PyQT: Differentiate between close() function and title-bar close [X]-CodePudding

I have the following function to ask the user if he really wants to quit the window:

def closeEvent(self, event):
    if self.running:
        reply = QMessageBox.question(self, 'QUIT',
                                     'Calculations are currently running!\n'
                                     'Do you really want to quit?',
                                     QMessageBox.Yes | QMessageBox.No,
                                     QMessageBox.No)
        if reply == QMessageBox.Yes:
            event.accept()
        else:
            event.ignore()
    else:
        return QMainWindow.closeEvent(self, event)

So when the user presses the red X the QMessageBox will be shown. But I still want to be able to terminate the window without the QMessageBox, for example if I use the close()-function inside the code. Is there a possibility to distinguish between different senders of the CloseEvent like the close()-function or the X-Button?

CodePudding user response：

You can distinguish between system and application events by calling the spontaneous method of the event object. So if the user tries to close the window by clicking the title-bar close button, or by pressing Alt F4, the spontaneous() method will return True.

Here's a simple demo:

from PyQt5 import QtWidgets

class Window(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()
        self.button = QtWidgets.QPushButton('Close')
        self.button.clicked.connect(self.close)
        self.check = QtWidgets.QCheckBox('Running')
        self.check.toggled.connect(lambda x: setattr(self, 'running', x))
        self.check.setChecked(True)
        layout = QtWidgets.QVBoxLayout(self)
        layout.addWidget(self.check)
        layout.addWidget(self.button)

    def closeEvent(self, event):
        if event.spontaneous():
            print('system close event')
            if self.running:
                reply = QtWidgets.QMessageBox.question(
                    self, 'QUIT',
                    'Calculations are currently running!\n'
                    'Do you really want to quit?',
                    QtWidgets.QMessageBox.Yes | QtWidgets.QMessageBox.No,
                    QtWidgets.QMessageBox.No)
                if reply == QtWidgets.QMessageBox.Yes:
                    event.accept()
                else:
                    event.ignore()
        else:
            print('program close event')

if __name__ == '__main__':

    app = QtWidgets.QApplication(['Test'])
    window = Window()
    window.show()
    app.exec_()