How to add a custom event to a PyQt5 Event loop

Question

I am trying to add an event that fires when the window is inactive (- where the user's mouse has clicked on another app or the desktop). I after reading a lot of the official documentation, I am still lost. I also hope to do this with other actions, but this would be the first step.

Answer 1

You have to use the activeChanged signal that is emitted every time the QWindow changes state and isActive() that indicates if it is active or not:

import sys

from PyQt5 import QtWidgets


app = QtWidgets.QApplication(sys.argv)

w = QtWidgets.QWidget()
w.show()

qwindow = w.windowHandle()

if qwindow is not None:

    def handle_activeChanged():
        print("isActive? {}".format(qwindow.isActive()))

    qwindow.activeChanged.connect(handle_activeChanged)

sys.exit(app.exec_())