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
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
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040: */
041:
042: package org.netbeans.modules.compapp.casaeditor.nodes;
043:
044: import java.lang.ref.WeakReference;
045: import java.util.Collection;
046: import java.util.Collections;
047: import java.util.List;
048: import org.netbeans.modules.compapp.casaeditor.model.casa.CasaComponent;
049: import org.openide.nodes.Children;
050:
051: /**
052: *
053: * @author Josh Sandusky
054: */
055: public abstract class CasaNodeChildren<T> extends Children.Keys<T> {
056:
057: protected CasaNodeFactory mNodeFactory;
058: private WeakReference mDataReference;
059: private Object mHardInitializationReference;
060:
061: public CasaNodeChildren(Object data, CasaNodeFactory factory) {
062: super ();
063: mNodeFactory = factory;
064:
065: // for casual data references, use a weak reference which allows our
066: // reference to be garbage collected when no longer needed
067: mDataReference = new WeakReference<Object>(data);
068:
069: // for initialization purposes, use a hard reference. we manually
070: // control when this reference is set to null. initialization needs
071: // a preserved handle to the data, even though the model may not.
072: mHardInitializationReference = data;
073: }
074:
075: protected Object getData() {
076: if (mDataReference != null) {
077: Object ref = mDataReference.get();
078: if (ref instanceof CasaComponent) {
079: if (!((CasaComponent) ref).isInDocumentModel()) {
080: return null;
081: }
082: }
083: return ref;
084: }
085: return null;
086: }
087:
088: public Object getChildKeys(Object data) {
089: List children = null;
090: if (data instanceof CasaComponent) {
091: children = ((CasaComponent) data).getChildren();
092: } else if (data instanceof List) {
093: children = (List) data;
094: }
095: return children;
096: }
097:
098: @Override
099: protected void addNotify() {
100: super .addNotify();
101:
102: // lazy initialization
103: initialize();
104: }
105:
106: @Override
107: protected void removeNotify() {
108: super .removeNotify();
109:
110: mHardInitializationReference = null;
111: }
112:
113: private void initialize() {
114: Object data = mHardInitializationReference;
115: if (data == null) {
116: return;
117: }
118: Object children = getChildKeys(data);
119: if (children instanceof Collection) {
120: setKeys((Collection<T>) children);
121: } else if (children instanceof Object[]) {
122: T[] x = (T[]) children; // ?
123: setKeys(x);
124: } else {
125: List<T> keys = Collections.emptyList();
126: setKeys(keys);
127: }
128: // We initialized, so we don't need the initialization reference anymore.
129: mHardInitializationReference = null;
130: }
131: }
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