hotcocoa.rb

require 'hotcocoa'
include HotCocoa
application do |app|
  window :size => [200, 100] do |win|
    win.view = layout_view :mode => :vertical do |layout|
      layout.spacing = 10

      b = button :title => "click me", :layout => {:align => :center}
      l = label :text => "", :layout => {:align => :center}

      b.on_action do |b|
        if l.text == "" || l.text == "World foo"
          l.text = "Hello"
        else
          l.text = "World foo"
        end
      end

      layout << b
      layout << l
    end
    win.will_close { exit }
  end
end