1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/context/src/main/java/org/netbeans/html/context/spi/Contexts.java Tue Aug 26 18:13:30 2014 +0200
1.3 @@ -0,0 +1,192 @@
1.4 +/**
1.5 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 + *
1.7 + * Copyright 2013-2014 Oracle and/or its affiliates. All rights reserved.
1.8 + *
1.9 + * Oracle and Java are registered trademarks of Oracle and/or its affiliates.
1.10 + * Other names may be trademarks of their respective owners.
1.11 + *
1.12 + * The contents of this file are subject to the terms of either the GNU
1.13 + * General Public License Version 2 only ("GPL") or the Common
1.14 + * Development and Distribution License("CDDL") (collectively, the
1.15 + * "License"). You may not use this file except in compliance with the
1.16 + * License. You can obtain a copy of the License at
1.17 + * http://www.netbeans.org/cddl-gplv2.html
1.18 + * or nbbuild/licenses/CDDL-GPL-2-CP. See the License for the
1.19 + * specific language governing permissions and limitations under the
1.20 + * License. When distributing the software, include this License Header
1.21 + * Notice in each file and include the License file at
1.22 + * nbbuild/licenses/CDDL-GPL-2-CP. Oracle designates this
1.23 + * particular file as subject to the "Classpath" exception as provided
1.24 + * by Oracle in the GPL Version 2 section of the License file that
1.25 + * accompanied this code. If applicable, add the following below the
1.26 + * License Header, with the fields enclosed by brackets [] replaced by
1.27 + * your own identifying information:
1.28 + * "Portions Copyrighted [year] [name of copyright owner]"
1.29 + *
1.30 + * Contributor(s):
1.31 + *
1.32 + * The Original Software is NetBeans. The Initial Developer of the Original
1.33 + * Software is Oracle. Portions Copyright 2013-2014 Oracle. All Rights Reserved.
1.34 + *
1.35 + * If you wish your version of this file to be governed by only the CDDL
1.36 + * or only the GPL Version 2, indicate your decision by adding
1.37 + * "[Contributor] elects to include this software in this distribution
1.38 + * under the [CDDL or GPL Version 2] license." If you do not indicate a
1.39 + * single choice of license, a recipient has the option to distribute
1.40 + * your version of this file under either the CDDL, the GPL Version 2 or
1.41 + * to extend the choice of license to its licensees as provided above.
1.42 + * However, if you add GPL Version 2 code and therefore, elected the GPL
1.43 + * Version 2 license, then the option applies only if the new code is
1.44 + * made subject to such option by the copyright holder.
1.45 + */
1.46 +package org.netbeans.html.context.spi;
1.47 +
1.48 +import java.util.ServiceLoader;
1.49 +import net.java.html.BrwsrCtx;
1.50 +import org.netbeans.html.context.impl.CtxImpl;
1.51 +
1.52 +/** Factory class to assign various technologies
1.53 + * to a {@link BrwsrCtx browser context}. Start with {@link #newBuilder()}
1.54 + * and then assign technologies with {@link Builder#register(java.lang.Class, java.lang.Object, int)}
1.55 + * method.
1.56 + *
1.57 + * @author Jaroslav Tulach
1.58 + */
1.59 +public final class Contexts {
1.60 + private Contexts() {
1.61 + }
1.62 +
1.63 + /** Creates new, empty builder for creation of {@link BrwsrCtx}. At the
1.64 + * end call the {@link Builder#build()} method to generate the context.
1.65 + *
1.66 + * @return new instance of the builder
1.67 + */
1.68 + public static Builder newBuilder() {
1.69 + return new Builder();
1.70 + }
1.71 +
1.72 + /** Seeks for the specified technology in the provided context.
1.73 + *
1.74 + * @param <Tech> type of the technology
1.75 + * @param context the context to seek in
1.76 + * (previously filled with ({@link Builder#register(java.lang.Class, java.lang.Object, int)})
1.77 + * @param technology class that identifies the technology
1.78 + * @return the technology in the context or <code>null</code>
1.79 + */
1.80 + public static <Tech> Tech find(BrwsrCtx context, Class<Tech> technology) {
1.81 + return CtxImpl.find(context, technology);
1.82 + }
1.83 +
1.84 + /** Seeks {@link ServiceLoader} for all registered instances of
1.85 + * {@link Provider} and asks them to {@link Provider#fillContext(org.netbeans.html.context.spi.Contexts.Builder, java.lang.Class) fill
1.86 + * the builder}.
