1.1 --- a/lookup/src/main/java/org/openide/util/lookup/InstanceContent.java Wed Jan 27 17:46:23 2010 -0500
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,378 +0,0 @@
1.4 -/*
1.5 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 - *
1.7 - * Copyright 1997-2009 Sun Microsystems, Inc. All rights reserved.
1.8 - *
1.9 - * The contents of this file are subject to the terms of either the GNU
1.10 - * General Public License Version 2 only ("GPL") or the Common
1.11 - * Development and Distribution License("CDDL") (collectively, the
1.12 - * "License"). You may not use this file except in compliance with the
1.13 - * License. You can obtain a copy of the License at
1.14 - * http://www.netbeans.org/cddl-gplv2.html
1.15 - * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
1.16 - * specific language governing permissions and limitations under the
1.17 - * License. When distributing the software, include this License Header
1.18 - * Notice in each file and include the License file at
1.19 - * nbbuild/licenses/CDDL-GPL-2-CP. Sun designates this
1.20 - * particular file as subject to the "Classpath" exception as provided
1.21 - * by Sun in the GPL Version 2 section of the License file that
1.22 - * accompanied this code. If applicable, add the following below the
1.23 - * License Header, with the fields enclosed by brackets [] replaced by
1.24 - * your own identifying information:
1.25 - * "Portions Copyrighted [year] [name of copyright owner]"
1.26 - *
1.27 - * Contributor(s):
1.28 - *
1.29 - * The Original Software is NetBeans. The Initial Developer of the Original
1.30 - * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun
1.31 - * Microsystems, Inc. All Rights Reserved.
1.32 - *
1.33 - * If you wish your version of this file to be governed by only the CDDL
1.34 - * or only the GPL Version 2, indicate your decision by adding
1.35 - * "[Contributor] elects to include this software in this distribution
1.36 - * under the [CDDL or GPL Version 2] license." If you do not indicate a
1.37 - * single choice of license, a recipient has the option to distribute
1.38 - * your version of this file under either the CDDL, the GPL Version 2 or
1.39 - * to extend the choice of license to its licensees as provided above.
1.40 - * However, if you add GPL Version 2 code and therefore, elected the GPL
1.41 - * Version 2 license, then the option applies only if the new code is
1.42 - * made subject to such option by the copyright holder.
1.43 - */
1.44 -package org.openide.util.lookup;
1.45 -
1.46 -import org.openide.util.lookup.AbstractLookup.Pair;
1.47 -
1.48 -import java.lang.ref.WeakReference;
1.49 -
1.50 -import java.util.*;
1.51 -import java.util.concurrent.Executor;
1.52 -import org.openide.util.Lookup.Item;
1.53 -
1.54 -
1.55 -/** A special content implementation that can be passed to AbstractLookup
1.56 - * and provides methods for registration of instances and lazy instances.
1.57 - * <PRE>
1.58 - * InstanceContent ic = new InstanceContent ();
1.59 - * AbstractLookup al = new AbstractLookup (ic);
1.60 - *
1.61 - * ic.add (new Object ());
1.62 - * ic.add (new Dimension (...));
1.63 - *
1.64 - * Dimension theDim = (Dimension)al.lookup (Dimension.class);
1.65 - * </PRE>
1.66 - *
1.67 - * @author Jaroslav Tulach
1.68 - *
1.69 - * @since 1.25
1.70 - */
1.71 -public final class InstanceContent extends AbstractLookup.Content {
1.72 - /**
1.73 - * Create a new, empty content.
1.74 - */
1.75 - public InstanceContent() {
1.76 - }
1.77 -
1.78 - /** Creates a content associated with an executor to handle dispatch
1.79 - * of changes.
1.80 - * @param notifyIn the executor to notify changes in
1.81 - * @since 7.16
1.82 - */
1.83 - public InstanceContent(Executor notifyIn) {
1.84 - super(notifyIn);
1.85 - }
1.86 - /** The method to add instance to the lookup with.
1.87 - * @param inst instance
1.88 - */
1.89 - public final void add(Object inst) {
1.90 - addPair(new SimpleItem<Object>(inst));
1.91 - }
1.92 -
1.93 - /** Adds a convertible instance into the lookup. The <code>inst</code>
1.94 - * argument is just a key, not the actual value to appear in the lookup.
1.95 - * The value will be created on demand, later when it is really needed
1.96 - * by calling <code>convertor</code> methods.
1.97 - * <p>
1.98 - * This method is useful to delay creation of heavy weight objects.
1.99 - * Instead just register lightweight key and a convertor.
1.100 - * <p>
1.101 - * To remove registered object from lookup use {@link #remove(java.lang.Object, org.openide.util.lookup.InstanceContent.Convertor)}
1.102 - * with the same arguments.
