src/declarative/qml/v8/qv8variantwrapper.cpp

   1 /****************************************************************************
   2 **
   3 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
   4 ** All rights reserved.
   5 ** Contact: Nokia Corporation (qt-info@nokia.com)
   6 **
   7 ** This file is part of the QtDeclarative module of the Qt Toolkit.
   8 **
   9 ** $QT_BEGIN_LICENSE:LGPL$
  10 ** GNU Lesser General Public License Usage
  11 ** This file may be used under the terms of the GNU Lesser General Public
  12 ** License version 2.1 as published by the Free Software Foundation and
  13 ** appearing in the file LICENSE.LGPL included in the packaging of this
  14 ** file. Please review the following information to ensure the GNU Lesser
  15 ** General Public License version 2.1 requirements will be met:
  16 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  17 **
  18 ** In addition, as a special exception, Nokia gives you certain additional
  19 ** rights. These rights are described in the Nokia Qt LGPL Exception
  20 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  21 **
  22 ** GNU General Public License Usage
  23 ** Alternatively, this file may be used under the terms of the GNU General
  24 ** Public License version 3.0 as published by the Free Software Foundation
  25 ** and appearing in the file LICENSE.GPL included in the packaging of this
  26 ** file. Please review the following information to ensure the GNU General
  27 ** Public License version 3.0 requirements will be met:
  28 ** http://www.gnu.org/copyleft/gpl.html.
  29 **
  30 ** Other Usage
  31 ** Alternatively, this file may be used in accordance with the terms and
  32 ** conditions contained in a signed written agreement between you and Nokia.
  33 **
  34 **
  35 **
  36 **
  37 **
  38 ** $QT_END_LICENSE$
  39 **
  40 ****************************************************************************/
  41
  42 #include "qv8variantwrapper_p.h"
  43 #include "qv8variantresource_p.h"
  44 #include "qv8engine_p.h"
  45 #include <private/qdeclarativeengine_p.h>
  46
  47 QT_BEGIN_NAMESPACE
  48
  49 QV8VariantResource::QV8VariantResource(QV8Engine *engine, const QVariant &data)
  50 : QV8ObjectResource(engine), QDeclarativeEnginePrivate::ScarceResourceData(data), m_isScarceResource(false), m_vmePropertyReferenceCount(0)
  51 {
  52 }
  53
  54 void QV8VariantResource::addVmePropertyReference()
  55 {
  56     if (m_isScarceResource && ++m_vmePropertyReferenceCount == 1) {
  57         // remove from the ep->scarceResources list
  58         // since it is now no longer eligible to be
  59         // released automatically by the engine.
  60         node.remove();
  61     }
  62 }
  63
  64 void QV8VariantResource::removeVmePropertyReference()
  65 {
  66     if (m_isScarceResource && --m_vmePropertyReferenceCount == 0) {
  67         // and add to the ep->scarceResources list
  68         // since it is now eligible to be released
  69         // automatically by the engine.
