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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 394 insertions, 0 deletions

diff --git a/src/corelib/kernel/qtimer.cpp b/src/corelib/kernel/qtimer.cpp
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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtimer.h"
+#include "qabstracteventdispatcher.h"
+#include "qcoreapplication.h"
+#include "qobject_p.h"
+
+QT_BEGIN_NAMESPACE
+
+/*!
+    \class QTimer
+    \brief The QTimer class provides repetitive and single-shot timers.
+
+    \ingroup events
+
+
+    The QTimer class provides a high-level programming interface for
+    timers. To use it, create a QTimer, connect its timeout() signal
+    to the appropriate slots, and call start(). From then on it will
+    emit the timeout() signal at constant intervals.
+
+    Example for a one second (1000 millisecond) timer (from the
+    \l{widgets/analogclock}{Analog Clock} example):
+
+    \snippet examples/widgets/analogclock/analogclock.cpp 4
+    \snippet examples/widgets/analogclock/analogclock.cpp 5
+    \snippet examples/widgets/analogclock/analogclock.cpp 6
+
+    From then on, the \c update() slot is called every second.
+
+    You can set a timer to time out only once by calling
+    setSingleShot(true). You can also use the static
+    QTimer::singleShot() function to call a slot after a specified
+    interval:
+
+    \snippet doc/src/snippets/timers/timers.cpp 3
+
+    In multithreaded applications, you can use QTimer in any thread
+    that has an event loop. To start an event loop from a non-GUI
+    thread, use QThread::exec(). Qt uses the timer's
+    \l{QObject::thread()}{thread affinity} to determine which thread
+    will emit the \l{QTimer::}{timeout()} signal. Because of this, you
+    must start and stop the timer in its thread; it is not possible to
+    start a timer from another thread.
+
+    As a special case, a QTimer with a timeout of 0 will time out as
+    soon as all the events in the window system's event queue have
+    been processed. This can be used to do heavy work while providing
+    a snappy user interface:
+
+    \snippet doc/src/snippets/timers/timers.cpp 4
+    \snippet doc/src/snippets/timers/timers.cpp 5
+    \snippet doc/src/snippets/timers/timers.cpp 6
+
+    \c processOneThing() will from then on be called repeatedly. It
+    should be written in such a way that it always returns quickly
+    (typically after processing one data item) so that Qt can deliver
+    events to widgets and stop the timer as soon as it has done all
+    its work. This is the traditional way of implementing heavy work
+    in GUI applications; multithreading is now becoming available on
+    more and more platforms, and we expect that zero-millisecond
+    QTimers will gradually be replaced by \l{QThread}s.
+
+    \section1 Accuracy and Timer Resolution
+
+    Timers will never time out earlier than the specified timeout value
+    and they are not guaranteed to time out at the exact value specified.
+    In many situations, they may time out late by a period of time that
+    depends on the accuracy of the system timers.
+
+    The accuracy of timers depends on the underlying operating system
+    and hardware. Most platforms support a resolution of 1 millisecond,
+    though the accuracy of the timer will not equal this resolution
+    in many real-world situations.
+
+    If Qt is unable to deliver the requested number of timer clicks,
+    it will silently discard some.
+
+    \section1 Alternatives to QTimer
+
+    An alternative to using QTimer is to call QObject::startTimer()
+    for your object and reimplement the QObject::timerEvent() event
+    handler in your class (which must inherit QObject). The
+    disadvantage is that timerEvent() does not support such
+    high-level features as single-shot timers or signals.
+
+    Another alternative to using QTimer is to use QBasicTimer. It is
+    typically less cumbersome than using QObject::startTimer()
+    directly. See \l{Timers} for an overview of all three approaches.
+
+    Some operating systems limit the number of timers that may be
+    used; Qt tries to work around these limitations.
+
+    \sa QBasicTimer, QTimerEvent, QObject::timerEvent(), Timers,
+        {Analog Clock Example}, {Wiggly Example}
+*/
+
+
+static const int INV_TIMER = -1;                // invalid timer id
+
+/*!
+    Constructs a timer with the given \a parent.
+*/
+
+QTimer::QTimer(QObject *parent)
+    : QObject(parent), id(INV_TIMER), inter(0), del(0), single(0), nulltimer(0)
+{
+}
+
+
+#ifdef QT3_SUPPORT
+/*!
+    Constructs a timer called \a name, with a \a parent.
+*/
+
+QTimer::QTimer(QObject *parent, const char *name)
+    : QObject(parent), id(INV_TIMER), single(0), nulltimer(0)
+{
+    setObjectName(QString::fromAscii(name));
+}
+#endif
+
+/*!
+    Destroys the timer.
+*/
+
+QTimer::~QTimer()
+{
+    if (id != INV_TIMER)                        // stop running timer
+        stop();
+}
+
+
+/*!
+    \fn void QTimer::timeout()
+
+    This signal is emitted when the timer times out.
+
+    \sa interval, start(), stop()
+*/
+
+/*!
+    \property QTimer::active
+    \since 4.3
+
+    This boolean property is true if the timer is running; otherwise
+    false.
+*/
+
+/*!
+    \fn bool QTimer::isActive() const
+
+    Returns true if the timer is running (pending); otherwise returns
+    false.
+*/
+
+/*!
