gnome-control-center/panels/microphone/cc-microphone-panel.ui

<?xml version="1.0" encoding="UTF-8"?>
<interface>
  <template class="CcMicrophonePanel" parent="CcPanel">

    <child type="titlebar-end">
      <object class="GtkSwitch" id="main_switch">
        <property name="valign">center</property>
        <accessibility>
          <property name="label" translatable="yes">Enable</property>
        </accessibility>
      </object>
    </child>

    <child type="content">
      <object class="AdwPreferencesPage">
        <child>
          <object class="AdwPreferencesGroup">
            <property name="description" translatable="yes">The following sandboxed apps have been given permission to use microphones. Apps that are not sandboxed can use microphones without asking for permission.</property>
            <child>
              <object class="GtkListBox" id="microphone_apps_list_box">
                <property name="can-focus">true</property>
                <property name="selection-mode">none</property>
                <style>
                  <class name="boxed-list"/>
                </style>

                <child type="placeholder">
                  <object class="GtkLabel">
                    <property name="margin-top">18</property>
                    <property name="margin-bottom">18</property>
                    <property name="margin-start">18</property>
                    <property name="margin-end">18</property>
                    <property name="label" translatable="yes">No sandboxed apps have asked for microphone access</property>
                    <property name="wrap">true</property>
                    <property name="max-width-chars">50</property>
                    <style>
                      <class name="dim-label" />
                    </style>
                  </object>
                </child>
              </object>
            </child>
          </object>
        </child>
      </object>
    </child>
  </template>
</interface>