/*
  modelevent.h

  This file is part of GammaRay, the Qt application inspection and
  manipulation tool.

  Copyright (C) 2015-2017 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com
  Author: Volker Krause <volker.krause@kdab.com>

  Licensees holding valid commercial KDAB GammaRay licenses may use this file in
  accordance with GammaRay Commercial License Agreement provided with the Software.

  Contact info@kdab.com if any conditions of this licensing are not clear to you.

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 2 of the License, or
  (at your option) any later version.

  This program 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 General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef GAMMARAY_MODELEVENT_H
#define GAMMARAY_MODELEVENT_H

#include "gammaray_common_export.h"

#include <QEvent>

QT_BEGIN_NAMESPACE
class QAbstractItemModel;
QT_END_NAMESPACE

namespace GammaRay {
/** Custom event to notify models about them being used/unused.
 *  Useful for suspending expensive operations.
 */
class GAMMARAY_COMMON_EXPORT ModelEvent : public QEvent
{
public:
    explicit ModelEvent(bool modelUsed);
    ~ModelEvent();

    /** Returns @c true if somebody is using the model. */
    bool used() const;

    /** Returns the event id for this type. */
    static QEvent::Type eventType();

private:
    Q_DISABLE_COPY(ModelEvent)
    bool m_used;
};

namespace Model {
/** Convenience function to send a ModelEvent indicating @p model is in use. */
void GAMMARAY_COMMON_EXPORT used(const QAbstractItemModel *model);
/** Convenience function to send a ModelEvent indicating nobody is using @p model. */
void GAMMARAY_COMMON_EXPORT unused(QAbstractItemModel *model);
}
}

#endif // GAMMARAY_MODELEVENT_H
