    001// Copyright 2007-2013 The Apache Software Foundation
    002//
    003// Licensed under the Apache License, Version 2.0 (the "License");
    004// you may not use this file except in compliance with the License.
    005// You may obtain a copy of the License at
    006//
    007//     http://www.apache.org/licenses/LICENSE-2.0
    008//
    009// Unless required by applicable law or agreed to in writing, software
    010// distributed under the License is distributed on an "AS IS" BASIS,
    011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012// See the License for the specific language governing permissions and
    013// limitations under the License.
    014
    015package org.apache.tapestry5;
    016
    017/**
    018 * Callback interface that allows for visiting the option groups and option models of a select model in correct order
    019 * order.
    020 */
    021public interface SelectModelVisitor
    022{
    023    /**
    024     * Invoked once for each {@link OptionGroupModel}, just before invoking {@link #option(OptionModel)} for each
    025     * embedded option within the group.
    026     */
    027    void beginOptionGroup(OptionGroupModel groupModel);
    028
    029    /**
    030     * Invoked for each option within a group, and at the end, for each ungrouped option.
    031     *
    032     * @param optionModel
    033     */
    034    void option(OptionModel optionModel);
    035
    036    /**
    037     * Invoked after all options within the group have been visited.
    038     */
    039    void endOptionGroup(OptionGroupModel groupModel);
    040}