SvgFitToViewBox.cs :  » GUI » SharpVectorGraphics » SharpVectors » Dom » Svg » C# / CSharp Open Source

using System;
using System.Xml;

using SharpVectors.Dom.Css;


namespace SharpVectors.Dom.Svg{
  public class SvgFitToViewBox
  {
    public SvgFitToViewBox(SvgElement ownerElement)
    {
      this.ownerElement = ownerElement;
      this.ownerElement.attributeChangeHandler += new NodeChangeHandler(AttributeChange);
    }

    #region Private fields
    protected SvgElement ownerElement;
    #endregion

    #region Update handling
    private void AttributeChange(Object src, XmlNodeChangedEventArgs args)
    {
      XmlAttribute attribute = src as XmlAttribute;

      if(attribute.NamespaceURI.Length == 0)
      {
        switch(attribute.LocalName)
        {
          case "viewBox":
            viewBox = null;
            break;
          case "preserveAspectRatio":
            preserveAspectRatio = null;
            break;
        }
      }
    }
    #endregion

    private ISvgAnimatedRect viewBox;
    public ISvgAnimatedRect ViewBox
    {
      get
      {
        if(viewBox == null)
        {
          string attr = ownerElement.GetAttribute("viewBox").Trim();
          if(attr.Length == 0)
          {
            double x = 0;
            double y = 0;
            double width = 0;
            double height = 0;
            if(ownerElement is SvgSvgElement)
            {
              SvgSvgElement svgSvgElm = ownerElement as SvgSvgElement;

              x = svgSvgElm.X.AnimVal.Value;
              y = svgSvgElm.Y.AnimVal.Value; 
              width = svgSvgElm.Width.AnimVal.Value;
              height = svgSvgElm.Height.AnimVal.Value;
            }
            viewBox = new SvgAnimatedRect(new SvgRect(x, y, width, height));
          }
          else
          {
            viewBox = new SvgAnimatedRect(attr);
          }
        }
        return viewBox;
      }
    }

    private ISvgAnimatedPreserveAspectRatio preserveAspectRatio;
    public ISvgAnimatedPreserveAspectRatio PreserveAspectRatio
    {
      get
      {
        if(preserveAspectRatio == null)
        {
          preserveAspectRatio = new SvgAnimatedPreserveAspectRatio(ownerElement.GetAttribute("preserveAspectRatio"), ownerElement);
        }
        return preserveAspectRatio;
      }
    }

  }
}