/******************************************************************************* * Copyright (c) 2005 IBM Corporation 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: *     IBM Corporation - initial API and implementation ******************************************************************************/package org.eclipse.core.commands;import java.util.HashMap;import java.util.Map;import java.util.Set;import org.eclipse.core.commands.common.NamedHandleObject;import org.eclipse.core.commands.common.NotDefinedException;/** * <p> * A named handle object that can carry state with it. This state can be used to * override the name or description. * </p> * <p> * Clients may neither instantiate nor extend this class. * </p> * <p> * <strong>EXPERIMENTAL</strong>. This class or interface has been added as * part of a work in progress. There is a guarantee neither that this API will * work nor that it will remain the same. Please do not use this API without * consulting with the Platform/UI team. * </p> *  * @since 3.2 */abstract class NamedHandleObjectWithState extends NamedHandleObject implements		IObjectWithState {	/**	 * The map of states currently held by this command. If this command has no	 * state, then this will be <code>null</code>.	 */	private Map states = null;	/**	 * Constructs a new instance of <code>NamedHandleObject<WithState/code>.	 * 	 * @param id	 *            The identifier for this handle; must not be <code>null</code>.	 */	protected NamedHandleObjectWithState(final String id) {		super(id);	}	public void addState(final String stateId, final IState state) {		if (state == null) {			throw new NullPointerException("Cannot add a null state"); //$NON-NLS-1$		}		if (states == null) {			states = new HashMap(3);		}		states.put(stateId, state);	}	public final String getDescription() throws NotDefinedException {		final String description = super.getDescription(); // Trigger a NDE.		final IState descriptionState = getState(INamedHandleStateIds.DESCRIPTION);		if (descriptionState != null) {			final Object value = descriptionState.getValue();			if (value != null) {				return value.toString();			}		}		return description;	}	public final String getName() throws NotDefinedException {		final String name = super.getName(); // Trigger a NDE, if necessary.		final IState nameState = getState(INamedHandleStateIds.NAME);		if (nameState != null) {			final Object value = nameState.getValue();			if (value != null) {				return value.toString();			}		}		return name;	}	public final IState getState(final String stateId) {		if ((states == null) || (states.isEmpty())) {			return null;		}		return (IState) states.get(stateId);	}	public final String[] getStateIds() {		if ((states == null) || (states.isEmpty())) {			return null;		}		final Set stateIds = states.keySet();		return (String[]) stateIds.toArray(new String[stateIds.size()]);	}	public void removeState(final String id) {		if (id == null) {			throw new NullPointerException("Cannot remove a null id"); //$NON-NLS-1$		}		if (states != null) {			states.remove(id);			if (states.isEmpty()) {				states = null;			}		}	}}