bundles/org.simantics.browsing.ui.common/src/org/simantics/browsing/ui/common/extension/EvaluatorBindingExtensionManager.java

   1 /*******************************************************************************
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   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
   8  *
   9  * Contributors:
  10  *     VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.browsing.ui.common.extension;
  13
  14 import java.util.Arrays;
  15 import java.util.Collection;
  16 import java.util.HashSet;
  17 import java.util.Set;
  18
  19 import org.eclipse.core.runtime.CoreException;
  20 import org.eclipse.core.runtime.IConfigurationElement;
  21 import org.eclipse.core.runtime.IExtension;
  22 import org.eclipse.core.runtime.IExtensionPoint;
  23 import org.eclipse.core.runtime.Platform;
  24 import org.eclipse.core.runtime.dynamichelpers.ExtensionTracker;
  25 import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;
  26 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;
  27 import org.eclipse.core.runtime.dynamichelpers.IFilter;
  28 import org.simantics.browsing.ui.common.Activator;
  29 import org.simantics.browsing.ui.common.extension.internal.EvaluatorBindingExtension;
  30 import org.simantics.browsing.ui.common.extension.internal.EvaluatorImplementationBinding;
  31 import org.simantics.browsing.ui.common.extension.internal.EvaluatorReferenceBinding;
  32 import org.simantics.utils.strings.StringUtils;
  33
  34 /**
  35  * @author Tuukka Lehtonen
  36  */
  37 public class EvaluatorBindingExtensionManager implements IExtensionChangeHandler {
  38
  39     private final static String                NAMESPACE    = Activator.PLUGIN_ID;
  40
  41     private final static String                EP_NAME      = "evaluatorBinding";
  42
  43     private ExtensionTracker                   tracker;
  44
  45     private EvaluatorBindingExtension[]            extensions   = new EvaluatorBindingExtension[0];
  46
  47     private static EvaluatorBindingExtensionManager INSTANCE;
  48
  49
  50     public static synchronized EvaluatorBindingExtensionManager getInstance() {
  51         if (INSTANCE == null)
  52             INSTANCE = new EvaluatorBindingExtensionManager();
  53         return INSTANCE;
  54     }
  55
  56     public static synchronized void dispose() {
  57         if (INSTANCE != null) {
  58             INSTANCE.close();
  59             INSTANCE = null;
  60         }
  61     }
  62
  63
  64     private EvaluatorBindingExtensionManager() {
  65         tracker = new ExtensionTracker();
  66
  67         // Cache defined actions
  68         IExtensionPoint expt = Platform.getExtensionRegistry().getExtensionPoint(NAMESPACE, EP_NAME);
  69         loadExtensions(expt.getConfigurationElements());
  70
  71         // Start tracking for new and removed extensions
  72         IFilter filter = ExtensionTracker.createExtensionPointFilter(expt);
  73         tracker.registerHandler(this, filter);
  74     }
  75
  76     private void close() {
  77         tracker.close();
  78         tracker = null;
  79         extensions = new EvaluatorBindingExtension[0];
  80     }
  81
  82     public EvaluatorBindingExtension[] getExtensions() {
  83         return extensions;
  84     }
  85
  86     private void loadExtensions(IConfigurationElement[] elements) {
  87
  88         Set<EvaluatorBindingExtension> newExtensions = new HashSet<EvaluatorBindingExtension>(Arrays.asList(extensions));
  89
  90         for (IConfigurationElement el : elements) {
  91
  92             String browseContext = StringUtils.safeString(el.getAttribute("browseContext"));
  93
  94             for(IConfigurationElement child : el.getChildren("reference")) {
  95
  96                 String factoryId = StringUtils.safeString(child.getAttribute("id"));
  97                 EvaluatorBindingExtension ext = new EvaluatorReferenceBinding(browseContext, factoryId);
  98
  99                 // Start tracking the new extension object, its removal will be notified of
 100                 // with removeExtension(extension, Object[]).
 101                 tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);
 102
 103                 newExtensions.add(ext);
 104
 105             }
 106
 107             for(IConfigurationElement child : el.getChildren("implementation")) {
 108
 109                 try {
 110
 111                     EvaluatorFactory factory = (EvaluatorFactory)child.createExecutableExtension("class");
 112                     EvaluatorBindingExtension ext = new EvaluatorImplementationBinding(browseContext, factory);
 113
 114                     // Start tracking the new extension object, its removal will be notified of
 115                     // with removeExtension(extension, Object[]).
 116                     tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);
 117
 118                     newExtensions.add(ext);
 119
 120                 } catch (CoreException e) {
 121
 122                     System.out.println(" == Could not load ViewpointContributionFactory '" + child.getAttribute("class") + "' due to the following error: " + e.getMessage()  );
 123
 124                 }
 125
 126             }
 127
 128         }
 129
 130         // Atomic assignment
 131         this.extensions = newExtensions.toArray(new EvaluatorBindingExtension[newExtensions.size()]);
 132     }
 133
 134     @Override
 135     public void addExtension(IExtensionTracker tracker, IExtension extension) {
 136         loadExtensions(extension.getConfigurationElements());
 137     }
 138
 139     @Override
 140     public void removeExtension(IExtension extension, Object[] objects) {
 141         Set<EvaluatorBindingExtension> newExtensions = new HashSet<EvaluatorBindingExtension>(Arrays.asList(extensions));
 142
 143         for (Object o : objects) {
 144             tracker.unregisterObject(extension, o);
 145             newExtensions.remove(o);
 146         }
 147
 148         // Atomic assignment
 149         this.extensions = newExtensions.toArray(new EvaluatorBindingExtension[newExtensions.size()]);
 150     }
 151
 152     public Collection<EvaluatorFactory> getBoundFactories(Set<String> browseContexts) {
 153
 154 //        ArrayList<EvaluatorFactory> result = new ArrayList<EvaluatorFactory>();
 155 //        for(EvaluatorBindingExtension binding : getExtensions()) {
 156 //            if(browseContexts.contains(binding.browserId())) {
 157 //                EvaluatorFactory factory = EvaluatorFactoryExtensionManager.getFactory(binding.factoryId());
 158 //                result.add(factory);
 159 //            }
 160 //        }
 161 //        return result;
 162
 163         HashSet<EvaluatorFactory> result = new HashSet<EvaluatorFactory>();
 164
 165         for(EvaluatorBindingExtension binding : getExtensions()) {
 166             if(browseContexts.contains(binding.getBrowseContext())) {
 167                 EvaluatorFactory factory = binding.getFactory();
 168                 if(factory != null) {
 169 //                    System.out.println("----------- Plugin contribution " + binding.getFactory());
 170                     result.add(factory);
 171                 } else {
 172 //                    System.out.println("FAILED: ----------- No factory for " + binding);
 173                 }
 174
 175             }
 176         }
 177
 178         return result;
 179
 180     }
 181
 182 }