Replaced some kernel services with OSGi declarative services.

refs 2598

org.fortiss.tooling.kernel/trunk/META-INF/MANIFEST.MF

@@ -32,4 +32,4 @@ Export-Package: org.fortiss.tooling.kernel;uses:="org.eclipse.core.runtime,org.o
  org.fortiss.tooling.kernel.service.base,
  org.fortiss.tooling.kernel.service.listener,
  org.fortiss.tooling.kernel.utils;uses:="org.eclipse.emf.ecore,org.eclipse.core.resources"
-Service-Component: OSGI-INF/EclipseResourceStorageService.xml, OSGI-INF/LoggingService.xml, OSGI-INF/TutorialService.xml
+Service-Component: OSGI-INF/CommandStackService.xml, OSGI-INF/EclipseResourceStorageService.xml, OSGI-INF/LoggingService.xml, OSGI-INF/TransformationService.xml, OSGI-INF/PersistencyService.xml, OSGI-INF/PrototypeService.xml, OSGI-INF/TutorialService.xml

org.fortiss.tooling.kernel/trunk/OSGI-INF/CommandStackService.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!--  
+  $Id: pom.xml 16107 2016-03-07 11:50:15Z hoelzl $
+  @version $Rev: 16107 $
+  @ConQAT.Rating YELLOW Hash: 1AB4E45B3940C00A982A3C49474361A1
+-->
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.fortiss.tooling.kernel.service.CommandStackService">
+   <implementation class="org.fortiss.tooling.kernel.internal.CommandStackService"/>
+   <service>
+      <provide interface="org.fortiss.tooling.kernel.service.ICommandStackService"/>
+   </service>
+</scr:component>

org.fortiss.tooling.kernel/trunk/OSGI-INF/PersistencyService.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!--  
+  $Id: pom.xml 16107 2016-03-07 11:50:15Z hoelzl $
+  @version $Rev: 16107 $
+  @ConQAT.Rating YELLOW Hash: 1AB4E45B3940C00A982A3C49474361A1
+-->
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.fortiss.tooling.kernel.service.PersistencyService">
+   <implementation class="org.fortiss.tooling.kernel.internal.PersistencyService"/>
+   <service>
+      <provide interface="org.fortiss.tooling.kernel.service.IPersistencyService"/>
+   </service>
+</scr:component>

org.fortiss.tooling.kernel/trunk/OSGI-INF/PrototypeService.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!--  
+  $Id: pom.xml 16107 2016-03-07 11:50:15Z hoelzl $
+  @version $Rev: 16107 $
+  @ConQAT.Rating YELLOW Hash: 1AB4E45B3940C00A982A3C49474361A1
+-->
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.fortiss.tooling.kernel.service.PrototypeService">
+   <implementation class="org.fortiss.tooling.kernel.internal.PrototypeService"/>
+   <service>
+      <provide interface="org.fortiss.tooling.kernel.service.IPrototypeService"/>
+   </service>
+</scr:component>

org.fortiss.tooling.kernel/trunk/OSGI-INF/TransformationService.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!--  
+  $Id: pom.xml 16107 2016-03-07 11:50:15Z hoelzl $
+  @version $Rev: 16107 $
+  @ConQAT.Rating YELLOW Hash: D68D970F24A29629569E61B8181D188F
+-->
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="org.fortiss.tooling.kernel.service.TransformationService">
+   <implementation class="org.fortiss.tooling.kernel.internal.TransformationService"/>
+   <service>
+      <provide interface="org.fortiss.tooling.kernel.service.ITransformationService"/>
+   </service>
+</scr:component>

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/ToolingKernel.java

@@ -114,8 +114,6 @@ public final class ToolingKernel {
 		ToolingKernelInternal.registerConnectionCompositor(compositor, sourceClass, targetClass);
 	}
 
-	/** Prints the given kernel phase message to system console. */
-
 	/** Prints the introduction message of the given phase */
 	public static void printPhase(String phase) {
 		phase = rightPad(phase, 40);

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/ToolingKernelActivator.java

@@ -18,8 +18,8 @@ $Id$
 package org.fortiss.tooling.kernel;
 
 import org.eclipse.core.runtime.Plugin;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 import org.osgi.framework.BundleContext;
-import org.osgi.framework.ServiceReference;
 
