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

using System;
using System.Xml;
using SharpVectors.Text;
using SharpVectors.Dom.Svg.Rendering;

namespace SharpVectors.Dom.Svg{
  /// <summary>
  /// The SvgSwitchElement interface corresponds to the 'switch' 
  /// element. 
  /// </summary>
  public class SvgSwitchElement : SvgTransformableElement , ISvgSwitchElement, IContainerElement
  {
    #region Constructors
    internal SvgSwitchElement(string prefix, string localname, string ns, SvgDocument doc) : base(prefix, localname, ns, doc) 
    {
      svgExternalResourcesRequired = new SvgExternalResourcesRequired(this);
      svgTests = new SvgTests(this);
    }

    #endregion

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

    #region Implementation of ISvgTests
    private SvgTests svgTests;
    public ISvgStringList RequiredFeatures
    {
      get { return svgTests.RequiredFeatures; }
    }

    public ISvgStringList RequiredExtensions
    {
      get { return svgTests.RequiredExtensions; }
    }

    public ISvgStringList SystemLanguage
    {
      get { return svgTests.SystemLanguage; }
    }

    public bool HasExtension(string extension)
    {
      return svgTests.HasExtension(extension);
    }
        #endregion

    #region Private methods
    private bool passesAllTest(ISvgTests element)
    {
      SvgDocument ownerDocument = ((SvgElement)element).OwnerDocument;
      if(element.RequiredFeatures.NumberOfItems>0)
      {
        foreach(string req in (SvgStringList)element.RequiredFeatures)
        {
          if(!ownerDocument.Supports(req, String.Empty)) return false;
        }
      }

      if(element.RequiredExtensions.NumberOfItems>0)
      {
        foreach(string req in (SvgStringList)element.RequiredExtensions)
        {
          if(!ownerDocument.Supports(req, String.Empty)) return false;
        }
      }
      if(element.SystemLanguage.NumberOfItems>0)
      {
        // TODO: or if one of the languages indicated by user preferences exactly equals a prefix of one of the languages given in the value of this parameter such that the first tag character following the prefix is "-".
        bool found = false;
        string currentLang = System.Globalization.CultureInfo.CurrentCulture.TwoLetterISOLanguageName;

        foreach(string req in (SvgStringList)element.SystemLanguage)
        {
          if(req == currentLang) found = true;
        }
        if(!found) return false;
      }
      return true;
    }
    #endregion

    #region Rendering
    public override void RenderChildren(ISvgRenderer renderer)
    {
      // search through all child elements and find one that passes all tests
      foreach ( XmlNode node in ChildNodes ) 
      {
        SvgElement element = node as SvgElement;
        ISvgTests testsElement = node as ISvgTests;
        if ( element != null && testsElement != null && passesAllTest(testsElement))
        {
          element.Render(renderer);

          // make sure we only render the first element that passes
          break;
        }
      }
    }
    #endregion
  }
}