SvgElementFactory.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Xml;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;

namespace Svg
{
    /// <summary>
    /// Provides the methods required in order to parse and create <see cref="SvgElement"/> instances from XML.
    /// </summary>
    internal class SvgElementFactory
    {
        private static List<ElementInfo> availableElements;

        /// <summary>
        /// Gets a list of available types that can be used when creating an <see cref="SvgElement"/>.
        /// </summary>
        private static List<ElementInfo> AvailableElements
        {
            get
            {
                if (availableElements == null)
                {
                    var svgTypes = from t in typeof(SvgDocument).Assembly.GetExportedTypes()
                                   where t.GetCustomAttributes(typeof(SvgElementAttribute), true).Length > 0
                                   && t.IsSubclassOf(typeof(SvgElement))
                                   select new ElementInfo { ElementName = ((SvgElementAttribute)t.GetCustomAttributes(typeof(SvgElementAttribute), true)[0]).ElementName, ElementType = t };

                    availableElements = svgTypes.ToList();
                }

                return availableElements;
            }
        }

        /// <summary>
        /// Creates an <see cref="SvgDocument"/> from the current node in the specified <see cref="XmlTextReader"/>.
        /// </summary>
        /// <param name="reader">The <see cref="XmlTextReader"/> containing the node to parse into an <see cref="SvgDocument"/>.</param>
        /// <exception cref="ArgumentNullException">The <paramref name="reader"/> parameter cannot be <c>null</c>.</exception>
        /// <exception cref="InvalidOperationException">The CreateDocument method can only be used to parse root &lt;svg&gt; elements.</exception>
        public static SvgDocument CreateDocument(XmlTextReader reader)
        {
            if (reader == null)
            {
                throw new ArgumentNullException("reader");
            }

            if (reader.LocalName != "svg")
            {
                throw new InvalidOperationException("The CreateDocument method can only be used to parse root <svg> elements.");
            }

            return (SvgDocument)CreateElement(reader, true, null);
        }

        /// <summary>
        /// Creates an <see cref="SvgElement"/> from the current node in the specified <see cref="XmlTextReader"/>.
        /// </summary>
        /// <param name="reader">The <see cref="XmlTextReader"/> containing the node to parse into a subclass of <see cref="SvgElement"/>.</param>
        /// <param name="document">The <see cref="SvgDocument"/> that the created element belongs to.</param>
        /// <exception cref="ArgumentNullException">The <paramref name="reader"/> and <paramref name="document"/> parameters cannot be <c>null</c>.</exception>
        public static SvgElement CreateElement(XmlTextReader reader, SvgDocument document)
        {
            if (reader == null)
            {
                throw new ArgumentNullException("reader");