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IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #ifndef V8AbstractEventListener_h #define V8AbstractEventListener_h #include "bindings/v8/DOMWrapperWorld.h" #include "bindings/v8/ScopedPersistent.h" #include "core/events/EventListener.h" #include <v8.h> #include "wtf/PassRefPtr.h" #include "wtf/RefCounted.h" namespace WebCore { class Event; // There are two kinds of event listeners: HTML or non-HMTL. onload, // onfocus, etc (attributes) are always HTML event handler type; Event // listeners added by Window.addEventListener or // EventTargetNode::addEventListener are non-HTML type. // // Why does this matter? // WebKit does not allow duplicated HTML event handlers of the same type, // but ALLOWs duplicated non-HTML event handlers. class V8AbstractEventListener : public EventListener { public: virtual ~V8AbstractEventListener(); static const V8AbstractEventListener* cast(const EventListener* listener) { return listener->type() == JSEventListenerType ? static_cast<const V8AbstractEventListener*>(listener) : 0; } static V8AbstractEventListener* cast(EventListener* listener) { return const_cast<V8AbstractEventListener*>(cast(const_cast<const EventListener*>(listener))); } // Implementation of EventListener interface. virtual bool operator==(const EventListener& other) OVERRIDE { return this == &other; } virtual void handleEvent(ExecutionContext*, Event*) OVERRIDE; virtual bool isLazy() const { return false; } // Returns the listener object, either a function or an object. v8::Local<v8::Object> getListenerObject(ExecutionContext* context) { // prepareListenerObject can potentially deref this event listener // as it may attempt to compile a function (lazy event listener), get an error // and invoke onerror callback which can execute arbitrary JS code. // Protect this event listener to keep it alive. RefPtr<V8AbstractEventListener> guard(this); prepareListenerObject(context); return m_listener.newLocal(m_isolate); } v8::Local<v8::Object> getExistingListenerObject() { return m_listener.newLocal(m_isolate); } // Provides access to the underlying handle for GC. Returned // value is a weak handle and so not guaranteed to stay alive. v8::Persistent<v8::Object>& existingListenerObjectPersistentHandle() { return m_listener.getUnsafe(); } bool hasExistingListenerObject() { return !m_listener.isEmpty(); } void clearListenerObject() { m_listener.clear(); } virtual bool belongsToTheCurrentWorld() const OVERRIDE FINAL; DOMWrapperWorld& world() const { return *m_world; } v8::Isolate* isolate() const { return m_isolate; } protected: V8AbstractEventListener(bool isAttribute, DOMWrapperWorld&, v8::Isolate*); virtual void prepareListenerObject(ExecutionContext*) { } void setListenerObject(v8::Handle<v8::Object> listener); void invokeEventHandler(ExecutionContext*, Event*, v8::Local<v8::Value> jsEvent); // Get the receiver object to use for event listener call. v8::Local<v8::Object> getReceiverObject(ExecutionContext*, Event*); private: // Implementation of EventListener function. virtual bool virtualisAttribute() const OVERRIDE { return m_isAttribute; } virtual v8::Local<v8::Value> callListenerFunction(ExecutionContext*, v8::Handle<v8::Value> jsevent, Event*) = 0; virtual bool shouldPreventDefault(v8::Local<v8::Value> returnValue); static void setWeakCallback(const v8::WeakCallbackData<v8::Object, V8AbstractEventListener>&); ScopedPersistent<v8::Object> m_listener; // Indicates if this is an HTML type listener. bool m_isAttribute; RefPtr<DOMWrapperWorld> m_world; v8::Isolate* m_isolate; }; } // namespace WebCore #endif // V8AbstractEventListener_h