mcs/class/System.Xaml/System.Xaml/XamlType.cs

   1 //
   2 // Copyright (C) 2010 Novell Inc. http://novell.com
   3 //
   4 // Permission is hereby granted, free of charge, to any person obtaining
   5 // a copy of this software and associated documentation files (the
   6 // "Software"), to deal in the Software without restriction, including
   7 // without limitation the rights to use, copy, modify, merge, publish,
   8 // distribute, sublicense, and/or sell copies of the Software, and to
   9 // permit persons to whom the Software is furnished to do so, subject to
  10 // the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be
  13 // included in all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22 //
  23 using System;
  24 using System.Collections;
  25 using System.Collections.Generic;
  26 using System.ComponentModel;
  27 using System.Linq;
  28 using System.Reflection;
  29 using System.Windows.Markup;
  30 using System.Xaml.Schema;
  31
  32 namespace System.Xaml
  33 {
  34         public class XamlType : IEquatable<XamlType>
  35         {
  36                 public XamlType (Type underlyingType, XamlSchemaContext schemaContext)
  37                         : this (underlyingType, schemaContext, null)
  38                 {
  39                 }
  40
  41 //              static readonly Type [] predefined_types = {
  42 //                              typeof (XData), typeof (Uri), typeof (TimeSpan), typeof (PropertyDefinition), typeof (MemberDefinition), typeof (Reference)
  43 //                      };
  44
  45                 public XamlType (Type underlyingType, XamlSchemaContext schemaContext, XamlTypeInvoker invoker)
  46                         : this (schemaContext, invoker)
  47                 {
  48                         if (underlyingType == null)
  49                                 throw new ArgumentNullException ("underlyingType");
  50                         type = underlyingType;
  51                         underlying_type = type;
  52
  53                         XamlType xt;
  54                         if (XamlLanguage.InitializingTypes) {
  55                                 Name = type.GetXamlName ();
  56                                 PreferredXamlNamespace = XamlLanguage.Xaml2006Namespace;
  57                         } else if ((xt = XamlLanguage.AllTypes.FirstOrDefault (t => t.UnderlyingType == type)) != null) {
  58                                 Name = xt.Name;
  59                                 PreferredXamlNamespace = XamlLanguage.Xaml2006Namespace;
  60                         } else {
  61                                 Name = type.GetXamlName ();
  62                                 PreferredXamlNamespace = String.Format ("clr-namespace:{0};assembly={1}", type.Namespace, type.Assembly.GetName ().Name);
  63                         }
  64                 }
  65
  66                 public XamlType (string unknownTypeNamespace, string unknownTypeName, IList<XamlType> typeArguments, XamlSchemaContext schemaContext)
  67                         : this (schemaContext, null)
  68                 {
  69                         if (unknownTypeNamespace == null)
  70                                 throw new ArgumentNullException ("unknownTypeNamespace");
  71                         if (unknownTypeName == null)
  72                                 throw new ArgumentNullException ("unknownTypeName");
  73                         if (schemaContext == null)
  74                                 throw new ArgumentNullException ("schemaContext");
  75
  76                         type = typeof (object);
  77                         Name = unknownTypeName;
  78                         PreferredXamlNamespace = unknownTypeNamespace;
  79                         TypeArguments = typeArguments != null && typeArguments.Count == 0 ? null : typeArguments;
  80                         explicit_ns = unknownTypeNamespace;
  81                 }
  82
  83                 protected XamlType (string typeName, IList<XamlType> typeArguments, XamlSchemaContext schemaContext)
  84                         : this (String.Empty, typeName, typeArguments, schemaContext)
  85                 {
  86                 }
  87
  88                 XamlType (XamlSchemaContext schemaContext, XamlTypeInvoker invoker)
  89                 {
  90                         if (schemaContext == null)
  91                                 throw new ArgumentNullException ("schemaContext");
  92                         SchemaContext = schemaContext;
  93                         this.invoker = invoker ?? new XamlTypeInvoker (this);
  94                 }
  95
  96                 Type type, underlying_type;
  97
  98                 string explicit_ns;
  99
 100                 // populated properties
 101                 XamlType base_type;
 102                 XamlTypeInvoker invoker;
 103
 104                 internal EventHandler<XamlSetMarkupExtensionEventArgs> SetMarkupExtensionHandler {
 105                         get { return LookupSetMarkupExtensionHandler (); }
 106                 }
 107
 108                 internal EventHandler<XamlSetTypeConverterEventArgs> SetTypeConverterHandler {
 109                         get { return LookupSetTypeConverterHandler (); }
 110                 }
 111
 112                 public IList<XamlType> AllowedContentTypes {
 113                         get { return LookupAllowedContentTypes (); }
