plugins/org.eclipse.amalgam.explorer.activity/src/org/eclipse/amalgam/explorer/activity/internal/viewer/diagram/actions/CloneDiagramCommand.java

/*******************************************************************************
 * Copyright (c)  2006, 2015 THALES GLOBAL SERVICES.
 * 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:
 *    Thales - initial API and implementation
 *******************************************************************************/
package org.eclipse.amalgam.explorer.activity.internal.viewer.diagram.actions;

/**
 */

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;

import org.eclipse.amalgam.explorer.activity.ActivityExplorerActivator;
import org.eclipse.amalgam.explorer.activity.api.editor.pages.helper.StringHelper;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.emf.common.command.AbstractCommand;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.sirius.business.api.dialect.DialectManager;
import org.eclipse.sirius.business.api.session.Session;
import org.eclipse.sirius.business.api.session.SessionManager;
import org.eclipse.sirius.viewpoint.DRepresentation;
import org.eclipse.sirius.viewpoint.DSemanticDecorator;

/**
 * A command thats clone specified representations.<br>
 * Warning, this command does not handle the transactional behavior.<br>
 * Thus it must be executed within a "calling" transaction.
 * 
 */
public class CloneDiagramCommand extends AbstractCommand {
	/**
	 * The representations to clone.
	 */
	private Collection<DRepresentation> _representations;
	/**
	 * Cloned representations.
	 */
	private Collection<DRepresentation> _clones;
	/**
	 * Clone life cycle listeners.
	 */
	private Collection<ICloneListener> _listeners;

	/**
	 * Constructor.
	 * 
	 * @param representations_p
	 */
	public CloneDiagramCommand(Collection<DRepresentation> representations_p) {
		super(Messages.CloneDiagramCommand_0);
		_representations = representations_p;
	}

	/**
	 * @see org.eclipse.emf.common.command.AbstractCommand#dispose()
	 */
	@Override
	public void dispose() {
		super.dispose();
		if (null != _clones) {
			_clones.clear();
			_clones = null;
		}
		if (null != _listeners) {
			_listeners.clear();
			_listeners = null;
		}
		if (null != _representations) {
			_representations = null;
		}
	}

	/**
	 * Add a clone life cycle listener.
	 * 
	 * @param listener_p
	 */
	public void addCloneListener(ICloneListener listener_p) {
		if (null == listener_p) {
			return;
		}
		// Lazy allocation.
		if (null == _listeners) {
			_listeners = new HashSet<ICloneListener>(1);
		}
		// Add listener.
		_listeners.add(listener_p);
	}

	/**
	 * Remove a registered clone life cycle listener.
	 * 
	 * @param listener_p
	 */
	public void removeCloneListener(ICloneListener listener_p) {
		if ((null == _listeners) || (null == listener_p)) {
			return;
		}
		// Remove listener.
		_listeners.remove(listener_p);
	}

	/**
	 * Send clone life cycle event.
	 * 
	 * @param type_p
	 * @param clone_p
	 * @param session_p
	 */
	protected void notifyListeners(EventType type_p, DRepresentation clone_p, Session session_p) {
		if ((null == _listeners) || _listeners.isEmpty()) {
			return;
		}
		// Clone listeners collection.
		ArrayList<ICloneListener> listeners = new ArrayList<ICloneListener>(_listeners);
		// Call listeners.
		for (ICloneListener listener : listeners) {
			try {
				if (EventType.ADD.equals(type_p)) {
					listener.cloneCreated(clone_p, session_p);
				} else if (EventType.REMOVE.equals(type_p)) {
					listener.cloneAboutToBeRemoved(clone_p, session_p);
				}
			} catch (Exception exception_p) {
				ActivityExplorerActivator.getDefault().sentToLogger("Unable to notify listeners !", IStatus.ERROR);
			}
		}
	}

	/**
	 * @see org.eclipse.emf.common.command.AbstractCommand#canUndo()
	 */
	@Override
	public boolean canUndo() {
		return (null != _clones) && (_clones.size() > 0);
	}

