Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.browsing.ui.common / src / org / simantics / browsing / ui / common / extension / internal / EvaluatorFactoryExtensionManager.java

diff --git a/bundles/org.simantics.browsing.ui.common/src/org/simantics/browsing/ui/common/extension/internal/EvaluatorFactoryExtensionManager.java b/bundles/org.simantics.browsing.ui.common/src/org/simantics/browsing/ui/common/extension/internal/EvaluatorFactoryExtensionManager.java
new file mode 100644 (file)
index 0000000..46e82d2
--- /dev/null
+++ b/bundles/org.simantics.browsing.ui.common/src/org/simantics/browsing/ui/common/extension/internal/EvaluatorFactoryExtensionManager.java
@@ -0,0 +1,134 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007, 2010 Association for Decentralized Information Management\r
+ * in Industry THTH ry.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     VTT Technical Research Centre of Finland - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.browsing.ui.common.extension.internal;\r
+\r
+import java.util.Arrays;\r
+import java.util.HashSet;\r
+import java.util.Set;\r
+\r
+import org.eclipse.core.runtime.CoreException;\r
+import org.eclipse.core.runtime.IConfigurationElement;\r
+import org.eclipse.core.runtime.IExtension;\r
+import org.eclipse.core.runtime.IExtensionPoint;\r
+import org.eclipse.core.runtime.Platform;\r
+import org.eclipse.core.runtime.dynamichelpers.ExtensionTracker;\r
+import org.eclipse.core.runtime.dynamichelpers.IExtensionChangeHandler;\r
+import org.eclipse.core.runtime.dynamichelpers.IExtensionTracker;\r
+import org.eclipse.core.runtime.dynamichelpers.IFilter;\r
+import org.simantics.browsing.ui.common.Activator;\r
+import org.simantics.browsing.ui.common.ErrorLogger;\r
+import org.simantics.browsing.ui.common.extension.EvaluatorFactory;\r
+\r
+/**\r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class EvaluatorFactoryExtensionManager implements IExtensionChangeHandler {\r
+\r
+    private final static String                NAMESPACE    = Activator.PLUGIN_ID;\r
+\r
+    private final static String                EP_NAME      = "evaluator";\r
+\r
+    private ExtensionTracker                   tracker;\r
+\r
+    private IEvaluatorFactoryExtension[]            extensions   = new IEvaluatorFactoryExtension[0];\r
+\r
+    private static EvaluatorFactoryExtensionManager INSTANCE;\r
+\r
+\r
+    public static synchronized EvaluatorFactoryExtensionManager getInstance() {\r
+        if (INSTANCE == null)\r
+            INSTANCE = new EvaluatorFactoryExtensionManager();\r
+        return INSTANCE;\r
+    }\r
+\r
+    public static synchronized void dispose() {\r
+        if (INSTANCE != null) {\r
+            INSTANCE.close();\r
+            INSTANCE = null;\r
+        }\r
+    }\r
+\r
+\r
+    private EvaluatorFactoryExtensionManager() {\r
+        tracker = new ExtensionTracker();\r
+\r
+        // Cache defined actions\r
+        IExtensionPoint expt = Platform.getExtensionRegistry().getExtensionPoint(NAMESPACE, EP_NAME);\r
+        loadExtensions(expt.getConfigurationElements());\r
+\r
+        // Start tracking for new and removed extensions\r
+        IFilter filter = ExtensionTracker.createExtensionPointFilter(expt);\r
+        tracker.registerHandler(this, filter);\r
+    }\r
+\r
+    private void close() {\r
+        tracker.close();\r
+        tracker = null;\r
+        extensions = new IEvaluatorFactoryExtension[0];\r
+    }\r
+\r
+    public IEvaluatorFactoryExtension[] getExtensions() {\r
+        return extensions;\r
+    }\r
+\r
+    private void loadExtensions(IConfigurationElement[] elements) {\r
+\r
+        Set<IEvaluatorFactoryExtension> newExtensions = new HashSet<IEvaluatorFactoryExtension>(Arrays.asList(extensions));\r
+\r
+        for (IConfigurationElement el : elements) {\r
+            try {\r
+\r
+                EvaluatorFactory factory = (EvaluatorFactory)el.createExecutableExtension("class");\r
+                IEvaluatorFactoryExtension ext = new EvaluatorFactoryExtension(factory);\r
+\r
+                // Start tracking the new extension object, its removal will be notified of\r
+                // with removeExtension(extension, Object[]).\r
+                tracker.registerObject(el.getDeclaringExtension(), ext, IExtensionTracker.REF_STRONG);\r
+\r
+                newExtensions.add(ext);\r
+            } catch (CoreException e) {\r
+                ErrorLogger.defaultLogError("Failed to initialize " + EP_NAME + " extension \"" + el.getName()\r
+                        + "\" with name \"" + el.getAttribute("name") + "\": "\r
+                        + e.getMessage(), e);\r
+            }\r
+        }\r
+\r
+        // Atomic assignment\r
+        this.extensions = newExtensions.toArray(new IEvaluatorFactoryExtension[newExtensions.size()]);\r
+    }\r
+\r
+    @Override\r
+    public void addExtension(IExtensionTracker tracker, IExtension extension) {\r
+        loadExtensions(extension.getConfigurationElements());\r
+    }\r
+\r
+    @Override\r
+    public void removeExtension(IExtension extension, Object[] objects) {\r
+        Set<IEvaluatorFactoryExtension> newExtensions = new HashSet<IEvaluatorFactoryExtension>(Arrays.asList(extensions));\r
+\r
+        for (Object o : objects) {\r
+            tracker.unregisterObject(extension, o);\r
+            newExtensions.remove(o);\r
+        }\r
+\r
+        // Atomic assignment\r
+        this.extensions = newExtensions.toArray(new IEvaluatorFactoryExtension[newExtensions.size()]);\r
+    }\r
+\r
+    public static EvaluatorFactory getFactory(String id) {\r
+        for(IEvaluatorFactoryExtension ext : getInstance().extensions) {\r
+            if(ext.factory().getClass().getCanonicalName().equals(id)) return ext.factory();\r
+        }\r
+        return null;\r
+    }\r
+\r
+}\r