'Update the font for the "Text size\' menu and the default font
used in the `CanvasScene`.'

def __updateFont(self):

    actions = self.__fontActionGroup.actions()
    font = self.font()
    for action in actions:
        size = action.font().pixelSize()
        action_font = QFont(font)
        action_font.setPixelSize(size)
        action.setFont(action_font)
    if self.__scene:
        self.__scene.setFont(font)
