File: System\Windows\Markup\ParserContext.cs
Web Access
Project: src\src\Microsoft.DotNet.Wpf\src\PresentationFramework\PresentationFramework.csproj (PresentationFramework)
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
//
// Description:
//   class for the main TypeConverterContext object passed to type converters
//
 
using System;
using System.Reflection;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Xml;
using MS.Utility;
using System.Diagnostics;
using MS.Internal.Xaml.Parser;
 
#if PBTCOMPILER
namespace MS.Internal.Markup
#else
using System.Windows;
using System.Security;
using MS.Internal;
 
namespace System.Windows.Markup
#endif
{
#if PBTCOMPILER

    ///<summary>
    ///     The IUriContext interface allows elements (like Frame, PageViewer) and type converters
    ///     (like BitmapImage TypeConverters) a way to ensure that base uri is set on them by the
    ///     parser, codegen for xaml, baml and caml cases.  The elements can then use this base uri
    ///     to navigate.
    ///</summary>
    internal interface IUriContext
    {
        /// <summary>
        ///     Provides the base uri of the current context.
        /// </summary>
        Uri BaseUri
        {
            get;
            set;
        }
    }
 
#endif
 
    /// <summary>
    ///  Provides all the context information required by Parser
    /// </summary>
#if PBTCOMPILER
    internal class ParserContext : IUriContext
#else
    public class ParserContext : IUriContext
#endif
    {
#region Public Methods
 
        ///    <summary>
        ///    Constructor
        ///    </summary>
        public ParserContext()
        {
            Initialize();
        }
 
        // Initialize the ParserContext to a known, default state.  DO NOT wipe out
        // data that may be able to be shared between seperate parses, such as the
        // xamlTypeMapper and the map table.
        internal void Initialize()
        {
            _xmlnsDictionary = null;    // created on its first use
#if !PBTCOMPILER
            _nameScopeStack    = null;
#endif
            _xmlLang        = String.Empty;
            _xmlSpace       = String.Empty;
        }
 
 
#if !PBTCOMPILER
        /// <summary>
        ///    Constructor that takes the XmlParserContext.
        ///    A parserContext object will be built based on this.
        /// </summary>
        /// <param name="xmlParserContext">xmlParserContext to use</param>
 
        public ParserContext(XmlParserContext xmlParserContext)
        {
            if (xmlParserContext == null)
            {
                throw new ArgumentNullException( "xmlParserContext" );
            }
 
            _xmlLang     = xmlParserContext.XmlLang;
 
            TypeConverter typeConverter = TypeDescriptor.GetConverter(typeof(XmlSpace));
            if (typeConverter != null)
                _xmlSpace = (string) typeConverter.ConvertToString(null, TypeConverterHelper.InvariantEnglishUS, xmlParserContext.XmlSpace);
            else
                _xmlSpace = String.Empty;
 
            _xmlnsDictionary = new XmlnsDictionary() ;
 
            if (xmlParserContext.BaseURI != null && xmlParserContext.BaseURI.Length > 0)
            {
                _baseUri = new Uri(xmlParserContext.BaseURI, UriKind.RelativeOrAbsolute);
            }
 
            XmlNamespaceManager xmlnsManager = xmlParserContext.NamespaceManager;
 
            if (null != xmlnsManager)
            {
                foreach (string key in xmlnsManager)
                {
                    _xmlnsDictionary.Add(key, xmlnsManager.LookupNamespace(key));
                }
            }
        }
#endif
 
#if !PBTCOMPILER
        /// <summary>
        /// Constructor overload that takes an XmlReader, in order to
        /// pull the BaseURI, Lang, and Space from it.
        /// </summary>
        internal ParserContext( XmlReader xmlReader )
        {
            if( xmlReader.BaseURI != null && xmlReader.BaseURI.Length != 0 )
            {
                BaseUri = new Uri( xmlReader.BaseURI );
            }
 
            XmlLang = xmlReader.XmlLang;
 
            if( xmlReader.XmlSpace != System.Xml.XmlSpace.None )
            {
                XmlSpace = xmlReader.XmlSpace.ToString();
            }
        }
#endif
 
