Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.wicket.markup.html.form; import java.util.List; import org.apache.wicket.markup.ComponentTag; import org.apache.wicket.model.IModel; /** * Essentially a drop down choice that doesn't drop down. Instead, it scrolls and displays a given * number of rows. * * @author Jonathan Locke * @author Johan Compagner * @author Eelco Hillenius * * @param <T> * The model object type */ public class ListChoice<T> extends DropDownChoice<T> { private static final long serialVersionUID = 1L; /** The default maximum number of rows to display. */ private static final int DEFAULT_MAX_ROWS = 8; /** The maximum number of rows to display. */ private int maxRows; /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String) */ public ListChoice(final String id) { this(id, null, (List<? extends T>) null, null, DEFAULT_MAX_ROWS); } /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, List) */ public ListChoice(final String id, final List<? extends T> choices) { this(id, null, choices, null, DEFAULT_MAX_ROWS); } /** * @param id * See Component * @param choices * The list of values in the list * @param renderer * See AbstractChoice * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, * List,IChoiceRenderer) */ public ListChoice(final String id, final List<? extends T> choices, final IChoiceRenderer<? super T> renderer) { this(id, null, choices, renderer, DEFAULT_MAX_ROWS); } /** * @param id * See Component * @param model * See Component * @param choices * The list of values in the list * @see DropDownChoice#DropDownChoice(String, IModel, List) */ public ListChoice(final String id, final IModel<T> model, final List<? extends T> choices) { this(id, model, choices, null, DEFAULT_MAX_ROWS); } /** * @param id * See Component * @param model * See Component * @param choices * The list of values in the list * @param maxRows * Maximum number of rows to show * @see DropDownChoice#DropDownChoice(String, IModel, List) */ public ListChoice(final String id, final IModel<T> model, final List<? extends T> choices, final int maxRows) { this(id, model, choices, null, maxRows); } /** * @param id * See Component * @param model * See Component * @param choices * The list of values in the list * @param renderer * See AbstractChoice * @see DropDownChoice#DropDownChoice(String, IModel, List) */ public ListChoice(final String id, final IModel<T> model, final List<? extends T> choices, final IChoiceRenderer<? super T> renderer) { this(id, model, choices, renderer, DEFAULT_MAX_ROWS); } /** * @param id * See Component * @param model * See Component * @param choices * The list of values in the list * @param renderer * See AbstractChoice * @param maxRows * Maximum number of rows to show * @see DropDownChoice#DropDownChoice(String, IModel, List) */ public ListChoice(final String id, final IModel<T> model, final List<? extends T> choices, final IChoiceRenderer<? super T> renderer, final int maxRows) { super(id, model, choices, renderer); this.maxRows = maxRows; } /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel) */ public ListChoice(String id, IModel<? extends List<? extends T>> choices) { this(id, null, choices, null, DEFAULT_MAX_ROWS); } /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel,IModel) */ public ListChoice(String id, IModel<T> model, IModel<? extends List<? extends T>> choices) { this(id, model, choices, null, DEFAULT_MAX_ROWS); } /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, * IModel,IChoiceRenderer) */ public ListChoice(String id, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer) { this(id, null, choices, renderer, DEFAULT_MAX_ROWS); } /** * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel, * IModel,IChoiceRenderer) */ public ListChoice(String id, IModel<T> model, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer) { this(id, model, choices, renderer, DEFAULT_MAX_ROWS); } /** * @param id * @param model * @param choices * @param renderer * @param maxRows * @see org.apache.wicket.markup.html.form.AbstractChoice#AbstractChoice(String, IModel, * IModel,IChoiceRenderer) */ public ListChoice(String id, IModel<T> model, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer, int maxRows) { super(id, model, choices, renderer); this.maxRows = maxRows; } /** * Gets the maximum number of rows to display. * * @return the maximum number of rows to display */ public final int getMaxRows() { return maxRows; } /** * Sets the maximum number of rows to display. * * @param maxRows * the maximum number of rows to display * @return This */ public final ListChoice<T> setMaxRows(int maxRows) { this.maxRows = maxRows; return this; } /** * @see org.apache.wicket.Component#onComponentTag(ComponentTag) */ @Override protected void onComponentTag(final ComponentTag tag) { super.onComponentTag(tag); if (!tag.getAttributes().containsKey("size")) { tag.put("size", maxRows); } } }