1.87 + *
1.88 + * @param requestor the application class for which to find the context
1.89 + * @param cb the context builder to register technologies into
1.90 + * @return <code>true</code>, if some instances of the provider were
1.91 + * found, <code>false</code> otherwise
1.92 + * @since 0.7.6
1.93 + */
1.94 + public static boolean fillInByProviders(Class<?> requestor, Contexts.Builder cb) {
1.95 + boolean found = false;
1.96 + ClassLoader l;
1.97 + try {
1.98 + l = requestor.getClassLoader();
1.99 + } catch (SecurityException ex) {
1.100 + l = null;
1.101 + }
1.102 + for (Provider cp : ServiceLoader.load(Provider.class, l)) {
1.103 + cp.fillContext(cb, requestor);
1.104 + found = true;
1.105 + }
1.106 + try {
1.107 + for (Provider cp : ServiceLoader.load(Provider.class, Provider.class.getClassLoader())) {
1.108 + cp.fillContext(cb, requestor);
1.109 + found = true;
1.110 + }
1.111 + } catch (SecurityException ex) {
1.112 + if (!found) {
1.113 + throw ex;
1.114 + }
1.115 + }
1.116 + if (!found) {
1.117 + for (Provider cp : ServiceLoader.load(Provider.class)) {
1.118 + cp.fillContext(cb, requestor);
1.119 + found = true;
1.120 + }
1.121 + }
1.122 + return found;
1.123 + }
1.124 +
1.125 + /** Implementors of various HTML technologies should
1.126 + * register their implementation via <code>org.openide.util.lookup.ServiceProvider</code>, so
1.127 + * {@link ServiceLoader} can find them, when their JARs are included
1.128 + * on the classpath of the running application.
1.129 + *
1.130 + * @author Jaroslav Tulach
1.131 + */
1.132 + public static interface Provider {
1.133 +
1.134 + /** Register into the context if suitable technology is
1.135 + * available for the requesting class.
1.136 + * The provider should check if its own technology is available in current
1.137 + * scope (e.g. proper JDK, proper browser, etc.). The provider
1.138 + * can also find the right context depending on requestor's classloader, etc.
1.139 + * <p>
1.140 + * Providers should use {@link Builder} to enrich appropriately
1.141 + * the context.
1.142 + *
1.143 + * @param context the context builder to fill with technologies
1.144 + * @param requestor the application class requesting access the the HTML page
1.145 + * @see BrwsrCtx#findDefault(java.lang.Class)
1.146 + */
1.147 + void fillContext(Builder context, Class<?> requestor);
1.148 + }
1.149 +
1.150 + /** Support for providers of new {@link BrwsrCtx}. Providers of different
1.151 + * technologies should be of particular interest in this class. End users
1.152 + * designing their application with existing technologies should rather
1.153 + * point their attention to {@link BrwsrCtx} and co.
1.154 + *
1.155 + * @author Jaroslav Tulach
1.156 + */
1.157 + public static final class Builder {
1.158 + private final CtxImpl impl = new CtxImpl();
1.159 +
1.160 + Builder() {
1.161 + }
1.162 +
1.163 + /** Registers new technology into the context. Each technology is
1.164 + * exactly identified by its implementation class and can be associated
1.165 + * with (positive) priority. In case of presence of multiple technologies
1.166 + * with the same class, the one with higher lower priority takes precedence.
1.167 + * @param <Tech> type of technology to register
1.168 + * @param type the real class of the technology type
1.169 + * @param impl an instance of the technology class
1.170 + * @param position the lower position, the more important implementation
1.171 + * which will be consulted sooner when seeking for a {@link Contexts#find(net.java.html.BrwsrCtx, java.lang.Class)}
1.172 + * an implementation
1.173 + * @return this builder
1.174 + */
1.175 + public <Tech> Builder register(Class<Tech> type, Tech impl, int position) {
1.176 + if (impl == null) {
1.177 + return this;
1.178 + }
1.179 + if (position <= 0) {
1.180 + throw new IllegalStateException();
1.181 + }
1.182 + this.impl.register(type, impl, position);
1.183 + return this;
1.184 + }
1.185 +
1.186 + /** Generates context based on values previously inserted into
1.187 + * this builder.
1.188 + *
1.189 + * @return new, immutable instance of {@link BrwsrCtx}
1.190 + */
1.191 + public BrwsrCtx build() {
1.192 + return impl.build();
1.193 + }
1.194 + }
1.195 +}