C++ jsc::JSObject类代码示例

/*!
  \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));
}

String getEventListenerHandlerBody(ScriptExecutionContext* context, ScriptState* scriptState, EventListener* eventListener)
{
    const JSEventListener* jsListener = JSEventListener::cast(eventListener);
    if (!jsListener)
        return "";
    JSC::JSObject* jsFunction = jsListener->jsFunction(context);
    if (!jsFunction)
        return "";
    return jsFunction->toString(scriptState);
}

String eventListenerHandlerBody(Document* document, EventListener* eventListener)
{
    const JSEventListener* jsListener = JSEventListener::cast(eventListener);
    if (!jsListener)
        return "";
    JSC::JSObject* jsFunction = jsListener->jsFunction(document);
    if (!jsFunction)
        return "";
    return ustringToString(jsFunction->toString(scriptStateFromNode(jsListener->isolatedWorld(), document)));
}

WebFrame* WebFrame::frameForContext(JSContextRef context)
{
    JSObjectRef globalObjectRef = JSContextGetGlobalObject(context);
    JSC::JSObject* globalObjectObj = toJS(globalObjectRef);
    if (strcmp(globalObjectObj->classInfo()->className, "JSDOMWindowShell") != 0)
        return 0;

    Frame* coreFrame = static_cast<JSDOMWindowShell*>(globalObjectObj)->window()->impl()->frame();
    return static_cast<WebFrameLoaderClient*>(coreFrame->loader()->client())->webFrame();
}

String eventListenerHandlerBody(Document* document, EventListener* eventListener)
{
    const JSEventListener* jsListener = JSEventListener::cast(eventListener);
    if (!jsListener)
        return "";
    JSLock lock(SilenceAssertionsOnly);
    JSC::JSObject* jsFunction = jsListener->jsFunction(document);
    if (!jsFunction)
        return "";
    ScriptState* scriptState = scriptStateFromNode(jsListener->isolatedWorld(), document);
    return ustringToString(jsFunction->toString(scriptState)->value(scriptState));
}

String eventListenerHandlerBody(Document* document, EventListener* eventListener)
{
    const JSEventListener* jsListener = JSEventListener::cast(eventListener);
    ASSERT(jsListener);
    if (!jsListener)
        return "";
    JSLockHolder lock(jsListener->isolatedWorld()->globalData());
    JSC::JSObject* jsFunction = jsListener->jsFunction(document);
    if (!jsFunction)
        return "";
    ScriptState* scriptState = scriptStateFromNode(jsListener->isolatedWorld(), document);
    return jsFunction->toString(scriptState)->value(scriptState);
}

void HTMLPlugInImageElement::didAddUserAgentShadowRoot(ShadowRoot* root)
{
    HTMLPlugInElement::didAddUserAgentShadowRoot(root);
    if (displayState() >= PreparingPluginReplacement)
        return;

    Page* page = document().page();
    if (!page)
        return;

    // Reset any author styles that may apply as we only want explicit
    // styles defined in the injected user agents stylesheets to specify
    // the look-and-feel of the snapshotted plug-in overlay. 
    root->setResetStyleInheritance(true);
    
    String mimeType = loadedMimeType();

    DOMWrapperWorld& isolatedWorld = plugInImageElementIsolatedWorld();
    document().ensurePlugInsInjectedScript(isolatedWorld);

    ScriptController& scriptController = document().frame()->script();
    JSDOMGlobalObject* globalObject = JSC::jsCast<JSDOMGlobalObject*>(scriptController.globalObject(isolatedWorld));
    JSC::ExecState* exec = globalObject->globalExec();

    JSC::JSLockHolder lock(exec);

    JSC::MarkedArgumentBuffer argList;
    argList.append(toJS(exec, globalObject, root));
    argList.append(jsString(exec, titleText(page, mimeType)));
    argList.append(jsString(exec, subtitleText(page, mimeType)));
    
    // This parameter determines whether or not the snapshot overlay should always be visible over the plugin snapshot.
    // If no snapshot was found then we want the overlay to be visible.
    argList.append(JSC::jsBoolean(!m_snapshotImage));

    // It is expected the JS file provides a createOverlay(shadowRoot, title, subtitle) function.
    JSC::JSObject* overlay = globalObject->get(exec, JSC::Identifier::fromString(exec, "createOverlay")).toObject(exec);
    if (!overlay) {
        ASSERT(exec->hadException());
        exec->clearException();
        return;
    }
    JSC::CallData callData;
    JSC::CallType callType = overlay->methodTable()->getCallData(overlay, callData);
    if (callType == JSC::CallType::None)
        return;

