Target Explorer: Cherry-Pick: Remove stepper and variant delegate extension points

1 files changed, 783 insertions, 737 deletions

diff --git a/target_explorer/plugins/org.eclipse.tcf.te.runtime.stepper/src/org/eclipse/tcf/te/runtime/stepper/stepper/Stepper.java b/target_explorer/plugins/org.eclipse.tcf.te.runtime.stepper/src/org/eclipse/tcf/te/runtime/stepper/stepper/Stepper.java
index 846b9ad6c..7c455cac7 100644
--- a/target_explorer/plugins/org.eclipse.tcf.te.runtime.stepper/src/org/eclipse/tcf/te/runtime/stepper/stepper/Stepper.java
+++ b/target_explorer/plugins/org.eclipse.tcf.te.runtime.stepper/src/org/eclipse/tcf/te/runtime/stepper/stepper/Stepper.java
@@ -1,737 +1,783 @@
-/*******************************************************************************
- * Copyright (c) 2011, 2012 Wind River Systems, Inc. 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:
- * Wind River Systems - initial API and implementation
- *******************************************************************************/
-package org.eclipse.tcf.te.runtime.stepper.stepper;
-
-import java.text.MessageFormat;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Date;
-import java.util.List;
-
-import org.eclipse.core.runtime.Assert;
-import org.eclipse.core.runtime.CoreException;
-import org.eclipse.core.runtime.IProgressMonitor;
-import org.eclipse.core.runtime.IStatus;
-import org.eclipse.core.runtime.MultiStatus;
-import org.eclipse.core.runtime.OperationCanceledException;
-import org.eclipse.core.runtime.Status;
-import org.eclipse.osgi.util.NLS;
-import org.eclipse.tcf.te.runtime.callback.Callback;
-import org.eclipse.tcf.te.runtime.concurrent.util.ExecutorsUtil;
-import org.eclipse.tcf.te.runtime.extensions.ExecutableExtension;
-import org.eclipse.tcf.te.runtime.interfaces.ISharedConstants;
-import org.eclipse.tcf.te.runtime.interfaces.properties.IPropertiesContainer;
-import org.eclipse.tcf.te.runtime.stepper.StepperManager;
-import org.eclipse.tcf.te.runtime.stepper.activator.CoreBundleActivator;
-import org.eclipse.tcf.te.runtime.stepper.extensions.StepExecutor;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IExtendedStep;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IFullQualifiedId;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStep;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepContext;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepExecutor;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroup;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroupIterator;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroupable;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepperProperties;
-import org.eclipse.tcf.te.runtime.stepper.interfaces.tracing.ITraceIds;
-import org.eclipse.tcf.te.runtime.stepper.nls.Messages;
-import org.eclipse.tcf.te.runtime.utils.ProgressHelper;
-import org.eclipse.tcf.te.runtime.utils.StatusHelper;
-
-/**
- * An abstract stepper implementation.
- */
-public class Stepper extends ExecutableExtension implements IStepper {
-
-	private boolean initialized = false;
-	private boolean finished = false;
-	private IPropertiesContainer data = null;
-	private IFullQualifiedId fullQualifiedId = null;
-	private IProgressMonitor monitor = null;
-	private IStepContext context = null;
-	private boolean cancelable = true;
-
-	/**
-	 * Internal helper describing a fully executed step.
-	 */
-	protected final class ExecutedContextStep {
-		final IFullQualifiedId id;
-		final IStep step;
-
-		public ExecutedContextStep(IFullQualifiedId id, IStep step) {
-			this.id = id;
-			this.step = step;
-		}
-	}
-
-	/**
-	 * Constructor.
-	 */
-	public Stepper() {
-		super();
-	}
-
-	/**
-	 * Returns a name to describe what is executed by the stepper.
-	 *
-	 * @return A name.
-	 */
-	protected String getName() {
-		return getData() != null ? getData().getStringProperty(IStepperProperties.PROP_NAME) : null;
-	}
-
-	/**
-	 * Returns the id of the step group to execute by the stepper.
-	 *
-	 * @return The step group id.
-	 */
-	protected String getStepGroupId() {
-		return getData() != null ? getData().getStringProperty(IStepperProperties.PROP_STEP_GROUP_ID) : null;
-	}
-
-	/**
-	 * Returns the step group for the given step group id.
-	 *
-	 * @param The step group id. Must not be <code>null</code>:
-	 * @return The step group or <code>null</code>.
-	 */
-	protected IStepGroup getStepGroup(String id) {
-		Assert.isNotNull(id);
-
-		CoreBundleActivator.getTraceHandler().trace("SingleContextStepper#getStepGroup:" //$NON-NLS-1$
-						+ " id = '" + id + "'", //$NON-NLS-1$ //$NON-NLS-2$
-						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-
-		return StepperManager.getInstance().getStepGroupExtManager().getStepGroup(id, false);
-	}
-
-	/**
-	 * Creates a new instance of the step executor to use for executing a step.
-	 *
-	 * @param step The step. Must not be <code>null</code>.
-	 * @param secondaryId The secondary id or <code>null</code>.
-	 * @param fullQualifiedStepId The fully qualified step id. Must not be <code>null</code>.
-	 *
-	 * @return The step executor instance.
-	 */
-	protected IStepExecutor doCreateStepExecutor(IStep step, String secondaryId, IFullQualifiedId fullQualifiedStepId) {
-		Assert.isNotNull(step);
-		Assert.isNotNull(fullQualifiedStepId);
-		return new StepExecutor();
-	}
-
-	/* (non-Javadoc)
-	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#initialize(org.eclipse.tcf.te.runtime.interfaces.properties.IPropertiesContainer, org.eclipse.tcf.te.runtime.stepper.interfaces.IFullQualifiedId, org.eclipse.core.runtime.IProgressMonitor)
-	 */
-	@Override
-	public final void initialize(IStepContext context, IPropertiesContainer data, IFullQualifiedId fullQualifiedId, IProgressMonitor monitor) throws IllegalStateException {
-		Assert.isNotNull(context);
-		Assert.isNotNull(data);
-		Assert.isNotNull(fullQualifiedId);
-		Assert.isNotNull(monitor);
-
-		// Assert stepper is not in use
-		if (isInitialized()) {
-			throw new IllegalStateException("Stepper instance already initialized!"); //$NON-NLS-1$
-		}
-
-		// set the initial stepper attributes
-		this.context = context;
-		this.data = data;
-		this.monitor = monitor;
-		this.fullQualifiedId = fullQualifiedId;
-
-		// but not finished yet
-		this.finished = false;
-
-		// call the hook for the subclasses to initialize themselves
-		onInitialize(data, fullQualifiedId, monitor);
-
-		setInitialized();
-
-		CoreBundleActivator.getTraceHandler().trace("Stepper#initialize:" //$NON-NLS-1$
-						+ " data = " + data, //$NON-NLS-1$
-						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-	}
-
-	/**
-	 * Hook for subclasses to overwrite if subclasses wants to initialize their own state.
-	 *
-	 * @param data The data. Must not be <code>null</code>.
-	 * @param fullQualifiedId The full qualified id of this stepper.
-	 * @param monitor The progress monitor. Must not be <code>null</code>.
-	 */
-	protected void onInitialize(IPropertiesContainer data, IFullQualifiedId fullQualifiedId, IProgressMonitor monitor) {
-		Assert.isNotNull(data);
-		Assert.isNotNull(fullQualifiedId);
-		Assert.isNotNull(monitor);
-	}
-
-	/**
-	 * Marks the stepper to be fully initialized.
-	 */
-	protected final void setInitialized() {
