qtimer.h

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#ifndef QTIMER_H
#define QTIMER_H
 
#include <QtCore/qglobal.h>
 
#ifndef QT_NO_QOBJECT
 
#include <QtCore/qbasictimer.h> // conceptual inheritance
#include <QtCore/qobject.h>
 
#include <chrono>
 
QT_BEGIN_NAMESPACE
 
class QTimerPrivate;
class Q_CORE_EXPORT QTimer : public QObject
{
    Q_OBJECT
    Q_PROPERTY(bool singleShot READ isSingleShot WRITE setSingleShot BINDABLE bindableSingleShot)
    Q_PROPERTY(int interval READ interval WRITE setInterval BINDABLE bindableInterval)
    Q_PROPERTY(int remainingTime READ remainingTime)
    Q_PROPERTY(Qt::TimerType timerType READ timerType WRITE setTimerType BINDABLE bindableTimerType)
    Q_PROPERTY(bool active READ isActive STORED false BINDABLE bindableActive)
public:
    explicit QTimer(QObject *parent = nullptr);
    ~QTimer();
 
    bool isActive() const;
    QBindable<bool> bindableActive();
    int timerId() const;
    Qt::TimerId id() const;
 
    void setInterval(int msec);
    int interval() const;
    QBindable<int> bindableInterval();
 
    int remainingTime() const;
 
    void setTimerType(Qt::TimerType atype);
    Qt::TimerType timerType() const;
    QBindable<Qt::TimerType> bindableTimerType();
 
    void setSingleShot(bool singleShot);
    bool isSingleShot() const;
    QBindable<bool> bindableSingleShot();
 
    QT_CORE_INLINE_SINCE(6, 8)
    static void singleShot(int msec, const QObject *receiver, const char *member);
 
    QT_CORE_INLINE_SINCE(6, 8)
    static void singleShot(int msec, Qt::TimerType timerType, const QObject *receiver, const char *member);
 
    // singleShot with context
#ifdef Q_QDOC
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval, const QObject *receiver, Functor &&slot);
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval, Qt::TimerType timerType,
                                  const QObject *receiver, Functor &&slot);
#else
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval,
                                  const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *receiver,
                                  Functor &&slot)
    {
        singleShot(interval, defaultTypeFor(interval), receiver, std::forward<Functor>(slot));
    }
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval, Qt::TimerType timerType,
                                  const typename QtPrivate::ContextTypeForFunctor<Functor>::ContextType *receiver,
                                  Functor &&slot)
    {
        using Prototype = void(*)();
        singleShotImpl(interval, timerType, receiver,
                       QtPrivate::makeCallableObject<Prototype>(std::forward<Functor>(slot)));
    }
#endif
 
    // singleShot without context
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval, Functor &&slot)
    {
        singleShot(interval, defaultTypeFor(interval), nullptr, std::forward<Functor>(slot));
    }
    template <typename Duration, typename Functor>
    static inline void singleShot(Duration interval, Qt::TimerType timerType, Functor &&slot)
    {
        singleShot(interval, timerType, nullptr, std::forward<Functor>(slot));
    }
 
#ifdef Q_QDOC
    template <typename Functor>
    QMetaObject::Connection callOnTimeout(Functor &&slot);
    template <typename Functor>
    QMetaObject::Connection callOnTimeout(const QObject *context, Functor &&slot, Qt::ConnectionType connectionType = Qt::AutoConnection);
#else
    template <typename ... Args>
    QMetaObject::Connection callOnTimeout(Args && ...args)
    {
        return QObject::connect(this, &QTimer::timeout, std::forward<Args>(args)... );
    }
 
#endif
 
public Q_SLOTS:
    void start(int msec);
 
    void start();
    void stop();
 
Q_SIGNALS:
    void timeout(QPrivateSignal);
 
public:
    void setInterval(std::chrono::milliseconds value);
 
    std::chrono::milliseconds intervalAsDuration() const
    {
        return std::chrono::milliseconds(interval());
    }
 
    std::chrono::milliseconds remainingTimeAsDuration() const
    {
        return std::chrono::milliseconds(remainingTime());
    }
 
    static void singleShot(std::chrono::milliseconds value, const QObject *receiver, const char *member)
    {
        singleShot(value, defaultTypeFor(value), receiver, member);
    }
    static void singleShot(std::chrono::milliseconds interval, Qt::TimerType timerType,
                           const QObject *receiver, const char *member);
 
    void start(std::chrono::milliseconds value);
 
protected:
    void timerEvent(QTimerEvent *) override;
 
private:
    Q_DISABLE_COPY(QTimer)
    Q_DECLARE_PRIVATE(QTimer)
 
    inline int startTimer(int){ return -1;}
    inline void killTimer(int){}
 
    static constexpr Qt::TimerType defaultTypeFor(int msecs) noexcept
    { return defaultTypeFor(std::chrono::milliseconds{msecs}); }
 
    static constexpr Qt::TimerType defaultTypeFor(std::chrono::milliseconds interval) noexcept
    {
        // coarse timers are worst in their first firing
        // so we prefer a high precision timer for something that happens only once
        // unless the timeout is too big, in which case we go for coarse anyway
        using namespace std::chrono_literals;
        return interval >= 2s ? Qt::CoarseTimer : Qt::PreciseTimer;
    }
 
    QT_CORE_INLINE_SINCE(6, 8)
    static void singleShotImpl(int msec, Qt::TimerType timerType,
                               const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj);
 
    static void singleShotImpl(std::chrono::milliseconds interval, Qt::TimerType timerType,
                               const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj);
};
 
#if QT_CORE_INLINE_IMPL_SINCE(6, 8)
void QTimer::singleShot(int msec, const QObject *receiver, const char *member)
{ singleShot(std::chrono::milliseconds{msec}, receiver, member); }
 
void QTimer::singleShot(int msec, Qt::TimerType timerType, const QObject *receiver,
                        const char *member)
{ singleShot(std::chrono::milliseconds{msec}, timerType, receiver, member); }
 
void QTimer::singleShotImpl(int msec, Qt::TimerType timerType,
                            const QObject *receiver, QtPrivate::QSlotObjectBase *slotObj)
{
    singleShotImpl(std::chrono::milliseconds{msec}, timerType, receiver, slotObj);
}
#endif
 
QT_END_NAMESPACE
 
#endif // QT_NO_QOBJECT
 
#endif // QTIMER_H