source: trunk/examples/declarative/cppextensions/plugins/plugin.cpp@ 846

/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation ([email protected])
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
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** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
**     the names of its contributors may be used to endorse or promote
**     products derived from this software without specific prior written
**     permission.
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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****************************************************************************/

#include <QtDeclarative/QDeclarativeExtensionPlugin>
#include <QtDeclarative/qdeclarative.h>
#include <qdebug.h>
#include <qdatetime.h>
#include <qbasictimer.h>
#include <qapplication.h>

// Implements a "TimeModel" class with hour and minute properties
// that change on-the-minute yet efficiently sleep the rest
// of the time.

class MinuteTimer : public QObject
{
    Q_OBJECT
public:
    MinuteTimer(QObject *parent) : QObject(parent)
    {
    }

    void start()
    {
        if (!timer.isActive()) {
            time = QTime::currentTime();
            timer.start(60000-time.second()*1000, this);
        }
    }

    void stop()
    {
        timer.stop();
    }

    int hour() const { return time.hour(); }
    int minute() const { return time.minute(); }

signals:
    void timeChanged();

protected:
    void timerEvent(QTimerEvent *)
    {
        QTime now = QTime::currentTime();
        if (now.second() == 59 && now.minute() == time.minute() && now.hour() == time.hour()) {
            // just missed time tick over, force it, wait extra 0.5 seconds
            time.addSecs(60);
            timer.start(60500, this);
        } else {
            time = now;
            timer.start(60000-time.second()*1000, this);
        }
        emit timeChanged();
    }

private:
    QTime time;
    QBasicTimer timer;
};

//![0]
class TimeModel : public QObject
{
    Q_OBJECT
    Q_PROPERTY(int hour READ hour NOTIFY timeChanged)
    Q_PROPERTY(int minute READ minute NOTIFY timeChanged)
//![0]

public:
    TimeModel(QObject *parent=0) : QObject(parent)
    {
        if (++instances == 1) {
            if (!timer)
                timer = new MinuteTimer(qApp);
            connect(timer, SIGNAL(timeChanged()), this, SIGNAL(timeChanged()));
            timer->start();
        }
    }

    ~TimeModel()
    {
        if (--instances == 0) {
            timer->stop();
        }
    }

    int minute() const { return timer->minute(); }
    int hour() const { return timer->hour(); }

signals:
    void timeChanged();

private:
    QTime t;
    static MinuteTimer *timer;
    static int instances;
};

int TimeModel::instances=0;
MinuteTimer *TimeModel::timer=0;

//![plugin]
class QExampleQmlPlugin : public QDeclarativeExtensionPlugin
{
    Q_OBJECT
public:
    void registerTypes(const char *uri)
    {
        Q_ASSERT(uri == QLatin1String("com.nokia.TimeExample"));
        qmlRegisterType<TimeModel>(uri, 1, 0, "Time");
    }
};
//![plugin]

#include "plugin.moc"

//![export]
Q_EXPORT_PLUGIN2(qmlqtimeexampleplugin, QExampleQmlPlugin);
//![export]