-		initialized = true;
-	}
-
-	/* (non-Javadoc)
-	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#isInitialized()
-	 */
-	@Override
-	public final boolean isInitialized() {
-		return initialized;
-	}
-
-	/**
-	 * Sets the cancelable state of the stepper.
-	 *
-	 * @param cancelable <code>True</code> if the stepper shall be cancelable, <code>false</code> if not.
-	 */
-	protected final void setCancelable(boolean cancelable) {
-		this.cancelable = cancelable;
-	}
-
-	/**
-	 * Returns the cancelable state of the stepper.
-	 *
-	 * @return <code>True</code> if the stepper is cancelable, <code>false</code> if not.
-	 */
-	protected final boolean isCancelable() {
-		return cancelable;
-	}
-
-	/**
-	 * Get the active context.
-	 *
-	 * @return The active context or <code>null</code>.
-	 */
-	protected IStepContext getContext() {
-		return context;
-	}
-
-	/**
-	 * Get the context id.
-	 *
-	 * @return The context id or <code>null</code>.
-	 */
-	protected String getContextId() {
-		return context != null ? context.getId() : null;
-	}
-
-	/**
-	 * Returns the currently associated data. The method returns <code>null</code> if the stepper is
-	 * not in initialized state.
-	 *
-	 * @return The data or <code>null</code>
-	 */
-	protected final IPropertiesContainer getData() {
-		return isInitialized() ? data : null;
-	}
-
-	/**
-	 * Returns the full qualified id for this stepper.
-	 *
-	 * @return The full qualified stepper id.
-	 */
-	protected final IFullQualifiedId getFullQualifiedId() {
-		return fullQualifiedId;
-	}
-
-	/**
-	 * Returns the currently associated progress monitor. The method returns
-	 * <code>null</code> if the stepper is not in initialized state.
-	 *
-	 * @return The progress monitor or <code>null</code>
-	 */
-	protected final IProgressMonitor getMonitor() {
-		return isInitialized() ? monitor : null;
-	}
-
-	/**
-	 * Marks the stepper to be finished.
-	 */
-	protected final void setFinished() {
-		finished = true;
-	}
-
-	/* (non-Javadoc)
-	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#isFinished()
-	 */
-	@Override
-	public final boolean isFinished() {
-		return finished;
-	}
-
-	/* (non-Javadoc)
-	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#cleanup()
-	 */
-	@Override
-	public void cleanup() {
-		// Set the progress monitor done here in any case
-		if (getMonitor() != null) {
-			getMonitor().done();
-		}
-
-		// Reset the initial stepper attributes
-		context = null;
-		data = null;
-		monitor = null;
-		fullQualifiedId = null;
-		finished = false;
-		initialized = false;
-	}
-
-	/* (non-Javadoc)
-	 * @see java.lang.Object#toString()
-	 */
-	@Override
-	public String toString() {
-		StringBuilder buffer = new StringBuilder(getClass().getSimpleName());
-		buffer.append(" (" + getLabel() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
-		buffer.append(": "); //$NON-NLS-1$
-		buffer.append("id = " + getId()); //$NON-NLS-1$
-		return buffer.toString();
-	}
-
-	/* (non-Javadoc)
-	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#execute()
-	 */
-	@Override
-	public final void execute() throws CoreException {
-		long startTime = System.currentTimeMillis();
-
-		CoreBundleActivator.getTraceHandler().trace("Stepper#execute: *** ENTERED", //$NON-NLS-1$
-						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-		CoreBundleActivator.getTraceHandler().trace(" [" + ISharedConstants.TIME_FORMAT.format(new Date(startTime)) + "]" //$NON-NLS-1$ //$NON-NLS-2$
-						+ " ***", //$NON-NLS-1$
-						0, ITraceIds.PROFILE_STEPPING, IStatus.WARNING, this);
-
-		try {
-			// stepper must be initialized before executing
-			if (!isInitialized()) {
-				throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(),
-								Messages.Stepper_error_initializeNotCalled));
-			}
-
-			// Create a container for collecting the non-severe status objects
-			// during the step execution. Non-severe status objects will
-			// be hold back till the execution completed or stopped with an error.
-			// Severe status objects are errors or cancellation.
-			List<IStatus> statusContainer = new ArrayList<IStatus>();
-
-			// start execution
-			internalExecute(statusContainer);
-
-			// If the warnings container is not empty, create a new status and
-			// throw a core exception
-			if (!statusContainer.isEmpty()) {
-				IStatus status = null;
-
-				// Check if we need a multi status
-				if (statusContainer.size() > 1) {
-					MultiStatus multiStatus =
-									new MultiStatus(CoreBundleActivator.getUniqueIdentifier(), 0,
-													NLS.bind(Messages.Stepper_multiStatus_finishedWithWarnings, getName()), null);
-					for (IStatus subStatus : statusContainer) {
-						multiStatus.merge(subStatus);
-					}
-					status = multiStatus;
-				}
-				else {
-					status = statusContainer.get(0);
-				}
-
-				throw new CoreException(status);
-			}
-		}
-		finally {
-			// Mark the stepper finished
-			setFinished();
-
-			long endTime = System.currentTimeMillis();
-			CoreBundleActivator.getTraceHandler().trace("Stepper#execute: *** DONE", //$NON-NLS-1$
-							0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-			CoreBundleActivator.getTraceHandler().trace(" [" + ISharedConstants.TIME_FORMAT.format(new Date(endTime)) //$NON-NLS-1$
-							+ " , delay = " + (endTime - startTime) + " ms]" //$NON-NLS-1$ //$NON-NLS-2$
-							+ " ***", //$NON-NLS-1$
-							0, ITraceIds.PROFILE_STEPPING, IStatus.WARNING, this);
-		}
-	}
-
-	/**
-	 * Executes a step or step group.
-	 *
-	 * @param statusContainer The status container. Must not be <code>null</code>.
-	 * @throws CoreException If the execution fails.
-	 */
-	protected void internalExecute(List<IStatus> statusContainer) throws CoreException {
-		Assert.isNotNull(statusContainer);
-
-		// Get the step group id
-		String stepGroupId = getStepGroupId();
-
-		// If no step group id is available, throw an exception
-		if (stepGroupId == null) {
-			throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(),
-							NLS.bind(Messages.Stepper_error_missingStepGroupId, getName())));
-		}
-
-		// Get the step group
-		IStepGroup stepGroup = getStepGroup(stepGroupId);
-
-		// If no step group could be found for any of the valid variants, throw an exception
-		if (stepGroup == null) {
-			throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(),
-							NLS.bind(Messages.Stepper_error_missingStepGroup, stepGroupId)));
-		}
-
-		// Initialize the progress monitor
-		getMonitor().beginTask(stepGroup.getLabel(), calculateTotalWork(stepGroup));
-
-		IFullQualifiedId fullQualifiedId = getFullQualifiedId().createChildId(ID_TYPE_CONTEXT_ID, getContextId(), null);
-		fullQualifiedId = fullQualifiedId.createChildId(ID_TYPE_STEP_GROUP_ID, stepGroup.getId(), null);
-		// Execute the step group
-		executeStepGroup(stepGroup, statusContainer, new ArrayList<ExecutedContextStep>(), fullQualifiedId);
-	}
-
-	/**
-	 * Executes a step group.
-	 *
-	 * @param stepGroup The step group. Must not be <code>null</code>.
-	 * @param statusContainer A list holding the warnings occurred during the execution. Must not be <code>null</code>.
-	 * @param executedSteps A list holding the id's of the steps executed before. Must not be <code>null</code>.
