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.Collection; import java.util.List; import java.util.Map; import org.apache.wicket.Page; import org.apache.wicket.markup.ComponentTag; import org.apache.wicket.markup.MarkupStream; import org.apache.wicket.model.IModel; import org.apache.wicket.settings.DebugSettings; import org.apache.wicket.util.convert.IConverter; import org.apache.wicket.util.lang.Args; import org.apache.wicket.util.string.AppendingStringBuffer; import org.apache.wicket.util.string.Strings; import org.apache.wicket.util.value.IValueMap; /** * A choice subclass that shows choices via checkboxes. * <p> * Java: * * <pre> * List SITES = Arrays.asList(new String[] { "The Server Side", "Java Lobby", "Java.Net" }); * // Add a set of checkboxes uses Input's 'site' property to designate the * // current selections, and that uses the SITES list for the available options. * form.add(new CheckBoxMultipleChoice("site", SITES)); * </pre> * * HTML: * * <pre> * <span valign="top" wicket:id="site"> * <input type="checkbox">site 1</input> * <input type="checkbox">site 2</input> * </span> * </pre> * * </p> * * @author Jonathan Locke * @author Johan Compagner * @author Martijn Dashorst * @author Gwyn Evans * @author Igor Vaynberg (ivaynberg) * * @param <T> * The model object type */ public class CheckBoxMultipleChoice<T> extends ListMultipleChoice<T> { private static final long serialVersionUID = 1L; private String prefix = ""; private String suffix = ""; private LabelPosition labelPosition = LabelPosition.AFTER; /** * Constructor * * @param id * See Component * @see org.apache.wicket.Component#Component(String) * @see AbstractChoice#AbstractChoice(String) */ public CheckBoxMultipleChoice(final String id) { super(id); } /** * Constructor * * @param id * See Component * @param choices * The collection of choices in the radio choice * @see org.apache.wicket.Component#Component(String) * @see AbstractChoice#AbstractChoice(String, java.util.List) */ public CheckBoxMultipleChoice(final String id, final List<? extends T> choices) { super(id, choices); } /** * Constructor * * @param id * See Component * @param renderer * The rendering engine * @param choices * The collection of choices in the radio choice * @see org.apache.wicket.Component#Component(String) * @see AbstractChoice#AbstractChoice(String, * java.util.List,org.apache.wicket.markup.html.form.IChoiceRenderer) */ public CheckBoxMultipleChoice(final String id, final List<? extends T> choices, final IChoiceRenderer<? super T> renderer) { super(id, choices, renderer); } /** * Constructor * * @param id * See Component * @param model * See Component * @param choices * The collection of choices in the radio choice * @see org.apache.wicket.Component#Component(String, org.apache.wicket.model.IModel) * @see AbstractChoice#AbstractChoice(String, org.apache.wicket.model.IModel, java.util.List) */ public CheckBoxMultipleChoice(final String id, IModel<? extends Collection<T>> model, final List<? extends T> choices) { super(id, model, choices); } /** * Constructor * * @param id * See Component * @param model * See Component * @param choices * The collection of choices in the radio choice * @param renderer * The rendering engine * @see org.apache.wicket.Component#Component(String, org.apache.wicket.model.IModel) * @see AbstractChoice#AbstractChoice(String, org.apache.wicket.model.IModel, * java.util.List,org.apache.wicket.markup.html.form.IChoiceRenderer) */ public CheckBoxMultipleChoice(final String id, IModel<? extends Collection<T>> model, final List<? extends T> choices, final IChoiceRenderer<? super T> renderer) { super(id, model, choices, renderer); } /** * Constructor * * @param id * See Component * @param choices * The collection of choices in the radio choice * @see org.apache.wicket.Component#Component(String) * @see AbstractChoice#AbstractChoice(String, org.apache.wicket.model.IModel) */ public CheckBoxMultipleChoice(String id, IModel<? extends List<? extends T>> choices) { super(id, choices); } /** * Constructor * * @param id * See Component * @param model * The model that is updated with changes in this component. See Component * @param choices * The collection of choices in the radio choice * @see AbstractChoice#AbstractChoice(String, * org.apache.wicket.model.IModel,org.apache.wicket.model.IModel) * @see org.apache.wicket.Component#Component(String, org.apache.wicket.model.IModel) */ public CheckBoxMultipleChoice(String id, IModel<? extends Collection<T>> model, IModel<? extends List<? extends T>> choices) { super(id, model, choices); } /** * Constructor * * @param id * See Component * @param choices * The collection of choices in the radio choice * @param