1 files changed, 105 insertions, 0 deletions
diff --git a/plugins/org.eclipse.xtend.backend/src/org/eclipse/xtend/middleend/internal/Activator.java b/plugins/org.eclipse.xtend.backend/src/org/eclipse/xtend/middleend/internal/Activator.java
new file mode 100644
index 00000000..ada8778e
--- /dev/null
+++ b/plugins/org.eclipse.xtend.backend/src/org/eclipse/xtend/middleend/internal/Activator.java
@@ -0,0 +1,105 @@
+/*
+Copyright (c) 2008 Arno Haase.
+All rights reserved. This program and the accompanying materials
+are made available under the terms of the Eclipse Public License v1.0
+which accompanies this distribution, and is available at
+http://www.eclipse.org/legal/epl-v10.html
+
+Contributors:
+    Arno Haase - initial API and implementation
+ */
+package org.eclipse.xtend.middleend.internal;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.eclipse.core.runtime.IConfigurationElement;
+import org.eclipse.core.runtime.RegistryFactory;
+import org.eclipse.xtend.middleend.plugins.LanguageSpecificMiddleEnd;
+import org.eclipse.xtend.middleend.plugins.LanguageSpecificMiddleEndFactory;
+import org.osgi.framework.BundleActivator;
+import org.osgi.framework.BundleContext;
+
+
+/**
+ * 
+ * @author Arno Haase (http://www.haase-consulting.com)
+ */
+public class Activator implements BundleActivator {
+    private static final Log _log = LogFactory.getLog (Activator.class);
+    
+    private static Activator _instance = null;
+    
+    public static Activator getInstance () {
+        return _instance;
+    }
+
+    private final List<LanguageSpecificMiddleEndFactory> _middleEndContributions = new ArrayList<LanguageSpecificMiddleEndFactory> ();
+    private boolean _isInitialized = false;
+
+    
+    public List<LanguageSpecificMiddleEnd> getFreshMiddleEnds (Map<Class<?>, Object> specificParams) {
+        init ();
+        
+        final List<LanguageSpecificMiddleEnd> result = new ArrayList<LanguageSpecificMiddleEnd>();
+        
+        for (LanguageSpecificMiddleEndFactory factory: _middleEndContributions) {
+            try {
+                result.add (factory.create (specificParams.get (factory.getClass())));
+            }
+            catch (IllegalArgumentException exc) {
+                // this is the official way for an implementation to withdraw from the pool for this call
+                _log.debug ("middle end implementation " + factory.getName() + " says it is not available: " + exc.getMessage());
+            }
+        }
+        
+        return result;
+    }
+    
+    public void start (BundleContext context) throws Exception {
+        //TODO Bernd: implement error handling and logging to be both robust and independent of Eclipse
+        
+        _isInitialized = false;
+        _instance = this;
+    }
+    
+    private void init () {
+        if (_isInitialized)
+            return;
+        
+        _isInitialized = true;
+        _middleEndContributions.clear ();
+
+        try {
+            final IConfigurationElement[] confEl = RegistryFactory.getRegistry().getConfigurationElementsFor ("org.eclipse.xtend.backend.MiddleEnd");
+
+            for (IConfigurationElement curEl: confEl) {
+                final Object o = curEl.createExecutableExtension ("class");
+                _middleEndContributions.add ((LanguageSpecificMiddleEndFactory) o);
+            }
+        }
+        catch (Exception exc) {
+            exc.printStackTrace ();
+        }
+        
+        Collections.sort (_middleEndContributions, new Comparator <LanguageSpecificMiddleEndFactory> () {
+            public int compare (LanguageSpecificMiddleEndFactory o1, LanguageSpecificMiddleEndFactory o2) {
+                return o1.getPriority() - o2.getPriority();
+            }
+        });
+        
+        _log.info ("Activating Eclipse Modeling Middle End - the following middle ends are registered:");
+        for (LanguageSpecificMiddleEndFactory factory: _middleEndContributions)
+            _log.info ("  " + factory.getName());
+    }
+
+    public void stop (BundleContext context) throws Exception {
+        _instance = null;
+        _middleEndContributions.clear();
+    }
+}