-	 * @param fullQualifiedGroupId The hierarchy of all parent step group id's separated by "::". Must not be <code>null</code>.
-	 *
-	 * @throws CoreException If the execution fails.
-	 */
-	private void executeStepGroup(IStepGroup stepGroup, List<IStatus> statusContainer, List<ExecutedContextStep> executedSteps, IFullQualifiedId fullQualifiedGroupId) throws CoreException {
-		Assert.isNotNull(stepGroup);
-		Assert.isNotNull(statusContainer);
-		Assert.isNotNull(executedSteps);
-		Assert.isNotNull(fullQualifiedGroupId);
-
-		// Return immediately if the user canceled the monitor in the meanwhile
-		if (isCancelable() && getMonitor().isCanceled()) {
-			rollback(executedSteps, Status.CANCEL_STATUS, getMonitor());
-			throw new CoreException(StatusHelper.getStatus(new OperationCanceledException()));
-		}
-
-		CoreBundleActivator.getTraceHandler().trace("Stepper#executeStepGroup: step group: '" + stepGroup.getLabel() + "'", //$NON-NLS-1$ //$NON-NLS-2$
-						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-
-		// Resolve the steps to execute
-		IStepGroupable[] groupables = stepGroup.getSteps(getContext());
-
-		IStepGroupIterator iterator = stepGroup.getStepGroupIterator();
-		IFullQualifiedId fullQualifiedIterationId = fullQualifiedGroupId;
-		int iteration = 0;
-
-		if (iterator != null) {
-			iterator.initialize(getContext(), getData(), fullQualifiedGroupId, getMonitor());
-		}
-		boolean next = iterator == null || iterator.hasNext(getContext(), getData(), fullQualifiedGroupId, getMonitor());
-
-		while (next) {
-			if (iterator != null) {
-				fullQualifiedIterationId = fullQualifiedGroupId.createChildId(ID_TYPE_STEP_GROUP_ITERATION_ID, iterator.getId(), ""+iteration); //$NON-NLS-1$
-				iterator.next(getContext(), getData(), fullQualifiedIterationId, getMonitor());
-			}
-			// Execute the steps or step groups.
-			for (IStepGroupable groupable : groupables) {
-				executeGroupable(groupable, statusContainer, executedSteps, fullQualifiedIterationId);
-			}
-			iteration++;
-			next = iterator != null && iterator.hasNext(getContext(), getData(), fullQualifiedGroupId, getMonitor());
-		}
-	}
-
-	/**
-	 * Executes a step groupable. The groupable might encapsulate a
-	 * step or a step group.
-	 *
-	 * @param step The step groupable. Must not be <code>null</code>.
-	 * @param statusContainer A list holding the warnings occurred during the execution. Must not be <code>null</code>.
-	 * @param executedSteps A list holding the id's of the steps executed before. Must not be <code>null</code>.
-	 * @param fullQualifiedParentId The hierarchy of all parent step group id's separated by "::". Must not be <code>null</code>.
-	 *
-	 * @throws CoreException If the execution failed.
-	 */
-	private void executeGroupable(IStepGroupable groupable, List<IStatus> statusContainer, List<ExecutedContextStep> executedSteps, IFullQualifiedId fullQualifiedParentId) throws CoreException {
-		Assert.isNotNull(groupable);
-		Assert.isNotNull(statusContainer);
-		Assert.isNotNull(executedSteps);
-		Assert.isNotNull(fullQualifiedParentId);
-
-		// Return immediately if the user canceled the monitor in the meanwhile
-		if (isCancelable() && getMonitor() != null && getMonitor().isCanceled()) {
-			rollback(executedSteps, Status.CANCEL_STATUS, getMonitor());
-			throw new CoreException(StatusHelper.getStatus(new OperationCanceledException()));
-		}
-
-		// If the passed in groupable is disabled -> we are done immediately
-		if (groupable.isDisabled()) {
-			CoreBundleActivator.getTraceHandler().trace("Stepper#executeGroupable: DROPPED DISABLED groupable: id = '" + groupable.getExtension().getId() + "'" //$NON-NLS-1$ //$NON-NLS-2$
-							+ ", secondaryId = '" + groupable.getSecondaryId() + "'", //$NON-NLS-1$ //$NON-NLS-2$
-							0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);
-			return;
-		}
-
-		// Check if all dependencies of the groupable have been executed before
-		checkForDependenciesExecuted(groupable, executedSteps);
-
-		if (groupable.getExtension() instanceof IStepGroup) {
-			IFullQualifiedId id = fullQualifiedParentId.createChildId(ID_TYPE_STEP_GROUP_ID, groupable.getExtension().getId(), groupable.getSecondaryId());
-			// If the passed in groupable is associated with a step group
-			// -> get the groupable from that group and execute them
-			executeStepGroup((IStepGroup)groupable.getExtension(), statusContainer, executedSteps, id);
-		}
-		else if (groupable.getExtension() instanceof IStep) {
-			// If the passed in groupable is associated with a step
-			// -> check if the required steps have been executed before,
-			//    create a step executor and invoke the executor.
-			IStep step = (IStep)groupable.getExtension();
-
-			IFullQualifiedId id = fullQualifiedParentId.createChildId(ID_TYPE_STEP_ID, step.getId(), groupable.getSecondaryId());
-
-			// Create the step executor now
-			IStepExecutor executor = doCreateStepExecutor(step, groupable.getSecondaryId(), id);
-			Assert.isNotNull(executor);
-
-			try {
-				executedSteps.add(new ExecutedContextStep(id, step));
-				// Invoke the executor now
-				executor.execute(step, id, getContext(), getData(), getMonitor());
-			}
-			catch (Exception e) {
-				// Catch the CoreException first hand as we need to continue the
-				// stepping if the step returned with warnings or information only.
-				CoreException coreException = normalizeStatus(e, statusContainer);
-				// If the exception has been not eaten, rollback previously executed
-				// steps and re-throw the exception.
-				if (coreException != null) {
-					// Rollback everything, if the step(s) are supporting this and
-					// the cleanup hasn't been done already.
-					if (isInitialized()) {
-						rollback(executedSteps, coreException.getStatus(), getMonitor());
-					}
-
-					// Re-throw the exception
-					throw coreException;
-				}
-			}
-		}
-	}
-
-	/**
-	 * Checks if all required dependencies have been executed before. If not, the method
-	 * will throw an error status.
-	 *
-	 * @param groupable The groupable. Must not be <code>null</code>.
-	 * @param executedSteps A list holding the id's of the steps executed before. Must not be <code>null</code>.
-	 *
-	 * @throws CoreException If a dependency has not been executed before.
-	 */
-	protected void checkForDependenciesExecuted(IStepGroupable groupable, List<ExecutedContextStep> executedSteps) throws CoreException {
-		Assert.isNotNull(groupable);
-		Assert.isNotNull(executedSteps);
-
-		// Build up the complete list of dependencies.
-		List<String> dependencies = new ArrayList<String>(Arrays.asList(groupable.getDependencies()));
-		// If the groupable wraps a step, the step can have additional dependencies to check
-		if (groupable.getExtension() instanceof IStep) {
-			dependencies.addAll(Arrays.asList(((IStep)groupable.getExtension()).getDependencies()));
-		}
-
-		// Check each dependency now.
-		for (String dependency : dependencies) {
-			// The dependencies might be fully qualified. Split out the primary id.
-			String[] splitted = dependency.split("##", 2); //$NON-NLS-1$
-			String primaryId = splitted.length == 2 ? splitted[0] : dependency;
-
-			// Check if the id is in the list of executed steps. As the list contains
