001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.markup.html.form;
018
019import org.apache.wicket.Application;
020import org.apache.wicket.Component;
021import org.apache.wicket.util.lang.Classes;
022
023/**
024 * {@link IChoiceRenderer} implementation that makes it easy to work with java 5 enums. This
025 * renderer will attempt to lookup strings used for the display value using a localizer of a given
026 * component. If the component is not specified, the global instance of localizer will be used for
027 * lookups.
028 * <p>
029 * display value resource key format: {@code <enum.getSimpleClassName()>.<enum.name()>}
030 * </p>
031 * <p>
032 * id value format: {@code <enum.name()>}
033 * </p>
034 * 
035 * @author igor.vaynberg
036 * 
037 * @param <T>
038 */
039public class EnumChoiceRenderer<T extends Enum<T>> extends ChoiceRenderer<T>
040{
041
042        private static final long serialVersionUID = 1L;
043
044        /**
045         * component used to resolve i18n resources for this renderer.
046         */
047        private final Component resourceSource;
048
049
050        /**
051         * Constructor that creates the choice renderer that will use global instance of localizer to
052         * resolve resource keys.
053         */
054        public EnumChoiceRenderer()
055        {
056                this(null);
057        }
058
059        /**
060         * Constructor
061         * 
062         * @param resourceSource
063         */
064        public EnumChoiceRenderer(Component resourceSource)
065        {
066                this.resourceSource = resourceSource;
067        }
068
069        /** {@inheritDoc} */
070        @Override
071        public Object getDisplayValue(T object)
072        {
073                final String value;
074
075                String key = resourceKey(object);
076
077                if (resourceSource != null)
078                {
079                        value = resourceSource.getString(key);
080                }
081                else
082                {
083                        value = Application.get().getResourceSettings().getLocalizer().getString(key, null);
084                }
085
086                return value;
087        }
088
089        /**
090         * Translates the {@code object} into resource key that will be used to lookup the value shown
091         * to the user
092         * 
093         * @param object
094         * @return resource key
095         */
096        protected String resourceKey(T object)
097        {
098                return Classes.simpleName(object.getDeclaringClass()) + '.' + object.name();
099        }
100
101        /** {@inheritDoc} */
102        @Override
103        public String getIdValue(T object, int index)
104        {
105                return object.name();
106        }
107}