SWT + JRuby Bootstrap example

my_swt_program.rb

require 'java'
require 'swt'

# Each Swt application need a display to interact with the operating system.
# It provides the event loop.
display = Swt::Widgets::Display.new

# Let's create a new window. It's called "Shell" in Swt vocabulary.
# Note that we pass in a display.
shell = Swt::Widgets::Shell.new(display)

# Let's set the title and the size of the shell.
shell.text = "My first Swt app"
shell.set_size(200, 150)

# Each shell require a layout. It's there to organize the widgets in the shell.
layout = Swt::Layout::GridLayout.new(2, false)
shell.setLayout(layout)

# Let's create a label and add it to the parent container (the shell)
label = Swt::Widgets::Label.new(shell, Swt::SWT::NONE)
label.text = "This is a label"

button = Swt::Widgets::Button.new(shell, Swt::SWT::PUSH)
button.text = "Click Me"

button.add_selection_listener do
  label.text = "clicked!"
end

# Ready to display the shell!
shell.open

# We need an event loop now.
while !shell.isDisposed

  # The application sleeps unless there's a new event.
  display.sleep unless display.read_and_dispatch
end

display.dispose