 /**
  * The activator class controls the plug-in life cycle.
@@ -62,8 +62,11 @@ public class ToolingKernelActivator extends Plugin {
 
 	/** Returns the service for the given interface. */
 	public static <SERVICE> SERVICE getService(Class<SERVICE> clazz) {
-		BundleContext context = plugin.getBundle().getBundleContext();
-		ServiceReference<SERVICE> ref = context.getServiceReference(clazz);
-		return context.getService(ref);
+		return ServicesUtils.getService(plugin.getBundle(), clazz);
+	}
+
+	/** Releases the OSGi service. */
+	public static boolean ungetService(Class<?> clazz) {
+		return ServicesUtils.ungetService(plugin.getBundle(), clazz);
 	}
 }

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/internal/CommandStackService.java

@@ -17,6 +17,8 @@ $Id$
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.kernel.internal;
 
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.getService;
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.ungetService;
 import static org.fortiss.tooling.kernel.utils.LoggingUtils.error;
 
 import org.eclipse.core.runtime.IProgressMonitor;
@@ -52,56 +54,71 @@ public class CommandStackService implements ICommandStackService {
 		if(target != null) {
 			target.removeCommandStackListener(listener);
 		} else {
-			for(ITopLevelElement top : IPersistencyService.getInstance().getTopLevelElements()) {
+			IPersistencyService ps = getService(IPersistencyService.class);
+			for(ITopLevelElement top : ps.getTopLevelElements()) {
 				top.removeCommandStackListener(listener);
 			}
+			ungetService(IPersistencyService.class);
 		}
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void runAsCommand(EObject target, Runnable runner) {
-		ITopLevelElement context = IPersistencyService.getInstance().getTopLevelElementFor(target);
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ITopLevelElement context = ps.getTopLevelElementFor(target);
 		context.runAsCommand(runner);
+		ungetService(IPersistencyService.class);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public boolean canUndo(EObject target) {
-		ITopLevelElement context = IPersistencyService.getInstance().getTopLevelElementFor(target);
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ITopLevelElement context = ps.getTopLevelElementFor(target);
+		ungetService(IPersistencyService.class);
 		return context != null && context.canUndo();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public boolean canRedo(EObject target) {
-		ITopLevelElement context = IPersistencyService.getInstance().getTopLevelElementFor(target);
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ITopLevelElement context = ps.getTopLevelElementFor(target);
+		ungetService(IPersistencyService.class);
 		return context != null && context.canRedo();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void undo(EObject target) {
-		IPersistencyService.getInstance().getTopLevelElementFor(target).undo();
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ps.getTopLevelElementFor(target).undo();
+		ungetService(IPersistencyService.class);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void redo(EObject target) {
-		IPersistencyService.getInstance().getTopLevelElementFor(target).redo();
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ps.getTopLevelElementFor(target).redo();
+		ungetService(IPersistencyService.class);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public boolean isDirty(EObject target) {
-		ITopLevelElement context = IPersistencyService.getInstance().getTopLevelElementFor(target);
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ITopLevelElement context = ps.getTopLevelElementFor(target);
+		ungetService(IPersistencyService.class);
 		return context != null && context.isDirty();
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public void doSave(EObject target, IProgressMonitor monitor) {
-		ITopLevelElement context = IPersistencyService.getInstance().getTopLevelElementFor(target);
+		IPersistencyService ps = getService(IPersistencyService.class);
+		ITopLevelElement context = ps.getTopLevelElementFor(target);
 		if(context != null && context.isDirty()) {
 			try {
 				context.doSave(monitor);
@@ -109,5 +126,6 @@ public class CommandStackService implements ICommandStackService {
 				error(ToolingKernelActivator.getDefault(), "Error while saving.", e);
 			}
 		}
+		ungetService(IPersistencyService.class);
 	}
 }

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/internal/PersistencyService.java

@@ -94,6 +94,9 @@ public class PersistencyService implements IPersistencyService, IIntrospectiveKe
 	private final List<IPersistencyServiceListener> listeners =
 			new ArrayList<IPersistencyServiceListener>();
 
