pcdsutils.qt.callbacks.WeakPartialMethodSlot

class pcdsutils.qt.callbacks.WeakPartialMethodSlot(signal_owner: QObject, signal: pyqtSignal, method: MethodType, *args, **kwargs)[source]

A PyQt-compatible slot for a partial method.

This utility handles deleting the connection when the method class instance gets garbage collected. This avoids cycles in the garbage collector that would prevent the instance from being garbage collected prior to the program exiting.

To use, create an instance of this class, and store a hard reference to that instance. The class will connect the slot to the signal:

class MyWidget(QtWidgets.QWidget):
    button: QtWidgets.QPushButton

    def __init__(self, *args, **kwargs):
        self._partial_slots: List[WeakPartialMethodSlot] = []
        slot = WeakPartialMethodSlot(
            self.button, self.button.clicked,
            self.foo_method, 'partial_foo'
        )
        self._partial_slots.append(slot)  # hold hard reference

        super().__init__(*args, **kwargs)

    def foo_method(self, my_arg):
        print(my_arg)

Parameters:

signal_ownerQtCore.QObject: The owner of the signal.
signalQtCore.Signal: The signal instance itself. Should be a signal on signal_owner
methodinstance method: The method slot to call when the signal fires. Should be a method on the containing class.
*args: Arguments to pass to the method.
**kwargs: Keyword arguments to pass to the method.

__init__(signal_owner: QObject, signal: pyqtSignal, method: MethodType, *args, **kwargs)[source]

Methods

__init__(signal_owner, signal, method, ...)