flutter_flutter/engine/core/events/EventTarget.cpp

/*
 * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
 *           (C) 1999 Antti Koivisto (koivisto@kde.org)
 *           (C) 2001 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
 *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. 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.
 *
 */

#include "sky/engine/core/events/EventTarget.h"

#include "gen/sky/platform/RuntimeEnabledFeatures.h"
#include "sky/engine/bindings/exception_state.h"
#include "sky/engine/core/dom/Document.h"
#include "sky/engine/core/dom/ExceptionCode.h"
#include "sky/engine/core/dom/ExecutionContext.h"
#include "sky/engine/core/editing/Editor.h"
#include "sky/engine/core/events/Event.h"
#include "sky/engine/core/frame/LocalDOMWindow.h"
#include "sky/engine/platform/EventDispatchForbiddenScope.h"
#include "sky/engine/tonic/dart_gc_visitor.h"
#include "sky/engine/wtf/StdLibExtras.h"
#include "sky/engine/wtf/Vector.h"

using namespace WTF;

namespace blink {

EventTargetData::EventTargetData()
{
}

EventTargetData::~EventTargetData()
{
}

EventTarget::EventTarget()
{
}

EventTarget::~EventTarget()
{
}

void EventTarget::AcceptDartGCVisitor(DartGCVisitor& visitor) const
{
    if (!visitor.have_found_set())
        visitor.AddToSetForRoot(this, dart_wrapper());
    EventListenerIterator iterator(this);
    while (EventListener* listener = iterator.nextListener())
        listener->AcceptDartGCVisitor(visitor);
    DartWrappable::AcceptDartGCVisitor(visitor);
}

Node* EventTarget::toNode()
{
    return 0;
}

LocalDOMWindow* EventTarget::toDOMWindow()
{
    return 0;
}

inline LocalDOMWindow* EventTarget::executingWindow()
{
    if (ExecutionContext* context = executionContext())
        return context->executingWindow();
    return 0;
}

bool EventTarget::addEventListener(const AtomicString& eventType, PassRefPtr<EventListener> listener, bool useCapture)
{
    // FIXME: listener null check should throw TypeError (and be done in
    // generated bindings), but breaks legacy content. http://crbug.com/249598
    if (!listener)
        return false;
    return ensureEventTargetData().eventListenerMap.add(eventType, listener, useCapture);
}

bool EventTarget::removeEventListener(const AtomicString& eventType, PassRefPtr<EventListener> listener, bool useCapture)
{
    EventTargetData* d = eventTargetData();
    if (!d)
        return false;

    size_t indexOfRemovedListener;

    if (!d->eventListenerMap.remove(eventType, listener.get(), useCapture, indexOfRemovedListener))
        return false;

    // Notify firing events planning to invoke the listener at 'index' that
    // they have one less listener to invoke.
    if (!d->firingEventIterators)
        return true;
    for (size_t i = 0; i < d->firingEventIterators->size(); ++i) {
        FiringEventIterator& firingIterator = d->firingEventIterators->at(i);
        if (eventType != firingIterator.eventType)
            continue;

        if (indexOfRemovedListener >= firingIterator.end)
            continue;

        --firingIterator.end;
        if (indexOfRemovedListener <= firingIterator.iterator)
            --firingIterator.iterator;
    }

    return true;
}

bool EventTarget::dispatchEvent(PassRefPtr<Event> event, ExceptionState& exceptionState)
{
    if (!event) {
        exceptionState.ThrowDOMException(InvalidStateError, "The event provided is null.");
        return false;
    }
    if (event->type().isEmpty()) {
        exceptionState.ThrowDOMException(InvalidStateError, "The event provided is uninitialized.");
        return false;
    }
    if (event->isBeingDispatched()) {
        exceptionState.ThrowDOMException(InvalidStateError, "The event is already being dispatched.");
        return false;
    }

    if (!executionContext())
        return false;

    return dispatchEvent(event);
}

bool EventTarget::dispatchEvent(PassRefPtr<Event> event)
{
    event->setTarget(this);
    event->setCurrentTarget(this);
    event->setEventPhase(Event::AT_TARGET);
    bool defaultPrevented = fireEventListeners(event.get());
    event->setEventPhase(0);
    return defaultPrevented;
}

bool EventTarget::fireEventListeners(Event* event)
{
    ASSERT(!EventDispatchForbiddenScope::isEventDispatchForbidden());
    ASSERT(event && !event->type().isEmpty());

    EventTargetData* data = eventTargetData();
    if (!data)
        return true;

    if (EventListenerVector* listeners = data->eventListenerMap.find(event->type()))
        fireEventListeners(event, data, *listeners);

    Editor::countEvent(executionContext(), event);
    return !event->defaultPrevented();
}

void EventTarget::fireEventListeners(Event* event, EventTargetData* d, EventListenerVector& entry)
{
    RefPtr<EventTarget> protect(this);

    // Fire all listeners registered for this event. Don't fire listeners removed
    // during event dispatch. Also, don't fire event listeners added during event
    // dispatch. Conveniently, all new event listeners will be added after or at
    // index |size|, so iterating up to (but not including) |size| naturally excludes
    // new event listeners.

    size_t i = 0;
    size_t size = entry.size();
    if (!d->firingEventIterators)
        d->firingEventIterators = adoptPtr(new FiringEventIteratorVector);
    d->firingEventIterators->append(FiringEventIterator(event->type(), i, size));
    for ( ; i < size; ++i) {
        RegisteredEventListener& registeredListener = entry[i];
        if (event->eventPhase() == Event::CAPTURING_PHASE && !registeredListener.useCapture)
            continue;
        if (event->eventPhase() == Event::BUBBLING_PHASE && registeredListener.useCapture)
            continue;

        // If stopImmediatePropagation has been called, we just break out immediately, without
        // handling any more events on this target.
        if (event->immediatePropagationStopped())
            break;

        ExecutionContext* context = executionContext();
        if (!context)
            break;

        // To match Mozilla, the AT_TARGET phase fires both capturing and bubbling
        // event listeners, even though that violates some versions of the DOM spec.
        registeredListener.listener->handleEvent(context, event);
    }
    d->firingEventIterators->removeLast();
}

const EventListenerVector& EventTarget::getEventListeners(const AtomicString& eventType)
{
    DEFINE_STATIC_LOCAL(EventListenerVector, emptyVector, ());

    EventTargetData* d = eventTargetData();
    if (!d)
        return emptyVector;

    EventListenerVector* listenerVector = d->eventListenerMap.find(eventType);
    if (!listenerVector)
        return emptyVector;

    return *listenerVector;
}

Vector<AtomicString> EventTarget::eventTypes()
{
    EventTargetData* d = eventTargetData();
    return d ? d->eventListenerMap.eventTypes() : Vector<AtomicString>();
}

void EventTarget::removeAllEventListeners()
{
    EventTargetData* d = eventTargetData();
    if (!d)
        return;
    d->eventListenerMap.clear();

    // Notify firing events planning to invoke the listener at 'index' that
    // they have one less listener to invoke.
    if (d->firingEventIterators) {
        for (size_t i = 0; i < d->firingEventIterators->size(); ++i) {
            d->firingEventIterators->at(i).iterator = 0;
            d->firingEventIterators->at(i).end = 0;
        }
    }
}

} // namespace blink