+	/** The tutorial service instance. */
+	private ITutorialService tutorialService;
+
 	/** Initializes the service. */
 	public void initializeService() {
 		setupStorageProviders();
@@ -109,6 +112,7 @@ public class PersistencyService implements IPersistencyService, IIntrospectiveKe
 	/** Starts the service. */
 	public void startService() {
 		KernelIntrospectionSystemService.getInstance().registerService(this);
+		tutorialService = ToolingKernelActivator.getService(ITutorialService.class);
 	}
 
 	/** Registers the given storage provider with the service. */
@@ -135,9 +139,8 @@ public class PersistencyService implements IPersistencyService, IIntrospectiveKe
 	/** {@inheritDoc} */
 	@Override
 	public synchronized UnmodifiableList<ITopLevelElement> getTopLevelElements() {
-		if(ITutorialService.getInstance().isTutorialActive()) {
-			EObject activeRootElement =
-					ITutorialService.getInstance().getActiveTutorial().getRootElement();
+		if(tutorialService != null && tutorialService.isTutorialActive()) {
+			EObject activeRootElement = tutorialService.getActiveTutorial().getRootElement();
 			return asUnmodifiable(elementCache.stream()
 					.filter(t -> t.getRootModelElement() == activeRootElement)
 					.collect(Collectors.toList()));

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/internal/PrototypeService.java

@@ -67,6 +67,8 @@ public class PrototypeService implements IPrototypeService, IIntrospectiveKernel
 	/** Stores the registered prototype providers. */
 	private final List<IPrototypeProvider> prototypeProviderList =
 			new ArrayList<IPrototypeProvider>();
+	/** The tutorial service instance. */
+	private ITutorialService tutorialService;
 
 	/** Initializes the service. */
 	public void initializeService() {
@@ -76,6 +78,7 @@ public class PrototypeService implements IPrototypeService, IIntrospectiveKernel
 	/** Starts the service. */
 	public void startService() {
 		KernelIntrospectionSystemService.getInstance().registerService(this);
+		tutorialService = ToolingKernelActivator.getService(ITutorialService.class);
 	}
 
 	/** Registers the given provider with the service. */
@@ -118,10 +121,10 @@ public class PrototypeService implements IPrototypeService, IIntrospectiveKernel
 	/** {@inheritDoc} */
 	@Override
 	public UnmodifiableList<Prototype> getAllPrototypes() {
-		if(ITutorialService.getInstance().isTutorialActive()) {
-			ITutorialService service = ITutorialService.getInstance();
+		if(tutorialService.isTutorialActive()) {
 			return asUnmodifiable(getPrototypes(false, true).stream()
-					.filter(proto -> service.prototypeActive(proto)).collect(Collectors.toList()));
+					.filter(proto -> tutorialService.prototypeActive(proto))
+					.collect(Collectors.toList()));
 		}
 		return asUnmodifiable(getPrototypes(false, false));
 	}
@@ -129,10 +132,10 @@ public class PrototypeService implements IPrototypeService, IIntrospectiveKernel
 	/** {@inheritDoc} */
 	@Override
 	public UnmodifiableList<Prototype> getPrimaryPrototypes() {
-		if(ITutorialService.getInstance().isTutorialActive()) {
-			ITutorialService service = ITutorialService.getInstance();
+		if(tutorialService.isTutorialActive()) {
 			return asUnmodifiable(getPrototypes(true, true).stream()
-					.filter(proto -> service.prototypeActive(proto)).collect(Collectors.toList()));
+					.filter(proto -> tutorialService.prototypeActive(proto))
+					.collect(Collectors.toList()));
 		}
 		return asUnmodifiable(getPrototypes(true, false));
 	}

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/internal/TutorialService.java

@@ -19,6 +19,8 @@ package org.fortiss.tooling.kernel.internal;
 
 import static java.util.Collections.emptyMap;
 import static org.conqat.lib.commons.collections.CollectionUtils.asUnmodifiable;
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.getService;
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.ungetService;
 import static org.fortiss.tooling.kernel.utils.LoggingUtils.error;
 
 import java.util.ArrayList;
@@ -76,6 +78,11 @@ public final class TutorialService implements ITutorialService, CommandStackList
 	/** The active top-level element. */
 	private ITopLevelElement activeTopElement = null;
 
