| /* |
| * 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; |
| |
| import java.io.Serializable; |
| import java.util.Collections; |
| import java.util.Set; |
| import java.util.TreeSet; |
| import java.util.regex.Pattern; |
| |
| import org.apache.wicket.behavior.AttributeAppender; |
| import org.apache.wicket.util.string.Strings; |
| |
| /** |
| * An AttributeModifier specialized in managing the <em>CSS class</em> |
| * attribute |
| */ |
| public abstract class ClassAttributeModifier extends AttributeAppender |
| { |
| private static final Pattern SPLITTER = Pattern.compile("\\s+"); |
| |
| /** |
| * Constructor. |
| */ |
| public ClassAttributeModifier() |
| { |
| super("class", null, " "); |
| } |
| |
| @Override |
| protected Serializable newValue(String currentValue, String appendValue) |
| { |
| String[] classes; |
| if (Strings.isEmpty(currentValue)) |
| { |
| classes = new String[0]; |
| } |
| else |
| { |
| classes = SPLITTER.split(currentValue.trim()); |
| } |
| Set<String> oldClasses = new TreeSet<>(); |
| Collections.addAll(oldClasses, classes); |
| |
| Set<String> newClasses = update(oldClasses); |
| |
| String separator = getSeparator(); |
| StringBuilder result = new StringBuilder(); |
| for (String cls : newClasses) |
| { |
| if (result.length() > 0) |
| { |
| result.append(separator); |
| } |
| result.append(cls); |
| } |
| return result.length() > 0 ? result.toString() : VALUELESS_ATTRIBUTE_REMOVE; |
| } |
| |
| /** |
| * Callback to update the CSS class values for a tag. |
| * |
| * @param oldClasses |
| * A set with the old class values |
| * @return A set with the new class values |
| */ |
| protected abstract Set<String> update(Set<String> oldClasses); |
| } |