JavaScriptCore/runtime/StringObjectThatMasqueradesAsUndefined.h

   1 /*
   2  *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
   3  *  Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
   4  *
   5  *  This library is free software; you can redistribute it and/or
   6  *  modify it under the terms of the GNU Lesser General Public
   7  *  License as published by the Free Software Foundation; either
   8  *  version 2 of the License, or (at your option) any later version.
   9  *
  10  *  This library is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *  Lesser General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Lesser General Public
  16  *  License along with this library; if not, write to the Free Software
  17  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  18  *
  19  */
  20
  21 #ifndef StringObjectThatMasqueradesAsUndefined_h
  22 #define StringObjectThatMasqueradesAsUndefined_h
  23
  24 #include "JSGlobalObject.h"
  25 #include "StringObject.h"
  26 #include "UString.h"
  27
  28 namespace JSC {
  29
  30     // WebCore uses this to make style.filter undetectable
  31     class StringObjectThatMasqueradesAsUndefined : public StringObject {
  32     public:
  33         static StringObjectThatMasqueradesAsUndefined* create(ExecState* exec, const UString& string)
  34         {
  35             return new (exec) StringObjectThatMasqueradesAsUndefined(exec,
  36                 createStructure(exec->lexicalGlobalObject()->stringPrototype()), string);
  37         }
  38
  39     private:
  40         StringObjectThatMasqueradesAsUndefined(ExecState* exec, NonNullPassRefPtr<Structure> structure, const UString& string)
  41             : StringObject(exec, structure, string)
  42         {
  43         }
  44
  45         static PassRefPtr<Structure> createStructure(JSValue proto)
  46         {
  47             return Structure::create(proto, TypeInfo(ObjectType, StructureFlags));
  48         }
  49
  50         static const unsigned StructureFlags = OverridesGetOwnPropertySlot | MasqueradesAsUndefined | OverridesGetPropertyNames | StringObject::StructureFlags;
  51
  52         virtual bool toBoolean(ExecState*) const { return false; }
  53     };
  54
  55 } // namespace JSC
  56
  57 #endif // StringObjectThatMasqueradesAsUndefined_h