+	/** The persistency service. */
+	private IPersistencyService persistencyService;
+	/** The command stack service. */
+	private ICommandStackService commandStackService;
+
 	/** Initializes the service. */
 	public void initializeService() {
 		// nothing to do here
@@ -154,6 +161,8 @@ public final class TutorialService implements ITutorialService, CommandStackList
 	/** {@inheritDoc} */
 	@Override
 	public void startTutorial(Class<? extends ITutorialProvider> provider) {
+		persistencyService = getService(IPersistencyService.class);
+		commandStackService = getService(ICommandStackService.class);
 		try {
 			activeTutorial = provider.newInstance();
 			List<TutorialStepBase> rootSteps = activeTutorial.getDefinition().getSteps();
@@ -163,9 +172,8 @@ public final class TutorialService implements ITutorialService, CommandStackList
 			activeStep = atomicStepList.get(0);
 			finalAtomicStep = atomicStepList.get(atomicStepList.size() - 1);
 			EObject root = activeTutorial.getRootElement();
-			activeTopElement =
-					IPersistencyService.getInstance().addDummyEObjectAsTopLevelElement(root);
-			ICommandStackService.getInstance().addCommandStackListener(activeTopElement, this);
+			activeTopElement = persistencyService.addDummyEObjectAsTopLevelElement(root);
+			commandStackService.addCommandStackListener(activeTopElement, this);
 			fireTutorialStarted();
 		} catch(InstantiationException e) {
 			error(ToolingKernelActivator.getDefault(), e.getMessage(), e);
@@ -190,9 +198,12 @@ public final class TutorialService implements ITutorialService, CommandStackList
 	@Override
 	public void stopTutorial() {
 		fireTutorialStopped();
-		ICommandStackService.getInstance().removeCommandStackListener(activeTopElement, this);
-		IPersistencyService.getInstance().removeDummyTopLevelElement(
-				activeTutorial.getRootElement());
+		commandStackService.removeCommandStackListener(activeTopElement, this);
+		ungetService(ICommandStackService.class);
+		commandStackService = null;
+		persistencyService.removeDummyTopLevelElement(activeTutorial.getRootElement());
+		ungetService(IPersistencyService.class);
+		persistencyService = null;
 		activeTopElement = null;
 		atomicStepList.clear();
 		activeStep = null;

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/service/ICommandStackService.java

@@ -20,8 +20,9 @@ package org.fortiss.tooling.kernel.service;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.emf.common.command.CommandStackListener;
 import org.eclipse.emf.ecore.EObject;
+import org.fortiss.tooling.kernel.ToolingKernelActivator;
 import org.fortiss.tooling.kernel.extension.data.ITopLevelElement;
-import org.fortiss.tooling.kernel.internal.CommandStackService;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 
 /**
  * The command stack service manages the access to the command stack and editing
@@ -38,17 +39,16 @@ import org.fortiss.tooling.kernel.internal.CommandStackService;
  */
 public interface ICommandStackService {
 	/**
-	 * Returns the singleton instance of the service.
+	 * Returns the service instance.
 	 * 
-	 * @deprecated
-	 *             use {@link #getInstance()} instead
+	 * @deprecated use {@link ServicesUtils#getService(org.osgi.framework.Bundle, Class)} and
+	 *             {@link ServicesUtils#ungetService(org.osgi.framework.Bundle, Class)}, instead.
+	 *             See also {@link ToolingKernelActivator#getService(Class)} and
+	 *             {@link ToolingKernelActivator#ungetService(Class)}
 	 */
 	@Deprecated
-	public static final ICommandStackService INSTANCE = new CommandStackService();
-
-	/** Returns the service instance. */
 	public static ICommandStackService getInstance() {
-		return INSTANCE;
+		return ToolingKernelActivator.getService(ICommandStackService.class);
 	}
 
 	/** Adds a command stack listener to the stack of the given target element. */

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/service/IPersistencyService.java

@@ -21,11 +21,12 @@ import java.util.List;
 
