C++ EventTarget类代码示例

void NodeRemovedFromDocument(Node* node)
{
	NodeList* childNodes = node->get_childNodes();

	unsigned int length = childNodes->get_length();

	for (unsigned int i = 0; i < length; ++i)
	{
		Node* child = childNodes->item(i);

		NodeRemovedFromDocument(child);
	}

	Document* ownerDocument = node->get_ownerDocument();

	DocumentEvent* ownerDocumentEvent = dynamic_cast<DocumentEvent*>(ownerDocument);
	ASSERT(ownerDocumentEvent != nullptr);

	MutationEvent* event = dynamic_cast<MutationEvent*>(ownerDocumentEvent->createEvent(S("MutationEvent")));

	event->initMutationEvent(S("DOMNodeRemovedFromDocument"), false, false, NULL/*relatedNode*/, nullptr, nullptr, nullptr, CHANGE_UNKNOWN);

	EventTarget* target = dynamic_cast<EventTarget*>(node);

	target->dispatchEvent(event);
}

bool ScriptExecutionContext::dispatchErrorEvent(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, CachedScript* cachedScript)
{
    EventTarget* target = errorEventTarget();
    if (!target)
        return false;

#if PLATFORM(IOS)
    if (target == target->toDOMWindow() && isDocument()) {
        Settings* settings = static_cast<Document*>(this)->settings();
        if (settings && !settings->shouldDispatchJavaScriptWindowOnErrorEvents())
            return false;
    }
#endif

    String message = errorMessage;
    int line = lineNumber;
    int column = columnNumber;
    String sourceName = sourceURL;
    sanitizeScriptError(message, line, column, sourceName, cachedScript);

    ASSERT(!m_inDispatchErrorEvent);
    m_inDispatchErrorEvent = true;
    RefPtr<ErrorEvent> errorEvent = ErrorEvent::create(message, sourceName, line, column);
    target->dispatchEvent(errorEvent);
    m_inDispatchErrorEvent = false;
    return errorEvent->defaultPrevented();
}

ScriptPromise ImageBitmapFactories::createImageBitmap(ScriptState* scriptState, EventTarget& eventTarget, HTMLVideoElement* video, int sx, int sy, int sw, int sh, ExceptionState& exceptionState)
{
    // This variant does not work in worker threads.
    ASSERT(eventTarget.toDOMWindow());

    if (video->networkState() == HTMLMediaElement::NETWORK_EMPTY) {
        exceptionState.throwDOMException(InvalidStateError, "The provided element has not retrieved data.");
        return ScriptPromise();
    }
    if (video->readyState() <= HTMLMediaElement::HAVE_METADATA) {
        exceptionState.throwDOMException(InvalidStateError, "The provided element's player has no current data.");
        return ScriptPromise();
    }
    if (!sw || !sh) {
        exceptionState.throwDOMException(IndexSizeError, String::format("The source %s provided is 0.", sw ? "height" : "width"));
        return ScriptPromise();
    }
    if (!video->hasSingleSecurityOrigin()) {
        exceptionState.throwSecurityError("The source video contains image data from multiple origins.");
        return ScriptPromise();
    }
    if (!video->webMediaPlayer()->didPassCORSAccessCheck()
        && eventTarget.toDOMWindow()->document()->securityOrigin()->taintsCanvas(video->currentSrc())) {
        exceptionState.throwSecurityError("Cross-origin access to the source video is denied.");
        return ScriptPromise();
    }
    // FIXME: make ImageBitmap creation asynchronous crbug.com/258082
    return fulfillImageBitmap(scriptState, ImageBitmap::create(video, IntRect(sx, sy, sw, sh)));
}

  void revoke() {
    ExecutionContext* executionContext = m_scriptState->getExecutionContext();
    if (!executionContext)
      return;

    ScriptState::Scope scope(m_scriptState);
    v8::Local<v8::Value> value = m_promise.newLocal(m_scriptState->isolate());
    v8::Local<v8::Value> reason =
        m_exception.newLocal(m_scriptState->isolate());
    // Either collected or https://crbug.com/450330
    if (value.IsEmpty() || !value->IsPromise())
      return;

