/*
 * Copyright 2008 Benjamin C. Meyer <ben@meyerhome.net>
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

/****************************************************************************
**
** Copyright (C) 2007-2008 Trolltech ASA. All rights reserved.
**
** This file is part of the demonstration applications of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License versions 2.0 or 3.0 as published by the Free Software
** Foundation and appearing in the files LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file.  Alternatively you may (at
** your option) use any later version of the GNU General Public
** License if such license has been publicly approved by Trolltech ASA
** (or its successors, if any) and the KDE Free Qt Foundation. In
** addition, as a special exception, Trolltech gives you certain
** additional rights. These rights are described in the Trolltech GPL
** Exception version 1.2, which can be found at
** http://www.trolltech.com/products/qt/gplexception/ and in the file
** GPL_EXCEPTION.txt in this package.
**
** Please review the following information to ensure GNU General
** Public Licensing requirements will be met:
** http://trolltech.com/products/qt/licenses/licensing/opensource/. If
** you are unsure which license is appropriate for your use, please
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** or contact the sales department at sales@trolltech.com.
**
** In addition, as a special exception, Trolltech, as the sole
** copyright holder for Qt Designer, grants users of the Qt/Eclipse
** Integration plug-in the right for the Qt/Eclipse Integration to
** link to functionality provided by Qt Designer and its related
** libraries.
**
** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE. Trolltech reserves all rights not expressly
** granted herein.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "autosaver.h"

#include <qdir.h>
#include <qcoreapplication.h>
#include <qmetaobject.h>

#include <qdebug.h>

#define AUTOSAVE_IN  1000 * 3  // seconds
#define MAXWAIT      1000 * 15 // seconds

AutoSaver::AutoSaver(QObject *parent) : QObject(parent)
{
    Q_ASSERT(parent);
}

AutoSaver::~AutoSaver()
{
    if (m_timer.isActive()) {
        qWarning() << "AutoSaver: still active when destroyed, changes not saved.";
        if (parent() && parent()->metaObject())
            qWarning() << parent() << parent()->metaObject()->className() << "should call saveIfNeccessary";
    }
}

void AutoSaver::changeOccurred()
{
    if (m_firstChange.isNull())
        m_firstChange.start();

    if (m_firstChange.elapsed() > MAXWAIT) {
        saveIfNeccessary();
    } else {
        m_timer.start(AUTOSAVE_IN, this);
    }
}

void AutoSaver::timerEvent(QTimerEvent *event)
{
    if (event->timerId() == m_timer.timerId()) {
        saveIfNeccessary();
    } else {
        QObject::timerEvent(event);
    }
}

void AutoSaver::saveIfNeccessary()
{
    if (!m_timer.isActive())
        return;
    m_timer.stop();
    m_firstChange = QTime();
    if (!QMetaObject::invokeMethod(parent(), "save", Qt::DirectConnection)) {
        qWarning() << "AutoSaver: error invoking slot save() on parent";
    }
}