001: /*
002: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
003: *
004: * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
005: *
006: * The contents of this file are subject to the terms of either the GNU
007: * General Public License Version 2 only ("GPL") or the Common
008: * Development and Distribution License("CDDL") (collectively, the
009: * "License"). You may not use this file except in compliance with the
010: * License. You can obtain a copy of the License at
011: * http://www.netbeans.org/cddl-gplv2.html
012: * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
013: * specific language governing permissions and limitations under the
014: * License. When distributing the software, include this License Header
015: * Notice in each file and include the License file at
016: * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
017: * particular file as subject to the "Classpath" exception as provided
018: * by Sun in the GPL Version 2 section of the License file that
019: * accompanied this code. If applicable, add the following below the
020: * License Header, with the fields enclosed by brackets [] replaced by
021: * your own identifying information:
022: * "Portions Copyrighted [year] [name of copyright owner]"
023: *
024: * Contributor(s):
025: *
026: * The Original Software is NetBeans. The Initial Developer of the Original
027: * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
028: * Microsystems, Inc. All Rights Reserved.
029: *
030: * If you wish your version of this file to be governed by only the CDDL
031: * or only the GPL Version 2, indicate your decision by adding
032: * "[Contributor] elects to include this software in this distribution
033: * under the [CDDL or GPL Version 2] license." If you do not indicate a
034: * single choice of license, a recipient has the option to distribute
035: * your version of this file under either the CDDL, the GPL Version 2 or
036: * to extend the choice of license to its licensees as provided above.
037: * However, if you add GPL Version 2 code and therefore, elected the GPL
038: * Version 2 license, then the option applies only if the new code is
039: * made subject to such option by the copyright holder.
040: */
041: package org.netbeans.api.java.source.support;
042:
043: import com.sun.source.tree.Tree;
044: import com.sun.source.util.TreePathScanner;
045: import java.util.concurrent.atomic.AtomicBoolean;
046:
047: /**
048: *
049: * @author Jan Lahoda
050: */
051: public class CancellableTreePathScanner<R, P> extends
052: TreePathScanner<R, P> {
053:
054: private final AtomicBoolean internalCanceled;
055: private final AtomicBoolean canceled;
056:
057: /**Construct a new CancellableTreePathScanner which can be canceled by calling
058: * the {@link #cancel} method.
059: */
060: public CancellableTreePathScanner() {
061: this (null);
062: }
063:
064: /**Construct a new CancellableTreePath Scanner which can be canceled either by calling
065: * the {@link #cancel} method, or by setting <code>true</code> into the provided
066: * <code>canceled</code> {@link AtomicBoolean}.
067: *
068: * @param canceled an {@link AtomicBoolean} through which this scanner can be canceled.
069: * The scanner never changes the state of the {@link AtomicBoolean}.
070: * @since 0.29
071: */
072: public CancellableTreePathScanner(AtomicBoolean canceled) {
073: this .canceled = canceled;
074:
075: this .internalCanceled = new AtomicBoolean();
076: }
077:
078: protected boolean isCanceled() {
079: return internalCanceled.get()
080: || (canceled != null && canceled.get());
081: }
082:
083: public void cancel() {
084: internalCanceled.set(true);
085: }
086:
087: /** @inheritDoc
088: */
089: public R scan(Tree tree, P p) {
090: if (isCanceled())
091: return null;
092:
093: return super .scan(tree, p);
094: }
095:
096: /** @inheritDoc
097: */
098: public R scan(Iterable<? extends Tree> trees, P p) {
099: if (isCanceled())
100: return null;
101:
102: return super.scan(trees, p);
103: }
104:
105: }
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