import os
import sys

from PySide2.QtCore import QObject, Slot
from PySide2.QtQml import QQmlApplicationEngine, qmlRegisterType
from PySide2.QtGui import QGuiApplication, QVector3D

class DemoClass(QObject):
    
    def __init__(self, parent: QObject = None):
        super().__init__(parent)
    
    @staticmethod
    @Slot(QVector3D, result=bool)
    def call_static(vec: QVector3D) -> bool:
        return vec.isNull()
        
    @Slot(QVector3D, result=bool)
    def call_self(self, vec: QVector3D) -> bool:
        return vec.isNull()

if __name__ == "__main__":
    app = QGuiApplication(sys.argv)
    # Set application basic info, this will allow QSettings and other Qt behavior
    app.setApplicationName("myapp")
    app.setApplicationDisplayName("My App")
    app.setOrganizationDomain("com.amotus.myapp")
    app.setOrganizationName("Amotus")

    #  Add controllers to qml application engine
    engine = QQmlApplicationEngine()

    # There is no qmlRegisterSingletonType, so we cannot declare the class as singleton from python :-(
    qmlRegisterType(DemoClass, 'DemoModule', 1, 0, 'DemoClass')
    
    #Load the QML file
    engine.load('main.qml')

    #Show the window
    if not engine.rootObjects():
        sys.exit(-1)
    sys.exit(app.exec_())