C++ QScriptEnginePrivate::scriptValueToJSCValue方法代码示例

/*!
  \internal
  \since 4.5

  Adds the given \a object to the front of this context's scope chain.

  If \a object is not an object, this function does nothing.
*/
void QScriptContext::pushScope(const QScriptValue &object)
{
    activationObject(); //ensure the creation of the normal scope for native context
    if (!object.isObject())
        return;
    else if (object.engine() != engine()) {
        qWarning("QScriptContext::pushScope() failed: "
                 "cannot push an object created in "
                 "a different engine");
        return;
    }
    JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(this);
    QScriptEnginePrivate *engine = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(engine);
    JSC::JSObject *jscObject = JSC::asObject(engine->scriptValueToJSCValue(object));
    if (jscObject == engine->originalGlobalObjectProxy)
        jscObject = engine->originalGlobalObject();
    JSC::ScopeChainNode *scope = frame->scopeChain();
    Q_ASSERT(scope != 0);
    if (!scope->object) {
        // pushing to an "empty" chain
        if (!jscObject->isGlobalObject()) {
            qWarning("QScriptContext::pushScope() failed: initial object in scope chain has to be the Global Object");
            return;
        }
        scope->object = jscObject;
    }
    else
        frame->setScopeChain(scope->push(jscObject));
}

bool ClassObjectDelegate::getOwnPropertySlot(QScriptObject* object,
                                             JSC::ExecState *exec,
                                             const JSC::Identifier &propertyName,
                                             JSC::PropertySlot &slot)
{
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    QScript::SaveFrameHelper saveFrame(engine, exec);
    // for compatibility with the old back-end, normal JS properties
    // are queried first.
    if (QScriptObjectDelegate::getOwnPropertySlot(object, exec, propertyName, slot))
        return true;

    QScriptValue scriptObject = engine->scriptValueFromJSCValue(object);
    QScriptString scriptName;
    QScriptStringPrivate scriptName_d(engine, propertyName, QScriptStringPrivate::StackAllocated);
    QScriptStringPrivate::init(scriptName, &scriptName_d);
    uint id = 0;
    QScriptClass::QueryFlags flags = m_scriptClass->queryProperty(
        scriptObject, scriptName, QScriptClass::HandlesReadAccess, &id);
    if (flags & QScriptClass::HandlesReadAccess) {
        QScriptValue value = m_scriptClass->property(scriptObject, scriptName, id);
        if (!value.isValid()) {
            // The class claims to have the property, but returned an invalid
            // value. Silently convert to undefined to avoid the invalid value
            // "escaping" into JS.
            value = QScriptValue(QScriptValue::UndefinedValue);
        }
        slot.setValue(engine->scriptValueToJSCValue(value));
        return true;
    }
    return false;
}

bool ClassObjectDelegate::getOwnPropertySlot(QScriptObject* object,
                                             JSC::ExecState *exec,
                                             const JSC::Identifier &propertyName,
                                             JSC::PropertySlot &slot)
{
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    QScript::SaveFrameHelper saveFrame(engine, exec);
    // for compatibility with the old back-end, normal JS properties
    // are queried first.
    if (QScriptObjectDelegate::getOwnPropertySlot(object, exec, propertyName, slot))
        return true;

    QScriptValue scriptObject = engine->scriptValueFromJSCValue(object);
    QScriptString scriptName;
    QScriptStringPrivate scriptName_d(engine, propertyName, QScriptStringPrivate::StackAllocated);
    QScriptStringPrivate::init(scriptName, &scriptName_d);
    uint id = 0;
    QScriptClass::QueryFlags flags = m_scriptClass->queryProperty(
        scriptObject, scriptName, QScriptClass::HandlesReadAccess, &id);
    if (flags & QScriptClass::HandlesReadAccess) {
        QScriptValue value = m_scriptClass->property(scriptObject, scriptName, id);
        slot.setValue(engine->scriptValueToJSCValue(value));
        return true;
    }
    return false;
}

bool GlobalObject::getOwnPropertySlot(JSC::ExecState* exec,
                                      const JSC::Identifier& propertyName,
                                      JSC::PropertySlot& slot)
{
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    if (propertyName == exec->propertyNames().arguments && engine->currentFrame->argumentCount() > 0) {
        JSC::JSValue args = engine->scriptValueToJSCValue(engine->contextForFrame(engine->currentFrame)->argumentsObject());
        slot.setValue(args);
        return true;
    }
    if (customGlobalObject)
        return customGlobalObject->getOwnPropertySlot(exec, propertyName, slot);
    return JSC::JSGlobalObject::getOwnPropertySlot(exec, propertyName, slot);
}

/*!
  Sets the activation object of this QScriptContext to be the given \a
  activation.

  If \a activation is not an object, this function does nothing.