#if !PBTCOMPILER
        /// <summary>
        ///    Constructor that takes the ParserContext.
        ///    A parserContext object will be built based on this.
        /// </summary>
        /// <param name="parserContext">xmlParserContext to use</param>
        internal ParserContext(ParserContext parserContext)
        {
            _xmlLang     = parserContext.XmlLang;
            _xmlSpace    = parserContext.XmlSpace;
            _xamlTypeMapper      = parserContext.XamlTypeMapper;
            _mapTable    = parserContext.MapTable;
            _baseUri     = parserContext.BaseUri;
            _masterBracketCharacterCache = parserContext.MasterBracketCharacterCache;
            
            _rootElement = parserContext._rootElement;
            if (parserContext._nameScopeStack != null)
                _nameScopeStack = (Stack)parserContext._nameScopeStack.Clone();
            else
                _nameScopeStack = null;
 
            // Don't want to force the lazy init so we just set privates
            _skipJournaledProperties = parserContext._skipJournaledProperties;
 
            _xmlnsDictionary = null;
 
            // when there are no namespace prefix mappings in incoming ParserContext,
             // we are not going to create an empty XmlnsDictionary.
            if (parserContext._xmlnsDictionary != null &&
                parserContext._xmlnsDictionary.Count > 0)
            {
                _xmlnsDictionary = new XmlnsDictionary();
 
                XmlnsDictionary xmlDictionaryFrom = parserContext.XmlnsDictionary;
 
                if (null != xmlDictionaryFrom)
                {
                    foreach (string key in xmlDictionaryFrom.Keys)
                    {
                        _xmlnsDictionary[key] = xmlDictionaryFrom[key];
                    }
                }
            }
        }
#endif
 
        /// <summary>
        /// Constructs a cache of all the members in this particular type that have 
        /// MarkupExtensionBracketCharactersAttribute set on them. This cache is added to a master
        /// cache which stores the BracketCharacter cache for each type.
        /// </summary>
        internal Dictionary<string, SpecialBracketCharacters> InitBracketCharacterCacheForType(Type type)
        {
            if (!MasterBracketCharacterCache.ContainsKey(type))
            {
                Dictionary<string, SpecialBracketCharacters> map = BuildBracketCharacterCacheForType(type);
                MasterBracketCharacterCache.Add(type, map);
            }
 
            return MasterBracketCharacterCache[type];
        }
 
        /// <summary>
        /// Pushes the context scope stack (modifications to the ParserContext only apply to levels below
        /// the modification in the stack, except for the XamlTypeMapper property)
        /// </summary>
        internal void PushScope()
        {
            _repeat++;
            _currentFreezeStackFrame.IncrementRepeatCount();
 
            // Wait till the context needs XmlnsDictionary, create on first use.
            if (_xmlnsDictionary != null)
                _xmlnsDictionary.PushScope();
        }
 
        /// <summary>
        /// Pops the context scope stack
        /// </summary>
        internal void PopScope()
        {
            // Pop state off of the _langSpaceStack
            if (_repeat > 0)
            {
                _repeat--;
            }
            else
            {
                if (null != _langSpaceStack && _langSpaceStack.Count > 0)
                {
                    _repeat = (int) _langSpaceStack.Pop();
                    _targetType = (Type) _langSpaceStack.Pop();
                    _xmlSpace = (string) _langSpaceStack.Pop();
                    _xmlLang = (string) _langSpaceStack.Pop();
                }
            }
 
            // Pop state off of _currentFreezeStackFrame
            if (!_currentFreezeStackFrame.DecrementRepeatCount())
            {
                // If the end of the current frame has been reached, pop
                // the next frame off the freeze stack
                _currentFreezeStackFrame = (FreezeStackFrame) _freezeStack.Pop();
            }
 
            // Wait till the context needs XmlnsDictionary, create on first use.
            if (_xmlnsDictionary != null)
                _xmlnsDictionary.PopScope();
        }
 
        /// <summary>
        /// XmlNamespaceDictionary
        /// </summary>
        public XmlnsDictionary  XmlnsDictionary
        {
            get
            {
                // Entry Point to others, initialize if null.
                if (_xmlnsDictionary == null)
                    _xmlnsDictionary = new XmlnsDictionary();
 
                return _xmlnsDictionary;
            }
        }
 
        /// <summary>
        /// XmlLang property
        /// </summary>
        public string XmlLang
        {
            get
            {
                return _xmlLang;
            }
            set
            {
                EndRepeat();
                _xmlLang = (null == value ? String.Empty : value);
            }
        }
 