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.emf.ecore.EObject;
+import org.fortiss.tooling.kernel.ToolingKernelActivator;
 import org.fortiss.tooling.kernel.extension.IStorageProvider;
 import org.fortiss.tooling.kernel.extension.data.ITopLevelElement;
 import org.fortiss.tooling.kernel.extension.data.ModelStorageError;
-import org.fortiss.tooling.kernel.internal.PersistencyService;
 import org.fortiss.tooling.kernel.service.listener.IPersistencyServiceListener;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 
 /**
  * The persistency service provides the transparent access to the different
@@ -46,17 +47,16 @@ import org.fortiss.tooling.kernel.service.listener.IPersistencyServiceListener;
  */
 public interface IPersistencyService {
 	/**
-	 * Returns the singleton instance of the service.
+	 * Returns the service instance.
 	 * 
-	 * @deprecated
-	 *             use {@link #getInstance()} instead
+	 * @deprecated use {@link ServicesUtils#getService(org.osgi.framework.Bundle, Class)} and
+	 *             {@link ServicesUtils#ungetService(org.osgi.framework.Bundle, Class)}, instead.
+	 *             See also {@link ToolingKernelActivator#getService(Class)} and
+	 *             {@link ToolingKernelActivator#ungetService(Class)}
 	 */
 	@Deprecated
-	public static final IPersistencyService INSTANCE = new PersistencyService();
-
-	/** Returns the service instance. */
 	public static IPersistencyService getInstance() {
-		return INSTANCE;
+		return ToolingKernelActivator.getService(IPersistencyService.class);
 	}
 
 	/**

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/service/IPrototypeService.java

@@ -17,14 +17,17 @@ $Id$
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.kernel.service;
 
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.getService;
+
 import java.util.List;
 
 import org.conqat.lib.commons.collections.UnmodifiableList;
 import org.eclipse.emf.ecore.EObject;
+import org.fortiss.tooling.kernel.ToolingKernelActivator;
 import org.fortiss.tooling.kernel.extension.IPrototypeProvider;
 import org.fortiss.tooling.kernel.extension.data.Prototype;
 import org.fortiss.tooling.kernel.extension.data.PrototypeCategory;
-import org.fortiss.tooling.kernel.internal.PrototypeService;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 
 /**
  * The prototype service provides registration and access to model element
@@ -43,17 +46,16 @@ import org.fortiss.tooling.kernel.internal.PrototypeService;
  */
 public interface IPrototypeService {
 	/**
-	 * Returns the singleton instance of the service.
+	 * Returns the service instance.
 	 * 
-	 * @deprecated
-	 *             use {@link #getInstance()} instead
+	 * @deprecated use {@link ServicesUtils#getService(org.osgi.framework.Bundle, Class)} and
+	 *             {@link ServicesUtils#ungetService(org.osgi.framework.Bundle, Class)}, instead.
+	 *             See also {@link ToolingKernelActivator#getService(Class)} and
+	 *             {@link ToolingKernelActivator#ungetService(Class)}
 	 */
 	@Deprecated
-	public static final IPrototypeService INSTANCE = new PrototypeService();
-
-	/** Returns the service instance. */
 	public static IPrototypeService getInstance() {
-		return INSTANCE;
+		return getService(IPrototypeService.class);
 	}
 
 	/** Returns the list of all registered prototype providers. */

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/service/ITransformationService.java

@@ -17,13 +17,16 @@ $Id$
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.kernel.service;
 
+import static org.fortiss.tooling.kernel.ToolingKernelActivator.getService;
+
 import java.util.List;
 
+import org.fortiss.tooling.kernel.ToolingKernelActivator;
 import org.fortiss.tooling.kernel.extension.ITransformationProvider;
 import org.fortiss.tooling.kernel.extension.data.ITransformationContext;
 import org.fortiss.tooling.kernel.extension.data.TransformationProviderChain;
 import org.fortiss.tooling.kernel.extension.exception.TransformationFailedException;
-import org.fortiss.tooling.kernel.internal.TransformationService;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 
 /**
  * The transformation service provides registration and access to transformation
@@ -40,17 +43,16 @@ import org.fortiss.tooling.kernel.internal.TransformationService;
  */
 public interface ITransformationService {
 	/**
-	 * Returns the singleton instance of the service.
+	 * Returns the service instance.
 	 * 
-	 * @deprecated
-	 *             use {@link #getInstance()} instead
+	 * @deprecated use {@link ServicesUtils#getService(org.osgi.framework.Bundle, Class)} and
+	 *             {@link ServicesUtils#ungetService(org.osgi.framework.Bundle, Class)}, instead.
+	 *             See also {@link ToolingKernelActivator#getService(Class)} and
+	 *             {@link ToolingKernelActivator#ungetService(Class)}
 	 */
 	@Deprecated
-	public static final ITransformationService INSTANCE = new TransformationService();
-
-	/** Returns the service instance. */
 	public static ITransformationService getInstance() {
-		return INSTANCE;
+		return getService(ITransformationService.class);
 	}
 
