1 files changed, 84 insertions, 0 deletions
diff --git a/bundles/org.eclipse.e4.core.di.extensions/src/org/eclipse/e4/core/di/internal/extensions/BundleContextObjectSupplier.java b/bundles/org.eclipse.e4.core.di.extensions/src/org/eclipse/e4/core/di/internal/extensions/BundleContextObjectSupplier.java
new file mode 100644
index 000000000..f2547e422
--- /dev/null
+++ b/bundles/org.eclipse.e4.core.di.extensions/src/org/eclipse/e4/core/di/internal/extensions/BundleContextObjectSupplier.java
@@ -0,0 +1,84 @@
+/*******************************************************************************
+ * Copyright (c) 2013 Markus Alexander Kuppe and others. 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:
+ *   Markus Alexander Kuppe - initial API and implementation
+ ******************************************************************************/
+package org.eclipse.e4.core.di.internal.extensions;
+
+import java.util.HashMap;
+import java.util.Map;
+import org.eclipse.e4.core.di.InjectionException;
+import org.eclipse.e4.core.di.annotations.Optional;
+import org.eclipse.e4.core.di.suppliers.ExtendedObjectSupplier;
+import org.eclipse.e4.core.di.suppliers.IObjectDescriptor;
+import org.eclipse.e4.core.di.suppliers.IRequestor;
+import org.osgi.framework.Bundle;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.BundleEvent;
+import org.osgi.framework.BundleListener;
+import org.osgi.framework.FrameworkUtil;
+import org.osgi.framework.SynchronousBundleListener;
+
+public class BundleContextObjectSupplier extends ExtendedObjectSupplier {
+
+	/**
+	 * A Map of Requestor to BundleListener. Each Requestor will only ever request its own bundle and thus there is a 1:1 relationship between R and BL.
+	 */
+	private final Map<IRequestor, BundleListener> requestor2listener = new HashMap<IRequestor, BundleListener>();
+
+	private final BundleContext localBundleContext = FrameworkUtil.getBundle(BundleContextObjectSupplier.class).getBundleContext();
+
+	@Override
+	public Object get(IObjectDescriptor descriptor, IRequestor requestor, boolean track, boolean group) {
+		final Class<?> requestingObjectClass = requestor.getRequestingObjectClass();
+		final Bundle bundle = FrameworkUtil.getBundle(requestingObjectClass);
+
+		// Cannot use BundleListener as a BL can only be registered with a BC (which might be null)
+		if (track) {
+			if (!requestor2listener.containsKey(requestor)) {
+				track(bundle, requestor);
+			}
+		} else {
+			untrack(requestor);
+		}
+
+		final BundleContext bundleContext = bundle.getBundleContext();
+		if (bundleContext != null) {
+			return bundleContext;
+		} else if (descriptor.getQualifier(Optional.class) != null) {
+			// Do not have a bundle context but requestor has marked the parameter/field optional
+			return null;
+		}
+		throw new InjectionException("Unable to inject BundleContext: " + bundle.getSymbolicName() + " bundle is not active or starting/stopping"); //$NON-NLS-1$  //$NON-NLS-2$
+	}
+
+	private void untrack(final IRequestor requestor) {
+		synchronized (requestor2listener) {
+			BundleListener l = requestor2listener.remove(requestor);
+			localBundleContext.removeBundleListener(l);
+		}
+	}
+
+	private void track(final Bundle bundle, final IRequestor requestor) {
+		// A _synchronous_ BundleListener asserts that the BC is un-injected,
+		// _before_ it becomes invalid (state-wise). 
+		BundleListener listener = new SynchronousBundleListener() {
+			public void bundleChanged(BundleEvent event) {
+				if (event.getBundle().equals(bundle)) {
+					if (requestor.isValid()) {
+						requestor.resolveArguments(false);
+						requestor.execute();
+					}
+				}
+			}
+		};
+		synchronized (requestor2listener) {
+			localBundleContext.addBundleListener(listener);
+			requestor2listener.put(requestor, listener);
+		}
+	}
+}