C++ QScriptEnginePrivate::originalGlobalObject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));
}

/*!
  Returns the callee. The callee is the function object that this
  QScriptContext represents an invocation of.
*/
QScriptValue QScriptContext::callee() const
{
    const JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(this);
    QScriptEnginePrivate *eng = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(eng);
    if (frame->callee() == eng->originalGlobalObject()) {
        // This is a pushContext()-created context; the callee is a lie.
        Q_ASSERT(QScriptEnginePrivate::contextFlags(const_cast<JSC::CallFrame*>(frame)) & QScriptEnginePrivate::NativeContext);
        return QScriptValue();
    }
    return eng->scriptValueFromJSCValue(frame->callee());
}

/*!
  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;
    }
}