 	/**

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/service/ITutorialService.java

@@ -23,12 +23,13 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
+import org.fortiss.tooling.kernel.ToolingKernelActivator;
 import org.fortiss.tooling.kernel.extension.ITutorialProvider;
 import org.fortiss.tooling.kernel.extension.ITutorialWhitelistProvider;
 import org.fortiss.tooling.kernel.extension.data.TutorialAtomicStep;
 import org.fortiss.tooling.kernel.extension.data.TutorialStepBase;
-import org.fortiss.tooling.kernel.internal.TutorialService;
 import org.fortiss.tooling.kernel.service.listener.ITutorialServiceListener;
+import org.fortiss.tooling.kernel.utils.ServicesUtils;
 
 /**
  * The tutorial service provides pre-defined models with step-wise
@@ -47,15 +48,14 @@ import org.fortiss.tooling.kernel.service.listener.ITutorialServiceListener;
  */
 public interface ITutorialService extends ITutorialWhitelistProvider {
 	/**
-	 * Returns the singleton instance of the service.
+	 * Returns the service instance.
 	 * 
-	 * @deprecated
-	 *             use {@link #getInstance()} instead
+	 * @deprecated use {@link ServicesUtils#getService(org.osgi.framework.Bundle, Class)} and
+	 *             {@link ServicesUtils#ungetService(org.osgi.framework.Bundle, Class)}, instead.
+	 *             See also {@link ToolingKernelActivator#getService(Class)} and
+	 *             {@link ToolingKernelActivator#ungetService(Class)}
 	 */
 	@Deprecated
-	public static final ITutorialService INSTANCE = new TutorialService();
-
-	/** Returns the service instance. */
 	public static ITutorialService getInstance() {
 		return getService(ITutorialService.class);
 	}

org.fortiss.tooling.kernel/trunk/src/org/fortiss/tooling/kernel/utils/ServicesUtils.java

@@ -22,6 +22,9 @@ import java.util.List;
 import org.eclipse.emf.ecore.EObject;
 import org.fortiss.tooling.kernel.extension.data.IConstraintViolation;
 import org.fortiss.tooling.kernel.service.IConstraintCheckerService;
+import org.osgi.framework.Bundle;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.ServiceReference;
 
 /**
  * Utility methods to ease the access to kernel services.
@@ -36,7 +39,21 @@ public class ServicesUtils {
 	/** Proxy for {@link IConstraintCheckerService#performAllConstraintChecksRecursively(EObject)} */
 	public static List<IConstraintViolation<? extends EObject>>
 			performAllConstraintChecksRecursively(EObject modelElement) {
-		return IConstraintCheckerService.getInstance()
-				.performAllConstraintChecksRecursively(modelElement);
+		return IConstraintCheckerService.getInstance().performAllConstraintChecksRecursively(
+				modelElement);
+	}
+
+	/** Returns the service for the given interface. */
+	public static <SERVICE> SERVICE getService(Bundle bundle, Class<SERVICE> clazz) {
+		BundleContext context = bundle.getBundleContext();
+		ServiceReference<SERVICE> ref = context.getServiceReference(clazz);
+		return context.getService(ref);
+	}
+
+	/** Releases the use of the given service. */
+	public static boolean ungetService(Bundle bundle, Class<?> clazz) {
+		BundleContext context = bundle.getBundleContext();
+		ServiceReference<?> ref = context.getServiceReference(clazz);
+		return context.ungetService(ref);
 	}
 }