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.modules.java.editor.semantic;
042:
043: import com.sun.source.tree.Tree;
044: import java.util.concurrent.atomic.AtomicBoolean;
045: import org.netbeans.api.java.source.CancellableTask;
046: import org.netbeans.api.java.source.support.CancellableTreePathScanner;
047: import org.netbeans.api.java.source.support.CancellableTreeScanner;
048:
049: /**
050: *
051: * @author Jan Lahoda
052: */
053: public abstract class ScanningCancellableTask<T> implements
054: CancellableTask<T> {
055:
056: protected AtomicBoolean canceled = new AtomicBoolean();
057:
058: /** Creates a new instance of ScanningCancellableTask */
059: protected ScanningCancellableTask() {
060: }
061:
062: public final synchronized void cancel() {
063: canceled.set(true);
064:
065: if (pathScanner != null) {
066: pathScanner.cancel();
067: }
068: if (scanner != null) {
069: scanner.cancel();
070: }
071: }
072:
073: public abstract void run(T parameter) throws Exception;
074:
075: protected final synchronized boolean isCancelled() {
076: return canceled.get();
077: }
078:
079: protected final synchronized void resume() {
080: canceled.set(false);
081: }
082:
083: private CancellableTreePathScanner pathScanner;
084: private CancellableTreeScanner scanner;
085:
086: protected <R, P> R scan(CancellableTreePathScanner<R, P> scanner,
087: Tree toScan, P p) {
088: if (isCancelled())
089: return null;
090:
091: try {
092: synchronized (this ) {
093: this .pathScanner = scanner;
094: }
095:
096: if (isCancelled())
097: return null;
098:
099: return scanner.scan(toScan, p);
100: } finally {
101: synchronized (this ) {
102: this .pathScanner = null;
103: }
104: }
105: }
106:
107: protected <R, P> R scan(CancellableTreeScanner<R, P> scanner,
108: Tree toScan, P p) {
109: if (isCancelled())
110: return null;
111:
112: try {
113: synchronized (this) {
114: this.scanner = scanner;
115: }
116:
117: if (isCancelled())
118: return null;
119:
120: return scanner.scan(toScan, p);
121: } finally {
122: synchronized (this) {
123: this.scanner = null;
124: }
125: }
126: }
127:
128: }
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