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.border; import java.io.IOException; import java.util.Locale; import org.apache.wicket.Application; import org.apache.wicket.Component; import org.apache.wicket.MarkupContainer; import org.apache.wicket.WicketRuntimeException; import org.apache.wicket.behavior.Behavior; import org.apache.wicket.core.util.resource.locator.IResourceStreamLocator; import org.apache.wicket.markup.ContainerInfo; import org.apache.wicket.markup.IMarkupFragment; import org.apache.wicket.markup.MarkupElement; import org.apache.wicket.markup.MarkupFactory; import org.apache.wicket.markup.MarkupResourceStream; import org.apache.wicket.markup.MarkupStream; import org.apache.wicket.markup.MarkupType; import org.apache.wicket.markup.WicketTag; import org.apache.wicket.request.Response; import org.apache.wicket.util.resource.IResourceStream; /** * This is a behavior implementation that can be used if you have markup that should be around a * component. It works just like {@link Border} so you have to have a <wicket:border>HTML * before<wicket:body/>HTML after</wicket:border> in the html of your subclass. But different than * Border you can not add components to the Border markup, only to the BorderBody. * * @author jcompagner */ public class BorderBehavior extends Behavior { private static final long serialVersionUID = 1L; // markup stream associated with this border. bonus of keeping a reference // is that when renderAfter starts the stream will be very close to its // needed position because renderBefore has executed private transient MarkupStream markupStream; @Override public void beforeRender(final Component component) { final MarkupStream stream = getMarkupStream(component); final Response response = component.getResponse(); stream.setCurrentIndex(0); boolean insideBorderMarkup = false; while (stream.isCurrentIndexInsideTheStream()) { MarkupElement elem = stream.get(); stream.next(); if (elem instanceof WicketTag) { WicketTag wTag = (WicketTag) elem; if (!insideBorderMarkup) { if (wTag.isBorderTag() && wTag.isOpen()) { insideBorderMarkup = true; continue; } else { throw new WicketRuntimeException( "Unexpected tag encountered in markup of component border " + getClass().getName() + ". Tag: " + wTag.toString() + ", expected tag: <wicket:border>"); } } else { if (wTag.isBodyTag()) { break; } else { throw new WicketRuntimeException("Unexpected tag encountered in markup of component border " + getClass().getName() + ". Tag: " + wTag.toString() + ", expected tag: <wicket:body> or </wicket:body>"); } } } if (insideBorderMarkup) { response.write(elem.toCharSequence()); } } if (!stream.isCurrentIndexInsideTheStream()) { throw new WicketRuntimeException("Markup for component border " + getClass().getName() + " ended prematurely, was expecting </wicket:border>"); } } @Override public void afterRender(final Component component) { final MarkupStream stream = getMarkupStream(component); final Response response = component.getResponse(); while (stream.isCurrentIndexInsideTheStream()) { MarkupElement elem = stream.get(); stream.next(); if (elem instanceof WicketTag) { WicketTag wTag = (WicketTag) elem; if (wTag.isBorderTag() && wTag.isClose()) { break; } else { throw new WicketRuntimeException( "Unexpected tag encountered in markup of component border " + getClass().getName() + ". Tag: " + wTag.toString() + ", expected tag: </wicket:border>"); } } response.write(elem.toCharSequence()); } } /** * * @param component * @return markup stream */ private MarkupStream getMarkupStream(final Component component) { if (markupStream == null) { markupStream = findMarkupStream(component); } return markupStream; } /** * * @param owner * @return markup stream */ private MarkupStream findMarkupStream(final Component owner) { final MarkupType markupType = getMarkupType(owner); if (markupType == null) { return null; } // TODO we need to expose this functionality for any class not just for // markupcontainers in markupcache so we don't have to replicate this // logic here // Get locator to search for the resource final IResourceStreamLocator locator = Application.get().getResourceSettings().getResourceStreamLocator(); final String style = owner.getStyle(); final String variation = owner.getVariation(); final Locale locale = owner.getLocale(); MarkupResourceStream markupResourceStream = null; Class<?> containerClass = getClass(); while (!(containerClass.equals(BorderBehavior.class))) { String path = containerClass.getName().replace('.', '/'); IResourceStream resourceStream = locator.locate(containerClass, path, style, variation, locale, markupType.getExtension(), false); // Did we find it already? if (resourceStream != null) { ContainerInfo ci = new ContainerInfo(containerClass, locale, style, variation, markupType); markupResourceStream = new MarkupResourceStream(resourceStream, ci, containerClass); break; } // Walk up the class hierarchy one level, if markup has not // yet been found containerClass = containerClass.getSuperclass(); } if (markupResourceStream == null) { throw new WicketRuntimeException( "Could not find markup for component border `" + getClass().getName() + "`"); } try { IMarkupFragment markup = MarkupFactory.get().newMarkupParser(markupResourceStream).parse(); return new MarkupStream(markup); } catch (Exception e) { throw new WicketRuntimeException( "Could not parse markup from markup resource stream: " + markupResourceStream.toString(), e); } finally { try { markupResourceStream.close(); } catch (IOException e) { throw new WicketRuntimeException("Cannot close markup resource stream: " + markupResourceStream, e); } } } /** * * @param component * @return markup type */ private MarkupType getMarkupType(final Component component) { final MarkupType markupType; if (component instanceof MarkupContainer) { markupType = ((MarkupContainer) component).getMarkupType(); } else { markupType = component.getParent().getMarkupType(); } return markupType; } }