Simple Timer Class

#region WatiN Copyright (C) 2006-2011 Jeroen van Menen

//Copyright 2006-2011 Jeroen van Menen
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

#endregion Copyright

using System;
using System.Diagnostics;

namespace WatiN.Core.UtilityClasses
{
    /// <summary>
    /// This class provides a simple way to handle loops that have to time out after 
    /// a specified number of seconds.
    /// </summary>
    /// <example>
    /// This is an example how you could use this class in your code.
    /// <code>
    /// // timer should elapse after 30 seconds
    /// SimpleTimer timeoutTimer = new SimpleTimer(30);
    ///
    /// do
    /// {
    ///   // Your check logic goes here
    ///   
    ///   // wait 200 miliseconds
    ///   Thread.Sleep(200);
    /// } while (!timeoutTimer.Elapsed);
    /// </code>
    /// </example>
    public class SimpleTimer
    {
        public readonly TimeSpan timeout;
        public Stopwatch stopwatch;

        /// <summary>
        /// Initializes a new instance of the <see cref="SimpleTimer"/> class.
        /// </summary>
        /// <param name="timeout">The timeout.</param>
        /// <exception cref="ArgumentOutOfRangeException">Thrown if <paramref name="timeout"/> is negative.</exception>
        public SimpleTimer(TimeSpan timeout)
        {
            if (timeout.Ticks < 0)
                throw new ArgumentOutOfRangeException("timeout", timeout, "Should be equal are greater then zero.");

            this.timeout = timeout;

            stopwatch = Stopwatch.StartNew();
        }

        /// <summary>
        /// Gets a value indicating whether this <see cref="SimpleTimer"/> is elapsed.
        /// </summary>
        /// <value><c>true</c> if elapsed; otherwise, <c>false</c>.</value>
        public bool Elapsed
        {
            get { return stopwatch.Elapsed >= timeout; }
        }

        /// <summary>
        /// The amount of time after which this timer times out. The time out can only be
        /// set through the constructor.
        /// </summary>
        public TimeSpan Timeout
        {
            get { return timeout; }
        }
    }
}