mainwindow.glade (Código)

<?xml version="1.0" encoding="UTF-8"?>
<!-- Generated with glade 3.38.2 -->
<interface>
    <requires lib="gtk+" version="3.24"/>
    <object class="GtkMenu" id="menu">
        <property name="visible">True</property>
        <property name="can-focus">False</property>
        <property name="rect-anchor-dx">-30</property>
    </object>
    <object class="GtkApplicationWindow" id="MainWindow">
        <property name="can-focus">False</property>
        <property name="default-width">683</property>
        <property name="default-height">384</property>
        <property name="icon">../../../assets/icons/icon.png</property>
        <child>
            <placeholder/>
        </child>
        <child type="titlebar">
            <object class="GtkHeaderBar">
                <property name="visible">True</property>
                <property name="can-focus">False</property>
                <property name="title" translatable="yes">Gtk.MenuButton</property>
                <property name="subtitle" translatable="yes">Gtk.MenuButton</property>
                <property name="show-close-button">True</property>
                <child>
                    <object class="GtkMenuButton">
                        <property name="visible">True</property>
                        <property name="can-focus">True</property>
                        <property name="receives-default">True</property>
                        <property name="popup">menu</property>
                        <child>
                            <object class="GtkImage">
                                <property name="visible">True</property>
                                <property name="can-focus">False</property>
                                <property name="icon-name">open-menu-symbolic</property>
                            </object>
                        </child>
                    </object>
                    <packing>
                        <property name="pack-type">end</property>
                    </packing>
                </child>
            </object>
        </child>
    </object>
</interface>