Reimplementing event handler

Events in PyQt4 are processed often by reimplementing event handlers.

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
ZetCode PyQt4 tutorial 

In this example, we reimplement an
event handler. 

author: Jan Bodnar
website: zetcode.com
last edited: October 2011
"""

import sys
from PyQt4 import QtGui, QtCore

class Example(QtGui.QWidget):

    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):      

        self.setGeometry(300, 300, 250, 150)
        self.setWindowTitle(‘Event handler‘)
        self.show()

    def keyPressEvent(self, e):

        if e.key() == QtCore.Qt.Key_Escape:
            self.close()

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())

if __name__ == ‘__main__‘:
    main()

In our example, we reimplement the keyPressEvent() event handler.

def keyPressEvent(self, e):

    if e.key() == QtCore.Qt.Key_Escape:
        self.close()

If we click the Escape button, the application terminates.