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## Qt暴露QObject给JSC引擎的API源码

void QWebFrameAdapter::addToJavaScriptWindowObject(const QString& name, QObject* object, ValueOwnership ownership){    if (!pageAdapter->settings->testAttribute(QWebSettings::JavascriptEnabled))        return;    JSC::Bindings::QtInstance::ValueOwnership valueOwnership = static_cast
   
    (ownership);    JSDOMWindow* window = toJSDOMWindow(frame, mainThreadNormalWorld());    JSC::Bindings::RootObject* root;    if (valueOwnership == JSC::Bindings::QtInstance::QtOwnership)        root = frame->script()->cacheableBindingRootObject();    else        root = frame->script()->bindingRootObject();    if (!window) {        qDebug() << "Warning: couldn't get window object";        return;    }    if (!root) {        qDebug() << "Warning: couldn't get root object";        return;    }    JSC::ExecState* exec = window->globalExec();    JSC::JSLockHolder lock(exec);    JSC::JSObject* runtimeObject = JSC::Bindings::QtInstance::getQtInstance(object, root, valueOwnership)->createRuntimeObject(exec);    JSC::PutPropertySlot slot;    window->methodTable()->put(window, exec, JSC::Identifier(&exec->vm(), reinterpret_cast_ptr
    
     (name.constData()), name.length()), runtimeObject, slot);}
    
   

#include "config.h"#include "BridgeJSC.h"#include "JSDOMWindowBase.h"#include "runtime_object.h"#include "runtime_root.h"#include "runtime/JSLock.h"#include "runtime/ObjectPrototype.h"#if PLATFORM(QT)#include "qt_instance.h"#endifnamespace JSC {namespace Bindings {Array::Array(PassRefPtr
   
     rootObject)    : m_rootObject(rootObject){    ASSERT(m_rootObject);}Array::~Array(){}Instance::Instance(PassRefPtr
    
      rootObject)    : m_rootObject(rootObject){    ASSERT(m_rootObject);}Instance::~Instance(){    ASSERT(!m_runtimeObject);}void Instance::begin(){    virtualBegin();}void Instance::end(){    virtualEnd();}JSObject* Instance::createRuntimeObject(ExecState* exec){    ASSERT(m_rootObject);    ASSERT(m_rootObject->isValid());    if (RuntimeObject* existingObject = m_runtimeObject.get())        return existingObject;    JSLockHolder lock(exec);    RuntimeObject* newObject = newRuntimeObject(exec);    m_runtimeObject = PassWeak
     
      (newObject);    m_rootObject->addRuntimeObject(exec->vm(), newObject);    return newObject;}RuntimeObject* Instance::newRuntimeObject(ExecState* exec){    JSLockHolder lock(exec);    // FIXME: deprecatedGetDOMStructure uses the prototype off of the wrong global object    // We need to pass in the right global object for "i".    return RuntimeObject::create(exec, exec->lexicalGlobalObject(), WebCore::deprecatedGetDOMStructure
      
       (exec), this);}void Instance::willInvalidateRuntimeObject(){    m_runtimeObject.clear();}RootObject* Instance::rootObject() const{    return m_rootObject && m_rootObject->isValid() ? m_rootObject.get() : 0;}
      
     
    
   

## Qt基于JSC内定的bridge实例进行继承和扩展(为qt平台方便访问)

class QtInstance : public Instance {public:    enum ValueOwnership {        QtOwnership,        ScriptOwnership,        AutoOwnership    };    ~QtInstance();    virtual Class* getClass() const;    virtual RuntimeObject* newRuntimeObject(ExecState*);    virtual void begin();    virtual void end();    virtual JSValue valueOf(ExecState*) const;    virtual JSValue defaultValue(ExecState*, PreferredPrimitiveType) const;    virtual JSValue getMethod(ExecState*, PropertyName);    virtual JSValue invokeMethod(ExecState*, RuntimeMethod*);    virtual void getPropertyNames(ExecState*, PropertyNameArray&);    JSValue stringValue(ExecState* exec) const;    JSValue numberValue(ExecState* exec) const;    JSValue booleanValue() const;    QObject* getObject() const { return m_object.data(); }    QObject* hashKey() const { return m_hashkey; }    static PassRefPtr
   
     getQtInstance(QObject*, PassRefPtr
    
     , ValueOwnership);    virtual bool getOwnPropertySlot(JSObject*, ExecState*, PropertyName, PropertySlot&);    virtual void put(JSObject*, ExecState*, PropertyName, JSValue, PutPropertySlot&);    static QtInstance* getInstance(JSObject*);private:    static PassRefPtr
     
       create(QObject *instance, PassRefPtr
      
        rootObject, ValueOwnership ownership)    {        return adoptRef(new QtInstance(instance, rootObject, ownership));    }    friend class QtClass;    friend class QtField;    friend class QtRuntimeMethod;    QtInstance(QObject*, PassRefPtr
       
        , ValueOwnership); // Factory produced only..    mutable QtClass* m_class;    QPointer
        
          m_object; QObject* m_hashkey; mutable QHash
         
           m_methods; mutable QHash
          
            m_fields; ValueOwnership m_ownership;};
          
         
        
       
      
     
    
   

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