renderer * The rendering engine * @see AbstractChoice#AbstractChoice(String, * org.apache.wicket.model.IModel,org.apache.wicket.markup.html.form.IChoiceRenderer) * @see org.apache.wicket.Component#Component(String) */ public CheckBoxMultipleChoice(String id, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer) { super(id, choices, renderer); } /** * Constructor * * @param id * See Component * @param model * The model that is updated with changes in this component. See Component * @param choices * The collection of choices in the radio choice * @param renderer * The rendering engine * @see org.apache.wicket.Component#Component(String, org.apache.wicket.model.IModel) * @see AbstractChoice#AbstractChoice(String, org.apache.wicket.model.IModel, * org.apache.wicket.model.IModel,org.apache.wicket.markup.html.form.IChoiceRenderer) */ public CheckBoxMultipleChoice(String id, IModel<? extends Collection<T>> model, IModel<? extends List<? extends T>> choices, IChoiceRenderer<? super T> renderer) { super(id, model, choices, renderer); } /** * @return Prefix to use before choice */ public String getPrefix() { return prefix; } /** * @param index * index of the choice * @param choice * the choice itself * @return Prefix to use before choice. The default implementation just returns * {@link #getPrefix()}. Override to have a prefix dependent on the choice item. */ protected String getPrefix(int index, T choice) { return getPrefix(); } /** * @param index * index of the choice * @param choice * the choice itself * @return Separator to use between radio options. The default implementation just returns * {@link #getSuffix()}. Override to have a prefix dependent on the choice item. */ protected String getSuffix(int index, T choice) { return getSuffix(); } /** * @param prefix * Prefix to use before choice * @return this */ public final CheckBoxMultipleChoice<T> setPrefix(final String prefix) { // Tell the page that this component's prefix was changed final Page page = findPage(); if (page != null) { addStateChange(); } this.prefix = prefix; return this; } /** * @return Separator to use between radio options */ public String getSuffix() { return suffix; } /** * @param suffix * Separator to use between radio options * @return this */ public final CheckBoxMultipleChoice<T> setSuffix(final String suffix) { // Tell the page that this component's suffix was changed final Page page = findPage(); if (page != null) { addStateChange(); } this.suffix = suffix; return this; } /** * Sets the preferred position of the <label> for each choice * * @param labelPosition * The preferred position for the label * @return {@code this} instance, for chaining */ public CheckBoxMultipleChoice<T> setLabelPosition(LabelPosition labelPosition) { Args.notNull(labelPosition, "labelPosition"); this.labelPosition = labelPosition; return this; } /** * @see org.apache.wicket.markup.html.form.ListMultipleChoice#onComponentTag(org.apache.wicket.markup.ComponentTag) */ @Override protected void onComponentTag(ComponentTag tag) { super.onComponentTag(tag); // No longer applicable, breaks XHTML validation. tag.remove("multiple"); tag.remove("size"); tag.remove("disabled"); tag.remove("name"); } /** * @see org.apache.wicket.Component#onComponentTagBody(org.apache.wicket.markup.MarkupStream, * org.apache.wicket.markup.ComponentTag) */ @Override public final void onComponentTagBody(final MarkupStream markupStream, final ComponentTag openTag) { // Iterate through choices final List<? extends T> choices = getChoices(); // Buffer to hold generated body final AppendingStringBuffer buffer = new AppendingStringBuffer(70 * (choices.size() + 1)); // Value of this choice final String selected = getValue(); // Loop through choices for (int index = 0; index < choices.size(); index++) { // Get next choice final T choice = choices.get(index); appendOptionHtml(buffer, choice, index, selected); } // Replace body replaceComponentTagBody(markupStream, openTag, buffer); } /** * Generates and appends html for a single choice into the provided buffer * * @param buffer * Appending string buffer that will have the generated html appended * @param choice * Choice object * @param index * The index of this option * @param selected * The currently selected string value */ @SuppressWarnings("unchecked") @Override protected void appendOptionHtml(final AppendingStringBuffer buffer, final T choice, int index, final String selected) { Object displayValue = getChoiceRenderer().getDisplayValue(choice); Class<?