GObjectEventListener.cpp   [plain text]

/*
 *  Copyright (C) 2010, 2011 Igalia S.L.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "config.h"
#include "GObjectEventListener.h"

#include "Event.h"
#include "WebKitDOMEvent.h"
#include "WebKitDOMEventPrivate.h"
#include "WebKitDOMEventTarget.h"
#include <wtf/HashMap.h>

namespace WebCore {

GObjectEventListener::GObjectEventListener(GObject* target, EventTarget* coreTarget, const char* domEventName, GClosure* handler, bool capture)
    : EventListener(GObjectEventListenerType)
    , m_target(target)
    , m_coreTarget(coreTarget)
    , m_domEventName(domEventName)
    , m_handler(handler)
    , m_capture(capture)
{
    ASSERT(m_coreTarget);
    if (G_CLOSURE_NEEDS_MARSHAL(m_handler.get()))
        g_closure_set_marshal(m_handler.get(), g_cclosure_marshal_generic);
    g_object_weak_ref(m_target, reinterpret_cast<GWeakNotify>(GObjectEventListener::gobjectDestroyedCallback), this);
}

GObjectEventListener::~GObjectEventListener()
{
    if (!m_coreTarget)
        return;
    g_object_weak_unref(m_target, reinterpret_cast<GWeakNotify>(GObjectEventListener::gobjectDestroyedCallback), this);
}

void GObjectEventListener::gobjectDestroyed()
{
    ASSERT(m_coreTarget);

    // Protect 'this' class in case the 'm_coreTarget' holds the last reference,
    // which may cause, inside removeEventListener(), free of this object
    // and later use-after-free with the m_handler = 0; assignment.
    RefPtr<GObjectEventListener> protectedThis(this);

    m_coreTarget->removeEventListener(m_domEventName.data(), *this, m_capture);
    m_coreTarget = nullptr;
    m_handler = nullptr;
}

void GObjectEventListener::handleEvent(ScriptExecutionContext*, Event* event)
{
    GValue parameters[2] = { G_VALUE_INIT, G_VALUE_INIT };
    g_value_init(&parameters[0], WEBKIT_DOM_TYPE_EVENT_TARGET);
    g_value_set_object(&parameters[0], m_target);

    GRefPtr<WebKitDOMEvent> domEvent = adoptGRef(WebKit::kit(event));
    g_value_init(&parameters[1], WEBKIT_DOM_TYPE_EVENT);
    g_value_set_object(&parameters[1], domEvent.get());

    g_closure_invoke(m_handler.get(), 0, 2, parameters, NULL);
    g_value_unset(parameters + 0);
    g_value_unset(parameters + 1);
}

bool GObjectEventListener::operator==(const EventListener& listener) const
{
    if (const GObjectEventListener* gobjectEventListener = GObjectEventListener::cast(&listener))
        return m_target == gobjectEventListener->m_target
            && reinterpret_cast<GCClosure*>(m_handler.get())->callback == reinterpret_cast<GCClosure*>(gobjectEventListener->m_handler.get())->callback;

    return false;
}

}