/src/net45/amarok.presentation/Presentation/Converter/Object/IndexToObjectConverter.cs

#region Copyright (c) 07/18/2012, Olaf Kober <amarok.projects@gmail.com>

//================================================================================

//	Permission is hereby granted, free of charge, to any person obtaining a copy

//	of this software and associated documentation files (the "Software"), to deal

//	in the Software without restriction, including without limitation the rights

//	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

//	copies of the Software, and to permit persons to whom the Software is

//	furnished to do so, subject to the following conditions:

//

//	The above copyright notice and this permission notice shall be included in

//	all copies or substantial portions of the Software.

//

//	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

//	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

//	THE SOFTWARE.

//================================================================================

#endregion



using System;

using System.Collections.Generic;

using System.Globalization;

using System.Windows;

using System.Windows.Data;

using System.Windows.Markup;





namespace Amarok.Presentation

{

	/// <summary>

	/// Converts the given Int32 to the Object at the index position in the set Values collection.

	/// 

	/// :: Convert

	/// 0..n          ...  Object at the Index position

	/// Out-Of-Range  ...  DefaultValue

	/// 

	/// :: ConvertBack

	/// equal to Object at Index position   ...  Index

	/// not equal to any Object             ...  DependencyProperty.Unset

	/// </summary>

	[ContentProperty("Values")]

	[ValueConversion(typeof(Int32), typeof(Object))]

	public sealed class IndexToObjectConverter : ValueConverter<Int32, Object>

	{

		/// <summary>

		/// Gets or sets a collection of Objects. The Convert() method uses this collection to return the Object 

		/// at the index that is represented by the supplied Int32 value. Defaults to an empty list.

		/// </summary>

		public List<Object> Values

		{

			get;

			set;

		}



		/// <summary>

		/// Gets or sets the Object that is returned by the Convert() method when the supplied Int32 value 

		/// is outside of the list collection bounds. Defaults to DependencyProperty.UnsetValue.

		/// </summary>

		public Object DefaultValue

		{

			get;

			set;

		}



		/// <summary>

		/// Gets or sets the Object that is returned by the ConvertBack() method when the supplied Object is not 

		/// equal to any of the Objects stored in the Values collection. Defaults to DependencyProperty.UnsetValue.

		/// </summary>

		public Object DefaultIndex

		{

			get;

			set;

		}





		/// <summary>

		/// Initializes a new instance.

		/// </summary>

		public IndexToObjectConverter()

		{

			this.Values = new List<Object>();

			this.DefaultValue = DependencyProperty.UnsetValue;

			this.DefaultIndex = DependencyProperty.UnsetValue;

		}





		/// <summary>

		/// </summary>

		protected override Object OnConvert(Int32 value, Type targetType, Object parameter, CultureInfo culture)

		{

			if (this.Values == null)

				return this.DefaultValue;

			if (value < 0 || value >= this.Values.Count)

				return this.DefaultValue;



			return this.Values[value];

		}



		/// <summary>

		/// </summary>

		protected override Object OnConvertBack(Object value, Type targetType, Object parameter, CultureInfo culture)

		{

			if (this.Values == null)

				return this.DefaultIndex;



			for (Int32 i = 0; i < this.Values.Count; i++)

			{

				if (Object.Equals(this.Values[i], value))

					return i;

			}



			return this.DefaultIndex;

		}



	}

}