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 1997-2007 Sun
028: * Microsystems, Inc. All Rights Reserved.
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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
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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:
042: package org.netbeans.modules.search;
043:
044: import java.util.ArrayList;
045: import java.util.List;
046: import javax.swing.event.ChangeEvent;
047: import javax.swing.event.ChangeListener;
048: import org.netbeans.modules.search.SearchScope;
049: import org.openide.filesystems.FileObject;
050: import org.openidex.search.SearchInfo;
051: import org.openidex.search.SearchInfoFactory;
052:
053: /**
054: * Base class for implementations of search scopes.
055: *
056: * @author Marian Petras
057: */
058: public abstract class AbstractSearchScope extends SearchScope {
059:
060: private List<ChangeListener> changeListeners;
061: private Boolean applicable;
062:
063: protected AbstractSearchScope() {
064: }
065:
066: protected final boolean isApplicable() {
067:
068: /* thread: <any> */
069:
070: boolean currState;
071: synchronized (getListenersLock()) {
072: if ((applicable == null) && isListening()) {
073: applicable = Boolean.valueOf(checkIsApplicable());
074: }
075: if (applicable != null) {
076: return applicable.booleanValue();
077: }
078: }
079:
080: return checkIsApplicable();
081: }
082:
083: protected final void setApplicable(boolean applicable) {
084: List<ChangeListener> listeners;
085:
086: synchronized (getListenersLock()) {
087: if (!isListening()) {
088: return;
089: }
090: if ((this .applicable != null)
091: && (applicable == this .applicable.booleanValue())) {
092: return;
093: }
094: this .applicable = Boolean.valueOf(applicable);
095: listeners = (changeListeners != null)
096: && !changeListeners.isEmpty() ? new ArrayList<ChangeListener>(
097: changeListeners)
098: : null;
099: }
100:
101: if (listeners != null) {
102: final ChangeEvent e = new ChangeEvent(this );
103: for (ChangeListener l : listeners) {
104: l.stateChanged(e);
105: }
106: }
107: }
108:
109: protected final void updateIsApplicable() {
110: setApplicable(checkIsApplicable());
111: }
112:
113: protected abstract boolean checkIsApplicable();
114:
115: protected abstract void startListening();
116:
117: protected abstract void stopListening();
118:
119: protected final boolean isListening() {
120:
121: /* thread: <any> */
122:
123: synchronized (getListenersLock()) {
124: return changeListeners != null;
125: }
126: }
127:
128: protected void addChangeListener(ChangeListener l) {
129: if (l == null) {
130: throw new IllegalArgumentException("null"); //NOI18N
131: }
132:
133: /* thread: <any> */
134:
135: synchronized (getListenersLock()) {
136: boolean firstListener = !isListening();
137: if (changeListeners == null) {
138: changeListeners = new ArrayList<ChangeListener>(1);
139: }
140: changeListeners.add(l);
141: if (firstListener) {
142: assert applicable == null;
143: startListening();
144: }
145: assert isListening();
146: }
147: }
148:
149: protected void removeChangeListener(ChangeListener l) {
150: if (l == null) {
151: throw new IllegalArgumentException("null"); //NOI18N
152: }
153:
154: /* thread: <any> */
155:
156: synchronized (getListenersLock()) {
157: if (changeListeners.remove(l) && changeListeners.isEmpty()) {
158: changeListeners = null;
159: stopListening();
160: applicable = null;
161: assert !isListening();
162: }
163: }
164: }
165:
166: protected SearchInfo createEmptySearchInfo() {
167: return SearchInfoFactory.createSearchInfo(new FileObject[0],
168: false, null);
169: }
170:
171: }
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