <object class="GtkWindow" id="window1">
    <property name="visible">True</property>
    <property name="can_focus">False</property>
    <property name="default_width">440</property>
    <property name="default_height">250</property>
    <signal name="destroy" handler="gtk_main_quit" swapped="no"/>
    <child>
      <object class="GtkLayout" id="layout1">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <child>
          <object class="GtkButton" id="somethingbutton">
            <property name="label" translatable="yes">Something!</property>
            <property name="use_action_appearance">False</property>
            <property name="width_request">100</property>
            <property name="height_request">80</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
            <property name="use_action_appearance">False</property>
            <signal name="clicked" handler="something" swapped="no"/>
          </object>
          <packing>
            <property name="x">151</property>
            <property name="y">33</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton" id="quitbutton">
            <property name="label" translatable="yes">QUIT</property>
            <property name="use_action_appearance">False</property>
            <property name="width_request">100</property>
            <property name="height_request">80</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
            <property name="use_action_appearance">False</property>
            <signal name="clicked" handler="gtk_main_quit" swapped="no"/>
          </object>
          <packing>
            <property name="x">21</property>
            <property name="y">31</property>
          </packing>
        </child>
        <child>
          <object class="GtkButton" id="sleep">
            <property name="label" translatable="yes">zZz</property>
            <property name="use_action_appearance">False</property>
            <property name="width_request">100</property>
            <property name="height_request">80</property>
            <property name="visible">True</property>
            <property name="can_focus">True</property>
            <property name="receives_default">True</property>
            <property name="use_action_appearance">False</property>
            <signal name="clicked" handler="zzz" swapped="no"/>
          </object>
          <packing>
            <property name="x">278</property>
            <property name="y">33</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>