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

using System;
using System.Xml;
using System.Collections;
using System.Drawing;

namespace SharpVectors.Dom.Svg{
  public enum SvgSpreadMethod{
    Pad, 
    Reflect, 
    Repeat
  }

  public class SvgGradientElement : SvgStyleableElement, ISvgGradientElement
  {
    internal SvgGradientElement(string prefix, string localname, string ns, SvgDocument doc)
      : base(prefix, localname, ns, doc)
    {
      svgURIReference = new SvgURIReference(this);
      svgExternalResourcesRequired = new SvgExternalResourcesRequired(this);
    }

    #region Implementation of ISvgGradientElement
    private ISvgAnimatedEnumeration gradientUnits;
    public ISvgAnimatedEnumeration GradientUnits
    {
      get
      {
        if(!HasAttribute("gradientUnits") && ReferencedElement != null)
        {
          return ReferencedElement.GradientUnits;
        }
        else
        {
          if(gradientUnits == null)
          {
            SvgUnitType gradUnit;
            switch(GetAttribute("gradientUnits"))
            {
              case "userSpaceOnUse":
                gradUnit = SvgUnitType.UserSpaceOnUse;
                break;
              default:
                gradUnit = SvgUnitType.ObjectBoundingBox;
                break;
            }

            gradientUnits = new SvgAnimatedEnumeration((ushort)gradUnit);
          }
          return gradientUnits;
        }
      }
    }

    private ISvgAnimatedTransformList gradientTransform;
    public ISvgAnimatedTransformList GradientTransform
    {
      get
      {
        if(!HasAttribute("gradientTransform") && ReferencedElement != null)
        {
          return ReferencedElement.GradientTransform;
        }
        else
        {
          if(gradientTransform == null)
          {
            gradientTransform = new SvgAnimatedTransformList(GetAttribute("gradientTransform"));
          }
          return gradientTransform;
        }
      }
    }

    private ISvgAnimatedEnumeration spreadMethod;
    public ISvgAnimatedEnumeration SpreadMethod
    {
      get
      {
        if(!HasAttribute("spreadMethod") && ReferencedElement != null)
        {
          return ReferencedElement.SpreadMethod;
        }
        else
        {
          if(spreadMethod == null)
          {
            SvgSpreadMethod spreadMeth;
            switch(GetAttribute("spreadMethod"))
            {
              case "reflect":
                spreadMeth = SvgSpreadMethod.Reflect;
                break;
              case "repeat":
                spreadMeth = SvgSpreadMethod.Repeat;
                break;
              default:
                spreadMeth = SvgSpreadMethod.Pad;
                break;
            }

            spreadMethod = new SvgAnimatedEnumeration((ushort)spreadMeth);
          }
          return spreadMethod;
        }
      }
    }

    #endregion

    #region Implementation of ISvgURIReference
    private SvgURIReference svgURIReference;
    public ISvgAnimatedString Href
    {
      get
      {
        return svgURIReference.Href;
      }
    }

    public SvgGradientElement ReferencedElement
    {
      get
      {
        return svgURIReference.ReferencedNode as SvgGradientElement;
      }
    }
    #endregion

    #region Implementation of ISvgExternalResourcesRequired
    private SvgExternalResourcesRequired svgExternalResourcesRequired;
    public ISvgAnimatedBoolean ExternalResourcesRequired
    {
      get
      {
        return svgExternalResourcesRequired.ExternalResourcesRequired;
      }
    }
    #endregion

    #region Other public fields
    public XmlNodeList Stops
    {
      get
      {
        XmlNodeList stops = SelectNodes("svg:stop", OwnerDocument.NamespaceManager);
        if(stops.Count > 0)
        {
          return stops;
        }
        else
        {
          // check any eventually referenced gradient
          if(ReferencedElement == null)
          {
            // return an empty list
            return stops;
          }
          else
          {
            return ReferencedElement.Stops;
          }
        }
      }
    }
    #endregion

    #region Update handling
    public override void HandleAttributeChange(XmlAttribute attribute)
    {
      if(attribute.NamespaceURI.Length == 0)
      {
        switch(attribute.LocalName)
        {
          case "gradientUnits":
            gradientUnits = null;
            break;
          case "gradientTransform":
            gradientTransform = null;
            break;
          case "spreadMethod":
            spreadMethod = null;
            break;
        }
      }
      base.HandleAttributeChange(attribute);
    }
    #endregion
  }
}