examples/declarative/cppextensions/plugins/plugin.cpp
author Dremov Kirill (Nokia-D-MSW/Tampere) <kirill.dremov@nokia.com>
Tue, 06 Jul 2010 15:10:48 +0300
changeset 30 5dc02b23752f
child 33 3e2da88830cd
permissions -rw-r--r--
Revision: 201025 Kit: 2010127

/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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** This file is part of the examples of the Qt Toolkit.
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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;
};

class TimeModel : public QObject
{
    Q_OBJECT
    Q_PROPERTY(int hour READ hour NOTIFY timeChanged)
    Q_PROPERTY(int minute READ minute NOTIFY timeChanged)

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;

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");
    }
};

#include "plugin.moc"

Q_EXPORT_PLUGIN2(qtimeexampleqmlplugin, QExampleQmlPlugin);