// 
// IconId.cs
//  
// Author:
//       Lluis Sanchez Gual <lluis@novell.com>
// 
// Copyright (c) 2010 Novell, Inc (http://www.novell.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.

using System;

namespace MonoDevelop.Core
{
	[System.Diagnostics.DebuggerDisplay ("{id}")]
	public struct IconId: IEquatable<IconId>
	{
		string id;
		
		public static readonly IconId Null = new IconId (null);
		
		public static IconNameRequestHandler IconNameRequestHandler;

		public IconId (string id)
		{
			this.id = id;
		}

		public bool IsNull {
			get { return id == null; }
		}
		
		public string Name {
			get {
				// If the icon is converted to string, fire the icon request event, to ensure that
				// the icon it represents is loaded.
				if (IconNameRequestHandler != null)
					IconNameRequestHandler (id);
				return id; 
			}
		}

		public static implicit operator IconId (string name)
		{
			return new IconId (name);
		}

		public static implicit operator string (IconId icon)
		{
			return icon.Name;
		}

		public static bool operator == (IconId name1, IconId name2)
		{
			return name1.id == name2.id;
		}

		public static bool operator != (IconId name1, IconId name2)
		{
			return name1.id != name2.id;
		}

		public static bool operator == (IconId name1, string name2)
		{
			return name1.id == name2;
		}

		public static bool operator != (IconId name1, string name2)
		{
			return name1.id != name2;
		}

		public override bool Equals (object obj)
		{
			if (obj == null && !(obj is IconId))
				return false;

			IconId fn = (IconId) obj;
			return id == fn.id;
		}

		public override int GetHashCode ( )
		{
			if (id == null)
				return 0;
			return id.GetHashCode ();
		}

		public override string ToString ()
		{
			return Name;
		}

		bool IEquatable<IconId>.Equals (IconId other)
		{
			return this.id == other.id;
		}
	}
	
	public delegate void IconNameRequestHandler (string id);
}

