[PyQt] Small doc fix

[Elvis Stansvik]

2016-05-08 17:44 GMT+02:00 Elvis Stansvik <elvstone at gmail.com>:
> Hi Phil,
>
> A small fix for:
>
>     http://pyqt.sourceforge.net/Docs/PyQt5/qt_properties.html
>
> would be to change:
>
>     notify – the optional unbound notify signal. It is ignored by Python
>
> to
>
>     notify – the optional unbound notify signal. Only needed if you
> want to use the property in QML property bindings
>
> since it seems I must use it if I want to use the property in QML
> property bindings, e.g:
>
> Window {
>     color: machine.initializing ? "red" : "green"
>     ...
> }
>
> or else I'll get errors like:
>
>     QQmlExpression: Expression
> file:///home/estan/Projekt/orexplore/dev/src/orexplore.machine/orexplore/hmi/qml/main.qml:15:12
> depends on non-NOTIFYable properties: Machine::initializing

Correct me if I'm doing something else wrong of course :) The property
is defined like (only relevant parts shown):

class Machine(QObject):

    initializingChanged = pyqtSignal(bool, arguments=['initializing'])

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self._initializing = False

    @pyqtProperty(bool)
    def initializing(self):
        return self._initializing

    @initializing.setter
    def initializing(self, initializing):
        if initializing != self._initializing:
            self._initializing = initializing
            self.initializingChanged.emit(self._initializing)

and adding notify=initializingChanged to @pyqtProperty fixes the error.

Elvis

>
> Cheers,
> Elvis