/*******************************************************************************
 * Copyright (c) 2005, 2006 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.jface.bindings.keys;


/**
 * <p>
 * A factory class for <code>ILookup</code> instances. This factory can be
 * used to retrieve instances of look-ups defined by this package. It also
 * allows you to define your own look-up for use in the classes.
 * </p>
 * 
 * @since 3.1
 */
public final class KeyLookupFactory {

	/**
	 * The SWT key look-up defined by this package.
	 */
	private static final SWTKeyLookup SWT_KEY_LOOKUP = new SWTKeyLookup();

	/**
	 * The instance that should be used by <code>KeyStroke</code> in
	 * converting string representations to instances.
	 */
	private static IKeyLookup defaultLookup = SWT_KEY_LOOKUP;

	/**
	 * Provides an instance of <code>SWTKeyLookup</code>.
	 * 
	 * @return The SWT look-up table for key stroke format information; never
	 *         <code>null</code>.
	 */
	public static final IKeyLookup getSWTKeyLookup() {
		return SWT_KEY_LOOKUP;
	}

	/**
	 * An accessor for the current default look-up.
	 * 
	 * @return The default look-up; never <code>null</code>.
	 */
	public static final IKeyLookup getDefault() {
		return defaultLookup;
	}

	/**
	 * Sets the default look-up.
	 * 
	 * @param defaultLookup
	 *            the default look-up. Must not be <code>null</code>.
	 */
	public static final void setDefault(final IKeyLookup defaultLookup) {
		if (defaultLookup == null) {
			throw new NullPointerException("The look-up must not be null"); //$NON-NLS-1$
		}

		KeyLookupFactory.defaultLookup = defaultLookup;
	}

	/**
	 * This class should not be instantiated.
	 */
	private KeyLookupFactory() {
		// Not to be constructred.
	}
}