        /// <summary>
        /// XmlSpace property
        /// </summary>
        // (Why isn't this of type XmlSpace?)
        public string XmlSpace
        {
            get
            {
                return _xmlSpace;
            }
            set
            {
                EndRepeat();
                _xmlSpace = value;
            }
        }
 
        //
        // TargetType
        //
        // Keep track of the Style/Template TargetType's in the current context.  This allows Setters etc
        // to interpret properties without walking up the reader stack to see it.  This is internal and
        // hard-coded to target type, but the intent in the future is to generalize this so that we don't
        // have to have the custom parser, and so that the designer can provide the same contextual information.
        //
        internal Type TargetType
        {
            get
            {
                return _targetType;
            }
 
#if !PBTCOMPILER
            set
            {
                EndRepeat();
                _targetType = value;
            }
#endif
        }
 
        // Items specific to XAML
 
        /// <summary>
        ///  XamlTypeMapper that should be used when resolving XML
        /// </summary>
        public XamlTypeMapper XamlTypeMapper
        {
            get
            {
                return _xamlTypeMapper ;
            }
            set
            {
                // The BamlMapTable must always be kept in sync with the XamlTypeMapper.  If
                // the XamlTypeMapper changes, then the map table must also be reset.
                if (_xamlTypeMapper != value)
                {
                    _xamlTypeMapper = value;
                    _mapTable = new BamlMapTable(value);
                    _xamlTypeMapper.MapTable = _mapTable;
                }
            }
        }
#if !PBTCOMPILER
        /// <summary>
        ///  Gets or sets the list of INameScopes in parent chain
        /// </summary>
        internal Stack NameScopeStack
        {
            get
            {
               if (_nameScopeStack == null)
                   _nameScopeStack = new Stack(2);
 
               return _nameScopeStack;
            }
        }
#endif
 
        /// <summary>
        ///    Gets or sets the base Uri
        /// </summary>
        public Uri BaseUri
        {
            get
            {
                return _baseUri ;
            }
            set
            {
                _baseUri = value;
            }
        }
 
#if !PBTCOMPILER
        /// <summary>
        /// Should DependencyProperties marked with the Journal metadata flag be set or skipped?
        /// </summary>
        /// <value></value>
        internal bool SkipJournaledProperties
        {
            get { return _skipJournaledProperties; }
            set { _skipJournaledProperties = value; }
        }
 
        //
        // The Assembly which hosts the Baml stream.
        // 
        internal Assembly StreamCreatedAssembly 
        {
            get { return _streamCreatedAssembly; }
 
            set { _streamCreatedAssembly = value; }
        }
#endif
 
        /// <summary>
        ///    Operator for Converting a ParserContext to an XmlParserContext
        /// </summary>
        /// <param name="parserContext">ParserContext to Convert</param>
        /// <returns>XmlParserContext</returns>
        public static implicit operator XmlParserContext(ParserContext parserContext)
        {
            return ParserContext.ToXmlParserContext(parserContext);
        }
 
 
        /// <summary>
        ///    Operator for Converting a ParserContext to an XmlParserContext
        /// </summary>
        /// <param name="parserContext">ParserContext to Convert</param>
        /// <returns>XmlParserContext</returns>
        public static XmlParserContext ToXmlParserContext(ParserContext parserContext)
        {
            if (parserContext == null)
            {
                throw new ArgumentNullException( "parserContext" );
            }
 
            XmlNamespaceManager xmlnsMgr = new XmlNamespaceManager(new NameTable());
            XmlSpace xmlSpace = System.Xml.XmlSpace.None;
 
            if (parserContext.XmlSpace != null && parserContext.XmlSpace.Length != 0)
            {
                TypeConverter typeConverter = TypeDescriptor.GetConverter(typeof(System.Xml.XmlSpace));
                if (null != typeConverter)
                {
                    try
                    {
                        xmlSpace = (System.Xml.XmlSpace)typeConverter.ConvertFromString(null, TypeConverterHelper.InvariantEnglishUS, parserContext.XmlSpace);
                    }
                    catch (System.FormatException)  // If it's not a valid space value, ignore it
                    {
                        xmlSpace = System.Xml.XmlSpace.None;
                    }
                }
            }
 
