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="GtkImage" id="img_go_next">
        <property name="visible">True</property>
        <property name="can-focus">False</property>
        <property name="icon-name">go-next</property>
    </object>
    <object class="GtkImage" id="img_go_previous">
        <property name="visible">True</property>
        <property name="can-focus">False</property>
        <property name="icon-name">go-previous</property>
    </object>
    <object class="GtkApplicationWindow" id="MainWindow">
        <property name="can-focus">False</property>
        <property name="title" translatable="yes">Gtk.Overlay</property>
        <property name="default-width">683</property>
        <property name="default-height">384</property>
        <property name="icon">../../../assets/icons/icon.png</property>
        <signal name="check-resize" handler="_image_resize" swapped="no"/>
        <child>
            <object class="GtkOverlay">
                <property name="visible">True</property>
                <property name="can-focus">False</property>
                <child type="overlay">
                    <object class="GtkImage" id="image">
                        <property name="visible">True</property>
                        <property name="can-focus">False</property>
                        <property name="stock">gtk-missing-image</property>
                    </object>
                    <packing>
                        <property name="index">-1</property>
                    </packing>
                </child>
                <child type="overlay">
                    <object class="GtkButton" id="go_next">
                        <property name="visible">True</property>
                        <property name="can-focus">True</property>
                        <property name="receives-default">True</property>
                        <property name="halign">end</property>
                        <property name="valign">center</property>
                        <property name="image">img_go_next</property>
                    </object>
                    <packing>
                        <property name="index">1</property>
                    </packing>
                </child>
                <child type="overlay">
                    <object class="GtkButton" id="go_previous">
                        <property name="visible">True</property>
                        <property name="can-focus">True</property>
                        <property name="receives-default">True</property>
                        <property name="halign">start</property>
                        <property name="valign">center</property>
                        <property name="image">img_go_previous</property>
                    </object>
                    <packing>
                        <property name="index">1</property>
                    </packing>
                </child>
            </object>
        </child>
    </object>
</interface>