Pyqt4 Nested Classes - "runtimeerror: Underlying C/c++ Object Has Been Deleted"

I'm trying to build a cool app, but it seems I lack some knowledge. Read lots of infos and examples in internet, but it doesn't help: Understanding the 'underlying C/C++ object has

Solution 1:

Thanks to everyone who tried to answer! Unfortunately no one said what a bunch of crap I wrote! *smile*

My line is already a widget and I don't need to create itself inside itself. All I had to do is to create layout inside setup_ui and add widgets to it. Finally it looks like:

classLine(QtGui.QWidget):
    def__init__(self, parent=None):
        super(Line, self).__init__(parent)
        self.setup_ui(parent)

    defsetup_ui(self, parent):
        line = QtGui.QHBoxLayout(self)

        add_button = QtGui.QPushButton()
        add_button.setObjectName("add_button")

        line.addWidget(add_button)

        # to get reference from outside
        self.add_button = add_button

    defset_controls(self, add_button=True, remove_button=True):
        self.add_button.setEnabled(add_button)

Special thanks to nymk and Avaris!

Solution 2:

I could not reproduce an error with the code you showed us (apart from an error about the variable line not being defined in Line.setup_ui). If I replaced line with self, I got no error.

However, I could get a crash if I set line to a QWidget that I created and didn't keep a reference to. In other words, I added

line = QtGui.QWidget()

to Line.setup_ui, and found that this crashed on the same line of code you reported, complaining that the wrapped C/C++ object had been deleted.