def __init__(self, parent=None): super(MainWidget, self).__init__(parent) # get controller self.installController = InstallController(self) self.howToController = HowToController(self) self.helpController = HelpController(self) self.homeController = HomeController(self) self.completeController = CompleteController(self) self.setFixedSize(860, 600) self.stack = QStackedWidget() layout = QVBoxLayout(self) layout.addWidget(self.stack) self.homeWidget = Ui_homeWidget(self) self.installWidget = Ui_installWidget(self) self.completeWidget = Ui_completeWidget(self) self.howToWidget = Ui_howToWidget(self) self.helpWidget = Ui_helpWidget(self) self.stack.addWidget(self.homeWidget) self.stack.addWidget(self.installWidget) self.stack.addWidget(self.completeWidget) self.stack.addWidget(self.howToWidget) self.stack.addWidget(self.helpWidget) self.stack.setCurrentWidget(self.homeWidget) self.setSignalAndSlot()