kjs/property_slot.h

   1 // -*- c-basic-offset: 4 -*-
   2 /*
   3  *  Copyright (C) 2005, 2007 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 Library 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  *  Library General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU Library General Public License
  16  *  along with this library; see the file COPYING.LIB.  If not, write to
  17  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18  *  Boston, MA 02110-1301, USA.
  19  *
  20  */
  21
  22 #ifndef KJS_PROPERTY_SLOT_H
  23 #define KJS_PROPERTY_SLOT_H
  24
  25 #include "identifier.h"
  26 #include "value.h"
  27 #include <wtf/Assertions.h>
  28
  29 namespace KJS {
  30
  31 class ExecState;
  32 class JSObject;
  33
  34 struct HashEntry;
  35
  36 #define KJS_VALUE_SLOT_MARKER 0
  37 #define KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER reinterpret_cast<GetValueFunc>(1)
  38
  39 class PropertySlot {
  40 public:
  41     typedef JSValue* (*GetValueFunc)(ExecState*, JSObject* originalObject, const Identifier&, const PropertySlot&);
  42     typedef JSValue* (*GetValueNumericFunc)(ExecState*, JSObject* originalObject, unsigned index, const PropertySlot&);
  43
  44     JSValue* getValue(ExecState* exec, JSObject* originalObject, const Identifier& propertyName) const
  45     {
  46         if (m_getValue == KJS_VALUE_SLOT_MARKER)
  47             return *m_data.valueSlot;
  48         ASSERT(m_getValue != KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER);
  49         return m_getValue(exec, originalObject, propertyName, *this);
  50     }
  51
  52     JSValue* getValue(ExecState* exec, JSObject* originalObject, unsigned propertyName) const
  53     {
  54         if (m_getValue == KJS_VALUE_SLOT_MARKER)
  55             return *m_data.valueSlot;
  56         if (m_getValue == KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER)
  57             return m_data.numericFunc(exec, originalObject, propertyName, *this);
  58         return m_getValue(exec, originalObject, Identifier::from(propertyName), *this);
  59     }
  60
  61     void setValueSlot(JSObject* slotBase, JSValue** valueSlot)
  62     {
  63         m_getValue = KJS_VALUE_SLOT_MARKER;
  64         m_slotBase = slotBase;
  65         m_data.valueSlot = valueSlot;
  66     }
  67
  68     void setStaticEntry(JSObject* slotBase, const HashEntry* staticEntry, GetValueFunc getValue)
  69     {
  70         ASSERT(getValue);
  71         m_getValue = getValue;
  72         m_slotBase = slotBase;
  73         m_data.staticEntry = staticEntry;
  74     }
  75
  76     void setCustom(JSObject* slotBase, GetValueFunc getValue)
  77     {
  78         ASSERT(getValue);
  79         m_getValue = getValue;
  80         m_slotBase = slotBase;
  81     }
  82
  83     void setCustomIndex(JSObject* slotBase, unsigned index, GetValueFunc getValue)
  84     {
  85         ASSERT(getValue);
  86         m_getValue = getValue;
  87         m_slotBase = slotBase;
  88         m_data.index = index;
  89     }
  90
  91     void setCustomNumeric(JSObject* slotBase, GetValueNumericFunc getValue)
  92     {
  93         ASSERT(getValue);
  94         m_slotBase = slotBase;
  95         m_getValue = KJS_NUMERIC_PROPERTY_NAME_SLOT_MARKER;
  96         m_data.numericFunc = getValue;
  97     }
  98
  99     void setGetterSlot(JSObject* slotBase, JSObject* getterFunc)
 100     {
 101         m_getValue = functionGetter;
 102         m_slotBase = slotBase;
 103         m_data.getterFunc = getterFunc;
 104     }
 105
 106     void setUndefined(JSObject *slotBase)
 107     {
 108         m_slotBase = slotBase;
 109         m_getValue = undefinedGetter;
 110     }
 111
 112     void setUngettable(JSObject* slotBase) // Used to signal that you have a property, but trying to get it at this time is an error.
 113     {
 114         m_slotBase = slotBase;
 115         m_getValue = ungettableGetter;
 116     }
 117
 118     JSObject* slotBase() const { return m_slotBase; }
 119
 120     const HashEntry* staticEntry() const { return m_data.staticEntry; }
 121     unsigned index() const { return m_data.index; }
 122
 123 private:
 124     static JSValue* undefinedGetter(ExecState*, JSObject*, const Identifier&, const PropertySlot&);
 125     static JSValue* ungettableGetter(ExecState*, JSObject*, const Identifier&, const PropertySlot&);
 126     static JSValue* functionGetter(ExecState*, JSObject*, const Identifier&, const PropertySlot&);
 127
 128     GetValueFunc m_getValue;
 129
 130     JSObject* m_slotBase;
 131     union {
 132         JSObject* getterFunc;
 133         JSValue** valueSlot;
 134         const HashEntry* staticEntry;
 135         unsigned index;
 136         GetValueNumericFunc numericFunc;
 137     } m_data;
 138 };
 139
 140 }
 141
 142 #endif // KJS_PROPERTY_SLOT_H