-			// the fully qualified id's, we cannot just check for contained
-			boolean requiredStepExecuted = false;
-			for (ExecutedContextStep step : executedSteps) {
-				if (step.step.getId().equals(primaryId)) {
-					requiredStepExecuted = true;
-					break;
-				}
-			}
-
-			if (!requiredStepExecuted) {
-				throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(),
-								MessageFormat.format(Messages.Stepper_error_requiredStepNotExecuted,
-												NLS.bind(groupable.getExtension() instanceof IStep ? Messages.Stepper_error_step : Messages.Stepper_error_step, groupable.getExtension().getId()),
-												NLS.bind(Messages.Stepper_error_requiredStepOrGroup, dependency), ""))); //$NON-NLS-1$
-			}
-
-			// Recursive checking is not necessary here as the step or step group
-			// id's would have made it the executed steps list of they missed required
-			// steps or step groups.
-		}
-
-	}
-
-	/**
-	 * Rollback the steps previously executed to the failed step. The rollback
-	 * is executed in reverse order and the step must be of type {@link IExtendedStep}
-	 * to participate in the rollback.
-	 *
-	 * @param executedSteps
-	 * @param progress
-	 */
-	protected final void rollback(final List<ExecutedContextStep> executedSteps, final IStatus rollBackStatus, IProgressMonitor progress) {
-		Assert.isNotNull(executedSteps);
-
-		final IProgressMonitor rollbackProgress = ProgressHelper.getProgressMonitor(progress, 1);
-		ProgressHelper.beginTask(rollbackProgress, "Cancel", executedSteps.size()); //$NON-NLS-1$
-		final Callback finalCallback = new Callback();
-		final Callback rollbackCallback = new Callback() {
-			@Override
-			protected void internalDone(Object caller, IStatus status) {
-				if (!executedSteps.isEmpty()) {
-					setProperty(PROPERTY_IS_DONE, false);
-					ExecutedContextStep executedStep = executedSteps.remove(executedSteps.size()-1);
-					if (executedStep.step instanceof IExtendedStep) {
-						IExtendedStep step = (IExtendedStep)executedStep.step;
-						step.rollback(getContext(), getData(), rollBackStatus, executedStep.id, rollbackProgress, this);
-					}
-					else {
-						this.done(this, status);
-					}
-				}
-				else {
-					finalCallback.done(this, Status.OK_STATUS);
-				}
-			}
-		};
-
-		rollbackCallback.done(this, rollBackStatus);
-		ExecutorsUtil.waitAndExecute(0, finalCallback.getDoneConditionTester(null));
-	}
-
-	/**
-	 * Calculates the total work required for the step group. The total
-	 * work is the sum of the total work of each sub step. If one of the
-	 * steps returns {@link IProgressMonitor#UNKNOWN}, the total work will
-	 * be unknown for the whole step group.
-	 *
-	 * @param stepGroup The step group. Must not be <code>null</code>.
-	 * @return The total work required or {@link IProgressMonitor#UNKNOWN}.
-	 *
-	 * @throws CoreException If the total work of the step group cannot be determined.
-	 */
-	protected int calculateTotalWork(IStepGroup stepGroup) throws CoreException {
-		Assert.isNotNull(stepGroup);
-
-		int totalWork = 0;
-
-		// Loop the group steps and summarize the returned total work
-		IStepGroupable[] groupables = stepGroup.getSteps(getContext());
-		for (IStepGroupable groupable : groupables) {
-			int work = groupable.getExtension() instanceof IStep
-							? ((IStep)groupable.getExtension()).getTotalWork(getContext(), getData())
-											: groupable.getExtension() instanceof IStepGroup
-											? calculateTotalWork((IStepGroup)groupable.getExtension())
-															: IProgressMonitor.UNKNOWN;
-
-											if (work == IProgressMonitor.UNKNOWN) {
-												totalWork = IProgressMonitor.UNKNOWN;
-												break;
-											}
-
-											totalWork += work;
-		}
-
-		return totalWork;
-	}
-
-	/**
-	 * Normalize the associated status object of the given {@link CoreException}.
-	 * <p>
-	 * If the associated status contains only WARNING or INFORMATION status objects,
-	 * the objects are added to the passed in status container. The passed in exception
-	 * is dropped and the method will return <code>null</code>.
-	 * <p>
-	 * If the associated status contains only OK status objects, the passed in
-	 * exception and the associated status are dropped and the method will return
-	 * <code>null</code>.
-	 * <p>
-	 * If the associated status contain ERROR status objects, the passed in exception
-	 * and the associated status objects are returned if the passed in status container
-	 * is empty. If the status container is not empty, a new exception and multi status
-	 * object is created and returned. The multi status object will contain all status
-	 * objects from the status container and all objects of the originally associated
-	 * status.
-	 * <p>
-	 * If the associated status contains a CANCEL status object, the passed in
-	 * exception and the associated status objects are returned unmodified.
-	 *
-	 * @param e The core exception. Must not be <code>null</code>.
-	 * @param statusContainer The list of non-severe status objects. Must not be <code>null</code>.
-	 * @return The exception to re-throw or <code>null</code>.
-	 */
-	private CoreException normalizeStatus(Exception e, List<IStatus> statusContainer) {
-		Assert.isNotNull(statusContainer);
-
-		CoreException coreException = null;
-
-		IStatus status = Status.OK_STATUS;
-		// Get the associated status from the exception
-		if (e instanceof CoreException) {
-			status = ((CoreException)e).getStatus();
-			coreException = (CoreException)e;
-		}
-		else if (e instanceof OperationCanceledException) {
-			status = new Status(IStatus.CANCEL, CoreBundleActivator.getUniqueIdentifier(), e.getLocalizedMessage(), e);
-			coreException = new CoreException(status);
-		}
-		else if (e != null) {
-			status = new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), e.getLocalizedMessage(), e);
-			coreException = new CoreException(status);
-		}
-
-		// Check the severity
-		// PS: MultiStatus.getSeverity() returns always the highest severity.
-		if (status.getSeverity() == IStatus.OK) {
-			// OK -> drop completely and return null
-			coreException = null;
-		}
-		else if (status.getSeverity() == IStatus.CANCEL) {
-			// CANCEL -> Check monitor to be canceled.
-			if (isCancelable()) {
-				if (getMonitor() != null && !getMonitor().isCanceled()) {
-					getMonitor().setCanceled(true);
-				}
-			}
-		}
-		else if (status.getSeverity() == IStatus.WARNING || status.getSeverity() == IStatus.INFO) {
-			// WARNING or INFORMATION -> add to the list and return null
-			statusContainer.add(status);
-			coreException = null;
-		}
-		else if (status.getSeverity() == IStatus.ERROR) {
-			// Error -> If the warnings container not empty, create
-			//          a new MultiStatus.
-			if (!statusContainer.isEmpty()) {
-				MultiStatus multiStatus = new MultiStatus(status.getPlugin(), status.getCode(),
-								NLS.bind(Messages.Stepper_multiStatus_finishedWithErrors, getName()), null);
-				for (IStatus stat : statusContainer) {
-					multiStatus.merge(stat);
-				}
-				// Re-throw via a new CoreException
-				coreException = new CoreException(multiStatus);
-			}
-		}
-
-		return coreException;
-	}
-}
+/*******************************************************************************

