Reimplement Qt method

def resizeEvent(self, event):
        """Reimplement Qt method"""
        if not self.isMaximized() and not self.fullscreen_flag:
            self.window_size = self.size()
        QMainWindow.resizeEvent(self, event)

        # To be used by the tour to be able to resize
        self.sig_resized.emit(event)