  70         QDeclarativeEnginePrivate::get(engine->engine())->scarceResources.insert(this);
  71     }
  72 }
  73
  74 QV8VariantWrapper::QV8VariantWrapper()
  75 : m_engine(0)
  76 {
  77 }
  78
  79 QV8VariantWrapper::~QV8VariantWrapper()
  80 {
  81 }
  82
  83 void QV8VariantWrapper::init(QV8Engine *engine)
  84 {
  85     m_engine = engine;
  86     m_toString = qPersistentNew<v8::Function>(v8::FunctionTemplate::New(ToString)->GetFunction());
  87     m_valueOf = qPersistentNew<v8::Function>(v8::FunctionTemplate::New(ValueOf)->GetFunction());
  88
  89     {
  90     v8::Local<v8::FunctionTemplate> ft = v8::FunctionTemplate::New();
  91     ft->InstanceTemplate()->SetFallbackPropertyHandler(Getter, Setter);
  92     ft->InstanceTemplate()->SetHasExternalResource(true);
  93     ft->InstanceTemplate()->MarkAsUseUserObjectComparison();
  94     ft->InstanceTemplate()->SetAccessor(v8::String::New("toString"), ToStringGetter, 0,
  95                                         m_toString, v8::DEFAULT,
  96                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
  97     ft->InstanceTemplate()->SetAccessor(v8::String::New("valueOf"), ValueOfGetter, 0,
  98                                         m_valueOf, v8::DEFAULT,
  99                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
 100     m_constructor = qPersistentNew<v8::Function>(ft->GetFunction());
 101     }
 102     {
 103     m_preserve = qPersistentNew<v8::Function>(v8::FunctionTemplate::New(Preserve)->GetFunction());
 104     m_destroy = qPersistentNew<v8::Function>(v8::FunctionTemplate::New(Destroy)->GetFunction());
 105     v8::Local<v8::FunctionTemplate> ft = v8::FunctionTemplate::New();
 106     ft->InstanceTemplate()->SetFallbackPropertyHandler(Getter, Setter);
 107     ft->InstanceTemplate()->SetHasExternalResource(true);
 108     ft->InstanceTemplate()->MarkAsUseUserObjectComparison();
 109     ft->InstanceTemplate()->SetAccessor(v8::String::New("preserve"), PreserveGetter, 0,
 110                                         m_preserve, v8::DEFAULT,
 111                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
 112     ft->InstanceTemplate()->SetAccessor(v8::String::New("destroy"), DestroyGetter, 0,
 113                                         m_destroy, v8::DEFAULT,
 114                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
 115     ft->InstanceTemplate()->SetAccessor(v8::String::New("toString"), ToStringGetter, 0,
 116                                         m_toString, v8::DEFAULT,
 117                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
 118     ft->InstanceTemplate()->SetAccessor(v8::String::New("valueOf"), ValueOfGetter, 0,
 119                                         m_valueOf, v8::DEFAULT,
 120                                         v8::PropertyAttribute(v8::ReadOnly | v8::DontDelete));
 121     m_scarceConstructor = qPersistentNew<v8::Function>(ft->GetFunction());
 122     }
 123
 124 }
 125
 126 void QV8VariantWrapper::destroy()
 127 {
 128     qPersistentDispose(m_valueOf);
 129     qPersistentDispose(m_toString);
 130     qPersistentDispose(m_destroy);
 131     qPersistentDispose(m_preserve);
 132     qPersistentDispose(m_scarceConstructor);
 133     qPersistentDispose(m_constructor);
 134 }
 135
 136 v8::Local<v8::Object> QV8VariantWrapper::newVariant(const QVariant &value)
 137 {
 138     bool scarceResource = value.type() == QVariant::Pixmap ||
 139                           value.type() == QVariant::Image;
 140
 141     // XXX NewInstance() should be optimized
 142     v8::Local<v8::Object> rv;
 143     QV8VariantResource *r = new QV8VariantResource(m_engine, value);
 144
 145     if (scarceResource) {
 146         QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(m_engine->engine());
 147         Q_ASSERT(ep->scarceResourcesRefCount);
 148         rv = m_scarceConstructor->NewInstance();
 149         r->m_isScarceResource = true;
 150         ep->scarceResources.insert(r);
 151     } else {
 152         rv = m_constructor->NewInstance();
 153     }
 154
 155     rv->SetExternalResource(r);
 156     return rv;
 157 }
 158
 159 bool QV8VariantWrapper::isVariant(v8::Handle<v8::Value> value)
 160 {
 161     return value->IsObject() && v8_resource_cast<QV8VariantResource>(value->ToObject());
 162 }
 163