            // We start getting Keys list only if we have non-empty dictionary
 
            if (parserContext._xmlnsDictionary != null)
            {
                foreach (string key in parserContext._xmlnsDictionary.Keys)
                {
                    xmlnsMgr.AddNamespace(key, parserContext._xmlnsDictionary[key]);
                }
            }
 
            XmlParserContext xmlParserContext = new XmlParserContext(null, xmlnsMgr, parserContext.XmlLang, xmlSpace);
            if( parserContext.BaseUri == null)
            {
                xmlParserContext.BaseURI = null;
            }
            else
            {
                string serializedSafe = parserContext.BaseUri.GetComponents(UriComponents.SerializationInfoString, UriFormat.SafeUnescaped);
                Uri sameUri = new Uri(serializedSafe);
                string cannonicalString =  sameUri.GetComponents(UriComponents.SerializationInfoString, UriFormat.UriEscaped);
                xmlParserContext.BaseURI = cannonicalString;
            }
 
            return xmlParserContext;
        }
 
#endregion Public Methods
 
#region Internal
 
        internal bool FromRestrictiveReader { get; set; }
 
        // Reset stack to default state
        private void EndRepeat()
        {
            if (_repeat > 0)
            {
                if (null == _langSpaceStack)
                {
                    _langSpaceStack = new Stack(1);
                }
 
                _langSpaceStack.Push(XmlLang);
                _langSpaceStack.Push(XmlSpace);
                _langSpaceStack.Push(TargetType);
                _langSpaceStack.Push(_repeat);
                _repeat = 0;
            }
        }
 
        /// <summary>
        /// LineNumber for the first character in the given
        /// stream. This is used when parsing a section of a larger file so
        /// that proper line number in the overall file can be calculated.
        /// </summary>
        internal int LineNumber
        {
            get { return _lineNumber; }
#if !PBTCOMPILER
            set { _lineNumber = value; }
#endif
        }
 
 
        /// <summary>
        /// LinePosition for the first character in the given
        /// stream. This is used when parsing a section of a larger file so
        /// that proper line positions in the overall file can be calculated.
        /// </summary>
        internal int LinePosition
        {
            get { return _linePosition; }
#if !PBTCOMPILER
            set { _linePosition = value; }
#endif
        }
 
#if !PBTCOMPILER
        internal bool IsDebugBamlStream
        {
            get { return _isDebugBamlStream; }
            set { _isDebugBamlStream = value; }
        }
 
        /// <summary>
        /// Gets or sets the object at the root of the portion of the tree
        /// currently being parsed.  Note that this may not be the very top of the tree
        /// if the parsing operation is scoped to a specific subtree, such as in Style
        /// parsing.
        /// </summary>
        internal object RootElement
        {
            get { return _rootElement; }
            set { _rootElement = value; }
        }
 
        // If this is false (default), then the parser does not own the stream and so if 
        // it has any defer loaded content, it needs to copy it into a byte array since
        // the owner\caller will close the stream when parsing is complete. Currently, this
        // is set to true only by the theme engine since the stream is a system-wide resource
        // an dso will always be open for teh lifetime of the process laoding the theme and so
        // it can be re-used for perf reasons.
        internal bool OwnsBamlStream
        {
            get { return _ownsBamlStream; }
            set { _ownsBamlStream = value; }
        }
#endif
 
        /// <summary>
        /// Allows sharing a map table between instances of BamlReaders and Writers.
        /// </summary>
 
        internal BamlMapTable MapTable
        {
            get { return _mapTable; }
#if !PBTCOMPILER
            set
            {
                // The XamlTypeMapper and the map table must always be kept in sync.  If the
                // map table changes, update the XamlTypeMapper also
                if (_mapTable != value)
                {
                    _mapTable = value;
                    _xamlTypeMapper = _mapTable.XamlTypeMapper;
                    _xamlTypeMapper.MapTable = _mapTable;
                }
            }
#endif
        }
 
