继承Gtk.MessageDialog时遭遇弃用警告与transient_for类型错误的问题咨询

我在几个项目里用了一个继承自Gtk.MessageDialog的自定义类，出于好奇我用-Wd参数运行测试脚本：

python3 -Wd dialogs_test.py

结果在__init__里使用parent=参数时，收到了两条警告：

.../dialogs_test.py:15: PyGTKDeprecationWarning: Using positional arguments with the GObject constructor has been deprecated. Please specify keyword(s) for "parent" or use a class specific constructor. See: https://wiki.gnome.org/PyGObject/InitializerDeprecations
  super().__init__(self,

/usr/lib/python3/dist-packages/gi/overrides/Gtk.py:577: PyGTKDeprecationWarning: The keyword(s) "parent" have been deprecated in favor of "transient_for" respectively. See: https://wiki.gnome.org/PyGObject/InitializerDeprecations

于是我把__init__里的parent=改成了transient_for=，结果又碰到了类型错误：

See above
...
TypeError: could not convert value for property `transient_for' from Dialog to GtkWindow

我明明在__init__里用了关键字参数，为啥第一条警告还会出现？而且我也搞不清该怎么正确使用transient_for，也找不到相关的文档说明。

下面是我简化后的测试脚本：

#!/usr/bin/env python3

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk


class Dialog(Gtk.MessageDialog):
    def __init__(self, message_type, buttons, title, text):

        # Search for parent
        parent = next((w for w in Gtk.Window.list_toplevels() if w.get_title()), None)

        # Initialize the dialog object
        super().__init__(self,
                         parent=parent,
                         message_type=message_type,
                         buttons=buttons,
                         text=text)

        # Set title
        self.set_title(title)

    def show_dialog(self):
        """ Show the dialog """
        response = self.run() in (Gtk.ResponseType.YES,
                                  Gtk.ResponseType.APPLY,
                                  Gtk.ResponseType.OK,
                                  Gtk.ResponseType.ACCEPT)
        self.destroy()
        return response

def message_dialog(*args, **kwargs):
    """ Show message dialog """
    #return kwargs
    return Dialog(Gtk.MessageType.INFO, Gtk.ButtonsType.OK, *args, **kwargs).show_dialog() 


class MessageDialogWindow(Gtk.Window):

    def __init__(self):
        super().__init__(title="MessageDialog Test")
        self.set_default_size(500, 100)
        box = Gtk.Box()
        self.add(box)
        
        button = Gtk.Button.new_with_label("Info dialog by class")
        button.connect("clicked", self.on_info_clicked)
        button.set_hexpand(True)
        box.add(button)
        
    def on_info_clicked(self, widget):
        result = message_dialog(title='button title', text='button text')
        print((f"button result: {result}"))
        

win = MessageDialogWindow()
win.connect("destroy", Gtk.main_quit)
win.show_all()
Gtk.main()

解决方案 #

问题的根源在于调用父类构造函数时多传了self参数，同时需要把parent=替换成transient_for=，修改后的父类初始化代码如下：

super().__init__(transient_for=parent,
                 message_type=message_type,
                 buttons=buttons,
                 text=text)

这样既解决了弃用警告，也不会再出现类型错误了。

备注：内容来源于stack exchange，提问作者user8780038