custom button examples

# -*- coding: utf-8 -*-
import sys
from PyQt4 import QtCore, QtGui
from edytor import Ui_notatnik

class StartQT4(QtGui.QMainWindow):
	def __init__(self, parent=None):
		QtGui.QWidget.__init__(self, parent)
		self.ui = Ui_notatnik()
		self.ui.setupUi(self)
		QtCore.QObject.connect(self.ui.button_open,QtCore.SIGNAL("clicked()"), self.file_dialog)
		QtCore.QObject.connect(self.ui.button_save,QtCore.SIGNAL("clicked()"), self.file_save)
		QtCore.QObject.connect(self.ui.editor_window,QtCore.SIGNAL("textChanged()"), self.enable_save)
	def file_dialog(self):
		response = False
# buttons texts
SAVE = 'Save'
DISCARD = 'Discard'
CANCEL = 'Cancel'
# if we have changes then ask about them
if self.ui.button_save.isEnabled() and self.filename:
	message = QtGui.QMessageBox(self)
	message.setText('What to do about unsaved changes ?')
	message.setWindowTitle('Notepad')
	message.setIcon(QtGui.QMessageBox.Question)
	message.addButton(SAVE, QtGui.QMessageBox.AcceptRole)
	message.addButton(DISCARD, QtGui.QMessageBox.DestructiveRole)
	message.addButton(CANCEL, QtGui.QMessageBox.RejectRole)
	message.setDetailedText('Unsaved changes in file: ' + str(self.filename))
	message.exec_()
	response = message.clickedButton().text()
	# save  file
	if response == SAVE:
		self.file_save()
		self.ui.button_save.setEnabled(False)
	# discard changes
	elif response == DISCARD:
		self.ui.button_save.setEnabled(False)
# if we didn't cancelled show the file dialogue
if response != CANCEL:


if __name__ == "__main__":
	app = QtGui.QApplication(sys.argv)
	myapp = StartQT4()
	myapp.show()
	sys.exit(app.exec_()))