#if !PBTCOMPILER
 
 
 
        internal IStyleConnector StyleConnector
        {
            get { return _styleConnector; }
            set { _styleConnector = value; }
        }
 
        // Keep a cached ProvideValueProvider so that we don't have to keep re-creating one.
        internal ProvideValueServiceProvider ProvideValueProvider
        {
            get
            {
                if (_provideValueServiceProvider == null)
                {
                    _provideValueServiceProvider = new ProvideValueServiceProvider(this);
                }
                
                return _provideValueServiceProvider;
            }
        }
        
        /// <summary>
        /// This is used to resolve a StaticResourceId record within a deferred content 
        /// section against a StaticResourceExtension on the parent dictionary.
        /// </summary>
        internal List<object[]> StaticResourcesStack
        {
            get 
            { 
                if (_staticResourcesStack == null)
                {
                    _staticResourcesStack = new List<object[]>();
                }
                
                return _staticResourcesStack; 
            }
        }
 
        /// <summary>
        /// Says if we are we currently loading deferred content
        /// </summary>
        internal bool InDeferredSection
        {
            get { return (_staticResourcesStack != null && _staticResourcesStack.Count > 0); }
        }
#endif
 
        // Return a new Parser context that has the same instance variables as this instance, with
        // only scope dependent variables deep copied.  Variables that are not dependent on scope
        // (such as the baml map table) are not deep copied.
 
#if !PBTCOMPILER
        internal ParserContext ScopedCopy()
        {
            return ScopedCopy( true /* copyNameScopeStack */ );
        }
#endif
 
#if !PBTCOMPILER
        internal ParserContext ScopedCopy(bool copyNameScopeStack)
        {
            ParserContext context = new ParserContext();
 
            context._baseUri = _baseUri;
            context._skipJournaledProperties = _skipJournaledProperties;
            context._xmlLang = _xmlLang;
            context._xmlSpace = _xmlSpace;
            context._repeat = _repeat;
            context._lineNumber = _lineNumber;
            context._linePosition = _linePosition;
            context._isDebugBamlStream = _isDebugBamlStream;
            context._mapTable = _mapTable;
            context._xamlTypeMapper = _xamlTypeMapper;
            context._targetType = _targetType;
 
            context._streamCreatedAssembly = _streamCreatedAssembly;
            context._rootElement = _rootElement;
            context._styleConnector = _styleConnector;
 
            // Copy the name scope stack, if necessary.
 
            if (_nameScopeStack != null && copyNameScopeStack)
                context._nameScopeStack = (_nameScopeStack != null) ? (Stack)_nameScopeStack.Clone() : null;
            else
                context._nameScopeStack = null;
 
            // Deep copy only selected scope dependent instance variables
            context._langSpaceStack = (_langSpaceStack != null) ? (Stack)_langSpaceStack.Clone() : null;
 
            if (_xmlnsDictionary != null)
                context._xmlnsDictionary = new XmlnsDictionary(_xmlnsDictionary);
            else
                context._xmlnsDictionary = null;
 
            context._currentFreezeStackFrame = _currentFreezeStackFrame;
            context._freezeStack = (_freezeStack != null) ? (Stack) _freezeStack.Clone() : null;
 
            return context;
        }
#endif
 
        //
        // This is called by a user of a parser context when it is a good time to drop unnecessary
        // references (today, just an empty stack).
        //
 
#if !PBTCOMPILER
        internal void TrimState()
        {
                if( _nameScopeStack != null && _nameScopeStack.Count == 0 )
                {
                    _nameScopeStack = null;
                }
        }
#endif
 
        /// <summary>
        /// Master cache of Bracket Characters which stores the BracketCharacter cache for each Type.
        /// </summary>
        internal Dictionary<Type, Dictionary<string, SpecialBracketCharacters>> MasterBracketCharacterCache
        {
            get
            {
                if (_masterBracketCharacterCache == null)
                {
                    _masterBracketCharacterCache = new Dictionary<Type, Dictionary<string, SpecialBracketCharacters>>();
                }
 
                return _masterBracketCharacterCache;
            }
        }
 
        // Return a new Parser context that has the same instance variables as this instance,
        // will all scoped and non-scoped complex properties deep copied.
#if !PBTCOMPILER
        internal ParserContext Clone()
        {
            ParserContext context = ScopedCopy();
 