+ * Copyright (c) 2011, 2012 Wind River Systems, Inc. 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:

+ * Wind River Systems - initial API and implementation

+ *******************************************************************************/

+package org.eclipse.tcf.te.runtime.stepper.stepper;

+

+import java.text.MessageFormat;

+import java.util.ArrayList;

+import java.util.Arrays;

+import java.util.Date;

+import java.util.List;

+

+import org.eclipse.core.runtime.Assert;

+import org.eclipse.core.runtime.CoreException;

+import org.eclipse.core.runtime.IProgressMonitor;

+import org.eclipse.core.runtime.IStatus;

+import org.eclipse.core.runtime.MultiStatus;

+import org.eclipse.core.runtime.OperationCanceledException;

+import org.eclipse.core.runtime.Status;

+import org.eclipse.osgi.util.NLS;

+import org.eclipse.tcf.te.runtime.callback.Callback;

+import org.eclipse.tcf.te.runtime.concurrent.util.ExecutorsUtil;

+import org.eclipse.tcf.te.runtime.interfaces.ISharedConstants;

+import org.eclipse.tcf.te.runtime.interfaces.properties.IPropertiesContainer;

+import org.eclipse.tcf.te.runtime.stepper.StepperManager;

+import org.eclipse.tcf.te.runtime.stepper.activator.CoreBundleActivator;

+import org.eclipse.tcf.te.runtime.stepper.extensions.StepExecutor;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IExtendedStep;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IFullQualifiedId;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStep;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepContext;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepExecutor;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroup;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroupIterator;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepGroupable;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.IStepperProperties;

+import org.eclipse.tcf.te.runtime.stepper.interfaces.tracing.ITraceIds;

+import org.eclipse.tcf.te.runtime.stepper.nls.Messages;

+import org.eclipse.tcf.te.runtime.utils.ProgressHelper;

+import org.eclipse.tcf.te.runtime.utils.StatusHelper;

+

+/**

+ * An abstract stepper implementation.

+ */

+public class Stepper implements IStepper {

+

+	private boolean initialized = false;

+	private boolean finished = false;

+	private IPropertiesContainer data = null;

+	private IFullQualifiedId fullQualifiedId = null;

+	private IProgressMonitor monitor = null;

+	private IStepContext context = null;

+	private boolean cancelable = true;

+

+	/**

+	 * Internal helper describing a fully executed step.

+	 */

+	protected final class ExecutedContextStep {

+		final IFullQualifiedId id;

+		final IStep step;

+

+		public ExecutedContextStep(IFullQualifiedId id, IStep step) {

+			this.id = id;

+			this.step = step;

+		}

+	}

+

+	/**

+	 * Constructor.

+	 */

+	public Stepper() {

+		super();

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#getId()

+	 */

+	@Override

+	public String getId() {

+		return getClass().getName();

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#getLabel()

+	 */

+	@Override

+	public String getLabel() {

+		return getClass().getName();

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#getDescription()

+	 */

+	@Override

+	public String getDescription() {

+		return null;

+	}

+

+	/**

+	 * Returns the id of the step group to execute by the stepper.

+	 * 

+	 * @return The step group id.

+	 */

+	protected String getStepGroupId() {

+		return getData() != null ? getData()

+						.getStringProperty(IStepperProperties.PROP_STEP_GROUP_ID) : null;

+	}

+

+	/**

+	 * Returns the step group for the given step group id.

+	 * 

+	 * @param The step group id. Must not be <code>null</code>:

+	 * @return The step group or <code>null</code>.

+	 */

+	protected IStepGroup getStepGroup(String id) {

+		Assert.isNotNull(id);

+

+		CoreBundleActivator.getTraceHandler().trace("SingleContextStepper#getStepGroup:" //$NON-NLS-1$

+						+ " id = '" + id + "'", //$NON-NLS-1$ //$NON-NLS-2$

+						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+

+		return StepperManager.getInstance().getStepGroupExtManager().getStepGroup(id, false);

+	}

+

+	/**

+	 * Creates a new instance of the step executor to use for executing a step.

+	 * 

+	 * @param step The step. Must not be <code>null</code>.

+	 * @param secondaryId The secondary id or <code>null</code>.

+	 * @param fullQualifiedStepId The fully qualified step id. Must not be <code>null</code>.

+	 * 

+	 * @return The step executor instance.

+	 */

+	protected IStepExecutor doCreateStepExecutor(IStep step, String secondaryId, IFullQualifiedId fullQualifiedStepId) {

+		Assert.isNotNull(step);

+		Assert.isNotNull(fullQualifiedStepId);

+		return new StepExecutor();

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see

+	 * org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#initialize(org.eclipse.tcf.te.runtime

+	 * .interfaces.properties.IPropertiesContainer,

+	 * org.eclipse.tcf.te.runtime.stepper.interfaces.IFullQualifiedId,

+	 * org.eclipse.core.runtime.IProgressMonitor)

+	 */

+	@Override

+	public final void initialize(IStepContext context, IPropertiesContainer data, IFullQualifiedId fullQualifiedId, IProgressMonitor monitor) throws IllegalStateException {

+		Assert.isNotNull(context);

+		Assert.isNotNull(data);

+		Assert.isNotNull(fullQualifiedId);

+		Assert.isNotNull(monitor);

+

+		// Assert stepper is not in use

+		if (isInitialized()) {

+			throw new IllegalStateException("Stepper instance already initialized!"); //$NON-NLS-1$

+		}

+

+		// set the initial stepper attributes

+		this.context = context;

+		this.data = data;

+		this.monitor = monitor;

+		this.fullQualifiedId = fullQualifiedId;

+

+		// but not finished yet

+		this.finished = false;

+

+		// call the hook for the subclasses to initialize themselves

+		onInitialize(data, fullQualifiedId, monitor);

+

+		setInitialized();

+

+		CoreBundleActivator.getTraceHandler().trace("Stepper#initialize:" //$NON-NLS-1$

+						+ " data = " + data, //$NON-NLS-1$

+						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+	}

+

+	/**

+	 * Hook for subclasses to overwrite if subclasses wants to initialize their own state.

+	 * 

+	 * @param data The data. Must not be <code>null</code>.

+	 * @param fullQualifiedId The full qualified id of this stepper.

+	 * @param monitor The progress monitor. Must not be <code>null</code>.

+	 */

+	protected void onInitialize(IPropertiesContainer data, IFullQualifiedId fullQualifiedId, IProgressMonitor monitor) {

+		Assert.isNotNull(data);

+		Assert.isNotNull(fullQualifiedId);

+		Assert.isNotNull(monitor);

+	}

+

+	/**

+	 * Marks the stepper to be fully initialized.

+	 */

+	protected final void setInitialized() {

+		initialized = true;

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#isInitialized()

+	 */

+	@Override

+	public final boolean isInitialized() {

+		return initialized;

+	}

+

+	/**

+	 * Sets the cancelable state of the stepper.

+	 * 

+	 * @param cancelable <code>True</code> if the stepper shall be cancelable, <code>false</code> if

+	 *            not.

+	 */

+	protected final void setCancelable(boolean cancelable) {

+		this.cancelable = cancelable;

+	}

+

+	/**

+	 * Returns the cancelable state of the stepper.

