source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Charts/Shapes/ViewportLine.cs @ 12503

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Media;
using System.Windows;

namespace Microsoft.Research.DynamicDataDisplay.Charts.Shapes
{
  /// <summary>
  /// Represents a line in viewport space, coming through given points.
  /// </summary>
  public class ViewportLine : ViewportShape
  {
    private LineGeometry lineGeometry = new LineGeometry();

    /// <summary>
    /// Initializes a new instance of the <see cref="ViewportLine"/> class.
    /// </summary>
    public ViewportLine() { }

    #region Properties

    #region Point1 property

    /// <summary>
    /// Gets or sets the first point. It is a DependencyProperty.
    /// </summary>
    /// <value>The point1.</value>
    public Point Point1
    {
      get { return (Point)GetValue(Point1Property); }
      set { SetValue(Point1Property, value); }
    }

    public static readonly DependencyProperty Point1Property = DependencyProperty.Register(
      "Point1",
      typeof(Point),
      typeof(ViewportLine),
      new FrameworkPropertyMetadata(new Point(0, 0), OnPointReplaced));

    private static void OnPointReplaced(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
      ViewportLine owner = (ViewportLine)d;
      owner.UpdateUIRepresentation();
    }

    #endregion

    #region Point2 property

    /// <summary>
    /// Gets or sets the second point. It is a DependencyProperty.
    /// </summary>
    /// <value>The point2.</value>
    public Point Point2
    {
      get { return (Point)GetValue(Point2Property); }
      set { SetValue(Point2Property, value); }
    }

    public static readonly DependencyProperty Point2Property = DependencyProperty.Register(
      "Point2",
      typeof(Point),
      typeof(ViewportLine),
      new FrameworkPropertyMetadata(new Point(1, 1), OnPointReplaced));

    #endregion

    #endregion

    protected override void UpdateUIRepresentationCore()
    {
      base.UpdateUIRepresentationCore();

      Viewport2D viewport = Plotter.Viewport;
      double deltaX = Point1.X - Point2.X;
      double deltaY = Point1.Y - Point2.Y;
      double m = deltaY / deltaX;
      double b = Point1.Y - Point1.X * deltaY / deltaX;

      Func<double, double> func = x => m * x + b;

      double xMin = viewport.Visible.XMin;
      double xMax = viewport.Visible.XMax;
      Point p1 = new Point(xMin, func(xMin)).DataToScreen(viewport.Transform);
      Point p2 = new Point(xMax, func(xMax)).DataToScreen(viewport.Transform);

      lineGeometry.StartPoint = p1;
      lineGeometry.EndPoint = p2;
    }

    protected override Geometry DefiningGeometry
    {
      get { return lineGeometry; }
    }
  }
}