lookAndFeel/plugins/org.eclipse.papyrus.uml.diagram.clazz.lf.autosizeableclasses/src/org/eclipse/papyrus/uml/diagram/clazz/lf/autosizeableclasses/statemachine/StateMachineManager.java

/*****************************************************************************
 * Copyright (c) 2019 CEA LIST.
 *
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *  Xavier Le Pallec (for CEA LIST) xlepallec@lilo.org - Bug 558456
 *
 *****************************************************************************/

package org.eclipse.papyrus.uml.diagram.clazz.lf.autosizeableclasses.statemachine;

import java.util.HashMap;
import java.util.Map;

import org.eclipse.gef.EditPart;
import org.eclipse.gef.RootEditPart;

/**
 * This class defines a mechanism to store a state machine for each class
 * diagram with an indexation based on the root edit part of the diagram. A
 * HashMap is used for that.
 */
public class StateMachineManager {

	static StateMachineManager INSTANCE = new StateMachineManager();
	private Map<RootEditPart, StateMachine> stateMachines;

	/**
	 * Get access to the manager (singleton).
	 * 
	 * @return the state machine manager.
	 */
	public static StateMachineManager getInstance() {
		return INSTANCE;
	}

	/**
	 * the basic constructor only creates the dedicated hashmap.
	 */
	public StateMachineManager() {
		stateMachines = new HashMap<>();
	}

	/**
	 * This method gets the state machine associated to the diagram where the edit
	 * part (parameter) is.
	 * 
	 * @param editPart an edit part representing an element of a diagram.
	 * @return the state machine associated to the diagram where the edit part
	 *         (parameter) is.
	 */
	public StateMachine getStateMachine(EditPart editPart) {
		return getStateMachine(editPart.getRoot());
	}

	/**
	 * This method gets the state machine associated to the diagram represented by
	 * the root edit part (parameter).
	 * 
	 * @param rootEditPart the edit part associated to a diagram
	 * @return the state machine associated to the diagram represented by the root
	 *         edit part.
	 */
	public StateMachine getStateMachine(RootEditPart rootEditPart) {
		StateMachine stateMachine = stateMachines.get(rootEditPart);
		if (stateMachine == null) {
			stateMachine = new StateMachine(rootEditPart);
			stateMachines.put(rootEditPart, stateMachine);
		}
		return stateMachine;
	}

}