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** This file is part of the plugins of the Qt Toolkit.
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** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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****************************************************************************/

#include "qeventdispatcher_glib_p.h"

#include "qguiapplication.h"

#include "qplatformdefs.h"

#include <glib.h>
#include "private/qguiapplication_p.h"

#include <qdebug.h>

QT_BEGIN_NAMESPACE

struct GUserEventSource
{
    GSource source;
    QPAEventDispatcherGlib *q;
};

static gboolean userEventSourcePrepare(GSource *s, gint *timeout)
{
    Q_UNUSED(s)
    Q_UNUSED(timeout)

    return QWindowSystemInterface::windowSystemEventsQueued() > 0;
}

static gboolean userEventSourceCheck(GSource *source)
{
    return userEventSourcePrepare(source, 0);
}

static gboolean userEventSourceDispatch(GSource *source, GSourceFunc, gpointer)
{
    GUserEventSource *userEventSource = reinterpret_cast<GUserEventSource *>(source);
    QPAEventDispatcherGlib *dispatcher = userEventSource->q;
    QWindowSystemInterface::sendWindowSystemEvents(dispatcher->m_flags);
    return true;
}

static GSourceFuncs userEventSourceFuncs = {
    userEventSourcePrepare,
    userEventSourceCheck,
    userEventSourceDispatch,
    NULL,
    NULL,
    NULL
};

QPAEventDispatcherGlibPrivate::QPAEventDispatcherGlibPrivate(GMainContext *context)
    : QEventDispatcherGlibPrivate(context)
{
    Q_Q(QPAEventDispatcherGlib);
    userEventSource = reinterpret_cast<GUserEventSource *>(g_source_new(&userEventSourceFuncs,
                                                                       sizeof(GUserEventSource)));
    userEventSource->q = q;
    g_source_set_can_recurse(&userEventSource->source, true);
    g_source_attach(&userEventSource->source, mainContext);
}


QPAEventDispatcherGlib::QPAEventDispatcherGlib(QObject *parent)
    : QEventDispatcherGlib(*new QPAEventDispatcherGlibPrivate, parent)
    , m_flags(QEventLoop::AllEvents)
{
    Q_D(QPAEventDispatcherGlib);
    d->userEventSource->q = this;
}

QPAEventDispatcherGlib::~QPAEventDispatcherGlib()
{
    Q_D(QPAEventDispatcherGlib);

    g_source_destroy(&d->userEventSource->source);
    g_source_unref(&d->userEventSource->source);
    d->userEventSource = 0;
}

bool QPAEventDispatcherGlib::processEvents(QEventLoop::ProcessEventsFlags flags)
{
    m_flags = flags;
    return QEventDispatcherGlib::processEvents(m_flags);
}

QT_END_NAMESPACE