 114                 }
 115
 116                 public XamlType BaseType {
 117                         get { return LookupBaseType (); }
 118                 }
 119
 120                 public bool ConstructionRequiresArguments {
 121                         get { return LookupConstructionRequiresArguments (); }
 122                 }
 123
 124                 public XamlMember ContentProperty {
 125                         get { return LookupContentProperty (); }
 126                 }
 127
 128                 public IList<XamlType> ContentWrappers {
 129                         get { return LookupContentWrappers (); }
 130                 }
 131
 132                 public XamlValueConverter<XamlDeferringLoader> DeferringLoader {
 133                         get { return LookupDeferringLoader (); }
 134                 }
 135
 136                 public XamlTypeInvoker Invoker {
 137                         get { return LookupInvoker (); }
 138                 }
 139
 140                 public bool IsAmbient {
 141                         get { return LookupIsAmbient (); }
 142                 }
 143
 144                 public bool IsArray {
 145                         get { return LookupCollectionKind () == XamlCollectionKind.Array; }
 146                 }
 147
 148                 // it somehow treats array as not a collection...
 149                 public bool IsCollection {
 150                         get { return LookupCollectionKind () == XamlCollectionKind.Collection; }
 151                 }
 152
 153                 public bool IsConstructible {
 154                         get { return LookupIsConstructible (); }
 155                 }
 156
 157                 public bool IsDictionary {
 158                         get { return LookupCollectionKind () == XamlCollectionKind.Dictionary; }
 159                 }
 160
 161                 public bool IsGeneric {
 162                         get { return type.IsGenericType; }
 163                 }
 164
 165                 public bool IsMarkupExtension {
 166                         get { return LookupIsMarkupExtension (); }
 167                 }
 168                 public bool IsNameScope {
 169                         get { return LookupIsNameScope (); }
 170                 }
 171                 public bool IsNameValid {
 172                         get { return XamlLanguage.IsValidXamlName (Name); }
 173                 }
 174
 175                 public bool IsNullable {
 176                         get { return LookupIsNullable (); }
 177                 }
 178
 179                 public bool IsPublic {
 180                         get { return LookupIsPublic (); }
 181                 }
 182
 183                 public bool IsUnknown {
 184                         get { return LookupIsUnknown (); }
 185                 }
 186
 187                 public bool IsUsableDuringInitialization {
 188                         get { return LookupUsableDuringInitialization (); }
 189                 }
 190
 191                 public bool IsWhitespaceSignificantCollection {
 192                         get { return LookupIsWhitespaceSignificantCollection (); }
 193                 }
 194
 195                 public bool IsXData {
 196                         get { return LookupIsXData (); }
 197                 }
 198
 199                 public XamlType ItemType {
 200                         get { return LookupItemType (); }
 201                 }
 202
 203                 public XamlType KeyType {
 204                         get { return LookupKeyType (); }
 205                 }
 206
 207                 public XamlType MarkupExtensionReturnType {
 208                         get { return LookupMarkupExtensionReturnType (); }
 209                 }
 210
 211                 public string Name { get; private set; }
 212
 213                 public string PreferredXamlNamespace { get; private set; }
 214
 215                 public XamlSchemaContext SchemaContext { get; private set; }
 216
 217                 public bool TrimSurroundingWhitespace {
 218                         get { return LookupTrimSurroundingWhitespace (); }
 219                 }
 220
 221                 public IList<XamlType> TypeArguments { get; private set; }
 222
 223                 public XamlValueConverter<TypeConverter> TypeConverter {
 224                         get { return LookupTypeConverter (); }
 225                 }
 226
 227                 public Type UnderlyingType {
 228                         get { return LookupUnderlyingType (); }
 229                 }
 230
 231                 public XamlValueConverter<ValueSerializer> ValueSerializer {
 232                         get { return LookupValueSerializer (); }
 233                 }
 234
 235                 public static bool operator == (XamlType left, XamlType right)
 236                 {
 237                         return IsNull (left) ? IsNull (right) : left.Equals (right);
 238                 }
 239
 240                 static bool IsNull (XamlType a)
 241                 {
 242                         return Object.ReferenceEquals (a, null);
 243                 }
 244
 245                 public static bool operator != (XamlType left, XamlType right)
 246                 {
 247                         return !(left == right);
 248                 }
 249
 250                 public bool Equals (XamlType other)