1.103 - *
1.104 - * @param inst instance
1.105 - * @param conv convertor which postponing an instantiation,
1.106 - * if <code>conv==null</code> then the instance is registered directly.
1.107 - */
1.108 - public final <T,R> void add(T inst, Convertor<T,R> conv) {
1.109 - addPair(new ConvertingItem<T,R>(inst, conv));
1.110 - }
1.111 -
1.112 - /** Remove instance.
1.113 - * @param inst instance
1.114 - */
1.115 - public final void remove(Object inst) {
1.116 - removePair(new SimpleItem<Object>(inst));
1.117 - }
1.118 -
1.119 - /** Remove instance added with a convertor.
1.120 - * @param inst instance
1.121 - * @param conv convertor, if <code>conv==null</code> it is same like
1.122 - * remove(Object)
1.123 - */
1.124 - public final <T,R> void remove(T inst, Convertor<T,R> conv) {
1.125 - removePair(new ConvertingItem<T,R>(inst, conv));
1.126 - }
1.127 -
1.128 - /** Changes all pairs in the lookup to new values. Converts collection of
1.129 - * instances to collection of pairs.
1.130 - * @param col the collection of (Item) objects
1.131 - * @param conv the convertor to use or null
1.132 - */
1.133 - public final <T,R> void set(Collection<T> col, Convertor<T,R> conv) {
1.134 - ArrayList<Pair<?>> l = new ArrayList<Pair<?>>(col.size());
1.135 - Iterator<T> it = col.iterator();
1.136 -
1.137 - if (conv == null) {
1.138 - while (it.hasNext()) {
1.139 - l.add(new SimpleItem<T>(it.next()));
1.140 - }
1.141 - } else {
1.142 - while (it.hasNext()) {
1.143 - l.add(new ConvertingItem<T,R>(it.next(), conv));
1.144 - }
1.145 - }
1.146 -
1.147 - setPairs(l);
1.148 - }
1.149 -
1.150 - /** Convertor postpones an instantiation of an object.
1.151 - * @since 1.25
1.152 - */
1.153 - public static interface Convertor<T,R> {
1.154 - /** Convert obj to other object. There is no need to implement
1.155 - * cache mechanism. It is provided by
1.156 - * {@link Item#getInstance()} method itself. However the
1.157 - * method can be called more than once because instance is held
1.158 - * just by weak reference.
1.159 - *
1.160 - * @param obj the registered object
1.161 - * @return the object converted from this object
1.162 - */
1.163 - public R convert(T obj);
1.164 -
1.165 - /** Return type of converted object. Accessible via
1.166 - * {@link Item#getType()}
1.167 - * @param obj the registered object
1.168 - * @return the class that will be produced from this object (class or
1.169 - * superclass of convert (obj))
1.170 - */
1.171 - public Class<? extends R> type(T obj);
1.172 -
1.173 - /** Computes the ID of the resulted object. Accessible via
1.174 - * {@link Item#getId()}.
1.175 - * @param obj the registered object
1.176 - * @return the ID for the object
1.177 - */
1.178 - public String id(T obj);
1.179 -
1.180 - /** The human presentable name for the object. Accessible via
1.181 - * {@link Item#getDisplayName()}.
1.182 - * @param obj the registered object
1.183 - * @return the name representing the object for the user
1.184 - */
1.185 - public String displayName(T obj);
1.186 - }
1.187 -
1.188 - /** Instance of one item representing an object.
1.189 - */
1.190 - final static class SimpleItem<T> extends Pair<T> {
1.191 - private T obj;
1.192 -
1.193 - /** Create an item.
1.194 - * @obj object to register
1.195 - */
1.196 - public SimpleItem(T obj) {
1.197 - if (obj == null) {
1.198 - throw new NullPointerException();
1.199 - }
1.200 - this.obj = obj;
1.201 - }
1.202 -
1.203 - /** Tests whether this item can produce object
1.204 - * of class c.
1.205 - */
1.206 - public boolean instanceOf(Class<?> c) {
1.207 - return c.isInstance(obj);
1.208 - }
1.209 -
1.210 - /** Get instance of registered object. If convertor is specified then
1.211 - * method InstanceLookup.Convertor.convertor is used and weak reference
1.212 - * to converted object is saved.
1.213 - * @return the instance of the object.
1.214 - */
1.215 - public T getInstance() {
1.216 - return obj;
1.217 - }
1.218 -
1.219 - @Override
1.220 - public boolean equals(Object o) {
1.221 - if (o instanceof SimpleItem) {
1.222 - return obj.equals(((SimpleItem) o).obj);
1.223 - } else {
1.224 - return false;
1.225 - }
1.226 - }
1.227 -
1.228 - @Override
1.229 - public int hashCode() {
1.230 - return obj.hashCode();
1.231 - }
1.232 -
1.233 - /** An identity of the item.
