#!/usr/bin/env python

import sys
from qt import *

class HelloApplication(QApplication):
    
    def __init__(self, args):
        """ In the constructor we're doing everything to get our application
            started, which is basically constructing a basic QApplication by 
            its __init__ method, then adding our widgets and finally starting 
            the exec_loop."""
        QApplication.__init__(self, args)
        self.addWidgets()
        self.exec_loop()        
        
    def addWidgets(self):
        """ In this method, we're adding widgets and connecting signals from 
            these widgets to methods of our class, the so-called "slots" 
        """
        self.hellobutton = QPushButton("Say 'Hello world!'",None)
        self.connect(self.hellobutton, SIGNAL("clicked()"), self.slotSayHello)
        self.setMainWidget(self.hellobutton)
        self.hellobutton.show()
        
    def slotSayHello(self):
        """ This is an example slot, a method that gets called when a signal is 
            emitted """
        print "Hello, World!"

# Only actually do something if this script is run standalone, so we can test our 
# application, but we're also able to import this program without actually running
# any code.
if __name__ == "__main__":
    app = HelloApplication(sys.argv)