/*
  	 Uiml.Net: a Uiml.Net renderer (http://lumumba.uhasselt.be/kris/research/uiml.net/)
   
	 Copyright (C) 2003  Kris Luyten (kris.luyten@uhasselt.be)
	                     Expertise Centre for Digital Media (http://edm.uhasselt.be)
								Hasselt University

	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU Lesser General Public License
	as published by the Free Software Foundation; either version 2.1
	of	the License, or (at your option) any later version.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/

namespace Uiml.Executing
{
	using Uiml;
	
	using System;
	using System.Xml;
	using System.Collections;
	using System.IO;

	
	public class Op :  IExecutable, IUimlElement
	{
		private ArrayList m_children;
        private string m_type; // type of the OP => && || == != < >
		private Part m_top;

		public Op()
		{
			m_children = new ArrayList();
		}

		public Op(XmlNode xmlNode, Part partTop) : this()
        {
            m_top = partTop;
			Process(xmlNode);
		}

		public void Process(XmlNode n)
		{
			if(n.Name == OP)
			{
                ReadAttributes(n);

				if(n.HasChildNodes)
				{
					XmlNodeList xnl = n.ChildNodes;
					for(int i=0; i<xnl.Count; i++)
					{
						switch(xnl[i].Name)
						{
							case CONSTANT:
								m_children.Add(new Constant(xnl[i]));
								break;
							case PROPERTY:
								m_children.Add(new Property(xnl[i]));
								break;
							case REFERENCE:
								m_children.Add(new Reference(xnl[i]));
								break;
							case CALL:
								m_children.Add(new Call(xnl[i]));
								break;
							case OP:
								m_children.Add(new Op(xnl[i], m_top));
								break;
							case EVENT:
								m_children.Add(new Event(xnl[i]));
								break;
						}
					}
				}
			}
		}

        public void ReadAttributes(XmlNode node)
        {
            XmlAttributeCollection xac = node.Attributes;

            if (xac.GetNamedItem(NAME) != null)
                Type = xac.GetNamedItem(NAME).Value;
            else
                throw new AttributeException("An <op> needs an attribute called 'name'");
        }

		public void GetEvents(ArrayList al)
		{
            for (int i = 0; i < Children.Count; i++)
            {
                if (Children[i] is Op)
                    ((Op)Children[i]).GetEvents(al);
                else
                    al.Add(Children[i]);
            }
		}

        public Object Execute()
		{
			return null;
		}

		public Object Execute(Uiml.Rendering.IRenderer renderer)
		{
			return Execute();
		}

		public ArrayList Children
		{
			get { return m_children; }
		}

        public string Type
        {
            get { return m_type; }
            set { m_type = value; }
        }

        public bool CheckCondition()
        {
            return true;
            //throw new Exception("The method or operation is not implemented.");
        }


		public const string ACTION      = "action";
		public const string PROPERTY    = "property";
		public const string CALL        = "call";
		public const string OP          = "op";
		public const string EVENT       = "event";
		public const string REFERENCE   = "reference";		
		public const string CONSTANT    = "constant";
        public const string AND         = "and";            // &&
        public const string OR          = "or";             // ||
        public const string EQUAL       = "equal";          // ==
        public const string NOTEQUAL    = "notequal";       // !=
        public const string LESSTHAN    = "lessthan";       // <
        public const string GREATERTHAN = "greatherthan";   // >
        public const string NAME        = "name";
    }
	
}