[Python,Gtk4] Gtk.PopoverMenuBarの使用について②　XMLを使用したメニューバーの作成

import gi
gi.require_version('Gtk', '4.0')
from gi.repository import Gtk, Gio


APPID = 'com.github.taniyoshima.g4_fblog_menubar2'

MENUBAR_XML = """
<!--?xml version="1.0" encoding="UTF-8"?-->
<interface>
    <menu id="menu">
        <submenu>
            <attribute name="label">ファイル</attribute>
            <item>
                <attribute name="label">ラベル変更</attribute>
                <attribute name="action">win.label_tc</attribute>
            </item>
            <item>
                <attribute name="label">終了</attribute>
                <attribute name="action">app.quit</attribute>
            </item>
        </submenu>
        <submenu>
            <attribute name="label">ヘルプ</attribute>
            <item>
                <attribute name="label">バージョン情報</attribute>
                <attribute name="action">app.about</attribute>
            </item>
        </submenu>
    </menu>
</interface>
"""


class Gtk4TestTest(Gtk.ApplicationWindow):

    def __init__(self, app):
        Gtk.Window.__init__(
            self, application=app, title='Gtk.PopoverMenuBar2 Test',
            height_request=150, width_request=350
        )

        # 'ラベル変更'用のアクション
        action = Gio.SimpleAction.new("label_tc", None)
        action.connect("activate", self.on_label_change)
        self.add_action(action)

        builder = Gtk.Builder.new_from_string(MENUBAR_XML, -1)
        menu = builder.get_object("menu")

        menubar = Gtk.PopoverMenuBar.new_from_model(menu)

        vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
        vbox.append(menubar)
        self.label = Gtk.Label(label='hello')
        vbox.append(self.label)
        self.set_child(vbox)

    # アクションlabel_tcの処理
    def on_label_change(self, action, param):
        self.label.set_text('Good-Bye')


class Gtk4TestApp(Gtk.Application):

    def __init__(self):
        Gtk.Application.__init__(self, application_id=APPID)

    def do_startup(self):
        Gtk.Application.do_startup(self)

        # '終了'用のアクション
        action = Gio.SimpleAction.new('quit', None)
        action.connect('activate', self.on_quit)
        self.add_action(action)

        # 'バージョン情報'用のアクション
        action = Gio.SimpleAction.new("about", None)
        action.connect("activate", self.on_about)
        self.add_action(action)

    def do_activate(self):
        window = Gtk4TestTest(self)
        window.present()

    # アクションquitの処理
    def on_quit(self, action, param):
        self.quit()

    # アクションaboutの処理
    def on_about(self, action, param):
        icon = Gtk.Picture.new_for_filename('icon.png').get_paintable()
        dialog = Gtk.AboutDialog(
            authors=['taniyoshima'],
            comments='AboutDialogのサンプル',
            license_type=Gtk.License.MIT_X11,
            version='1.0.0',
            program_name='Gtk.AboutDialog Test',
            logo=icon
        )

        dialog.present()


def main():
    app = Gtk4TestApp()
    app.run()


if __name__ == '__main__':
    main()