	/**
	 * @see org.eclipse.emf.common.command.Command#execute()
	 */
	public void execute() {
		// Initialize clones list.
		if (null == _clones) {
			_clones = new ArrayList<DRepresentation>(0);
		} else {
			// Ensure emptiness.
			if (_clones.size() > 0) {
				_clones.clear();
			}
		}
		// Copy all representations.
		for (DRepresentation representation : _representations) {
			if (representation instanceof DSemanticDecorator) {
				// Get target semantic element.
				EObject target = ((DSemanticDecorator) representation).getTarget();
				// Get session.
				Session session = SessionManager.INSTANCE.getSession(target);
				// Copy representation.
				DRepresentation copyRepresentation = DialectManager.INSTANCE.copyRepresentation(representation,
						getCloneName(representation, session), session, null);
				// Retain copied reference.
				_clones.add(copyRepresentation);
				// Notify listeners.
				// S0024665 Not sure that is really needed as viewer has been
				// already notified through the session
				// notifyListeners(EventType.ADD, copyRepresentation, session);
			} else {

				ActivityExplorerActivator
						.getDefault()
						.getLog()
						.log(new Status(IStatus.WARNING, ActivityExplorerActivator.ID,
								"Clone is not supported for " + representation.getName())); //$NON-NLS-1$
			}
		}
	}

	/**
	 * Get clone name for specified representation.
	 * 
	 * @param representation_p
	 * @return
	 */
	protected String getCloneName(DRepresentation representation_p, Session session_p) {
		String message = "GET_NAME_PREFIX "; //$NON-NLS-1$
		String cloneName = StringHelper.formatMessage(message, new Object[] { "", representation_p.getName() }); //$NON-NLS-1$
		boolean cloneNameFound = false;
		Collection<DRepresentation> allRepresentations = DialectManager.INSTANCE.getAllRepresentations(session_p);
		int i = 1;
		while (!cloneNameFound) {
			boolean collision = false;
			for (DRepresentation representation : allRepresentations) {
				if (cloneName.equals(representation.getName())) {
					collision = true;
					break;
				}
			}
			if (collision) {
				cloneName = StringHelper.formatMessage(message, new Object[] { "" + ++i + ' ', //$NON-NLS-1$
						representation_p.getName() });
			}
			cloneNameFound = !collision;
		}
		return cloneName;
	}

	/**
	 * @see org.eclipse.emf.common.command.AbstractCommand#prepare()
	 */
	@Override
	protected boolean prepare() {
		return true;
	}

	/**
	 * @see org.eclipse.emf.common.command.Command#redo()
	 */
	public void redo() {
		execute();
	}

	/**
	 * @see org.eclipse.emf.common.command.AbstractCommand#undo()
	 */
	@Override
	public void undo() {
		// Delete all cloned representations.
		for (DRepresentation representation : _clones) {
			Session session = SessionManager.INSTANCE.getSession(((DSemanticDecorator) representation).getTarget());
			// Notify listeners.
			// S0024665 Not sure that is really needed as viewer has been
			// already notified through the session
			// notifyListeners(EventType.REMOVE, representation, session);
			// Then execute delete.
			DialectManager.INSTANCE.deleteRepresentation(representation, session);
		}
		// Clean clones collection.
		_clones.clear();
	}

	/**
	 * Clone event type.
	 * 
	 */
	protected enum EventType {
		ADD, REMOVE
	}

	/**
	 * Clone listener.
	 * 
	 */
	public interface ICloneListener {
		/**
		 * Specified clone has just been added to specified session.
		 * 
		 * @param clone_p
		 * @param session_p
		 */
		void cloneCreated(DRepresentation clone_p, Session session_p);

		/**
		 * Specified clone is about to be removed from specified session.
		 * 
		 * @param clone_p
		 * @param session_p
		 */
		void cloneAboutToBeRemoved(DRepresentation clone_p, Session session_p);
	}
}