1.234 - * @return string representing the item, that can be used for
1.235 - * persistance purposes to locate the same item next time
1.236 - */
1.237 - public String getId() {
1.238 - return "IL[" + obj.toString(); // NOI18N
1.239 - }
1.240 -
1.241 - /** Getter for display name of the item.
1.242 - */
1.243 - public String getDisplayName() {
1.244 - return obj.toString();
1.245 - }
1.246 -
1.247 - /** Method that can test whether an instance of a class has been created
1.248 - * by this item.
1.249 - *
1.250 - * @param obj the instance
1.251 - * @return if the item has already create an instance and it is the same
1.252 - * as obj.
1.253 - */
1.254 - protected boolean creatorOf(Object obj) {
1.255 - return obj == this.obj;
1.256 - }
1.257 -
1.258 - /** The class of this item.
1.259 - * @return the correct class
1.260 - */
1.261 - @SuppressWarnings("unchecked")
1.262 - public Class<? extends T> getType() {
1.263 - return (Class<? extends T>)obj.getClass();
1.264 - }
1.265 - }
1.266 - // end of SimpleItem
1.267 -
1.268 - /** Instance of one item registered in the map.
1.269 - */
1.270 - final static class ConvertingItem<T,R> extends Pair<R> {
1.271 - /** registered object */
1.272 - private T obj;
1.273 -
1.274 - /** Reference to converted object. */
1.275 - private WeakReference<R> ref;
1.276 -
1.277 - /** convertor to use */
1.278 - private Convertor<? super T,R> conv;
1.279 -
1.280 - /** Create an item.
1.281 - * @obj object to register
1.282 - * @conv a convertor, can be <code>null</code>.
1.283 - */
1.284 - public ConvertingItem(T obj, Convertor<? super T,R> conv) {
1.285 - this.obj = obj;
1.286 - this.conv = conv;
1.287 - }
1.288 -
1.289 - /** Tests whether this item can produce object
1.290 - * of class c.
1.291 - */
1.292 - public boolean instanceOf(Class<?> c) {
1.293 - return c.isAssignableFrom(getType());
1.294 - }
1.295 -
1.296 - /** Returns converted object or null if obj has not been converted yet
1.297 - * or reference was cleared by garbage collector.
1.298 - */
1.299 - private R getConverted() {
1.300 - if (ref == null) {
1.301 - return null;
1.302 - }
1.303 -
1.304 - return ref.get();
1.305 - }
1.306 -
1.307 - /** Get instance of registered object. If convertor is specified then
1.308 - * method InstanceLookup.Convertor.convertor is used and weak reference
1.309 - * to converted object is saved.
1.310 - * @return the instance of the object.
1.311 - */
1.312 - public synchronized R getInstance() {
1.313 - R converted = getConverted();
1.314 -
1.315 - if (converted == null) {
1.316 - converted = conv.convert(obj);
1.317 - ref = new WeakReference<R>(converted);
1.318 - }
1.319 -
1.320 - return converted;
1.321 - }
1.322 -
1.323 - @Override
1.324 - public boolean equals(Object o) {
1.325 - if (o instanceof ConvertingItem) {
1.326 - return obj.equals(((ConvertingItem) o).obj);
1.327 - } else {
1.328 - return false;
1.329 - }
1.330 - }
1.331 -
1.332 - @Override
1.333 - public int hashCode() {
1.334 - return obj.hashCode();
1.335 - }
1.336 -
1.337 - /** An identity of the item.
1.338 - * @return string representing the item, that can be used for
1.339 - * persistance purposes to locate the same item next time
1.340 - */
1.341 - public String getId() {
1.342 - return conv.id(obj);
1.343 - }
1.344 -
1.345 - /** Getter for display name of the item.
1.346 - */
1.347 - public String getDisplayName() {
1.348 - return conv.displayName(obj);
1.349 - }
1.350 -
1.351 - /** Method that can test whether an instance of a class has been created
1.352 - * by this item.
1.353 - *
1.354 - * @param obj the instance
1.355 - * @return if the item has already create an instance and it is the same
1.356 - * as obj.
1.357 - */
1.358 - protected boolean creatorOf(Object obj) {
1.359 - if (conv == null) {
1.360 - return obj == this.obj;
1.361 - } else {
1.362 - return obj == getConverted();
1.363 - }
1.364 - }
1.365 -
1.366 - /** The class of this item.
1.367 - * @return the correct class
1.368 - */
1.369 - @SuppressWarnings("unchecked")
1.370 - public Class<? extends R> getType() {
1.371 - R converted = getConverted();
1.372 -
1.373 - if (converted == null) {
1.374 - return conv.type(obj);
1.375 - }
1.376 -
1.377 - return (Class<? extends R>)converted.getClass();
1.378 - }
1.379 - }
1.380 - // end of ConvertingItem
1.381 -}