| /******************************************************************************* |
| * Copyright (c) 2010, 2012 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0, which accompanies this distribution |
| * and is available at http://www.eclipse.org/legal/epl-v10.html. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.internal; |
| |
| import java.io.Serializable; |
| |
| /** |
| * A <code>NotBooleanTransformer</code> will transform a |
| * {@link Boolean} to its NOT value:<ul> |
| * <li>If the original {@link Boolean} is {@link Boolean#TRUE}, |
| * the transformer will return {@link Boolean#FALSE}. |
| * <li>If the original {@link Boolean} is {@link Boolean#FALSE}, |
| * the transformer will return {@link Boolean#TRUE}. |
| * <li>If the original {@link Boolean} is <code>null</code>, |
| * the transformer will return <code>null</code>. |
| * </ul> |
| */ |
| public class NotBooleanTransformer |
| implements BidiTransformer<Boolean, Boolean>, Serializable |
| { |
| public static final BidiTransformer<Boolean, Boolean> INSTANCE = new NotBooleanTransformer(); |
| |
| public static BidiTransformer<Boolean, Boolean> instance() { |
| return INSTANCE; |
| } |
| |
| // ensure single instance |
| private NotBooleanTransformer() { |
| super(); |
| } |
| |
| public Boolean transform(Boolean b) { |
| return (b == null) ? null : BooleanTools.not(b); |
| } |
| |
| public Boolean reverseTransform(Boolean b) { |
| return (b == null) ? null : BooleanTools.not(b); |
| } |
| |
| @Override |
| public String toString() { |
| return this.getClass().getSimpleName(); |
| } |
| |
| private static final long serialVersionUID = 1L; |
| private Object readResolve() { |
| // replace this object with the singleton |
| return INSTANCE; |
| } |
| } |