PySide 6.4 and QML: Property-Binding doesn't work as expected

ChristianL

I wanted to try out QML and Property-Binding with python. In the past I used Widgets only, but I did some QML programming under C++, and it worked as expected.

I would expect that every time the text in TextField is changed the property settings.name also is changed, but it doesn't happen. self.__name is always None . Did I miss something? I studied the Qt for Python documentation on the Property-Topic. Instead of the C++ Q_PROPERTY -Macro in Python the Property -Function is used with getter, setter and notifier. I decorated my class with @QmlElement . Here is the complete Code of my sample application:

AppWindow.qml

import QtQuick.Controls
import QtQuick.Layouts
import QtQuick

import com.example.app 1.0

Window {
    id: settingsDialog

    visible: true
    width: 500
    height: 250

    Settings {
        id: settings
    }

    GridLayout {
        columns: 2
        anchors.fill: parent

        Text { text: qsTr("Your Name") }
        TextField {
            id: name
            text: settings.name
        }
        Button {
            text: "Load"
            onClicked: {
                console.log("Load")
                settings.load()
            }
        }

        Button {
            text: "Save"
            onClicked: {
                console.log("Save")
                settings.save()
            }
        }
    }

    Component.onCompleted: {
        console.log("Component.onCompleted")
        settings.load()
    }
}

Settings.py

QML_IMPORT_NAME = "com.example.app"
QML_IMPORT_MAJOR_VERSION = 1

from PySide6.QtCore import QObject, Signal, Slot, Property, QSettings
from PySide6.QtQml import QmlElement

KEY_PERSONAL_NAME = 'personal/name'

@QmlElement
class Settings(QObject):

    def __init__(self, parent=None):
        QObject.__init__(self, parent)
        self.__name = None

    @Slot()
    def load(self):
        self.__settings = QSettings('settings.ini', QSettings.IniFormat)
        self.__name = self.__settings.value(KEY_PERSONAL_NAME)

    @Slot()
    def save(self):
        self.__settings.setValue(KEY_PERSONAL_NAME, self.__name)

    def get_name(self):
        return self.__name

    @Slot(str)
    def set_name(self, name):
        if self.__name != name:
            self.__name = name
            self.name_changed.emit(name)

    name_changed = Signal(str)

    name = Property(str, fget=get_name, fset=set_name, notify=name_changed)


if __name__ == '__main__':
    import sys
    from PySide6.QtCore import QUrl
    from PySide6.QtGui import QGuiApplication
    from PySide6.QtQml import QQmlApplicationEngine, qmlRegisterType

    from Settings import Settings

    app = QGuiApplication(sys.argv)

    qmlRegisterType(Settings, "com.example.app", 1,0, "Settings")
    engine = QQmlApplicationEngine(QUrl("AppWindow.qml"))

    app.exec()