    EventTarget* target = executionContext->errorEventTarget();
    if (target &&
        !executionContext->shouldSanitizeScriptError(m_resourceName,
                                                     m_corsStatus)) {
      PromiseRejectionEventInit init;
      init.setPromise(ScriptPromise(m_scriptState, value));
      init.setReason(ScriptValue(m_scriptState, reason));
      PromiseRejectionEvent* event = PromiseRejectionEvent::create(
          m_scriptState, EventTypeNames::rejectionhandled, init);
      target->dispatchEvent(event);
    }

    if (m_shouldLogToConsole && m_promiseRejectionId) {
      V8PerIsolateData* data = V8PerIsolateData::from(m_scriptState->isolate());
      if (data->threadDebugger())
        data->threadDebugger()->promiseRejectionRevoked(
            m_scriptState->context(), m_promiseRejectionId);
    }
  }

void
nsFormFillController::RemoveWindowListeners(nsPIDOMWindow *aWindow)
{
  if (!aWindow)
    return;

  StopControllingInput();

  nsCOMPtr<nsIDocument> doc = aWindow->GetDoc();
  RemoveForDocument(doc);

  EventTarget* target = aWindow->GetChromeEventHandler();

  if (!target)
    return;

  target->RemoveEventListener(NS_LITERAL_STRING("focus"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("blur"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("pagehide"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("mousedown"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("input"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("keypress"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("compositionstart"), this,
                              true);
  target->RemoveEventListener(NS_LITERAL_STRING("compositionend"), this,
                              true);
  target->RemoveEventListener(NS_LITERAL_STRING("contextmenu"), this, true);
}

void
nsFormFillController::AddWindowListeners(nsPIDOMWindow *aWindow)
{
  if (!aWindow)
    return;

  EventTarget* target = aWindow->GetChromeEventHandler();

  if (!target)
    return;

  target->AddEventListener(NS_LITERAL_STRING("focus"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("blur"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("pagehide"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("mousedown"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("input"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("keypress"), this, true, false);
  target->AddEventListener(NS_LITERAL_STRING("compositionstart"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("compositionend"), this,
                           true, false);
  target->AddEventListener(NS_LITERAL_STRING("contextmenu"), this,
                           true, false);

  // Note that any additional listeners added should ensure that they ignore
  // untrusted events, which might be sent by content that's up to no good.
}

void ScriptedAnimationController::dispatchEvents(const AtomicString& eventInterfaceFilter)
{
    WillBeHeapVector<RefPtrWillBeMember<Event> > events;
    if (eventInterfaceFilter.isEmpty()) {
        events.swap(m_eventQueue);
        m_perFrameEvents.clear();
    } else {
        WillBeHeapVector<RefPtrWillBeMember<Event> > remaining;
        for (auto& event : m_eventQueue) {
            if (event && event->interfaceName() == eventInterfaceFilter) {
                m_perFrameEvents.remove(eventTargetKey(event.get()));
                events.append(event.release());
            } else {
                remaining.append(event.release());
            }
        }
        remaining.swap(m_eventQueue);
    }


    for (size_t i = 0; i < events.size(); ++i) {
        EventTarget* eventTarget = events[i]->target();
        // FIXME: we should figure out how to make dispatchEvent properly virtual to avoid
        // special casting window.
        // FIXME: We should not fire events for nodes that are no longer in the tree.
        if (LocalDOMWindow* window = eventTarget->toDOMWindow())
            window->dispatchEvent(events[i], nullptr);
        else
            eventTarget->dispatchEvent(events[i]);

        InspectorInstrumentation::didRemoveEvent(eventTarget, events[i].get());
    }
}

    void revoke()
    {
        ExecutionContext* executionContext = m_scriptState->executionContext();
        if (!executionContext)
            return;

        ScriptState::Scope scope(m_scriptState);
        v8::Local<v8::Value> value = m_promise.newLocal(m_scriptState->isolate());
        v8::Local<v8::Value> reason = m_exception.newLocal(m_scriptState->isolate());
        // Either collected or https://crbug.com/450330
        if (value.IsEmpty() || !value->IsPromise())
            return;

