Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics / src / org / simantics / internal / startup / StartupRegistry.java

diff --git a/bundles/org.simantics/src/org/simantics/internal/startup/StartupRegistry.java b/bundles/org.simantics/src/org/simantics/internal/startup/StartupRegistry.java
new file mode 100644 (file)
index 0000000..d8485a8
--- /dev/null
+++ b/bundles/org.simantics/src/org/simantics/internal/startup/StartupRegistry.java
@@ -0,0 +1,103 @@
+/*******************************************************************************\r
+ * Copyright (c) 2015 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
+ *     Semantum Oy - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.internal.startup;\r
+\r
+import java.util.Arrays;\r
+import java.util.HashSet;\r
+import java.util.Set;\r
+\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
+\r
+/**\r
+ * Registry implementation for org.simantics.startup extensions.\r
+ * \r
+ * @author Tuukka Lehtonen\r
+ */\r
+public class StartupRegistry implements IExtensionChangeHandler {\r
+\r
+    private final static String    NAMESPACE  = "org.simantics";\r
+    private final static String    EP_NAME    = "startup";\r
+    private final static String    STARTUP    = "startup";\r
+\r
+    private final ExtensionTracker tracker;\r
+\r
+    private StartupExtension[]     extensions = {};\r
+\r
+    public StartupRegistry() {\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 loadExtensions(IConfigurationElement[] configurationElements) {\r
+        Set<StartupExtension> newExtensions = new HashSet<StartupExtension>(Arrays.asList(extensions));\r
+\r
+        // These are all "startup" elements with required attributes\r
+        //  - class\r
+        for (IConfigurationElement el : configurationElements) {\r
+            if (STARTUP.equals(el.getName())) {\r
+                String clazz = el.getAttribute(StartupExtension.CLASS);\r
+                if (clazz == null) {\r
+                    // No class defined.\r
+                    continue;\r
+                }\r
+\r
+                StartupExtension ext = new StartupExtension(el);\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
+            }\r
+        }\r
+\r
+        // Atomic assignment\r
+        this.extensions = newExtensions.toArray(new StartupExtension[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<StartupExtension> newExtensions = new HashSet<StartupExtension>(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 StartupExtension[newExtensions.size()]);\r
+    }\r
+\r
+    public StartupExtension[] getExtensions() {\r
+        return extensions;\r
+    }\r
+\r
+}\r