gnome-control-center/shell/cc-panel.ui

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <template class="CcPanel" parent="AdwBin">
    <child>
      <object class="GtkBox" id="main_box">
        <property name="hexpand">True</property>
        <property name="vexpand">True</property>
        <property name="orientation">vertical</property>

        <child>
          <object class="AdwBin" id="titlebar_bin">
            <property name="hexpand">True</property>
            <child>
              <object class="AdwHeaderBar" id="titlebar">
                <property name="show-end-title-buttons">True</property>
                <property name="show-start-title-buttons" bind-source="CcPanel" bind-property="folded" bind-flags="default|sync-create" />
                <child type="start">
                  <object class="GtkButton">
                    <property name="visible" bind-source="CcPanel" bind-property="folded" bind-flags="default|sync-create" />
                    <property name="icon-name">go-previous-symbolic</property>
                    <property name="action-name">window.navigate</property>
                    <property name="action-target">0</property> <!-- 0: ADW_NAVIGATION_DIRECTION_BACK -->
                  </object>
                </child>
                <property name="title-widget">
                  <object class="AdwWindowTitle">
                    <property name="title" bind-source="CcPanel" bind-property="title" bind-flags="default|sync-create" />
                  </object>
                </property>
              </object>
            </child>
          </object>
        </child>

        <child>
          <object class="AdwBin" id="content_bin">
            <property name="hexpand">True</property>
            <property name="vexpand">True</property>
          </object>
        </child>

      </object>
    </child>
  </template>
</interface>