QQuickCloseEvent Undefined Type?

Brian_Atakama

I am doing some refactoring of my QML and Python source to eliminate redundancy and condense the code base, and I noticed that this seemly innocuous change does not work.

The original QML files for Window components (Qt Quick 2 widgets) would register signal handlers for the closing signal as follows:
onClosing: handler_fn()

Rather than have every Window need to declare this handler, I tried to connect to this signal in Python using window.closing.connect(callback), however that doesn't seem to work. I see the following error in the logs: TypeError: Can't call meta function because I have no idea how to handle QQuickCloseEvent*

Looking at the Qt source, it seems that the QQuickCloseEvent type is undefined in PySide2, even though it isn't listed in the list of missing bindings.

Am I missing something here? How can I connect to this signal in Python?

Here's a test script to reproduce the issue:

from PySide2.QtWidgets import QApplication
from PySide2.QtQuick import QQuickWindow

def on_close(_):
    print('Closing window')

def mk_app():
    app = QApplication()
    app.setQuitOnLastWindowClosed(True)
    wnd = QQuickWindow()
    wnd.closing.connect(on_close)
    wnd.show()
    app.exec_()

if __name__ == '__main__':
    mk_app()

Brian_Atakama

I actually figured out a method. Turns out QQuickCloseEvent is a private type, so this was never going to work.

My solution is to simply use a event handler in the qml itself:

Window {
    onClosing: do_stuff()
    ...
}