[clue-cert] another simple Ruby Gk program

[Dennis J Perkins]

#! /usr/bin/env ruby

require "gtk2"

# Initialize GTK.
Gtk.init

# Create the toplevel window and make assign title.
win = Gtk::Window.new "Button Example 1"
win.border_width = 5

# Set the default size to a more convenient size.  Note that the button
# size grows and shrinks based on the parameters passed to this method.
win.set_default_size 150, 80

# Note the underscore preceding the O.  This causes the following letter
# to be underlined,  representing a keyboard accelerator.
# To activate the accelerator, press Alt and the key.
button = Gtk::Button.new "_OK"

# Assign an action to the "clicked" signal, otherwise the button will
# not do anything.
button.signal_connect("clicked") { puts "button clicked" }

# Assign an action to the "destroy" signal that is generated when
# The Close button is clickd.  If we don't do this, the pogram does not
# die when the window is destroyed.

win.signal_connect("destroy") {
    Gtk.main_quit
}

# Add button to toplevel window.
win.add button

# Show all widgets.  Compare this to the show method used in the first
# program.
win.show_all

# Start event loop.
Gtk.main