def __init__(self):
last_source = Gst.get_string('map-source-id')
Gst.bind_with_convert('map-source-id', MapView, 'map-source',
MAP_SOURCES.get, lambda x: x.get_id())
for source_id in sorted(MAP_SOURCES):
menu_item = RadioMenuItem(MAP_SOURCES[source_id])
if last_source == source_id:
menu_item.set_active(True)
Widgets.map_source_menu.show_all()