 164 QVariant QV8VariantWrapper::toVariant(v8::Handle<v8::Object> obj)
 165 {
 166     QV8VariantResource *r =  v8_resource_cast<QV8VariantResource>(obj);
 167     return r?r->data:QVariant();
 168 }
 169
 170 QVariant QV8VariantWrapper::toVariant(QV8ObjectResource *r)
 171 {
 172     Q_ASSERT(r->resourceType() == QV8ObjectResource::VariantType);
 173     return static_cast<QV8VariantResource *>(r)->data;
 174 }
 175
 176 QVariant &QV8VariantWrapper::variantValue(v8::Handle<v8::Value> value)
 177 {
 178     Q_ASSERT(isVariant(value));
 179     QV8VariantResource *r =  v8_resource_cast<QV8VariantResource>(value->ToObject());
 180     return static_cast<QV8VariantResource *>(r)->data;
 181 }
 182
 183 v8::Handle<v8::Value> QV8VariantWrapper::Getter(v8::Local<v8::String> /* property */,
 184                                                 const v8::AccessorInfo & /* info */)
 185 {
 186     return v8::Handle<v8::Value>();
 187 }
 188
 189 v8::Handle<v8::Value> QV8VariantWrapper::Setter(v8::Local<v8::String> /* property */,
 190                                                 v8::Local<v8::Value> value,
 191                                                 const v8::AccessorInfo & /* info */)
 192 {
 193     return value;
 194 }
 195
 196 v8::Handle<v8::Value> QV8VariantWrapper::PreserveGetter(v8::Local<v8::String> property,
 197                                                         const v8::AccessorInfo &info)
 198 {
 199     Q_UNUSED(property);
 200     return info.Data();
 201 }
 202
 203 v8::Handle<v8::Value> QV8VariantWrapper::DestroyGetter(v8::Local<v8::String> property,
 204                                                        const v8::AccessorInfo &info)
 205 {
 206     Q_UNUSED(property);
 207     return info.Data();
 208 }
 209
 210 v8::Handle<v8::Value> QV8VariantWrapper::ToStringGetter(v8::Local<v8::String> property,
 211                                                         const v8::AccessorInfo &info)
 212 {
 213     Q_UNUSED(property);
 214     return info.Data();
 215 }
 216
 217 v8::Handle<v8::Value> QV8VariantWrapper::ValueOfGetter(v8::Local<v8::String> property,
 218                                                        const v8::AccessorInfo &info)
 219 {
 220     Q_UNUSED(property);
 221     return info.Data();
 222 }
 223
 224 v8::Handle<v8::Value> QV8VariantWrapper::Preserve(const v8::Arguments &args)
 225 {
 226     QV8VariantResource *resource = v8_resource_cast<QV8VariantResource>(args.This());
 227     if (resource) {
 228         resource->node.remove();
 229     }
 230     return v8::Undefined();
 231 }
 232
 233 v8::Handle<v8::Value> QV8VariantWrapper::Destroy(const v8::Arguments &args)
 234 {
 235     QV8VariantResource *resource = v8_resource_cast<QV8VariantResource>(args.This());
 236     if (resource) {
 237         resource->data = QVariant();
 238         resource->node.remove();
 239     }
 240     return v8::Undefined();
 241 }
 242
 243 v8::Handle<v8::Value> QV8VariantWrapper::ToString(const v8::Arguments &args)
 244 {
 245     QV8VariantResource *resource = v8_resource_cast<QV8VariantResource>(args.This());
 246     if (resource) {
 247         QString result = resource->data.toString();
 248         if (result.isEmpty() && !resource->data.canConvert(QVariant::String))
 249             result = QString::fromLatin1("QVariant(%0)").arg(QString::fromLatin1(resource->data.typeName()));
 250         return resource->engine->toString(result);
 251     } else {
 252         return v8::Undefined();
 253     }
 254 }
 255
 256 v8::Handle<v8::Value> QV8VariantWrapper::ValueOf(const v8::Arguments &args)
 257 {
 258     QV8VariantResource *resource = v8_resource_cast<QV8VariantResource>(args.This());
 259     if (resource) {
 260         QVariant v = resource->data;
 261         switch (v.type()) {
 262         case QVariant::Invalid:
 263             return v8::Undefined();
 264         case QVariant::String:
 265             return resource->engine->toString(v.toString());
 266         case QVariant::Int:
 267         case QVariant::Double:
 268         case QVariant::UInt:
 269             return v8::Number::New(v.toDouble());
 270         case QVariant::Bool:
 271             return v8::Boolean::New(v.toBool());
 272         default:
 273             break;
 274         }
 275     }
 276     return args.This();
 277 }
 278
 279 QT_END_NAMESPACE