 251                 {
 252                         return !IsNull (other) &&
 253                                 UnderlyingType == other.UnderlyingType &&
 254                                 Name == other.Name &&
 255                                 PreferredXamlNamespace == other.PreferredXamlNamespace && TypeArguments.ListEquals (other.TypeArguments);
 256                 }
 257
 258                 public override bool Equals (object obj)
 259                 {
 260                         var a = obj as XamlType;
 261                         return Equals (a);
 262                 }
 263
 264                 public override int GetHashCode ()
 265                 {
 266                         if (UnderlyingType != null)
 267                                 return UnderlyingType.GetHashCode ();
 268                         int x = Name.GetHashCode () << 7 + PreferredXamlNamespace.GetHashCode ();
 269                         if (TypeArguments != null)
 270                                 foreach (var t in TypeArguments)
 271                                         x = t.GetHashCode () + x << 5;
 272                         return x;
 273                 }
 274
 275                 public override string ToString ()
 276                 {
 277                         return String.IsNullOrEmpty (PreferredXamlNamespace) ? Name : String.Concat ("{", PreferredXamlNamespace, "}", Name);
 278                 }
 279
 280                 public virtual bool CanAssignTo (XamlType xamlType)
 281                 {
 282                         throw new NotImplementedException ();
 283                 }
 284
 285                 public XamlMember GetAliasedProperty (XamlDirective directive)
 286                 {
 287                         return LookupAliasedProperty (directive);
 288                 }
 289
 290                 public ICollection<XamlMember> GetAllAttachableMembers ()
 291                 {
 292                         return new List<XamlMember> (LookupAllAttachableMembers ());
 293                 }
 294
 295                 public ICollection<XamlMember> GetAllMembers ()
 296                 {
 297                         return new List<XamlMember> (LookupAllMembers ());
 298                 }
 299
 300                 public XamlMember GetAttachableMember (string name)
 301                 {
 302                         return LookupAttachableMember (name);
 303                 }
 304
 305                 public XamlMember GetMember (string name)
 306                 {
 307                         return LookupMember (name, false);
 308                 }
 309
 310                 public IList<XamlType> GetPositionalParameters (int parameterCount)
 311                 {
 312                         return LookupPositionalParameters (parameterCount);
 313                 }
 314
 315                 public virtual IList<string> GetXamlNamespaces ()
 316                 {
 317                         throw new NotImplementedException ();
 318                         /* this does not work like documented!
 319                         if (explicit_ns != null)
 320                                 return new string [] {explicit_ns};
 321                         var l = SchemaContext.GetAllXamlNamespaces ();
 322                         if (l != null)
 323                                 return new List<string> (l);
 324                         return new string [] {String.Empty};
 325                         */
 326                 }
 327
 328                 // lookups
 329
 330                 protected virtual XamlMember LookupAliasedProperty (XamlDirective directive)
 331                 {
 332                         if (directive == XamlLanguage.Key) {
 333                                 var a = this.GetCustomAttribute<DictionaryKeyPropertyAttribute> ();
 334                                 return a != null ? GetMember (a.Name) : null;
 335                         }
 336                         if (directive == XamlLanguage.Name) {
 337                                 var a = this.GetCustomAttribute<RuntimeNamePropertyAttribute> ();
 338                                 return a != null ? GetMember (a.Name) : null;
 339                         }
 340                         if (directive == XamlLanguage.Uid) {
 341                                 var a = this.GetCustomAttribute<UidPropertyAttribute> ();
 342                                 return a != null ? GetMember (a.Name) : null;
 343                         }
 344                         if (directive == XamlLanguage.Lang) {
 345                                 var a = this.GetCustomAttribute<XmlLangPropertyAttribute> ();
 346                                 return a != null ? GetMember (a.Name) : null;
 347                         }
 348                         return null;
 349                 }
 350
 351                 protected virtual IEnumerable<XamlMember> LookupAllAttachableMembers ()
 352                 {
 353                         if (UnderlyingType == null)
 354                                 return BaseType != null ? BaseType.GetAllMembers () : null;
 355                         return DoLookupAllAttachableMembers ();
 356                 }
 357
 358                 IEnumerable<XamlMember> DoLookupAllAttachableMembers ()
 359                 {
 360                         yield break; // FIXME: what to return here?