            // Deep copy only selected instance variables
            context._mapTable = (_mapTable != null) ? _mapTable.Clone() : null;
            context._xamlTypeMapper = (_xamlTypeMapper != null) ? _xamlTypeMapper.Clone() : null;
 
            // Connect the XamlTypeMapper and bamlmaptable
            context._xamlTypeMapper.MapTable = context._mapTable;
            context._mapTable.XamlTypeMapper = context._xamlTypeMapper;
 
            return context;
        }
#endif
 
#if !PBTCOMPILER
        // Set/Get whether or not Freezables within the current scope
        // should be Frozen.
        internal bool FreezeFreezables
        {
            get
            {
                return _currentFreezeStackFrame.FreezeFreezables;
            }
 
            set
            {
                // If the freeze flag isn't actually changing, we don't need to 
                // register a change
                if (value != _currentFreezeStackFrame.FreezeFreezables)
                {
                    // When this scope was entered the repeat count was initially incremented,
                    // indicating no _freezeFreezables state changes within this scope.
                    //
                    // Now that a state change has been found, we need to replace that no-op with
                    // a directive to restore the old state by un-doing the increment
                    // and pushing the stack frame
#if DEBUG
                    bool canDecrement = 
#endif
                    _currentFreezeStackFrame.DecrementRepeatCount();
#if DEBUG
                    // We're replacing a no-op with a state change.  Detect if we accidently
                    // start replacing actual state changes.  This might happen if we allowed
                    // FreezeFreezable to be set twice within the same scope, for
                    // example.
                    Debug.Assert(canDecrement);
#endif
                    if (_freezeStack == null)
                    {
                        // Lazily allocate a _freezeStack if this is the first
                        // state change.
                        _freezeStack = new Stack();
                    }
 
                    // Save the old frame
                    _freezeStack.Push(_currentFreezeStackFrame);
 
                    // Set the new frame
                    _currentFreezeStackFrame.Reset(value);
                }
            }
        }
 
        internal bool TryCacheFreezable(string value, Freezable freezable)
        {
            if (FreezeFreezables)
            {
                if (freezable.CanFreeze)
                {
                    if (!freezable.IsFrozen)
                    {
                        freezable.Freeze();
                    }
                    if (_freezeCache == null)
                    {
                        _freezeCache = new Dictionary<string, Freezable>();
                    }
                    _freezeCache.Add(value, freezable);
                    return true;
                }
            }
 
            return false;
        }
 
        internal Freezable TryGetFreezable(string value)
        {
            Freezable freezable = null;
            if (_freezeCache != null)
            {
                _freezeCache.TryGetValue(value, out freezable);
            }
 
            return freezable;
        }
#endif
 
#endregion Internal
 
#region Date
 
        private XamlTypeMapper          _xamlTypeMapper;
        private Uri                     _baseUri;
 
        private XmlnsDictionary         _xmlnsDictionary;
        private String                  _xmlLang        = String.Empty;
        private String                  _xmlSpace       = String.Empty;
        private Stack                   _langSpaceStack;
        private int                     _repeat;
        private Type                    _targetType;
        private Dictionary<Type, Dictionary<string, SpecialBracketCharacters>> _masterBracketCharacterCache;
 
#if !PBTCOMPILER
        private bool                    _skipJournaledProperties;
        private Assembly                _streamCreatedAssembly;
        private bool                    _ownsBamlStream;
        private ProvideValueServiceProvider _provideValueServiceProvider;
        private IStyleConnector _styleConnector;
        private Stack                   _nameScopeStack;
        private List<object[]>          _staticResourcesStack;
 
        object                                      _rootElement;  // RootElement for the Page scoping [temporary, should be
                                                                   // something like page name or baseUri]
 
