main_window.py

        if self.isFullScreen():
            self.showNormal()
            self.actionToggle_full_screen.setIcon(get_icon('full-screen'))
        else:
            self.showFullScreen()
            self.actionToggle_full_screen.setIcon(get_icon('full-screen-exit'))


def start_scheduler(schedule: Optional[Schedule] = None) -> Schedule:
    """
    Start scheduler GUI.

    Parameters
    ----------
    schedule : Schedule, optional
        The schedule to start the editor with.

    Returns
    -------
    Schedule
        The edited schedule.
    """
    if not QApplication.instance():
        QApplication.setAttribute(Qt.AA_EnableHighDpiScaling)
        app = QApplication(sys.argv)
    else:
        app = QApplication.instance()
    window = ScheduleMainWindow()
    if schedule:
        window.open(schedule)
    window.show()
    app.exec_()
    return window.schedule


if __name__ == "__main__":
    start_scheduler()