 361                 }
 362
 363                 static readonly XamlMember [] empty_array = new XamlMember [0];
 364
 365                 protected virtual IEnumerable<XamlMember> LookupAllMembers ()
 366                 {
 367                         if (UnderlyingType == null)
 368                                 return BaseType != null ? BaseType.GetAllMembers () : empty_array;
 369                         if (all_members_cache == null)
 370                                 all_members_cache = new List<XamlMember> (DoLookupAllMembers ());
 371                         return all_members_cache;
 372                 }
 373
 374                 List<XamlMember> all_members_cache;
 375
 376                 IEnumerable<XamlMember> DoLookupAllMembers ()
 377                 {
 378                         // This is a hack that is likely required due to internal implementation difference in System.Uri. Our Uri has two readonly collection properties
 379                         if (this == XamlLanguage.Uri)
 380                                 yield break;
 381
 382                         var bf = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance;
 383
 384                         foreach (var pi in UnderlyingType.GetProperties (bf))
 385                                 if (pi.CanRead && (pi.CanWrite && pi.GetIndexParameters ().Length == 0 || IsCollectionType (pi.PropertyType)))
 386                                         yield return new XamlMember (pi, SchemaContext);
 387                         foreach (var ei in UnderlyingType.GetEvents (bf))
 388                                 yield return new XamlMember (ei, SchemaContext);
 389                 }
 390
 391                 static bool IsCollectionType (Type type)
 392                 {
 393                         if (type == null)
 394                                 return false;
 395                         if (type.IsArray)
 396                                 return true;
 397
 398                         Type [] ifaces = type.GetInterfaces ();
 399                         foreach (Type i in ifaces)
 400                                 if (i.IsGenericType && i.GetGenericTypeDefinition ().Equals (typeof (ICollection<>)))
 401                                         return true;
 402                         foreach (Type i in ifaces)
 403                                 if (i == typeof (IList))
 404                                         return true;
 405
 406                         foreach (var iface in type.GetInterfaces ())
 407                                 if (iface == typeof (IDictionary) || (iface.IsGenericType && iface.GetGenericTypeDefinition () == typeof (IDictionary<,>)))
 408                                         return true;
 409
 410                         return false;
 411                 }
 412
 413                 protected virtual IList<XamlType> LookupAllowedContentTypes ()
 414                 {
 415                         // the actual implementation is very different from what is documented :(
 416                         return null;
 417
 418                         /*
 419                         var l = new List<XamlType> ();
 420                         if (ContentWrappers != null)
 421                                 l.AddRange (ContentWrappers);
 422                         if (ContentProperty != null)
 423                                 l.Add (ContentProperty.Type);
 424                         if (ItemType != null)
 425                                 l.Add (ItemType);
 426                         return l.Count > 0 ? l : null;
 427                         */
 428                 }
 429
 430                 protected virtual XamlMember LookupAttachableMember (string name)
 431                 {
 432                         throw new NotImplementedException ();
 433                 }
 434
 435                 [MonoTODO]
 436                 protected virtual XamlType LookupBaseType ()
 437                 {
 438                         if (base_type == null) {
 439                                 if (UnderlyingType == null)
 440                                         // FIXME: probably something advanced is needed here.
 441                                         base_type = new XamlType (typeof (object), SchemaContext, Invoker);
 442                                 else
 443                                         base_type = type.BaseType == null || type.BaseType == typeof (object) ? null : new XamlType (type.BaseType, SchemaContext, Invoker);
 444                         }
 445                         return base_type;
 446                 }
 447
 448                 // This implementation is not verified. (No place to use.)
