WPF Alien Sokoban

#region File and License Information
/*
<File>
	<Copyright>Copyright © 2007, Daniel Vaughan. All rights reserved.</Copyright>
	<License see="prj:///Documentation/License.txt"/>
	<Owner Name="Daniel Vaughan" Email="dbvaughan@gmail.com"/>
	<CreationDate>2008-06-09 11:55:50Z</CreationDate>
	<LastSubmissionDate>$Date: $</LastSubmissionDate>
	<Version>$Revision: $</Version>
</File>
*/
#endregion

using System;

namespace Orpius.Sokoban.Commands
{
	/// <summary>
	/// Performs a move with the <see cref="Level"/>'s <see cref="Actor"/>
	/// instance. A move is a single step.
	/// </summary>
	public class MoveCommand : CommandBase
	{
		Level level;

		/// <summary>
		/// Gets or sets the direction for the <see cref="Move"/>.
		/// </summary>
		/// <value>The direction that the move will take place.</value>
		public Direction Direction
		{
			get;
			private set;
		}

		/// <summary>
		/// Initializes a new instance of the <see cref="MoveCommand"/> class.
		/// </summary>
		/// <param name="level">The level where the move will take place.</param>
		/// <param name="direction">The direction of the move.</param>
		public MoveCommand(Level level, Direction direction)
		{
			if (level == null)
			{
				throw new ArgumentNullException("level");
			}
			Direction = direction;
			this.level = level;
		}

		/// <summary>
		/// Executes this command.
		/// Move the <see cref="Actor"/> one step
		/// in the predefined <see cref="Direction"/>.
		/// </summary>
		public override void Execute()
		{
			Move move = new Move(Direction);
			level.Actor.DoMove(move);
		}

		/// <summary>
		/// Undoes that which was performed with <see cref="Execute"/>.
		/// Steps back to the original location.
		/// </summary>
		public override void Undo()
		{
			level.Actor.UndoMove();
		}

		/// <summary>
		/// Redoes this command after it has been undone. <see cref="Undo"/>.
		/// </summary>
		public override void Redo()
		{
			Execute();
		}
	}
}