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closeEvent not working

  • Because I don't know what to do.
    In PyQt5 I was doing something like that:

    Ui_MainWindow = uic.loadUiType("mainwindow.ui")[0] 

    and then

    class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
        def __init__(self, parent=None):
            super(MainWindow, self).__init__(parent)
            self.ui = Ui_MainWindow()

    But this is not working with PySide2.

    If you can share a PySyde2 working code it would be really appreciated.
    Thank you

  • @ZioLupo
    Purely OOI, while you are waiting for an answer, may I ask you: I use PyQt and am very happy with it, why are you moving over to PySide instead?

  • @JonB
    Well... it seems to me that PySide2 will be the "official" binding for Python.
    IMHO it should mean more support... but maybe I'm completely wrong!

  • @ZioLupo
    Well, I get any PyQt support I need via mailing list.

    Again OOI, for my reference, how much work are you finding you need to do to convert PyQt(5) to PySide? (Sorry if I'm hijacking thread, I won't ask another question...!)

  • It was done in a snapshot.
    Honestly speaking I ported a couple of very small app in a snapshot. Search & Replace is your friend.
    The only problem I had was with UI files.
    But the Pyside2 loader is returning an istance, not a class... so I believeI have to think differently.
    Moreover it's not my job, I'm an old C programmer shocked by the beauty of python... so maybe I don't have to loose time and keep everythink in PyQt5 ;-)

  • @ZioLupo I'm an old C programmer shocked by the ugliness of python!!

  • @ZioLupo what Python version are you using?
    I currently have no problems with 3.6.5 + PySide2 but my apps never close on the latest Python 3.7.

  • @ZioLupo said in closeEvent not working:

    As far as I know pyuic is not included in PySide2.

    its pyside2uic!
    I do from pyside2uic import compileUi , compile my ui-files whenever changed. and do:

        self.ui = compiled_ui.Ui_Form()

  • 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())
    def eventFilter(self, target, event):

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


    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:


    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?

  • @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

  • @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)

    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

  • Lifetime Qt Champion

    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.

  • 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):
            self.ui = QUiLoader().load("myfile.ui")
        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):
            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.

  • @ZioLupo said in closeEvent not working:

    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.

  • Lifetime Qt Champion

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

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


    and my event handlers (eventFilter()) work.

  • @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.

  • @ZioLupo As the content was loaded to self.ui, it's necessary to use instead of

  • This post is deleted!

  • 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

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