Using Gtk.Window defined in Glade for a class derived from Gtk.Window with Python GTK

Question

I am trying load a Gtk.Window, that I have defined with Glade, into an object that is derived from Gtk.Window. How can I do this?

Here is an example illustrating what I want to accomplish:

#!/usr/bin/env python3

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

GLADE_FILE = 'my_ui.glade' 
MAIN_WINDOW = 'main_window' 

class MyInheritedWindow(Gtk.Window):
    def __init__(self, something_special, **kwds):
        super(MyInheritedWindow, self).__init__(**kwds)

        self.my_word = something_special

                    #Load the user interface.
        self.builder = Gtk.Builder.new_from_file(GLADE_FILE)
        self.builder.connect_signals(self)

        self.window = self.builder.get_object(MAIN_WINDOW)
        self.builder.get_object('messagetext').set_text(self.my_word)

        ### WHAT DO I DO HERE TO MAKE THESE PRINT THE SAME OBJECT? ###

        print(f'My window: {self}')                #These are clearly
        print(f'The Glade window: {self.window}')  #different.




    def on_destroy(self, widget, data=None):                         
        Gtk.main_quit()

if __name__ == '__main__':
    inherited_window = MyInheritedWindow('Please work?')
    inherited_window.window.show_all()
    Gtk.main()

    inherited_window.show_all()
    inherited_window.connect('destroy', Gtk.main_quit)
    Gtk.main()

The first Gtk.main() makes a window that looks like the Glade specification, but the window being shown is just an attribute of MyInheritedWindow , and not an instance of it. The second Gtk.main() makes a generic Gtk.Window .

I would like to replace the Gtk.Window part of the MyInheritedWindow object with the Gtk.Window created from the Glade files.

Notes:

• I've found what I believe to be a similar question , but the accepted answer doesn't seem to do what I'm talking about.

• This also may be the same question, but the answer is pretty convoluted. There must be a simpler way?

• There also seems to be a way tell Glade about custom widgets but the article is from 2007.

For completeness, I'll add the glade file my_ui.glade here:

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.22.2 -->
<interface>
  <requires lib="gtk+" version="3.20"/>
  <object class="GtkWindow" id="main_window">
    <property name="can_focus">False</property>
    <property name="title" translatable="yes">Inheritance with Glade</property>
    <signal name="destroy" handler="on_destroy" swapped="no"/>
    <child type="titlebar">
      <object class="GtkHeaderBar">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="title" translatable="yes">Inheritance Example</property>
        <property name="subtitle" translatable="yes">(will it work?)</property>
        <property name="show_close_button">True</property>
      </object>
    </child>
    <child>
      <object class="GtkBox">
        <property name="visible">True</property>
        <property name="can_focus">False</property>
        <property name="orientation">vertical</property>
        <child>
          <object class="GtkLabel" id="messagetext">
            <property name="visible">True</property>
            <property name="can_focus">False</property>
            <property name="label" translatable="yes">Replace this text.</property>
          </object>
          <packing>
            <property name="expand">False</property>
            <property name="fill">True</property>
            <property name="position">0</property>
          </packing>
        </child>
      </object>
    </child>
  </object>
</interface>

Answer 1

This is the best I have come up with. I read the Gtk.Window using the Builder and then I add all the child widgets to my window (after removing them from the other window.

#!/usr/bin/env python3
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

GLADE_FILE = 'my_ui.glade'
MAIN_WINDOW = 'main_window'

class MyWindow(Gtk.Window):
    def __init__(self, something_special, **kwds):
        super(MyWindow, self).__init__(**kwds)

        self.my_word = something_special

                    #Load the user interface.
        self.builder = Gtk.Builder.new_from_file(GLADE_FILE)
        self.builder.connect_signals(self)

        window = self.builder.get_object(MAIN_WINDOW)
        self.builder.get_object('messagetext').set_text(self.my_word)
        self.messagetext = self.builder.get_object('messagetext')

        self.copy_window_children(window)

    def copy_window_children(self, window: Gtk.Window):
        """ Copy the window Header and other widgets """
        for child in window.get_children():
            window.remove(child)

            if type(child) == Gtk.HeaderBar:
                self.set_titlebar(child)
            else:
                self.add(child)


if __name__ == '__main__':
    mywindow = MyWindow('It worked.')
    mywindow.show_all()
    mywindow.connect('destroy', Gtk.main_quit)

    Gtk.main()