using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Windows;

using Microsoft.Research.DynamicDataDisplay.Common;



namespace Microsoft.Research.DynamicDataDisplay.ViewportConstraints

{

	/// <summary>

	/// Represents a constraint which returns data rectangle, intersected with specified data domain.

	/// </summary>

	public class DomainConstraint : ViewportConstraint

	{

		/// <summary>

		/// Initializes a new instance of the <see cref="DomainConstraint"/> class.

		/// </summary>

		public DomainConstraint() { }



		/// <summary>

		/// Initializes a new instance of the <see cref="DomainConstraint"/> class with given domain property.

		/// </summary>

		/// <param name="domain">The domain.</param>

		public DomainConstraint(DataRect domain)

		{

			this.Domain = domain;

		}



		private DataRect domain = new DataRect(-1, -1, 2, 2);

		/// <summary>

		/// Gets or sets the domain.

		/// </summary>

		/// <value>The domain.</value>

		public DataRect Domain

		{

			get { return domain; }

			set

			{

				if (domain != value)

				{

					domain = value;

					RaiseChanged();

				}

			}

		}



		/// <summary>

		/// Applies the specified old data rect.

		/// </summary>

		/// <param name="oldDataRect">The old data rect.</param>

		/// <param name="newDataRect">The new data rect.</param>

		/// <param name="viewport">The viewport.</param>

		/// <returns></returns>

		public override DataRect Apply(DataRect oldDataRect, DataRect newDataRect, Viewport2D viewport)

		{

			DataRect res = domain;

			if (domain.IsEmpty)

			{

				res = newDataRect;

			}

			else if (newDataRect.IntersectsWith(domain))

			{

				res = newDataRect;

				if (newDataRect.Size == oldDataRect.Size)

				{

					if (res.XMin < domain.XMin) res.XMin = domain.XMin;

					if (res.YMin < domain.YMin) res.YMin = domain.YMin;

					if (res.XMax > domain.XMax) res.XMin += domain.XMax - res.XMax;

					if (res.YMax > domain.YMax) res.YMin += domain.YMax - res.YMax;

				}

				else

				{

					res = DataRect.Intersect(newDataRect, domain);

				}

			}



			return res;

		}

	}

}