#endif
 
        /// <summary>
        /// Looks up all properties via reflection on the given type, and scans through the attributes on all of them
        /// to build a cache of properties which have MarkupExtensionBracketCharactersAttribute set on them.
        /// </summary>
        private Dictionary<string, SpecialBracketCharacters> BuildBracketCharacterCacheForType(Type extensionType)
        {
            Dictionary<string, SpecialBracketCharacters> cache = new Dictionary<string, SpecialBracketCharacters>(StringComparer.OrdinalIgnoreCase);
            PropertyInfo[] propertyInfo = extensionType.GetProperties(BindingFlags.Public | BindingFlags.Instance);
            Type constructorArgumentType = null;
            Type markupExtensionBracketCharacterType = null;
 
            foreach (PropertyInfo property in propertyInfo)
            {
                string propertyName = property.Name;
                string constructorArgumentName = null;
                IList<CustomAttributeData> customAttributes = CustomAttributeData.GetCustomAttributes(property);
                SpecialBracketCharacters bracketCharacters = null;
                foreach (CustomAttributeData attributeData in customAttributes)
                {
                    Type attributeType = attributeData.AttributeType;
                    Assembly xamlAssembly = attributeType.Assembly;
                    if (constructorArgumentType == null || markupExtensionBracketCharacterType == null)
                    {
                        constructorArgumentType =
                            xamlAssembly.GetType("System.Windows.Markup.ConstructorArgumentAttribute");
                        markupExtensionBracketCharacterType =
                            xamlAssembly.GetType("System.Windows.Markup.MarkupExtensionBracketCharactersAttribute");
                    }
 
                    if (attributeType.IsAssignableFrom(constructorArgumentType))
                    {
                        constructorArgumentName = attributeData.ConstructorArguments[0].Value as string;
                    }
                    else if (attributeType.IsAssignableFrom(markupExtensionBracketCharacterType))
                    {
                        if (bracketCharacters == null)
                        {
                            bracketCharacters = new SpecialBracketCharacters();
                        }
 
                        bracketCharacters.AddBracketCharacters((char)attributeData.ConstructorArguments[0].Value, (char)attributeData.ConstructorArguments[1].Value);
                    }
                }
 
                if (bracketCharacters != null)
                {
                    bracketCharacters.EndInit();
                    cache.Add(propertyName, bracketCharacters);
                    if (constructorArgumentName != null)
                    {
                        cache.Add(constructorArgumentName, bracketCharacters);
                    }
                }
            }
 
            return cache.Count == 0 ? null : cache;
        }
 
        // Struct that maintains both the freezeFreezable state & stack depth
        // between freezeFreezable state changes
        private struct FreezeStackFrame
        {
            internal void IncrementRepeatCount() { _repeatCount++; }
 
            // Returns false when the count reaches 0 such that the decrement can not occur
            internal bool DecrementRepeatCount()
            {
                if (_repeatCount > 0)
                {
                    _repeatCount--;
                    return true;
                }
                else
                {
                    return false;
                }
            }
 
#if !PBTCOMPILER
            // Accessors for private state
            internal bool FreezeFreezables
            {
                get { return _freezeFreezables; }
            }            
 
            // Reset's this frame to a new scope.  Only used with _currentFreezeStackFrame.
            internal void Reset(bool freezeFreezables)
            {
                _freezeFreezables = freezeFreezables;
                _repeatCount = 0;
            }
 
            // Whether or not Freezeables with the current scope should be Frozen            
            private bool _freezeFreezables;
 
#endif
 
            // The number of frames until the next state change.
            // We need to know how many times PopScope() is called until the 
            // state changes.  That information is tracked by _repeatCount.
            private int _repeatCount;
        }
            
        // First frame is maintained off of the _freezeStack to avoid allocating
        // a Stack<FreezeStackFlag> for the common case where Freeze isn't specified.
        FreezeStackFrame _currentFreezeStackFrame;
 
#if !PBTCOMPILER
        // When cloning, it isn't necessary to copy this cache of freezables.
        // This cache allows frozen freezables to use a shared instance and save on memory.
        private Dictionary<string, Freezable> _freezeCache;
#endif
 
        private Stack _freezeStack = null;
 
        private int _lineNumber = 0;    // number of lines between the start of the file and
                                        // our starting point (the starting point of this context)
        private int _linePosition=0;      // default start ot left of first character which is a zero
        private BamlMapTable _mapTable;
#if !PBTCOMPILER
        private bool _isDebugBamlStream = false;
#endif
#endregion Data
    }
}