 449                 protected virtual XamlCollectionKind LookupCollectionKind ()
 450                 {
 451                         if (UnderlyingType == null)
 452                                 return BaseType != null ? BaseType.LookupCollectionKind () : XamlCollectionKind.None;
 453                         if (type.IsArray)
 454                                 return XamlCollectionKind.Array;
 455
 456                         if (type.ImplementsAnyInterfacesOf (typeof (IDictionary), typeof (IDictionary<,>)))
 457                                 return XamlCollectionKind.Dictionary;
 458
 459                         if (type.ImplementsAnyInterfacesOf (typeof (ICollection), typeof (ICollection<>)))
 460                                 return XamlCollectionKind.Collection;
 461
 462                         return XamlCollectionKind.None;
 463                 }
 464
 465                 protected virtual bool LookupConstructionRequiresArguments ()
 466                 {
 467                         if (UnderlyingType == null)
 468                                 return false;
 469
 470                         // not sure if it is required, but MemberDefinition return true while they are abstract and it makes no sense.
 471                         if (UnderlyingType.IsAbstract)
 472                                 return true;
 473
 474                         // FIXME: probably some primitive types are treated as special.
 475                         switch (Type.GetTypeCode (UnderlyingType)) {
 476                         case TypeCode.String:
 477                                 return true;
 478                         case TypeCode.Object:
 479                                 if (UnderlyingType == typeof (TimeSpan))
 480                                         return false;
 481                                 break;
 482                         default:
 483                                 return false;
 484                         }
 485
 486                         return UnderlyingType.GetConstructor (BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance, null, Type.EmptyTypes, null) == null;
 487                 }
 488
 489                 protected virtual XamlMember LookupContentProperty ()
 490                 {
 491                         var a = this.GetCustomAttribute<ContentPropertyAttribute> ();
 492                         return a != null && a.Name != null ? GetMember (a.Name) : null;
 493                 }
 494
 495                 protected virtual IList<XamlType> LookupContentWrappers ()
 496                 {
 497                         if (CustomAttributeProvider == null)
 498                                 return null;
 499
 500                         var arr = CustomAttributeProvider.GetCustomAttributes (typeof (ContentWrapperAttribute), false);
 501                         if (arr == null || arr.Length == 0)
 502                                 return null;
 503                         var l = new XamlType [arr.Length];
 504                         for (int i = 0; i < l.Length; i++)
 505                                 l [i] = SchemaContext.GetXamlType (((ContentWrapperAttribute) arr [i]).ContentWrapper);
 506                         return l;
 507                 }
 508
 509                 internal ICustomAttributeProvider CustomAttributeProvider {
 510                         get { return LookupCustomAttributeProvider (); }
 511                 }
 512
 513                 protected virtual ICustomAttributeProvider LookupCustomAttributeProvider ()
 514                 {
 515                         return UnderlyingType;
 516                 }
 517                 protected virtual XamlValueConverter<XamlDeferringLoader> LookupDeferringLoader ()
 518                 {
 519                         throw new NotImplementedException ();
 520                 }
 521
 522                 protected virtual XamlTypeInvoker LookupInvoker ()
 523                 {
 524                         return invoker;
 525                 }
 526
 527                 protected virtual bool LookupIsAmbient ()
 528                 {
 529                         return this.GetCustomAttribute<AmbientAttribute> () != null;
 530                 }
 531
 532                 // It is documented as if it were to reflect spec. section 5.2,
 533                 // but the actual behavior shows it is *totally* wrong.
 534                 // Here I have implemented this based on the nunit test results. sigh.
 535                 protected virtual bool LookupIsConstructible ()
 536                 {
 537                         if (UnderlyingType == null)
 538                                 return true;
 539                         if (IsMarkupExtension)
 540                                 return true;
 541                         if (UnderlyingType.IsAbstract)
 542                                 return false;
 543                         if (!IsNameValid)
 544                                 return false;
 545                         return true;
 546                 }
 547
 548                 protected virtual bool LookupIsMarkupExtension ()
 549                 {
 550                         return typeof (MarkupExtension).IsAssignableFrom (UnderlyingType);
 551                 }
 552
 553                 protected virtual bool LookupIsNameScope ()
 554                 {
 555                         return typeof (INameScope).IsAssignableFrom (UnderlyingType);
 556                 }
 557
 558                 protected virtual bool LookupIsNullable ()
 559                 {
 560                         return !type.IsValueType || type.ImplementsInterface (typeof (Nullable<>));
 561                 }
 562
 563                 protected virtual bool LookupIsPublic ()
 564                 {
 565                         return underlying_type == null || underlying_type.IsPublic || underlying_type.IsNestedPublic;
 566                 }
 567
 568                 protected virtual bool LookupIsUnknown ()
 569                 {
 570                         return UnderlyingType == null;
 571                 }
 572
 573                 protected virtual bool LookupIsWhitespaceSignificantCollection ()
 574                 {
 575                         // probably for unknown types, it should preserve whitespaces.
