require 'Qt4'

class Test < Qt::Widget

slots "test()" , "timer_action()" , "process_finished()"

def initialize()
super
@button = Qt::PushButton.new self
@timer = Qt::Timer.new 
@process = Qt::Process.new

connect @button , SIGNAL("clicked()") , self , SLOT("test()")
connect @timer , SIGNAL("timeout()") , self , SLOT("timer_action()")
connect @process , SIGNAL("finished(int, QProcess::ExitStatus)") , self , SLOT("process_finished()")
end

def test
# process & some output
# @process.start 'ruby' , ['-e', '1.upto(3){|i| sleep 1; puts i}']

@process.start 'ruby' , ['-e', '3.times{|i| sleep 1; puts i+1}'] , Qt::IODevice::ReadOnly|Qt::IODevice::Unbuffered
@timer.start 1001
end

def timer_action
puts 'timer'
# @process.waitForReadyRead 0
txt = @process.readAll
# the problem: readAll doesn't pickup the output until the process finished, is there a way to get the output while the process is still running?
unless txt.empty?
puts 'live' , txt # doesn't get here
end
end

def process_finished
puts "process_finished"
# 
puts 'dead' ,  @process.readAll
@timer.stop
end

end

app = Qt::Application.new ARGV

t = Test.new
t.show

app.exec