source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/ViewportConstraints/ScaleInjectionConstraint.cs @ 12503

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

namespace Microsoft.Research.DynamicDataDisplay.ViewportConstraints
{
  public class ScaleInjectionConstraint : ViewportConstraint
  {
    private Viewport2D parentViewport;
    public ScaleInjectionConstraint(Viewport2D parentViewport)
    {
      if (parentViewport == null)
        throw new ArgumentNullException("parentViewport");

      this.parentViewport = parentViewport;
      parentViewport.PropertyChanged += parentViewport_PropertyChanged;
    }

    private void parentViewport_PropertyChanged(object sender, ExtendedPropertyChangedEventArgs e)
    {
      if (e.PropertyName == "Visible")
      {
        RaiseChanged();
      }
    }

    public void SetHorizontalTransform(double parentMin, double childMin, double parentMax, double childMax)
    {
      xScale = (childMax - childMin) / (parentMax - parentMin);
      xShift = childMin - parentMin;
    }

    public void SetVerticalTransform(double parentMin, double childMin, double parentMax, double childMax)
    {
      yScale = (childMax - childMin) / (parentMax - parentMin);
      yShift = childMin - parentMin;
    }

    private double xShift = 0;
    private double xScale = 1;
    private double yShift = 0;
    private double yScale = 1;

    public override DataRect Apply(DataRect previousDataRect, DataRect proposedDataRect, Viewport2D viewport)
    {
      DataRect parentVisible = parentViewport.Visible;

      double xmin = parentVisible.XMin * xScale + xShift;
      double xmax = parentVisible.XMax * xScale + xShift;
      double ymin = parentVisible.YMin * yScale + yShift;
      double ymax = parentVisible.YMax * yScale + yShift;

      return DataRect.Create(xmin, ymin, xmax, ymax);
    }
  }
}