source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Charts/LineGraph.cs @ 13834

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Globalization;
using System.Linq;
using System.Windows;
using System.Windows.Media;
using Microsoft.Research.DynamicDataDisplay.Charts;
using Microsoft.Research.DynamicDataDisplay.Charts.Legend_items;
using Microsoft.Research.DynamicDataDisplay.DataSources;
using Microsoft.Research.DynamicDataDisplay.Filters;
using System.Windows.Shapes;


namespace Microsoft.Research.DynamicDataDisplay
{
  /// <summary>
  /// Represents a series of points connected by one polyline.
  /// </summary>
  public class LineGraph : PointsGraphBase
  {
    static LineGraph()
    {
      Type thisType = typeof(LineGraph);

      Legend.DescriptionProperty.OverrideMetadata(thisType, new FrameworkPropertyMetadata("LineGraph"));
      Legend.LegendItemsBuilderProperty.OverrideMetadata(thisType, new FrameworkPropertyMetadata(new LegendItemsBuilder(DefaultLegendItemsBuilder)));
    }

    private static IEnumerable<FrameworkElement> DefaultLegendItemsBuilder(IPlotterElement plotterElement)
    {
      LineGraph lineGraph = (LineGraph)plotterElement;

      Line line = new Line { X1 = 0, Y1 = 10, X2 = 20, Y2 = 0, Stretch = Stretch.Fill, DataContext = lineGraph };
      line.SetBinding(Line.StrokeProperty, "Stroke");
      line.SetBinding(Line.StrokeThicknessProperty, "StrokeThickness");
      Legend.SetVisualContent(lineGraph, line);

      var legendItem = LegendItemsHelper.BuildDefaultLegendItem(lineGraph);
      yield return legendItem;
    }

    private readonly FilterCollection filters = new FilterCollection();

    /// <summary>
    /// Initializes a new instance of the <see cref="LineGraph"/> class.
    /// </summary>
    public LineGraph()
    {
      ManualTranslate = true;

      filters.CollectionChanged += filters_CollectionChanged;
    }

    private void filters_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
      filteredPoints = null;
      Update();
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="LineGraph"/> class.
    /// </summary>
    /// <param name="pointSource">The point source.</param>
    public LineGraph(IPointDataSource pointSource)
      : this()
    {
      DataSource = pointSource;
    }

    /// <summary>Provides access to filters collection</summary>
    public FilterCollection Filters
    {
      get { return filters; }
    }

    #region Pen

    /// <summary>
    /// Gets or sets the brush, using which polyline is plotted.
    /// </summary>
    /// <value>The line brush.</value>
    public Brush Stroke
    {
      get { return LinePen.Brush; }
      set
      {
        if (LinePen.Brush != value)
        {
          if (!LinePen.IsSealed)
          {
            LinePen.Brush = value;
            InvalidateVisual();
          }
          else
          {
            Pen pen = LinePen.Clone();
            pen.Brush = value;
            LinePen = pen;
          }

          RaisePropertyChanged("Stroke");
        }
      }
    }

    /// <summary>
    /// Gets or sets the line thickness.
    /// </summary>
    /// <value>The line thickness.</value>
    public double StrokeThickness
    {
      get { return LinePen.Thickness; }
      set
      {
        if (LinePen.Thickness != value)
        {
          if (!LinePen.IsSealed)
          {
            LinePen.Thickness = value; InvalidateVisual();
          }
          else
          {
            Pen pen = LinePen.Clone();
            pen.Thickness = value;
            LinePen = pen;
          }

          RaisePropertyChanged("StrokeThickness");
        }
      }
    }

    /// <summary>
    /// Gets or sets the line pen.
    /// </summary>
    /// <value>The line pen.</value>
    [NotNull]
    public Pen LinePen
    {
      get { return (Pen)GetValue(LinePenProperty); }
      set { SetValue(LinePenProperty, value); }
    }

    public static readonly DependencyProperty LinePenProperty =
      DependencyProperty.Register(
      "LinePen",
      typeof(Pen),
      typeof(LineGraph),
      new FrameworkPropertyMetadata(
        new Pen(Brushes.Blue, 1),
        FrameworkPropertyMetadataOptions.AffectsRender
        ),
      OnValidatePen);

    private static bool OnValidatePen(object value)
    {
      return value != null;
    }