 576                         return IsUnknown || this.GetCustomAttribute<WhitespaceSignificantCollectionAttribute> () != null;
 577                 }
 578
 579                 protected virtual bool LookupIsXData ()
 580                 {
 581                         // huh? XamlLanguage.XData.IsXData returns false(!)
 582                         // return typeof (XData).IsAssignableFrom (UnderlyingType);
 583                         return false;
 584                 }
 585
 586                 protected virtual XamlType LookupItemType ()
 587                 {
 588                         if (IsArray)
 589                                 return new XamlType (type.GetElementType (), SchemaContext);
 590                         if (!IsCollection)
 591                                 return null;
 592                         if (!IsGeneric)
 593                                 return new XamlType (typeof (object), SchemaContext);
 594                         return new XamlType (type.GetGenericArguments () [0], SchemaContext);
 595                 }
 596
 597                 protected virtual XamlType LookupKeyType ()
 598                 {
 599                         if (!IsDictionary)
 600                                 return null;
 601                         if (!IsGeneric)
 602                                 return new XamlType (typeof (object), SchemaContext);
 603                         return new XamlType (type.GetGenericArguments () [0], SchemaContext);
 604                 }
 605
 606                 protected virtual XamlType LookupMarkupExtensionReturnType ()
 607                 {
 608                         var a = this.GetCustomAttribute<MarkupExtensionReturnTypeAttribute> ();
 609                         return a != null ? new XamlType (a.ReturnType, SchemaContext) : null;
 610                 }
 611
 612                 protected virtual XamlMember LookupMember (string name, bool skipReadOnlyCheck)
 613                 {
 614                         // FIXME: verify if this does not filter out events.
 615                         return GetAllMembers ().FirstOrDefault (m => m.Name == name && (skipReadOnlyCheck || !m.IsReadOnly || m.Type.IsCollection || m.Type.IsDictionary || m.Type.IsArray));
 616                 }
 617
 618                 protected virtual IList<XamlType> LookupPositionalParameters (int parameterCount)
 619                 {
 620                         if (UnderlyingType == null/* || !IsMarkupExtension*/) // see nunit tests...
 621                                 return null;
 622
 623                         // check if there is applicable ConstructorArgumentAttribute.
 624                         // If there is, then return its type.
 625                         if (parameterCount == 1) {
 626                                 foreach (var xm in GetAllMembers ()) {
 627                                         var ca = xm.CustomAttributeProvider.GetCustomAttribute<ConstructorArgumentAttribute> (false);
 628                                         if (ca != null)
 629                                                 return new XamlType [] {xm.Type};
 630                                 }
 631                         }
 632
 633                         var methods = (from m in UnderlyingType.GetConstructors (BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance) where m.GetParameters ().Length == parameterCount select m).ToArray ();
 634                         if (methods.Length == 1)
 635                                 return (from p in methods [0].GetParameters () select SchemaContext.GetXamlType (p.ParameterType)).ToArray ();
 636
 637                         if (SchemaContext.SupportMarkupExtensionsWithDuplicateArity)
 638                                 throw new NotSupportedException ("The default LookupPositionalParameters implementation does not allow duplicate arity of markup extensions");
 639                         return null;
 640                 }
 641
 642                 BindingFlags flags_get_static = BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Static;
 643
 644                 protected virtual EventHandler<XamlSetMarkupExtensionEventArgs> LookupSetMarkupExtensionHandler ()
 645                 {
 646                         var a = this.GetCustomAttribute<XamlSetMarkupExtensionAttribute> ();
 647                         if (a == null)
 648                                 return null;
 649                         var mi = type.GetMethod (a.XamlSetMarkupExtensionHandler, flags_get_static);
 650                         if (mi == null)
 651                                 throw new ArgumentException ("Binding to XamlSetMarkupExtensionHandler failed");
 652                         return (EventHandler<XamlSetMarkupExtensionEventArgs>) Delegate.CreateDelegate (typeof (EventHandler<XamlSetMarkupExtensionEventArgs>), mi);
 653                 }
 654
 655                 protected virtual EventHandler<XamlSetTypeConverterEventArgs> LookupSetTypeConverterHandler ()