    JSC::call(exec, overlay, callType, callData, globalObject, argList);
    exec->clearException();
}

QScriptValue QScriptContext::activationObject() const
{
    JSC::CallFrame *frame = const_cast<JSC::ExecState*>(QScriptEnginePrivate::frameForContext(this));
    QScript::APIShim shim(QScript::scriptEngineFromExec(frame));
    JSC::JSObject *result = 0;

    uint flags = QScriptEnginePrivate::contextFlags(frame);
    if ((flags & QScriptEnginePrivate::NativeContext) && !(flags & QScriptEnginePrivate::HasScopeContext)) {
        //For native functions, lazily create it if needed
        QScript::QScriptActivationObject *scope = new (frame) QScript::QScriptActivationObject(frame);
        frame->setScopeChain(frame->scopeChain()->copy()->push(scope));
        result = scope;
        QScriptEnginePrivate::setContextFlags(frame, flags | QScriptEnginePrivate::HasScopeContext);
    } else {
        // look in scope chain
        JSC::ScopeChainNode *node = frame->scopeChain();
        JSC::ScopeChainIterator it(node);
        for (it = node->begin(); it != node->end(); ++it) {
            if ((*it) && (*it)->isVariableObject()) {
                result = *it;
                break;
            }
        }
    }
    if (!result) {
        if (!parentContext())
            return engine()->globalObject();

        qWarning("QScriptContext::activationObject:  could not get activation object for frame");
        return QScriptValue();
        /*JSC::CodeBlock *codeBlock = frame->codeBlock();
        if (!codeBlock) {
            // non-Qt native function 
            Q_ASSERT(true); //### this should in theorry not happen
            result = new (frame)QScript::QScriptActivationObject(frame);
        } else {
            // ### this is wrong
            JSC::FunctionBodyNode *body = static_cast<JSC::FunctionBodyNode*>(codeBlock->ownerNode());
            result = new (frame)JSC::JSActivation(frame, body);
        }*/
    }

    if (result && result->inherits(&QScript::QScriptActivationObject::info)
        && (static_cast<QScript::QScriptActivationObject*>(result)->delegate() != 0)) {
        // Return the object that property access is being delegated to
        result = static_cast<QScript::QScriptActivationObject*>(result)->delegate();
    }

    return QScript::scriptEngineFromExec(frame)->scriptValueFromJSCValue(result);
}

/*!
  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;
    }
}

void setDocumentEventHandlerAttribute(JSC::ExecState& state, JSC::JSObject& wrapper, HTMLElement& element, const AtomicString& eventType, JSC::JSValue value)
{
    ASSERT(wrapper.globalObject());
    auto& document = element.document();
    auto* documentWrapper = jsDocumentCast(toJS(&state, JSC::jsCast<JSDOMGlobalObject*>(wrapper.globalObject()), document));
    ASSERT(documentWrapper);
    document.setAttributeEventListener(eventType, createEventListenerForEventHandlerAttribute(state, value, *documentWrapper));
}

bool toVector(JSC::ExecState* exec, JSC::JSValue value, Vector<T, inlineCapacity>& vector)
{
    if (!value.isObject())
        return false;

    JSC::JSObject* object = asObject(value);
    int32_t length = object->get(exec, JSC::Identifier(exec, "length")).toInt32(exec);
    vector.resize(length);

    for (int32_t i = 0; i < length; ++i) {
        JSC::JSValue v = object->get(exec, i);
        if (exec->hadException())
            return false;
        vector[i] = static_cast<T>(v.toNumber(exec));
    }

    return true;
}

/*
Returns the scope chain entry at \a index.  If index is less than 0, returns
entries starting at the end.  For example, scopeChainValue(context, -1) will return
the value last in the scope chain.
*/
QScriptValue QScriptDeclarativeClass::scopeChainValue(QScriptContext *context, int index)
{
    context->activationObject(); //ensure the creation of the normal scope for native context
    const JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(context);
    QScriptEnginePrivate *engine = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(engine);

