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#include "autosaver.h"

#include <QtCore/QDir>

#include <QtCore/QCoreApplication>

#include <QtCore/QMetaObject>

#include <QtDebug>

#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.";

}

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";

    }

}