 656                 {
 657                         var a = this.GetCustomAttribute<XamlSetTypeConverterAttribute> ();
 658                         if (a == null)
 659                                 return null;
 660                         var mi = type.GetMethod (a.XamlSetTypeConverterHandler, flags_get_static);
 661                         if (mi == null)
 662                                 throw new ArgumentException ("Binding to XamlSetTypeConverterHandler failed");
 663                         return (EventHandler<XamlSetTypeConverterEventArgs>) Delegate.CreateDelegate (typeof (EventHandler<XamlSetTypeConverterEventArgs>), mi);
 664                 }
 665
 666                 protected virtual bool LookupTrimSurroundingWhitespace ()
 667                 {
 668                         return this.GetCustomAttribute<TrimSurroundingWhitespaceAttribute> () != null;
 669                 }
 670
 671                 protected virtual XamlValueConverter<TypeConverter> LookupTypeConverter ()
 672                 {
 673                         var t = UnderlyingType;
 674                         if (t == null)
 675                                 return null;
 676
 677                         // equivalent to TypeExtension.
 678                         // FIXME: not sure if it should be specially handled here.
 679                         if (t == typeof (Type))
 680                                 t = typeof (TypeExtension);
 681
 682                         var a = CustomAttributeProvider.GetCustomAttribute<TypeConverterAttribute> (false);
 683                         if (a != null)
 684                                 return SchemaContext.GetValueConverter<TypeConverter> (Type.GetType (a.ConverterTypeName), this);
 685
 686                         if (t == typeof (object))
 687                                 return SchemaContext.GetValueConverter<TypeConverter> (typeof (TypeConverter), this);
 688
 689                         // It's still not decent to check CollectionConverter.
 690                         var tct = TypeDescriptor.GetConverter (t).GetType ();
 691                         if (tct != typeof (TypeConverter) && tct != typeof (CollectionConverter) && tct != typeof (ReferenceConverter))
 692                                 return SchemaContext.GetValueConverter<TypeConverter> (tct, this);
 693                         return null;
 694                 }
 695
 696                 protected virtual Type LookupUnderlyingType ()
 697                 {
 698                         return underlying_type;
 699                 }
 700
 701                 protected virtual bool LookupUsableDuringInitialization ()
 702                 {
 703                         var a = this.GetCustomAttribute<UsableDuringInitializationAttribute> ();
 704                         return a != null && a.Usable;
 705                 }
 706
 707                 static XamlValueConverter<ValueSerializer> string_value_serializer;
 708
 709                 protected virtual XamlValueConverter<ValueSerializer> LookupValueSerializer ()
 710                 {
 711                         return LookupValueSerializer (this, CustomAttributeProvider);
 712                 }
 713
 714                 internal static XamlValueConverter<ValueSerializer> LookupValueSerializer (XamlType targetType, ICustomAttributeProvider provider)
 715                 {
 716                         if (provider == null)
 717                                 return null;
 718
 719                         var a = provider.GetCustomAttribute<ValueSerializerAttribute> (true);
 720                         if (a != null)
 721                                 return new XamlValueConverter<ValueSerializer> (a.ValueSerializerType ?? Type.GetType (a.ValueSerializerTypeName), targetType);
 722
 723                         if (targetType.BaseType != null) {
 724                                 var ret = targetType.BaseType.LookupValueSerializer ();
 725                                 if (ret != null)
 726                                         return ret;
 727                         }
 728
 729                         if (targetType.UnderlyingType == typeof (string)) {
 730                                 if (string_value_serializer == null)
 731                                         string_value_serializer = new XamlValueConverter<ValueSerializer> (typeof (StringValueSerializer), targetType);
 732                                 return string_value_serializer;
 733                         }
 734
 735                         return null;
 736                 }
 737
 738                 internal IEnumerable<XamlMember> GetConstructorArguments ()
 739                 {
 740                         return GetAllMembers ().Where (m => m.UnderlyingMember != null && m.CustomAttributeProvider.GetCustomAttribute<ConstructorArgumentAttribute> (false) != null);
 741                 }
 742         }
 743 }