1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.message.internal;
14 import java.util.ArrayList;
15 import java.util.Arrays;
16 import java.util.HashMap;
17 import java.util.HashSet;
21 import org.eclipse.core.runtime.IConfigurationElement;
22 import org.eclipse.core.runtime.IExtension;
23 import org.eclipse.core.runtime.IExtensionPoint;
24 import org.eclipse.core.runtime.Platform;
25 import org.eclipse.core.runtime.dynamichelpers.ExtensionTracker;
26 import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;
27 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
28 import org.eclipse.core.runtime.dynamichelpers.IFilter;
29 import org.simantics.message.IMessageDataSchemeExtension;
30 import org.simantics.message.IMessageSchemeManager;
31 import org.slf4j.Logger;
32 import org.slf4j.LoggerFactory;
35 * @author Tuukka Lehtonen
37 public class MessageSchemeManager implements IExtensionChangeHandler, IMessageSchemeManager {
39 private static final Logger LOGGER = LoggerFactory.getLogger(MessageSchemeManager.class);
40 public final static String NAMESPACE = "org.simantics.message";
41 public final static String ELEMENT_NAME = "scheme";
42 public final static String EP_NAME = "messageDataScheme";
44 private ExtensionTracker tracker;
46 private MessageDataSchemeExtension[] extensions = new MessageDataSchemeExtension[0];
48 public MessageSchemeManager() {
49 tracker = new ExtensionTracker();
51 // Cache defined actions
52 IExtensionPoint expt = Platform.getExtensionRegistry().getExtensionPoint(NAMESPACE, EP_NAME);
53 loadExtensions(expt.getConfigurationElements());
55 // Start tracking for new and removed extensions
56 IFilter filter = ExtensionTracker.createExtensionPointFilter(expt);
57 tracker.registerHandler(this, filter);
60 private String getDescription(IConfigurationElement el) {
61 for (IConfigurationElement desc : el.getChildren("description")) {
62 return desc.getValue();
67 private void loadExtensions(IConfigurationElement[] configurationElements) {
68 Set<MessageDataSchemeExtension> newExtensions = new HashSet<MessageDataSchemeExtension>(Arrays.asList(extensions));
70 // Initialize id -> extension lookup
71 Map<String, MessageDataSchemeExtension> schemes = new HashMap<String, MessageDataSchemeExtension>();
72 for (MessageDataSchemeExtension ext : newExtensions) {
73 schemes.put(ext.getId(), ext);
76 // 1st pass: load schemes
77 for (IConfigurationElement el : configurationElements) {
78 String name = el.getName();
79 if ("scheme".equals(name)) {
80 String id = el.getAttribute("id");
83 String scheme = el.getAttribute("scheme");
86 String description = getDescription(el);
88 MessageDataSchemeExtension ext = schemes.get(id);
90 // This scheme is already registered, two contributors are contributing the same scheme.
91 StringBuilder msg = new StringBuilder();
92 msg.append("Multiple contributors for message scheme '" + id + "':");
93 msg.append("\n 1st: " + ext.getSchemeElement().getContributor().getName());
94 msg.append("\n 2nd: " + el.getContributor().getName());
95 msg.append("\nUsing the first one.");
96 LOGGER.info(msg.toString());
100 ext = new MessageDataSchemeExtension(el, id, scheme, description);
102 // Start tracking the new extension object, its removal will be notified of
103 // with removeExtension(extension, Object[]).
104 tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);
106 newExtensions.add(ext);
107 schemes.put(id, ext);
111 // 2nd pass: load handlers
112 for (IConfigurationElement el : configurationElements) {
113 String name = el.getName();
114 if ("handler".equals(name)) {
115 String id = el.getAttribute("schemeId");
119 MessageDataSchemeExtension ext = schemes.get(id);
121 // Unusable handler since there is no scheme to use it for.
122 StringBuilder msg = new StringBuilder();
123 msg.append("No scheme extension for message scheme id '" + id + "'. Ignoring handler '" + el.getAttribute("handler") + "'");
124 msg.append("\nUsing the first one.");
125 LOGGER.info(msg.toString());
129 IConfigurationElement prev = ext.getHandlerElement();
131 // Unusable handler since there already exists a handler for this scheme.
132 StringBuilder msg = new StringBuilder();
133 msg.append("Multiple handler contributors for message scheme '" + id + "':\n");
134 msg.append("\n 1st: " + prev.getContributor().getName());
135 msg.append("\n 2nd: " + el.getContributor().getName());
136 msg.append("\nUsing the first one.");
137 LOGGER.info(msg.toString());
141 ext.setHandlerElement(el);
146 this.extensions = newExtensions.toArray(new MessageDataSchemeExtension[newExtensions.size()]);
150 public void addExtension(IExtensionTracker tracker, IExtension extension) {
151 loadExtensions(extension.getConfigurationElements());
155 public void removeExtension(IExtension extension, Object[] objects) {
156 Set<MessageDataSchemeExtension> newExtensions = new HashSet<MessageDataSchemeExtension>(Arrays.asList(extensions));
158 for (Object o : objects) {
159 tracker.unregisterObject(extension, o);
160 newExtensions.remove((IMessageDataSchemeExtension) o);
164 this.extensions = newExtensions.toArray(new MessageDataSchemeExtension[newExtensions.size()]);
168 public IMessageDataSchemeExtension[] getByScheme(String scheme) {
170 throw new IllegalArgumentException("null scheme");
172 ArrayList<MessageDataSchemeExtension> result = new ArrayList<MessageDataSchemeExtension>();
173 for (MessageDataSchemeExtension ext : extensions) {
174 if (scheme.equals(ext.getScheme()))
177 return result.toArray(new MessageDataSchemeExtension[result.size()]);