[Hiki] update - tut-gtk-helloworld2 (ruby-gnome2-doc-cvs) - Ruby-GNOME2

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REMOTE_ADDR = 200.216.151.125
REMOTE_HOST = 
        URL = http://ruby-gnome2.sourceforge.jp/en/?tut-gtk-helloworld2
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+ {{link "tut-gtk-signals-more", nil, "tut-gtk", "tut-gtk2-packing-intro"}}
  = An Upgraded Hello World

  {{image_right("helloworld2.png")}}

  Let's take a look at a slightly improved helloworld with better examples of callbacks block. 
  This will also introduce us to our next topic, packing widgets.

    #!/usr/bin/env ruby

    # Initializes Ruby/GTK2, as usual.
    require 'gtk2'
    Gtk.init

    # A push on a button will call this method.
    def callback(widget)
      # Display the 'label' property of the widget.
      # Refer to the API reference for more information.
      puts "Hello again - #{widget.label}(#{widget}) was pressed."
    end

    # Creates the window.
    window = Gtk::Window.new

    # Specify the title and border of the window.
    window.title = "Hello Buttons"
    window.border_width = 10

    # The program will directly end upon 'delete_event'.
    window.signal_connect('delete_event') do
      Gtk.main_quit
      false
    end

    # We create a box to pack widgets into.  
    # This is described in detail in the following section.
    # The box is not really visible, it is just used as a tool to arrange 
    # widgets.
    box1 = Gtk::HBox.new(false, 0)

    # Put the box into the main window.
    window.add(box1)

    # Creates a new button with the label "Button 1".
    button1 = Gtk::Button.new("Button 1")

    # Now when the button is clicked, we call the "callback" method
    # with a reference to "button 1" as its argument.
    button1.signal_connect( "clicked" ) do |w|
      callback(w)
    end

    # Instead of window.add, we pack this button into the invisible
    # box, which has been packed into the window.
    box1.pack_start(button1, true, true, 0)

    # Do these same steps again to create a second button.
    button2 = Gtk::Button.new("Button 2")

    # Call the same callback function with a different argument,
    # passing a reference to "button 2" instead.
    button2.signal_connect("clicked") do |w|
      callback(w)
    end

    # Pack the second button in a box as well.
    box1.pack_start(button2, true, true, 0)

    # You may call the show method of each widgets, as follows:
    #   button1.show
    #   button2.show
    #   box1.show
    #   window.show 
    window.show_all
    Gtk.main

  Like the first Hello World, you'll notice this time there is no easy way to exit the program, 
  you have to use your window manager or command line to kill it.  

  A good exercise for the reader would be to insert a third "Quit" button that will exit the program.  

  You may also wish to play with the options to Gtk::Box#pack_start while reading the next section. Try resizing the window, and observe the behavior.

Ruby-GNOME2

[ruby-gnome2-doc-cvs] [Hiki] update - tut-gtk-helloworld2