closeEvent not working

Saelyth

I was porting my code of a working program from PyQt5 to PySide2 and found the same issue:

def closeEvent(self, event):
    """Write window size and position to config file"""
    ini_options.setValue("menu_size", self.ui.size())
    ini_options.setValue("menu_position", self.ui.pos())
    event.accept()

def eventFilter(self, target, event):
    print(event.type())

I am using two Tabs and this was the result of me playing with the tabs. These are the only events printed:

PySide2.QtCore.QEvent.Type.PolishRequest
PySide2.QtCore.QEvent.Type.Move
PySide2.QtCore.QEvent.Type.Resize
PySide2.QtCore.QEvent.Type.Show
PySide2.QtCore.QEvent.Type.ShowToParent
PySide2.QtCore.QEvent.Type.UpdateLater
PySide2.QtCore.QEvent.Type.Paint
PySide2.QtCore.QEvent.Type.WindowDeactivate
PySide2.QtCore.QEvent.Type.Hide

closeEvent is never printed when I close the window. Shouldn't be somewhere after WindowDeactivate and before Hide?

If I just open the software and close it without playing with the tabs, them the events are:

PySide2.QtCore.QEvent.Type.PolishRequest
PySide2.QtCore.QEvent.Type.Destroy

I don't get why Destroy doesn't appears if I just switch to one tab to another (on the same MainWindow widget). Is the eventFilter bugged and it doesn't receives all the events?

ZioLupo

@ewerybody
As I wrote some message after, yes there is -of course - pyside2-uic!
But I don't like to use it.
Using it solve all of my problems because it produce a class and with the class I can do what I want (inheriting from it, for example).

But I would like to avoid to use it

ZioLupo

@Saelyth
I think that we really have the same issue.
AN issue that can be a wrong interpretation of how QtUiTools.QUiLoader().load works.
It is returning an instance, not a class as.
In this way we have two QMainWindow nested one in the other.
With this workaround it worked:

    def __init__(self, ui_file, parent=None):
        super(Form, self).__init__(parent)
        self.ui=QtUiTools.QUiLoader().load(ui_file)
        self.setCentralWidget(self.ui)

But you loose the geometry of the QMainWindow designed with Designer (and maybe something more but I don't have the skill for investigating further)

We should find a way to modify the inner closeEvent method but I don't know how to do it.
Moreover I don't like to have two QMainWindow.

Of course if someone has a real working sample code of a QMainWindow designed in Designer and then correctly loaded and used as a class... it would be really appreciated

SGaist

Then remove your Form class as it's not useful in your case.

You can then create a custom event filter object that should handle the close event and whatever you want to do in it.

Saelyth

With the original @ZioLupo code the override of eventFilter would works just fine, but closeEvent wouldn't (that was the issue).

class Form(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        self.ui = QUiLoader().load("myfile.ui")
        self.ui.buttonLoad.clicked.connect(self.load_something)

    def eventFilter(self, target, event):
        print("this works")
        return False

    def closeEvent(self, event):
        print("this doesn't works")

But that creates two QWidgets (one for the Form class and one for self.ui). if I understood you right, @Sgaist, you suggest to make the Form class a non-QWidget, as the Qwidget will be load into self.ui, right? But then, if the Form class is not a QWidget, I don't get how to set the closeEvent or eventFilter methods for the self.ui QWidget.

I tried to do what you suggest with my next code. The windows open just fine but no override works and no events get to my handlers.

class Form(object):
    def __init__(self):
        super().__init__()
        self.ui = QUiLoader().load("myfile.ui")
        self.ui.eventFilter = self.eventFilter
        self.ui.closeEvent = self.closeEvent

    def eventFilter(self, target, event):
        print("doesn't works")
        return False

    def closeEvent(self, event):
        print("doesn't works")

I think the issue here is that we were waiting for PySide2 while we were working temporary on PyQt5, and assumed that PySide2 would behave like PyQt5, where we would port our Qt Designer UI to .py with pyuic command. But when PySide2 was released, we saw an alternative way to do things (load the .ui file directly) and now we are trying to skip one of the step (it seems unnecesary to convert the .ui file to .py in PySide2 if we can directly load the .ui file). However, while trying to do that, we got lost in the process as we lost something which we were familiar with: the abbility to override the UI events.

A working example on how to load a .ui file with PySide2 where closeEvent works would help us a lot.

ewerybody

@ZioLupo said in closeEvent not working:

@ewerybody
As I wrote some message after, yes there is -of course - pyside2-uic!

Sorry. I didn't see you writing this.
What I just meant is that the name is NOT ~~pyside2-uic~~ (with a dash) but pyside2uic without the dash!

But I don't like to use it.
Using it solve all of my problems because it produce a class and with the class I can do what I want (inheriting from it, for example).

But I would like to avoid to use it

I would always avoid loading ui files directly and compile them only when changed. This way you can easily debug/step through the code. You see the generated structure and you can learn how UIs are written and you can strip a release of the ui files in the end.

SGaist

Just one thing: you are not using eventFilter correctly, you don't install it.

JonB

@Saelyth
As per what @SGaist has written, in my PyQt like yours (my page class is derived from QWidget) the __init__() ends with line:

    self.window().installEventFilter(self)

and my event handlers (eventFilter()) work.

Saelyth

@JonB On PyQt and PyQt5 it works (I've been using it that way) but on Pyside2 it doesn't. Note that I was installing the filters (I just forgot to type it in my previous message). Anyway I ended up using pyside2-uic (with a dash) to make my code safer to this issues.

L.Giuliano

@ZioLupo As the content was loaded to self.ui, it's necessary to use form.ui.show() instead of form.show().

L.Giuliano

This post is deleted!

sylvalas

is this thing solved?
it's 2021 almost 2022 now.
PySide6 still has the same issue I think.
as far as I know, with pyside6.QtUiTools.QUiLoader(), you can only load ui to an attribute of a shell class e.g. "self.ui" instead of to "self"
which causes some trouble triggering the modified closeEvent method.

The type of "self.ui" will still be QMainWindow(depends on what u use). I tried to override closeEvent() but it still won't work that's what confuses me.

Why cant they just add some method to let us load widgets to "self" -_- like "uic.loauUi()" in pyqt

HLsms

@sylvalas Still not solved by the looks of it, at least for me on pyside6, same issue if you load in the ui file (which I want to rather than compile).

However, a workaround exists (https://stackoverflow.com/questions/14834494/pyqt-clicking-x-doesnt-trigger-closeevent), which is to place:

app.aboutToQuit.connect(self.closeEvent)

inside the mainwindow class ( init or another func called when setting up the MW). This is kind of a cheat, as it is not capturing the close event, just the signal that it is about to close, so you cannot decline the event and stop the close. But functionally for me at least it is good enough to allow me to end other processes, safely disconnect hardware and tidy up before the close itself.

JonB

@HLsms
Completely untested, but because you are Python can't you monkey-patch self.ui.closeEvent = self.closeEvent?

HLsms

@JonB Yeah I used to do that, and it worked fine on PyQt5, but unfortunately it doesn't work at all on pyside6 (ditto pyside2 based on past discussion).