/*******************************************************************************
 * Copyright (c) 2004, 2015 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;

import org.eclipse.core.commands.ParameterizedCommand;
import org.eclipse.jface.bindings.Binding;
import org.eclipse.jface.bindings.TriggerSequence;

/**
 * <p>
 * A keyboard shortcut. This is a binding between some keyboard input and the
 * triggering of a command. This object is immutable.
 * </p>
 *
 * @since 3.1
 */
public final class KeyBinding extends Binding {

	/**
	 * The key sequence which triggers this binding. This sequence is never
	 * <code>null</code>.
	 */
	private final KeySequence keySequence;

	/**
	 * Constructs a new instance of <code>KeyBinding</code>.
	 *
	 * @param keySequence
	 *            The key sequence which should trigger this binding. This value
	 *            must not be <code>null</code>. It also must be a complete,
	 *            non-empty key sequence.
	 * @param command
	 *            The parameterized command to which this binding applies; this
	 *            value may be <code>null</code> if the binding is meant to
	 *            "unbind" a previously defined binding.
	 * @param schemeId
	 *            The scheme to which this binding belongs; this value must not
	 *            be <code>null</code>.
	 * @param contextId
	 *            The context to which this binding applies; this value must not
	 *            be <code>null</code>.
	 * @param locale
	 *            The locale to which this binding applies; this value may be
	 *            <code>null</code> if it applies to all locales.
	 * @param platform
	 *            The platform to which this binding applies; this value may be
	 *            <code>null</code> if it applies to all platforms.
	 * @param windowManager
	 *            The window manager to which this binding applies; this value
	 *            may be <code>null</code> if it applies to all window
	 *            managers. This value is currently ignored.
	 * @param type
	 *            The type of binding. This should be either <code>SYSTEM</code>
	 *            or <code>USER</code>.
	 */
	public KeyBinding(final KeySequence keySequence,
			final ParameterizedCommand command, final String schemeId,
			final String contextId, final String locale, final String platform,
			final String windowManager, final int type) {
		super(command, schemeId, contextId, locale, platform, windowManager,
				type);

		if (keySequence == null) {
			throw new NullPointerException("The key sequence cannot be null"); //$NON-NLS-1$
		}

		if (!keySequence.isComplete()) {
			throw new IllegalArgumentException(
					"Cannot bind to an incomplete key sequence"); //$NON-NLS-1$
		}

		if (keySequence.isEmpty()) {
			throw new IllegalArgumentException(
					"Cannot bind to an empty key sequence"); //$NON-NLS-1$
		}

		this.keySequence = keySequence;
	}

	/**
	 * Returns the key sequence which triggers this binding. The key sequence
	 * will not be <code>null</code>, empty or incomplete.
	 *
	 * @return The key sequence; never <code>null</code>.
	 */
	public final KeySequence getKeySequence() {
		return keySequence;
	}

	@Override
	public TriggerSequence getTriggerSequence() {
		return getKeySequence();
	}
}