    #endregion

    protected override void OnOutputChanged(Rect newRect, Rect oldRect)
    {
      filteredPoints = null;
      base.OnOutputChanged(newRect, oldRect);
    }

    protected override void OnDataChanged()
    {
      filteredPoints = null;
      base.OnDataChanged();
    }

    protected override void OnDataSourceChanged(DependencyPropertyChangedEventArgs args)
    {
      filteredPoints = null;
      base.OnDataSourceChanged(args);
    }

    protected override void OnVisibleChanged(DataRect newRect, DataRect oldRect)
    {
      if (newRect.Size != oldRect.Size)
      {
        filteredPoints = null;
      }

      base.OnVisibleChanged(newRect, oldRect);
    }

    private FakePointList filteredPoints;
    protected FakePointList FilteredPoints
    {
      get { return filteredPoints; }
      set { filteredPoints = value; }
    }

    protected override void UpdateCore()
    {
      if (DataSource == null) return;
      if (Plotter == null) return;

      Rect output = Viewport.Output;
      var transform = GetTransform();

      if (filteredPoints == null || !(transform.DataTransform is IdentityTransform))
      {
        IEnumerable<Point> points = GetPoints();

        var bounds = BoundsHelper.GetViewportBounds(points, transform.DataTransform);
        Viewport2D.SetContentBounds(this, bounds);

        // getting new value of transform as it could change after calculating and setting content bounds.
        transform = GetTransform();
        List<Point> transformedPoints = transform.DataToScreenAsList(points);

        // Analysis and filtering of unnecessary points
        filteredPoints = new FakePointList(FilterPoints(transformedPoints),
          output.Left, output.Right);

        if (ProvideVisiblePoints)
        {
          List<Point> viewportPointsList = new List<Point>(transformedPoints.Count);
          if (transform.DataTransform is IdentityTransform)
          {
            viewportPointsList.AddRange(points);
          }
          else
          {
            var viewportPoints = points.DataToViewport(transform.DataTransform);
            viewportPointsList.AddRange(viewportPoints);
          }

          SetVisiblePoints(this, new ReadOnlyCollection<Point>(viewportPointsList));
        }

        Offset = new Vector();
      }
      else
      {
        double left = output.Left;
        double right = output.Right;
        double shift = Offset.X;
        left -= shift;
        right -= shift;

        filteredPoints.SetXBorders(left, right);
      }
    }

    StreamGeometry streamGeometry = new StreamGeometry();
    protected override void OnRenderCore(DrawingContext dc, RenderState state)
    {
      if (DataSource == null) return;

      if (filteredPoints.HasPoints)
      {

        using (StreamGeometryContext context = streamGeometry.Open())
        {
          context.BeginFigure(filteredPoints.StartPoint, false, false);
          context.PolyLineTo(filteredPoints, true, smoothLinesJoin);
        }

        Brush brush = null;
        Pen pen = LinePen;

        bool isTranslated = IsTranslated;
        if (isTranslated)
        {
          dc.PushTransform(new TranslateTransform(Offset.X, Offset.Y));
        }
        dc.DrawGeometry(brush, pen, streamGeometry);
        if (isTranslated)
        {
          dc.Pop();
        }

#if __DEBUG
        FormattedText text = new FormattedText(filteredPoints.Count.ToString(),
          CultureInfo.InvariantCulture, FlowDirection.LeftToRight,
          new Typeface("Arial"), 12, Brushes.Black);
        dc.DrawText(text, Viewport.Output.GetCenter());
#endif
      }
    }

    private bool filteringEnabled = true;
    public bool FilteringEnabled
    {
      get { return filteringEnabled; }
      set
      {
        if (filteringEnabled != value)
        {
          filteringEnabled = value;
          filteredPoints = null;
          Update();
        }
      }
    }

    private bool smoothLinesJoin = true;
    public bool SmoothLinesJoin
    {
      get { return smoothLinesJoin; }
      set
      {
        smoothLinesJoin = value;
        Update();
      }
    }

    private List<Point> FilterPoints(List<Point> points)
    {
      if (!filteringEnabled)
        return points;

      var filteredPoints = filters.Filter(points, Viewport.Output);

      return filteredPoints;
    }
  }
}