+	 * 

+	 * @return <code>True</code> if the stepper is cancelable, <code>false</code> if not.

+	 */

+	protected final boolean isCancelable() {

+		return cancelable;

+	}

+

+	/**

+	 * Get the active context.

+	 * 

+	 * @return The active context or <code>null</code>.

+	 */

+	protected IStepContext getContext() {

+		return context;

+	}

+

+	/**

+	 * Get the context id.

+	 * 

+	 * @return The context id or <code>null</code>.

+	 */

+	protected String getContextId() {

+		return context != null ? context.getId() : null;

+	}

+

+	/**

+	 * Returns the currently associated data. The method returns <code>null</code> if the stepper is

+	 * not in initialized state.

+	 * 

+	 * @return The data or <code>null</code>

+	 */

+	protected final IPropertiesContainer getData() {

+		return isInitialized() ? data : null;

+	}

+

+	/**

+	 * Returns the full qualified id for this stepper.

+	 * 

+	 * @return The full qualified stepper id.

+	 */

+	protected final IFullQualifiedId getFullQualifiedId() {

+		return fullQualifiedId;

+	}

+

+	/**

+	 * Returns the currently associated progress monitor. The method returns <code>null</code> if

+	 * the stepper is not in initialized state.

+	 * 

+	 * @return The progress monitor or <code>null</code>

+	 */

+	protected final IProgressMonitor getMonitor() {

+		return isInitialized() ? monitor : null;

+	}

+

+	/**

+	 * Marks the stepper to be finished.

+	 */

+	protected final void setFinished() {

+		finished = true;

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#isFinished()

+	 */

+	@Override

+	public final boolean isFinished() {

+		return finished;

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#cleanup()

+	 */

+	@Override

+	public void cleanup() {

+		// Set the progress monitor done here in any case

+		if (getMonitor() != null) {

+			getMonitor().done();

+		}

+

+		// Reset the initial stepper attributes

+		context = null;

+		data = null;

+		monitor = null;

+		fullQualifiedId = null;

+		finished = false;

+		initialized = false;

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see java.lang.Object#toString()

+	 */

+	@Override

+	public String toString() {

+		StringBuilder buffer = new StringBuilder(getClass().getSimpleName());

+		buffer.append(" (" + getLabel() + ")"); //$NON-NLS-1$ //$NON-NLS-2$

+		buffer.append(": "); //$NON-NLS-1$

+		buffer.append("id = " + getId()); //$NON-NLS-1$

+		return buffer.toString();

+	}

+

+	/*

+	 * (non-Javadoc)

+	 * @see org.eclipse.tcf.te.runtime.stepper.interfaces.IStepper#execute()

+	 */

+	@Override

+	public final void execute() throws CoreException {

+		long startTime = System.currentTimeMillis();

+

+		CoreBundleActivator.getTraceHandler().trace("Stepper#execute: *** ENTERED", //$NON-NLS-1$

+						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+		CoreBundleActivator

+		.getTraceHandler()

+		.trace(" [" + ISharedConstants.TIME_FORMAT.format(new Date(startTime)) + "]" //$NON-NLS-1$ //$NON-NLS-2$

+						+ " ***", //$NON-NLS-1$

+						0, ITraceIds.PROFILE_STEPPING, IStatus.WARNING, this);

+

+		try {

+			// stepper must be initialized before executing

+			if (!isInitialized()) {

+				throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), Messages.Stepper_error_initializeNotCalled));

+			}

+

+			// Create a container for collecting the non-severe status objects

+			// during the step execution. Non-severe status objects will

+			// be hold back till the execution completed or stopped with an error.

+			// Severe status objects are errors or cancellation.

+			List<IStatus> statusContainer = new ArrayList<IStatus>();

+

+			// start execution

+			internalExecute(statusContainer);

+

+			// If the warnings container is not empty, create a new status and

+			// throw a core exception

+			if (!statusContainer.isEmpty()) {

+				IStatus status = null;

+

+				// Check if we need a multi status

+				if (statusContainer.size() > 1) {

+					MultiStatus multiStatus = new MultiStatus(CoreBundleActivator.getUniqueIdentifier(), 0, NLS

+									.bind(Messages.Stepper_multiStatus_finishedWithWarnings, getLabel()), null);

+					for (IStatus subStatus : statusContainer) {

+						multiStatus.merge(subStatus);

+					}

+					status = multiStatus;

+				}

+				else {

+					status = statusContainer.get(0);

+				}

+

+				throw new CoreException(status);

+			}

+		}

+		finally {

+			// Mark the stepper finished

+			setFinished();

+

+			long endTime = System.currentTimeMillis();

+			CoreBundleActivator.getTraceHandler().trace("Stepper#execute: *** DONE", //$NON-NLS-1$

+							0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+			CoreBundleActivator.getTraceHandler()

+			.trace(" [" + ISharedConstants.TIME_FORMAT.format(new Date(endTime)) //$NON-NLS-1$

+							+ " , delay = " + (endTime - startTime) + " ms]" //$NON-NLS-1$ //$NON-NLS-2$

+							+ " ***", //$NON-NLS-1$

+							0, ITraceIds.PROFILE_STEPPING, IStatus.WARNING, this);

+		}

+	}

+

+	/**

+	 * Executes a step or step group.

+	 * 

+	 * @param statusContainer The status container. Must not be <code>null</code>.

+	 * @throws CoreException If the execution fails.

+	 */

+	protected void internalExecute(List<IStatus> statusContainer) throws CoreException {

+		Assert.isNotNull(statusContainer);

+

+		// Get the step group id

+		String stepGroupId = getStepGroupId();

+

+		// If no step group id is available, throw an exception

+		if (stepGroupId == null) {

+			throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), NLS

+							.bind(Messages.Stepper_error_missingStepGroupId, getLabel())));

+		}

+

+		// Get the step group

+		IStepGroup stepGroup = getStepGroup(stepGroupId);

+

+		// If no step group could be found, throw an exception

+		if (stepGroup == null) {

+			throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), NLS

+							.bind(Messages.Stepper_error_missingStepGroup, stepGroupId)));

+		}

+

+		// Initialize the progress monitor

+		getMonitor().beginTask(stepGroup.getLabel(), calculateTotalWork(stepGroup));

+

+		IFullQualifiedId fullQualifiedId = getFullQualifiedId()

+						.createChildId(ID_TYPE_CONTEXT_ID, getContextId(), null);

+		fullQualifiedId = fullQualifiedId

+						.createChildId(ID_TYPE_STEP_GROUP_ID, stepGroup.getId(), null);

+		// Execute the step group

+		executeStepGroup(stepGroup, statusContainer, new ArrayList<ExecutedContextStep>(), fullQualifiedId);

+	}

+

+	/**

+	 * Executes a step group.

+	 * 

+	 * @param stepGroup The step group. Must not be <code>null</code>.

+	 * @param statusContainer A list holding the warnings occurred during the execution. Must not be

+	 *            <code>null</code>.

+	 * @param executedSteps A list holding the id's of the steps executed before. Must not be

+	 *            <code>null</code>.

+	 * @param fullQualifiedGroupId The hierarchy of all parent step group id's separated by "::".

+	 *            Must not be <code>null</code>.

+	 * 

+	 * @throws CoreException If the execution fails.

