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

   1 /*******************************************************************************\r
   2  * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
   3  * in Industry THTH ry.\r
   4  * All rights reserved. This program and the accompanying materials\r
   5  * are made available under the terms of the Eclipse Public License v1.0\r
   6  * which accompanies this distribution, and is available at\r
   7  * http://www.eclipse.org/legal/epl-v10.html\r
   8  *\r
   9  * Contributors:\r
  10  *     VTT Technical Research Centre of Finland - initial API and implementation\r
  11  *******************************************************************************/\r
  12 package org.simantics.browsing.ui.common.extension;\r
  13 \r
  14 import java.util.Arrays;\r
  15 import java.util.Collection;\r
  16 import java.util.HashSet;\r
  17 import java.util.Set;\r
  18 \r
  19 import org.eclipse.core.runtime.CoreException;\r
  20 import org.eclipse.core.runtime.IConfigurationElement;\r
  21 import org.eclipse.core.runtime.IExtension;\r
  22 import org.eclipse.core.runtime.IExtensionPoint;\r
  23 import org.eclipse.core.runtime.Platform;\r
  24 import org.eclipse.core.runtime.dynamichelpers.ExtensionTracker;\r
  25 import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;\r
  26 import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;\r
  27 import org.eclipse.core.runtime.dynamichelpers.IFilter;\r
  28 import org.simantics.browsing.ui.common.Activator;\r
  29 import org.simantics.browsing.ui.common.extension.internal.EvaluatorBindingExtension;\r
  30 import org.simantics.browsing.ui.common.extension.internal.EvaluatorImplementationBinding;\r
  31 import org.simantics.browsing.ui.common.extension.internal.EvaluatorReferenceBinding;\r
  32 import org.simantics.utils.strings.StringUtils;\r
  33 \r
  34 /**\r
  35  * @author Tuukka Lehtonen\r
  36  */\r
  37 public class EvaluatorBindingExtensionManager implements IExtensionChangeHandler {\r
  38 \r
  39     private final static String                NAMESPACE    = Activator.PLUGIN_ID;\r
  40 \r
  41     private final static String                EP_NAME      = "evaluatorBinding";\r
  42 \r
  43     private ExtensionTracker                   tracker;\r
  44 \r
  45     private EvaluatorBindingExtension[]            extensions   = new EvaluatorBindingExtension[0];\r
  46 \r
  47     private static EvaluatorBindingExtensionManager INSTANCE;\r
  48 \r
  49 \r
  50     public static synchronized EvaluatorBindingExtensionManager getInstance() {\r
  51         if (INSTANCE == null)\r
  52             INSTANCE = new EvaluatorBindingExtensionManager();\r
  53         return INSTANCE;\r
  54     }\r
  55 \r
  56     public static synchronized void dispose() {\r
  57         if (INSTANCE != null) {\r
  58             INSTANCE.close();\r
  59             INSTANCE = null;\r
  60         }\r
  61     }\r
  62 \r
  63 \r
  64     private EvaluatorBindingExtensionManager() {\r
  65         tracker = new ExtensionTracker();\r
  66 \r
  67         // Cache defined actions\r
  68         IExtensionPoint expt = Platform.getExtensionRegistry().getExtensionPoint(NAMESPACE, EP_NAME);\r
  69         loadExtensions(expt.getConfigurationElements());\r
  70 \r
  71         // Start tracking for new and removed extensions\r
  72         IFilter filter = ExtensionTracker.createExtensionPointFilter(expt);\r
  73         tracker.registerHandler(this, filter);\r
  74     }\r
  75 \r
  76     private void close() {\r
  77         tracker.close();\r
  78         tracker = null;\r
  79         extensions = new EvaluatorBindingExtension[0];\r
  80     }\r
  81 \r
  82     public EvaluatorBindingExtension[] getExtensions() {\r
  83         return extensions;\r
  84     }\r
  85 \r
  86     private void loadExtensions(IConfigurationElement[] elements) {\r
  87 \r
  88         Set<EvaluatorBindingExtension> newExtensions = new HashSet<EvaluatorBindingExtension>(Arrays.asList(extensions));\r
  89 \r
  90         for (IConfigurationElement el : elements) {\r
  91 \r