+    \fn int QTimer::timerId() const
+
+    Returns the ID of the timer if the timer is running; otherwise returns
+    -1.
+*/
+
+
+/*! \overload start()
+
+    Starts or restarts the timer with the timeout specified in \l interval.
+
+    If \l singleShot is true, the timer will be activated only once.
+*/
+void QTimer::start()
+{
+    if (id != INV_TIMER)                        // stop running timer
+        stop();
+    nulltimer = (!inter && single);
+    id = QObject::startTimer(inter);
+}
+
+/*!
+    Starts or restarts the timer with a timeout interval of \a msec
+    milliseconds.
+*/
+void QTimer::start(int msec)
+{
+    inter = msec;
+    start();
+}
+
+
+#ifdef QT3_SUPPORT
+/*! \overload start()
+
+  Call setSingleShot(\a sshot) and start(\a msec) instead.
+*/
+
+int QTimer::start(int msec, bool sshot)
+{
+    if (id >=0 && nulltimer && !msec && sshot)
+        return id;
+    stop();
+    setInterval(msec);
+    setSingleShot(sshot);
+    start();
+    return timerId();
+}
+#endif
+
+
+/*!
+    Stops the timer.
+
+    \sa start()
+*/
+
+void QTimer::stop()
+{
+    if (id != INV_TIMER) {
+        QObject::killTimer(id);
+        id = INV_TIMER;
+    }
+}
+
+
+/*!
+  \reimp
+*/
+void QTimer::timerEvent(QTimerEvent *e)
+{
+    if (e->timerId() == id) {
+        if (single)
+            stop();
+        emit timeout();
+    }
+}
+
+class QSingleShotTimer : public QObject
+{
+    Q_OBJECT
+    int timerId;
+public:
+    ~QSingleShotTimer();
+    QSingleShotTimer(int msec, QObject *r, const char * m);
+Q_SIGNALS:
+    void timeout();
+protected:
+    void timerEvent(QTimerEvent *);
+};
+
+QSingleShotTimer::QSingleShotTimer(int msec, QObject *receiver, const char *member)
+    : QObject(QAbstractEventDispatcher::instance())
+{
+    connect(this, SIGNAL(timeout()), receiver, member);
+    timerId = startTimer(msec);
+}
+
+QSingleShotTimer::~QSingleShotTimer()
+{
+    if (timerId > 0)
+        killTimer(timerId);
+}
+
+void QSingleShotTimer::timerEvent(QTimerEvent *)
+{
+    // need to kill the timer _before_ we emit timeout() in case the
+    // slot connected to timeout calls processEvents()
+    if (timerId > 0)
+        killTimer(timerId);
+    timerId = -1;
+    emit timeout();
+
+    // we would like to use delete later here, but it feels like a
+    // waste to post a new event to handle this event, so we just unset the flag
+    // and explicitly delete...
+    qDeleteInEventHandler(this);
+}
+
+QT_BEGIN_INCLUDE_NAMESPACE
+#include "qtimer.moc"
+QT_END_INCLUDE_NAMESPACE
+
+/*!
+    \reentrant
+    This static function calls a slot after a given time interval.
+
+    It is very convenient to use this function because you do not need
+    to bother with a \link QObject::timerEvent() timerEvent\endlink or
+    create a local QTimer object.
+
+    Example:
+    \snippet doc/src/snippets/code/src_corelib_kernel_qtimer.cpp 0
+
+    This sample program automatically terminates after 10 minutes
+    (600,000 milliseconds).
+
+    The \a receiver is the receiving object and the \a member is the
+    slot. The time interval is \a msec milliseconds.
+
+    \sa start()
+*/
+
+void QTimer::singleShot(int msec, QObject *receiver, const char *member)
+{
+    if (receiver && member) {
+        if (msec == 0) {
+            // special code shortpath for 0-timers
+            const char* bracketPosition = strchr(member, '(');
+            if (!bracketPosition || !(member[0] >= '0' && member[0] <= '3')) {
+                qWarning("QTimer::singleShot: Invalid slot specification");
+                return;
+            }
+            QByteArray methodName(member+1, bracketPosition - 1 - member); // extract method name
+            QMetaObject::invokeMethod(receiver, methodName.constData(), Qt::QueuedConnection);
+            return;
+        }
+        (void) new QSingleShotTimer(msec, receiver, member);
+    }
+}
+
+/*!
+    \property QTimer::singleShot
+    \brief whether the timer is a single-shot timer
+
+    A single-shot timer fires only once, non-single-shot timers fire
+    every \l interval milliseconds.
+
+    \sa interval, singleShot()
+*/
+
+/*!
+    \property QTimer::interval
+    \brief the timeout interval in milliseconds
+
+    The default value for this property is 0.  A QTimer with a timeout
+    interval of 0 will time out as soon as all the events in the window
+    system's event queue have been processed.
+
+    Setting the interval of an active timer changes its timerId().
+
+    \sa singleShot
+*/
+void QTimer::setInterval(int msec)
+{
+    inter = msec;
+    if (id != INV_TIMER) {                        // create new timer
+        QObject::killTimer(id);                        // restart timer
+        id = QObject::startTimer(msec);
+    }
+}
+
+/*! \fn void QTimer::changeInterval(int msec)
+
+   Use setInterval(msec) or start(msec) instead.
+*/
+
+QT_END_NAMESPACE