    JSC::ScopeChainNode *node = frame->scopeChain();
    JSC::ScopeChainIterator it(node);

    if (index < 0) {
        int count = 0;
        for (it = node->begin(); it != node->end(); ++it) 
            ++count;

        index = qAbs(index);
        if (index > count)
            return QScriptValue();
        else
            index = count - index;
    }

    for (it = node->begin(); it != node->end(); ++it) {

        if (index == 0) {

            JSC::JSObject *object = *it;
            if (!object) return QScriptValue();

            if (object->inherits(&QScript::QScriptActivationObject::info)
                    && (static_cast<QScript::QScriptActivationObject*>(object)->delegate() != 0)) {
                // Return the object that property access is being delegated to
                object = static_cast<QScript::QScriptActivationObject*>(object)->delegate();
            }
            return engine->scriptValueFromJSCValue(object);

        } else {
            --index;
        }

    }

    return QScriptValue();
}

bool toVector(JSC::ExecState& state, JSC::JSValue value, Vector<T, inlineCapacity>& vector)
{
    if (!value.isObject())
        return false;
    
    JSC::JSObject* object = asObject(value);
    int32_t length = object->get(&state, state.vm().propertyNames->length).toInt32(&state);
    
    if (!vector.tryReserveCapacity(length))
        return false;
    vector.resize(length);
    
    for (int32_t i = 0; i < length; ++i) {
        JSC::JSValue v = object->get(&state, i);
        if (state.hadException())
            return false;
        vector[i] = static_cast<T>(v.toNumber(&state));
    }
    
    return true;
}

/*!
  \internal
  \since 4.5

  Returns the scope chain of this QScriptContext.
*/
QScriptValueList QScriptContext::scopeChain() const
{
    activationObject(); //ensure the creation of the normal scope for native context
    const JSC::CallFrame *frame = QScriptEnginePrivate::frameForContext(this);
    QScriptEnginePrivate *engine = QScript::scriptEngineFromExec(frame);
    QScript::APIShim shim(engine);
    QScriptValueList result;
    JSC::ScopeChainNode *node = frame->scopeChain();
    JSC::ScopeChainIterator it(node);
    for (it = node->begin(); it != node->end(); ++it) {
        JSC::JSObject *object = *it;
        if (!object)
            continue;
        if (object->inherits(&QScript::QScriptActivationObject::info)
            && (static_cast<QScript::QScriptActivationObject*>(object)->delegate() != 0)) {
            // Return the object that property access is being delegated to
            object = static_cast<QScript::QScriptActivationObject*>(object)->delegate();
        }
        result.append(engine->scriptValueFromJSCValue(object));
    }
    return result;
}

bool WebFrame::stringByEvaluatingJavaScriptInScriptWorld(WebScriptWorld* world, void* jsGlobalObject, const char* script, const char** evaluationResult)
{
    if (!world || !jsGlobalObject || !evaluationResult)
        return false;
    *evaluationResult = 0;

    Frame* coreFrame = core(this);
    JSObjectRef globalObjectRef = reinterpret_cast<JSObjectRef>(jsGlobalObject);
    String string = String(script);

    // Start off with some guess at a frame and a global object, we'll try to do better...!
    JSDOMWindow* anyWorldGlobalObject = coreFrame->script()->globalObject(mainThreadNormalWorld());

    // The global object is probably a shell object? - if so, we know how to use this!
    JSC::JSObject* globalObjectObj = toJS(globalObjectRef);
    if (!strcmp(globalObjectObj->classInfo()->className, "JSDOMWindowShell"))
        anyWorldGlobalObject = static_cast<JSDOMWindowShell*>(globalObjectObj)->window();

    // Get the frame from the global object we've settled on.
    Frame* frame = anyWorldGlobalObject->impl()->frame();
    ASSERT(frame->document());
    JSC::JSValue result = frame->script()->executeScriptInWorld(world->world(), string, true).jsValue();

    if (!frame) // In case the script removed our frame from the page.
        return true;

    // This bizarre set of rules matches behavior from WebKit for Safari 2.0.
    // If you don't like it, use -[WebScriptObject evaluateWebScript:] or 
    // JSEvaluateScript instead, since they have less surprising semantics.
    if (!result || !result.isBoolean() && !result.isString() && !result.isNumber())
        return true;

    JSC::JSLock lock(JSC::SilenceAssertionsOnly);
    String resultString = ustringToString(result.toString(anyWorldGlobalObject->globalExec()));
    *evaluationResult = strdup(resultString.utf8().data());

    return true;
}