source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/ViewportConstraints/DomainConstraint.cs @ 13788

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;
    }
  }
}