| /******************************************************************************* |
| * Copyright (c) 2013 Oracle. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License 2.0, which accompanies this distribution |
| * and is available at https://www.eclipse.org/legal/epl-2.0/. |
| * |
| * Contributors: |
| * Oracle - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.jpt.common.utility.internal.predicate; |
| |
| import java.io.Serializable; |
| import org.eclipse.jpt.common.utility.internal.ObjectTools; |
| import org.eclipse.jpt.common.utility.predicate.Predicate; |
| import org.eclipse.jpt.common.utility.transformer.Transformer; |
| |
| /** |
| * Predicate that wraps a {@link Transformer} and converts its output value |
| * to a predicate evaluation result (i.e. <code>true</code> or |
| * <code>false</code>). If the transformer's output is <code>null</code>, |
| * the predicate will evaluate to its configured null value. |
| * |
| * @param <V> the type of objects to be evaluated by the predicate (i.e. |
| * passed to its transformer) |
| */ |
| public class TransformerPredicate<V> |
| implements Predicate<V>, Serializable |
| { |
| protected final Transformer<? super V, Boolean> transformer; |
| |
| private static final long serialVersionUID = 1L; |
| |
| |
| public TransformerPredicate(Transformer<? super V, Boolean> transformer) { |
| super(); |
| if (transformer == null) { |
| throw new NullPointerException(); |
| } |
| this.transformer = transformer; |
| } |
| |
| public boolean evaluate(V variable) { |
| return this.transformer.transform(variable).booleanValue(); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if ( ! (o instanceof TransformerPredicate)) { |
| return false; |
| } |
| @SuppressWarnings("unchecked") |
| TransformerPredicate<V> other = (TransformerPredicate<V>) o; |
| return this.transformer.equals(other.transformer); |
| } |
| |
| @Override |
| public int hashCode() { |
| return this.transformer.hashCode(); |
| } |
| |
| @Override |
| public String toString() { |
| return ObjectTools.toString(this, this.transformer); |
| } |
| } |