        EventTarget* target = executionContext->errorEventTarget();
        if (RuntimeEnabledFeatures::promiseRejectionEventEnabled() && target && !executionContext->shouldSanitizeScriptError(m_resourceName, m_corsStatus)) {
            PromiseRejectionEventInit init;
            init.setPromise(ScriptPromise(m_scriptState, value));
            init.setReason(ScriptValue(m_scriptState, reason));
            RefPtrWillBeRawPtr<PromiseRejectionEvent> event = PromiseRejectionEvent::create(m_scriptState, EventTypeNames::rejectionhandled, init);
            target->dispatchEvent(event);
        }

        if (m_shouldLogToConsole) {
            RefPtrWillBeRawPtr<ConsoleMessage> consoleMessage = ConsoleMessage::create(JSMessageSource, RevokedErrorMessageLevel, "Handler added to rejected promise");
            consoleMessage->setRelatedMessageId(m_consoleMessageId);
            executionContext->addConsoleMessage(consoleMessage.release());
        }
    }

bool ScriptExecutionContext::dispatchErrorEvent(const String& errorMessage, int lineNumber, int columnNumber, const String& sourceURL, JSC::Exception* exception, CachedScript* cachedScript)
{
    EventTarget* target = errorEventTarget();
    if (!target)
        return false;

#if PLATFORM(IOS)
    if (target->toDOMWindow() && is<Document>(*this)) {
        Settings* settings = downcast<Document>(*this).settings();
        if (settings && !settings->shouldDispatchJavaScriptWindowOnErrorEvents())
            return false;
    }
#endif

    String message = errorMessage;
    int line = lineNumber;
    int column = columnNumber;
    String sourceName = sourceURL;
    Deprecated::ScriptValue error = exception && exception->value() ? Deprecated::ScriptValue(vm(), exception->value()) : Deprecated::ScriptValue();
    sanitizeScriptError(message, line, column, sourceName, error, cachedScript);

    ASSERT(!m_inDispatchErrorEvent);
    m_inDispatchErrorEvent = true;
    Ref<ErrorEvent> errorEvent = ErrorEvent::create(message, sourceName, line, column, error);
    target->dispatchEvent(errorEvent);
    m_inDispatchErrorEvent = false;
    return errorEvent->defaultPrevented();
}

void EventListenerInfo::getEventListeners(EventTarget* target, WillBeHeapVector<EventListenerInfo>& eventInformation, bool includeAncestors)
{
    // The Node's Ancestors including self.
    WillBeHeapVector<RawPtrWillBeMember<EventTarget>> ancestors;
    ancestors.append(target);
    if (includeAncestors) {
        Node* node = target->toNode();
        for (ContainerNode* ancestor = node ? node->parentOrShadowHostNode() : nullptr; ancestor; ancestor = ancestor->parentOrShadowHostNode())
            ancestors.append(ancestor);
    }

    // Nodes and their Listeners for the concerned event types (order is top to bottom)
    for (size_t i = ancestors.size(); i; --i) {
        EventTarget* ancestor = ancestors[i - 1];
        Vector<AtomicString> eventTypes = ancestor->eventTypes();
        for (size_t j = 0; j < eventTypes.size(); ++j) {
            AtomicString& type = eventTypes[j];
            EventListenerVector* listeners = ancestor->getEventListeners(type);
            if (!listeners)
                continue;
            EventListenerVector filteredListeners;
            filteredListeners.reserveCapacity(listeners->size());
            for (size_t k = 0; k < listeners->size(); ++k) {
                if (listeners->at(k).listener->type() == EventListener::JSEventListenerType)
                    filteredListeners.append(listeners->at(k));
            }
            if (!filteredListeners.isEmpty())
                eventInformation.append(EventListenerInfo(ancestor, type, filteredListeners));
        }
    }
}

void ReplayController::willDispatchEvent(const Event& event, Frame* frame)
{
    EventTarget* target = event.target();
    if (!target && !frame)
        return;

    Document* document = frame ? frame->document() : nullptr;
    // Fetch the document from the event target, because the target could be detached.
    if (Node* node = target->toNode())
        document = node->inDocument() ? &node->document() : node->ownerDocument();
    else if (DOMWindow* window = target->toDOMWindow())
        document = window->document();

