001// Copyright 2007, 2008 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
017import java.util.List;
018
019/**
020 * Defines the possible options and option groups for a <select> [X]HTML element.
021 * <p/>
022 * Primarily used by the {@link org.apache.tapestry5.corelib.components.Select} component, but potentially used by
023 * anything similar, that needs to present a list of options to the user. Generally paired with a {@link
024 * org.apache.tapestry5.ValueEncoder} to create client-side representations of server-side values.
025 *
026 * @see org.apache.tapestry5.corelib.components.Palette
027 */
028public interface SelectModel
029{
030    /**
031     * The list of groups, each containing some number of individual options.
032     *
033     * @return the groups, or null
034     */
035    List<OptionGroupModel> getOptionGroups();
036
037    /**
038     * The list of ungrouped options, which appear after any grouped options. Generally, a model will either provide
039     * option groups or ungrouped options, but not both.
040     *
041     * @return the ungrouped options, or null
042     */
043    List<OptionModel> getOptions();
044
045    /**
046     * Allows access to all the {@link OptionGroupModel}s and {@link OptionModel}s within the SelectModel.
047     */
048    void visit(SelectModelVisitor visitor);
049}