ROS dynamic_reconfigure enum with variable value set.

dynamic_reconfigure_tools.py

def change_enum_items(type, parameter_name, new_items, default=None):
    """
    Take an enum-typed parameter in the given autogenerated cfg type and reset its possible values to new_items.

    You can then start a dynamic_reconfigure server which advertises the changed enum domain.
    To achieve this, you need to call this function before creating the server.

    :param type type: One of the autogenerated config types (package.cfg.*Config).
    :param basestring parameter_name: Name of the enum parameter to change.
    :param new_items: The items that will form the new domain of the enum.
    :type new_items: array of {'name': ..., 'value': ..., 'description': ...}
    :param any default: If provided, this value is used as the default. If not, the first value in new_items is used.

    :raises RuntimeError: If there is no valid enum parameter with the given name in the given type.
    """

    if not hasattr(type, 'config_description') or not hasattr(type, 'defaults'):
        raise RuntimeError('Type %s is not a valid dynamic reconfigure type.' % str(type))

    for param_desc in type.config_description['parameters']:
        if param_desc['name'] == parameter_name:
            if param_desc['edit_method'] == '':
                raise RuntimeError('Type %s has empty edit_method, which means it is not a proper enum.' % str(type))

            edit_method = eval(param_desc['edit_method'])
            enum = edit_method['enum']

            if len(enum) == 0:
                raise RuntimeError('Type %s edit_method has empty enum, which means it is not a proper enum.' %
                                   str(type))

            # we will copy all "unnecesarry" info (line number, filename etc.) from the first item
            sample_item = enum[0]

            new_enum = []
            for item in new_items:
                new_item = sample_item.copy()
                new_item['name'] = item['name']
                new_item['value'] = item['value']
                new_item['description'] = item['description']
                new_enum.append(new_item)

            edit_method['enum'] = new_enum
            param_desc['edit_method'] = repr(edit_method)

            # if no default value was explicitly specified, use the first value
            if default is None:
                default = new_enum[0]['value']

            param_desc['default'] = default
            type.defaults[param_desc['name']] = default

            return

    raise RuntimeError('Parameter "%s" not found.' % parameter_name)