    ASSERT(document);
    InputCursor& cursor = document->inputCursor();

#if !LOG_DISABLED
    bool eventIsUnrelated = !cursor.isCapturing() && !cursor.isReplaying();
    logDispatchedDOMEvent(event, eventIsUnrelated);
#else
    UNUSED_PARAM(cursor);
#endif

#if ENABLE_AGGRESSIVE_DETERMINISM_CHECKS
    // To ensure deterministic JS execution, all DOM events must be dispatched deterministically.
    // If these assertions fail, then this DOM event is being dispatched by a nondeterministic EventLoop
    // cycle, and may cause program execution to diverge if any JS code runs because of the DOM event.
    if (cursor.isCapturing() || cursor.isReplaying())
        ASSERT(cursor.withinEventLoopInputExtent());
    else if (cursor.isReplaying())
        ASSERT(dispatcher().isDispatching());
#endif
}

void
nsFormFillController::RemoveWindowListeners(nsIDOMWindow *aWindow)
{
  if (!aWindow)
    return;

  StopControllingInput();

  nsCOMPtr<nsIDOMDocument> domDoc;
  aWindow->GetDocument(getter_AddRefs(domDoc));
  nsCOMPtr<nsIDocument> doc = do_QueryInterface(domDoc);
  PwmgrInputsEnumData ed(this, doc);
  mPwmgrInputs.Enumerate(RemoveForDocumentEnumerator, &ed);

  nsCOMPtr<nsPIDOMWindow> privateDOMWindow(do_QueryInterface(aWindow));
  EventTarget* target = nullptr;
  if (privateDOMWindow)
    target = privateDOMWindow->GetChromeEventHandler();

  if (!target)
    return;

  target->RemoveEventListener(NS_LITERAL_STRING("focus"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("blur"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("pagehide"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("mousedown"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("input"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("keypress"), this, true);
  target->RemoveEventListener(NS_LITERAL_STRING("compositionstart"), this,
                              true);
  target->RemoveEventListener(NS_LITERAL_STRING("compositionend"), this,
                              true);
  target->RemoveEventListener(NS_LITERAL_STRING("contextmenu"), this, true);
}

nsresult
HTMLEditor::EndMoving()
{
  if (mPositioningShadow) {
    nsCOMPtr<nsIPresShell> ps = GetPresShell();
    NS_ENSURE_TRUE(ps, NS_ERROR_NOT_INITIALIZED);

    DeleteRefToAnonymousNode(std::move(mPositioningShadow), ps);

    mPositioningShadow = nullptr;
  }

  EventTarget* eventTarget = GetDOMEventTarget();
  if (eventTarget && mMouseMotionListenerP) {
    EventListenerManager* eventListenerManager =
      eventTarget->GetOrCreateListenerManager();
    eventListenerManager->RemoveEventListenerByType(
                            mMouseMotionListenerP,
                            NS_LITERAL_STRING("mousemove"),
                            TrustedEventsAtSystemGroupBubble());
  }
  mMouseMotionListenerP = nullptr;

  mGrabberClicked = false;
  mIsMoving = false;
  RefPtr<Selection> selection = GetSelection();
  if (!selection) {
    return NS_ERROR_NOT_INITIALIZED;
  }
  nsresult rv = RefereshEditingUI(*selection);
  if (NS_WARN_IF(NS_FAILED(rv))) {
    return rv;
  }
  return NS_OK;
}

void EventQueue::dispatchEvent(PassRefPtr<Event> event)
{
    EventTarget* eventTarget = event->target();
    if (eventTarget->toDOMWindow())
        eventTarget->toDOMWindow()->dispatchEvent(event, 0);
    else
        eventTarget->dispatchEvent(event);
}

bool MediaControls::containsRelatedTarget(Event* event) {
  if (!event->isMouseEvent())
    return false;
  EventTarget* relatedTarget = toMouseEvent(event)->relatedTarget();
  if (!relatedTarget)
    return false;
  return contains(relatedTarget->toNode());
}