  92             String browseContext = StringUtils.safeString(el.getAttribute("browseContext"));\r
  93 \r
  94             for(IConfigurationElement child : el.getChildren("reference")) {\r
  95 \r
  96                 String factoryId = StringUtils.safeString(child.getAttribute("id"));\r
  97                 EvaluatorBindingExtension ext = new EvaluatorReferenceBinding(browseContext, factoryId);\r
  98 \r
  99                 // Start tracking the new extension object, its removal will be notified of\r
 100                 // with removeExtension(extension, Object[]).\r
 101                 tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);\r
 102 \r
 103                 newExtensions.add(ext);\r
 104 \r
 105             }\r
 106 \r
 107             for(IConfigurationElement child : el.getChildren("implementation")) {\r
 108 \r
 109                 try {\r
 110 \r
 111                     EvaluatorFactory factory = (EvaluatorFactory)child.createExecutableExtension("class");\r
 112                     EvaluatorBindingExtension ext = new EvaluatorImplementationBinding(browseContext, factory);\r
 113 \r
 114                     // Start tracking the new extension object, its removal will be notified of\r
 115                     // with removeExtension(extension, Object[]).\r
 116                     tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);\r
 117 \r
 118                     newExtensions.add(ext);\r
 119 \r
 120                 } catch (CoreException e) {\r
 121 \r
 122                     System.out.println(" == Could not load ViewpointContributionFactory '" + child.getAttribute("class") + "' due to the following error: " + e.getMessage()  );\r
 123 \r
 124                 }\r
 125 \r
 126             }\r
 127 \r
 128         }\r
 129 \r
 130         // Atomic assignment\r
 131         this.extensions = newExtensions.toArray(new EvaluatorBindingExtension[newExtensions.size()]);\r
 132     }\r
 133 \r
 134     @Override\r
 135     public void addExtension(IExtensionTracker tracker, IExtension extension) {\r
 136         loadExtensions(extension.getConfigurationElements());\r
 137     }\r
 138 \r
 139     @Override\r
 140     public void removeExtension(IExtension extension, Object[] objects) {\r
 141         Set<EvaluatorBindingExtension> newExtensions = new HashSet<EvaluatorBindingExtension>(Arrays.asList(extensions));\r
 142 \r
 143         for (Object o : objects) {\r
 144             tracker.unregisterObject(extension, o);\r
 145             newExtensions.remove(o);\r
 146         }\r
 147 \r
 148         // Atomic assignment\r
 149         this.extensions = newExtensions.toArray(new EvaluatorBindingExtension[newExtensions.size()]);\r
 150     }\r
 151 \r
 152     public Collection<EvaluatorFactory> getBoundFactories(Set<String> browseContexts) {\r
 153 \r
 154 //        ArrayList<EvaluatorFactory> result = new ArrayList<EvaluatorFactory>();\r
 155 //        for(EvaluatorBindingExtension binding : getExtensions()) {\r
 156 //            if(browseContexts.contains(binding.browserId())) {\r
 157 //                EvaluatorFactory factory = EvaluatorFactoryExtensionManager.getFactory(binding.factoryId());\r
 158 //                result.add(factory);\r
 159 //            }\r
 160 //        }\r
 161 //        return result;\r
 162 \r
 163         HashSet<EvaluatorFactory> result = new HashSet<EvaluatorFactory>();\r
 164 \r
 165         for(EvaluatorBindingExtension binding : getExtensions()) {\r
 166             if(browseContexts.contains(binding.getBrowseContext())) {\r
 167                 EvaluatorFactory factory = binding.getFactory();\r
 168                 if(factory != null) {\r
 169 //                    System.out.println("----------- Plugin contribution " + binding.getFactory());\r
 170                     result.add(factory);\r
 171                 } else {\r
 172 //                    System.out.println("FAILED: ----------- No factory for " + binding);\r
 173                 }\r
 174 \r
 175             }\r
 176         }\r
 177 \r
 178         return result;\r
 179 \r
 180     }\r
 181 \r
 182 }\r