  \note For a context corresponding to a JavaScript function, this is only
  guaranteed to work if there was an QScriptEngineAgent active on the
  engine while the function was evaluated.
*/
void QScriptContext::setActivationObject(const QScriptValue &activation)
{
    if (!activation.isObject())
        return;
    else if (activation.engine() != engine()) {
        qWarning("QScriptContext::setActivationObject() failed: "
                 "cannot set an object created in "
                 "a different engine");
        return;
    }
    JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(this);
    QScriptEnginePrivate *engine = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(engine);
    JSC::JSObject *object = JSC::asObject(engine->scriptValueToJSCValue(activation));
    if (object == engine->originalGlobalObjectProxy)
        object = engine->originalGlobalObject();

    uint flags = QScriptEnginePrivate::contextFlags(frame);
    if ((flags & QScriptEnginePrivate::NativeContext) && !(flags & QScriptEnginePrivate::HasScopeContext)) {
        //For native functions, we create a scope node
        JSC::JSObject *scope = object;
        if (!scope->isVariableObject()) {
            // Create a QScriptActivationObject that acts as a proxy
            scope = new (frame) QScript::QScriptActivationObject(frame, scope);
        }
        frame->setScopeChain(frame->scopeChain()->copy()->push(scope));
        QScriptEnginePrivate::setContextFlags(frame, flags | QScriptEnginePrivate::HasScopeContext);
        return;
    }

    // else replace the first activation object in the scope chain
    JSC::ScopeChainNode *node = frame->scopeChain();
    while (node != 0) {
        if (node->object && node->object->isVariableObject()) {
            if (!object->isVariableObject()) {
                if (node->object->inherits(&QScript::QScriptActivationObject::info)) {
                    static_cast<QScript::QScriptActivationObject*>(node->object)->setDelegate(object);
                } else {
                    // Create a QScriptActivationObject that acts as a proxy
                    node->object = new (frame) QScript::QScriptActivationObject(frame, object);
                }
            } else {
                node->object = object;
            }
            break;
        }
        node = node->next;
    }
}

bool GlobalObject::getOwnPropertyDescriptor(JSC::ExecState* exec,
                                            const JSC::Identifier& propertyName,
                                            JSC::PropertyDescriptor& descriptor)
{
    // Must match the logic of getOwnPropertySlot().
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    if (propertyName == exec->propertyNames().arguments && engine->currentFrame->argumentCount() > 0) {
        // ### Can we get rid of this special handling of the arguments property?
        JSC::JSValue args = engine->scriptValueToJSCValue(engine->contextForFrame(engine->currentFrame)->argumentsObject());
        descriptor.setValue(args);
        return true;
    }
    if (customGlobalObject)
        return customGlobalObject->getOwnPropertyDescriptor(exec, propertyName, descriptor);
    return JSC::JSGlobalObject::getOwnPropertyDescriptor(exec, propertyName, descriptor);
}

bool ClassObjectDelegate::getOwnPropertyDescriptor(QScriptObject *object,
                                                   JSC::ExecState *exec,
                                                   const JSC::Identifier &propertyName,
                                                   JSC::PropertyDescriptor &descriptor)
{
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    QScript::SaveFrameHelper saveFrame(engine, exec);
    // for compatibility with the old back-end, normal JS properties
    // are queried first.
    if (QScriptObjectDelegate::getOwnPropertyDescriptor(object, exec, propertyName, descriptor))
        return true;

    QScriptValue scriptObject = engine->scriptValueFromJSCValue(object);
    QScriptString scriptName;
    QScriptStringPrivate scriptName_d(engine, propertyName, QScriptStringPrivate::StackAllocated);
    QScriptStringPrivate::init(scriptName, &scriptName_d);
    uint id = 0;
    QScriptClass::QueryFlags qflags = m_scriptClass->queryProperty(
        scriptObject, scriptName, QScriptClass::HandlesReadAccess, &id);
    if (qflags & QScriptClass::HandlesReadAccess) {
        QScriptValue::PropertyFlags pflags = m_scriptClass->propertyFlags(scriptObject, scriptName, id);
        unsigned attribs = 0;
        if (pflags & QScriptValue::ReadOnly)
            attribs |= JSC::ReadOnly;
        if (pflags & QScriptValue::SkipInEnumeration)
            attribs |= JSC::DontEnum;
        if (pflags & QScriptValue::Undeletable)
            attribs |= JSC::DontDelete;
        if (pflags & QScriptValue::PropertyGetter)
            attribs |= JSC::Getter;
        if (pflags & QScriptValue::PropertySetter)
            attribs |= JSC::Setter;
        attribs |= pflags & QScriptValue::UserRange;
        // Rather than calling the getter, we could return an access descriptor here.
        QScriptValue value = m_scriptClass->property(scriptObject, scriptName, id);
        if (!value.isValid()) {
            // The class claims to have the property, but returned an invalid
            // value. Silently convert to undefined to avoid the invalid value
            // "escaping" into JS.
            value = QScriptValue(QScriptValue::UndefinedValue);
        }
        descriptor.setDescriptor(engine->scriptValueToJSCValue(value), attribs);
        return true;
    }
    return false;
}

bool DeclarativeObjectDelegate::getOwnPropertySlot(QScriptObject* object,
        JSC::ExecState *exec,
        const JSC::Identifier &propertyName,
        JSC::PropertySlot &slot)
{
    QScriptEnginePrivate *engine = scriptEngineFromExec(exec);
    QScriptDeclarativeClass::Identifier identifier = (void *)propertyName.ustring().rep();

    QScriptDeclarativeClassPrivate *p = QScriptDeclarativeClassPrivate::get(m_class);
    p->context = reinterpret_cast<QScriptContext *>(exec);
    QScriptClass::QueryFlags flags =
        m_class->queryProperty(m_object, identifier, QScriptClass::HandlesReadAccess);
    if (flags & QScriptClass::HandlesReadAccess) {
        QScriptValue value = m_class->property(m_object, identifier);
        p->context = 0;
        slot.setValue(engine->scriptValueToJSCValue(value));
        return true;
    }
    p->context = 0;

    return QScriptObjectDelegate::getOwnPropertySlot(object, exec, propertyName, slot);
}