+	 */

+	private void executeStepGroup(IStepGroup stepGroup, List<IStatus> statusContainer, List<ExecutedContextStep> executedSteps, IFullQualifiedId fullQualifiedGroupId) throws CoreException {

+		Assert.isNotNull(stepGroup);

+		Assert.isNotNull(statusContainer);

+		Assert.isNotNull(executedSteps);

+		Assert.isNotNull(fullQualifiedGroupId);

+

+		// Return immediately if the user canceled the monitor in the meanwhile

+		if (isCancelable() && getMonitor().isCanceled()) {

+			rollback(executedSteps, Status.CANCEL_STATUS, getMonitor());

+			throw new CoreException(StatusHelper.getStatus(new OperationCanceledException()));

+		}

+

+		CoreBundleActivator

+		.getTraceHandler()

+		.trace("Stepper#executeStepGroup: step group: '" + stepGroup.getLabel() + "'", //$NON-NLS-1$ //$NON-NLS-2$

+						0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+

+		// Resolve the steps to execute

+		IStepGroupable[] groupables = stepGroup.getSteps(getContext());

+

+		IStepGroupIterator iterator = stepGroup.getStepGroupIterator();

+		IFullQualifiedId fullQualifiedIterationId = fullQualifiedGroupId;

+		int iteration = 0;

+

+		if (iterator != null) {

+			iterator.initialize(getContext(), getData(), fullQualifiedGroupId, getMonitor());

+		}

+		boolean next = iterator == null || iterator

+						.hasNext(getContext(), getData(), fullQualifiedGroupId, getMonitor());

+

+		while (next) {

+			if (iterator != null) {

+				fullQualifiedIterationId = fullQualifiedGroupId

+								.createChildId(ID_TYPE_STEP_GROUP_ITERATION_ID, iterator.getId(), "" + iteration); //$NON-NLS-1$

+				iterator.next(getContext(), getData(), fullQualifiedIterationId, getMonitor());

+			}

+			// Execute the steps or step groups.

+			for (IStepGroupable groupable : groupables) {

+				executeGroupable(groupable, statusContainer, executedSteps, fullQualifiedIterationId);

+			}

+			iteration++;

+			next = iterator != null && iterator

+							.hasNext(getContext(), getData(), fullQualifiedGroupId, getMonitor());

+		}

+	}

+

+	/**

+	 * Executes a step groupable. The groupable might encapsulate a step or a step group.

+	 * 

+	 * @param step The step groupable. Must not be <code>null</code>.

+	 * @param statusContainer A list holding the warnings occurred during the execution. Must not be

+	 *            <code>null</code>.

+	 * @param executedSteps A list holding the id's of the steps executed before. Must not be

+	 *            <code>null</code>.

+	 * @param fullQualifiedParentId The hierarchy of all parent step group id's separated by "::".

+	 *            Must not be <code>null</code>.

+	 * 

+	 * @throws CoreException If the execution failed.

+	 */

+	private void executeGroupable(IStepGroupable groupable, List<IStatus> statusContainer, List<ExecutedContextStep> executedSteps, IFullQualifiedId fullQualifiedParentId) throws CoreException {

+		Assert.isNotNull(groupable);

+		Assert.isNotNull(statusContainer);

+		Assert.isNotNull(executedSteps);

+		Assert.isNotNull(fullQualifiedParentId);

+

+		// Return immediately if the user canceled the monitor in the meanwhile

+		if (isCancelable() && getMonitor() != null && getMonitor().isCanceled()) {

+			rollback(executedSteps, Status.CANCEL_STATUS, getMonitor());

+			throw new CoreException(StatusHelper.getStatus(new OperationCanceledException()));

+		}

+

+		// If the passed in groupable is disabled -> we are done immediately

+		if (groupable.isDisabled()) {

+			CoreBundleActivator

+			.getTraceHandler()

+			.trace("Stepper#executeGroupable: DROPPED DISABLED groupable: id = '" + groupable.getExtension().getId() + "'" //$NON-NLS-1$ //$NON-NLS-2$

+							+ ", secondaryId = '" + groupable.getSecondaryId() + "'", //$NON-NLS-1$ //$NON-NLS-2$

+							0, ITraceIds.TRACE_STEPPING, IStatus.WARNING, this);

+			return;

+		}

+

+		// Check if all dependencies of the groupable have been executed before

+		checkForDependenciesExecuted(groupable, executedSteps);

+

+		if (groupable.getExtension() instanceof IStepGroup) {

+			IFullQualifiedId id = fullQualifiedParentId

+							.createChildId(ID_TYPE_STEP_GROUP_ID, groupable.getExtension().getId(), groupable

+											.getSecondaryId());

+			// If the passed in groupable is associated with a step group

+			// -> get the groupable from that group and execute them

+			executeStepGroup((IStepGroup) groupable.getExtension(), statusContainer, executedSteps, id);

+		}

+		else if (groupable.getExtension() instanceof IStep) {

+			// If the passed in groupable is associated with a step

+			// -> check if the required steps have been executed before,

+			// create a step executor and invoke the executor.

+			IStep step = (IStep) groupable.getExtension();

+

+			IFullQualifiedId id = fullQualifiedParentId

+							.createChildId(ID_TYPE_STEP_ID, step.getId(), groupable

+											.getSecondaryId());

+

+			// Create the step executor now

+			IStepExecutor executor = doCreateStepExecutor(step, groupable.getSecondaryId(), id);

+			Assert.isNotNull(executor);

+

+			try {

+				executedSteps.add(new ExecutedContextStep(id, step));

+				// Invoke the executor now

+				executor.execute(step, id, getContext(), getData(), getMonitor());

+			}

+			catch (Exception e) {

+				// Catch the CoreException first hand as we need to continue the

+				// stepping if the step returned with warnings or information only.

+				CoreException coreException = normalizeStatus(e, statusContainer);

+				// If the exception has been not eaten, rollback previously executed

+				// steps and re-throw the exception.

+				if (coreException != null) {

+					// Rollback everything, if the step(s) are supporting this and

+					// the cleanup hasn't been done already.

+					if (isInitialized()) {

+						rollback(executedSteps, coreException.getStatus(), getMonitor());

+					}

+

+					// Re-throw the exception

+					throw coreException;

+				}

+			}

+		}

+	}

+

+	/**

+	 * Checks if all required dependencies have been executed before. If not, the method will throw

+	 * an error status.

+	 * 

+	 * @param groupable The groupable. Must not be <code>null</code>.

+	 * @param executedSteps A list holding the id's of the steps executed before. Must not be

+	 *            <code>null</code>.

+	 * 

+	 * @throws CoreException If a dependency has not been executed before.

+	 */

+	protected void checkForDependenciesExecuted(IStepGroupable groupable, List<ExecutedContextStep> executedSteps) throws CoreException {

+		Assert.isNotNull(groupable);

+		Assert.isNotNull(executedSteps);

+

+		// Build up the complete list of dependencies.

+		List<String> dependencies = new ArrayList<String>(Arrays.asList(groupable.getDependencies()));

+		// If the groupable wraps a step, the step can have additional dependencies to check

+		if (groupable.getExtension() instanceof IStep) {

+			dependencies.addAll(Arrays.asList(((IStep) groupable.getExtension()).getDependencies()));

+		}

+

+		// Check each dependency now.

+		for (String dependency : dependencies) {

+			// The dependencies might be fully qualified. Split out the primary id.

