Ruby and Qt; using 'qtbindings' example of using signals and slots, demonstrating how to use parameter-less, simple and class-parameter for sending signals.

signal_slot.rb

require 'Qt'

# The class that will act as the receiver
class A < Qt::Object
	slots :receive, 'receive_int(int)', 'receive_path(QString)'

	def receive
		puts 'event received'
	end

	def receive_int(i)
		puts "received int #{i}"
	end

	def receive_path(path)
		puts path
	end
end

# Class that will act as the sender
# signal() creates the signal methods for us in the class
class B < Qt::Object
	signals :give, 'give_int(int)', 'give_path(QString)'
end

# Necessary for any Qt app
app = Qt::Application.new(ARGV)

# Instantiate the classes
a = A.new
b = B.new

# Connect signals and slots globally
app.connect(b, SIGNAL(:give), a, SLOT(:receive))
app.connect(b, SIGNAL('give_int(int)'), a, SLOT('receive_int(int)'))
app.connect(b, SIGNAL('give_path(QString)'), a, SLOT('receive_path(QString)'))

# Testing emitting the signals
b.give
b.give_int(5)
b.give_path('a test string')