source: branches/HeuristicLab.Problems.GrammaticalOptimization/DynamicDataDisplay/Viewport2DExtensions.cs @ 14161

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using Microsoft.Research.DynamicDataDisplay.Common.UndoSystem;

namespace Microsoft.Research.DynamicDataDisplay
{
  public static class Viewport2DExtensions
  {
    public static void Zoom(this Viewport2D viewport, double factor)
    {
      DataRect visible = viewport.Visible;
      DataRect oldVisible = visible;
      Point center = visible.GetCenter();
      Vector halfSize = new Vector(visible.Width * factor / 2, visible.Height * factor / 2);

      viewport.SetChangeType(ChangeType.Zoom);
      viewport.Visible = new DataRect(center - halfSize, center + halfSize);
      viewport.SetChangeType();

      viewport.Plotter.UndoProvider.AddAction(new DependencyPropertyChangedUndoAction(viewport, Viewport2D.VisibleProperty, oldVisible, visible));
    }
  }
}