+			String[] splitted = dependency.split("##", 2); //$NON-NLS-1$

+			String primaryId = splitted.length == 2 ? splitted[0] : dependency;

+

+			// Check if the id is in the list of executed steps. As the list contains

+			// the fully qualified id's, we cannot just check for contained

+			boolean requiredStepExecuted = false;

+			for (ExecutedContextStep step : executedSteps) {

+				if (step.step.getId().equals(primaryId)) {

+					requiredStepExecuted = true;

+					break;

+				}

+			}

+

+			if (!requiredStepExecuted) {

+				throw new CoreException(new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), MessageFormat

+								.format(Messages.Stepper_error_requiredStepNotExecuted, NLS.bind(groupable

+												.getExtension() instanceof IStep ? Messages.Stepper_error_step : Messages.Stepper_error_step, groupable

+																.getExtension().getId()), NLS

+																.bind(Messages.Stepper_error_requiredStepOrGroup, dependency), ""))); //$NON-NLS-1$

+			}

+

+			// Recursive checking is not necessary here as the step or step group

+			// id's would have made it the executed steps list of they missed required

+			// steps or step groups.

+		}

+

+	}

+

+	/**

+	 * Rollback the steps previously executed to the failed step. The rollback is executed in

+	 * reverse order and the step must be of type {@link IExtendedStep} to participate in the

+	 * rollback.

+	 * 

+	 * @param executedSteps

+	 * @param progress

+	 */

+	protected final void rollback(final List<ExecutedContextStep> executedSteps, final IStatus rollBackStatus, IProgressMonitor progress) {

+		Assert.isNotNull(executedSteps);

+

+		final IProgressMonitor rollbackProgress = ProgressHelper.getProgressMonitor(progress, 1);

+		ProgressHelper.beginTask(rollbackProgress, "Cancel", executedSteps.size()); //$NON-NLS-1$

+		final Callback finalCallback = new Callback();

+		final Callback rollbackCallback = new Callback() {

+			@Override

+			protected void internalDone(Object caller, IStatus status) {

+				if (!executedSteps.isEmpty()) {

+					setProperty(PROPERTY_IS_DONE, false);

+					ExecutedContextStep executedStep = executedSteps

+									.remove(executedSteps.size() - 1);

+					if (executedStep.step instanceof IExtendedStep) {

+						IExtendedStep step = (IExtendedStep) executedStep.step;

+						step.rollback(getContext(), getData(), rollBackStatus, executedStep.id, rollbackProgress, this);

+					}

+					else {

+						this.done(this, status);

+					}

+				}

+				else {

+					finalCallback.done(this, Status.OK_STATUS);

+				}

+			}

+		};

+

+		rollbackCallback.done(this, rollBackStatus);

+		ExecutorsUtil.waitAndExecute(0, finalCallback.getDoneConditionTester(null));

+	}

+

+	/**

+	 * Calculates the total work required for the step group. The total work is the sum of the total

+	 * work of each sub step. If one of the steps returns {@link IProgressMonitor#UNKNOWN}, the

+	 * total work will be unknown for the whole step group.

+	 * 

+	 * @param stepGroup The step group. Must not be <code>null</code>.

+	 * @return The total work required or {@link IProgressMonitor#UNKNOWN}.

+	 * 

+	 * @throws CoreException If the total work of the step group cannot be determined.

+	 */

+	protected int calculateTotalWork(IStepGroup stepGroup) throws CoreException {

+		Assert.isNotNull(stepGroup);

+

+		int totalWork = 0;

+

+		// Loop the group steps and summarize the returned total work

+		IStepGroupable[] groupables = stepGroup.getSteps(getContext());

+		for (IStepGroupable groupable : groupables) {

+			int work = groupable.getExtension() instanceof IStep ? ((IStep) groupable

+							.getExtension()).getTotalWork(getContext(), getData()) : groupable

+							.getExtension() instanceof IStepGroup ? calculateTotalWork((IStepGroup) groupable

+											.getExtension()) : IProgressMonitor.UNKNOWN;

+

+							if (work == IProgressMonitor.UNKNOWN) {

+								totalWork = IProgressMonitor.UNKNOWN;

+								break;

+							}

+

+							totalWork += work;

+		}

+

+		return totalWork;

+	}

+

+	/**

+	 * Normalize the associated status object of the given {@link CoreException}.

+	 * <p>

+	 * If the associated status contains only WARNING or INFORMATION status objects, the objects are

+	 * added to the passed in status container. The passed in exception is dropped and the method

+	 * will return <code>null</code>.

+	 * <p>

+	 * If the associated status contains only OK status objects, the passed in exception and the

+	 * associated status are dropped and the method will return <code>null</code>.

+	 * <p>

+	 * If the associated status contain ERROR status objects, the passed in exception and the

+	 * associated status objects are returned if the passed in status container is empty. If the

+	 * status container is not empty, a new exception and multi status object is created and

+	 * returned. The multi status object will contain all status objects from the status container

+	 * and all objects of the originally associated status.

+	 * <p>

+	 * If the associated status contains a CANCEL status object, the passed in exception and the

+	 * associated status objects are returned unmodified.

+	 * 

+	 * @param e The core exception. Must not be <code>null</code>.

+	 * @param statusContainer The list of non-severe status objects. Must not be <code>null</code>.

+	 * @return The exception to re-throw or <code>null</code>.

+	 */

+	private CoreException normalizeStatus(Exception e, List<IStatus> statusContainer) {

+		Assert.isNotNull(statusContainer);

+

+		CoreException coreException = null;

+

+		IStatus status = Status.OK_STATUS;

+		// Get the associated status from the exception

+		if (e instanceof CoreException) {

+			status = ((CoreException) e).getStatus();

+			coreException = (CoreException) e;

+		}

+		else if (e instanceof OperationCanceledException) {

+			status = new Status(IStatus.CANCEL, CoreBundleActivator.getUniqueIdentifier(), e.getLocalizedMessage(), e);

+			coreException = new CoreException(status);

+		}

+		else if (e != null) {

+			status = new Status(IStatus.ERROR, CoreBundleActivator.getUniqueIdentifier(), e.getLocalizedMessage(), e);

+			coreException = new CoreException(status);

+		}

+

+		// Check the severity

+		// PS: MultiStatus.getSeverity() returns always the highest severity.

+		if (status.getSeverity() == IStatus.OK) {

+			// OK -> drop completely and return null

+			coreException = null;

+		}

+		else if (status.getSeverity() == IStatus.CANCEL) {

+			// CANCEL -> Check monitor to be canceled.

+			if (isCancelable()) {

+				if (getMonitor() != null && !getMonitor().isCanceled()) {

+					getMonitor().setCanceled(true);

+				}

+			}

+		}

+		else if (status.getSeverity() == IStatus.WARNING || status.getSeverity() == IStatus.INFO) {

+			// WARNING or INFORMATION -> add to the list and return null

+			statusContainer.add(status);

+			coreException = null;

+		}

+		else if (status.getSeverity() == IStatus.ERROR) {

+			// Error -> If the warnings container not empty, create

+			// a new MultiStatus.

+			if (!statusContainer.isEmpty()) {

+				MultiStatus multiStatus = new MultiStatus(status.getPlugin(), status.getCode(), NLS.bind(Messages.Stepper_multiStatus_finishedWithErrors, getLabel()), null);

+				for (IStatus stat : statusContainer) {

+					multiStatus.merge(stat);

+				}

+				// Re-throw via a new CoreException

+				coreException = new CoreException(multiStatus);

+			}

+		}

+

+		return coreException;

+	}

+}