> objectClass = displayValue == null ? null : displayValue.getClass(); // Get label for choice String label = ""; if (objectClass != null && objectClass != String.class) { @SuppressWarnings("rawtypes") IConverter converter = getConverter(objectClass); label = converter.convertToString(displayValue, getLocale()); } else if (displayValue != null) { label = displayValue.toString(); } // If there is a display value for the choice, then we know that the // choice is automatic in some way. If label is /null/ then we know // that the choice is a manually created checkbox tag at some random // location in the page markup! if (label != null) { // Append option suffix buffer.append(getPrefix(index, choice)); String id = getChoiceRenderer().getIdValue(choice, index); final String idAttr = getCheckBoxMarkupId(id); // Add label for checkbox String display = label; if (localizeDisplayValues()) { display = getLocalizer().getString(label, this, label); } final CharSequence escaped = (getEscapeModelStrings() ? Strings.escapeMarkup(display) : display); // Allows user to add attributes to the <label..> tag IValueMap labelAttrs = getAdditionalAttributesForLabel(index, choice); StringBuilder extraLabelAttributes = new StringBuilder(); if (labelAttrs != null) { for (Map.Entry<String, Object> attr : labelAttrs.entrySet()) { extraLabelAttributes.append(' ').append(Strings.escapeMarkup(attr.getKey())).append("=\"") .append(Strings.escapeMarkup(attr.getValue().toString())).append('"'); } } switch (labelPosition) { case BEFORE: buffer.append("<label for=\"").append(Strings.escapeMarkup(idAttr)).append('"') .append(extraLabelAttributes).append('>').append(escaped).append("</label>"); break; case WRAP_BEFORE: buffer.append("<label").append(extraLabelAttributes).append('>').append(escaped).append(' '); break; case WRAP_AFTER: buffer.append("<label").append(extraLabelAttributes).append('>'); break; } // Add checkbox element buffer.append("<input name=\""); buffer.append(getInputName()); buffer.append('"'); buffer.append(" type=\"checkbox\""); if (isSelected(choice, index, selected)) { buffer.append(" checked=\"checked\""); } if (isDisabled(choice, index, selected) || !isEnabledInHierarchy()) { buffer.append(" disabled=\"disabled\""); } buffer.append(" value=\""); buffer.append(Strings.escapeMarkup(id)); buffer.append("\" id=\""); buffer.append(Strings.escapeMarkup(idAttr)); buffer.append('"'); // Allows user to add attributes to the <input..> tag { IValueMap attrs = getAdditionalAttributes(index, choice); if (attrs != null) { for (Map.Entry<String, Object> attr : attrs.entrySet()) { buffer.append(' ').append(Strings.escapeMarkup(attr.getKey())).append("=\"") .append(Strings.escapeMarkup(attr.getValue().toString())).append('"'); } } } DebugSettings debugSettings = getApplication().getDebugSettings(); String componentPathAttributeName = debugSettings.getComponentPathAttributeName(); if (Strings.isEmpty(componentPathAttributeName) == false) { CharSequence path = getPageRelativePath(); path = Strings.replaceAll(path, "_", "__"); path = Strings.replaceAll(path, ":", "_"); buffer.append(' ').append(componentPathAttributeName).append("=\"").append(path).append("_input_") .append(index).append('"'); } buffer.append("/>"); switch (labelPosition) { case WRAP_BEFORE: buffer.append("</label>"); break; case WRAP_AFTER: buffer.append(' ').append(escaped).append("</label>"); break; case AFTER: buffer.append("<label for=\"").append(Strings.escapeMarkup(idAttr)).append('"') .append(extraLabelAttributes).append('>').append(escaped).append("</label>"); break; } // Append option suffix buffer.append(getSuffix(index, choice)); } } /** * You may subclass this method to provide additional attributes to the <label ..> tag. * * @param index * index of the choice * @param choice * the choice itself * @return tag attribute name/value pairs. */ protected IValueMap getAdditionalAttributesForLabel(int index, T choice) { return null; } /** * You may subclass this method to provide additional attributes to the <input ..> tag. * * @param index * @param choice * @return tag attribute name/value pairs. */ protected IValueMap getAdditionalAttributes(final int index, final T choice) { return null; } /** * Creates markup id for the input tag used to generate the checkbox for the element with the * specified {@code id}. * <p> * NOTE It is useful to override this method if the contract for the generated ids should be * fixed, for example in cases when the id generation pattern in this method is used to predict * ids by some external javascript. If the contract is fixed in the user's code then upgrading * wicket versions will guarantee not to break it should the default contract be changed at a * later time. * </p> * * @param id * @return markup id for the input tag */ protected String getCheckBoxMarkupId(String id) { return getMarkupId() + '-' + getInputName() + '_' + id; } }