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diff --git a/doc/src/timers.qdoc b/doc/src/timers.qdoc deleted file mode 100644 index 462e8db..0000000 --- a/doc/src/timers.qdoc +++ /dev/null @@ -1,136 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). -** Contact: Nokia Corporation (qt-info@nokia.com) -** -** This file is part of the documentation 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. -** -** -** -** -** -** -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \page timers.html - \title Timers - \ingroup architecture - \brief How to use timers in your application. - - QObject, the base class of all Qt objects, provides the basic - timer support in Qt. With QObject::startTimer(), you start a - timer with an interval in milliseconds as argument. The function - returns a unique integer timer ID. The timer will now fire at - regular intervals until you explicitly call QObject::killTimer() - with the timer ID. - - For this mechanism to work, the application must run in an event - loop. You start an event loop with QApplication::exec(). When a - timer fires, the application sends a QTimerEvent, and the flow of - control leaves the event loop until the timer event is processed. - This implies that a timer cannot fire while your application is - busy doing something else. In other words: the accuracy of timers - depends on the granularity of your application. - - In multithreaded applications, you can use the timer mechanism in - any thread that has an event loop. To start an event loop from a - non-GUI thread, use QThread::exec(). Qt uses the object's - \l{QObject::thread()}{thread affinity} to determine which thread - will deliver the QTimerEvent. Because of this, you must start and - stop all timers in the object's thread; it is not possible to - start timers for objects in another thread. - - The upper limit for the interval value is determined by the number - of milliseconds that can be specified in a signed integer - (in practice, this is a period of just over 24 days). The accuracy - depends on the underlying operating system. Windows 98 has 55 - millisecond accuracy; other systems that we have tested can handle - 1 millisecond intervals. - - The main API for the timer functionality is QTimer. That class - provides regular timers that emit a signal when the timer fires, and - inherits QObject so that it fits well into the ownership structure - of most GUI programs. The normal way of using it is like this: - - \snippet doc/src/snippets/timers/timers.cpp 0 - \snippet doc/src/snippets/timers/timers.cpp 1 - \snippet doc/src/snippets/timers/timers.cpp 2 - - The QTimer object is made into a child of this widget so that, - when this widget is deleted, the timer is deleted too. - Next, its \l{QTimer::}{timeout()} signal is connected to the slot - that will do the work, it is started with a value of 1000 - milliseconds, indicating that it will time out every second. - - QTimer also provides a static function for single-shot timers. - For example: - - \snippet doc/src/snippets/timers/timers.cpp 3 - - 200 milliseconds (0.2 seconds) after this line of code is - executed, the \c updateCaption() slot will be called. - - For QTimer to work, you must have an event loop in your - application; that is, you must call QCoreApplication::exec() - somewhere. Timer events will be delivered only while the event - loop is running. - - 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. - - The \l{widgets/analogclock}{Analog Clock} example shows how to use - QTimer to redraw a widget at regular intervals. From \c{AnalogClock}'s - implementation: - - \snippet examples/widgets/analogclock/analogclock.cpp 0 - \snippet examples/widgets/analogclock/analogclock.cpp 2 - \snippet examples/widgets/analogclock/analogclock.cpp 3 - \snippet examples/widgets/analogclock/analogclock.cpp 4 - \snippet examples/widgets/analogclock/analogclock.cpp 5 - \snippet examples/widgets/analogclock/analogclock.cpp 6 - \dots - \snippet examples/widgets/analogclock/analogclock.cpp 7 - - Every second, QTimer will call the QWidget::update() slot to - refresh the clock's display. - - If you already have a QObject subclass and want an easy - optimization, you can use QBasicTimer instead of QTimer. With - QBasicTimer, you must reimplement - \l{QObject::timerEvent()}{timerEvent()} in your QObject subclass - and handle the timeout there. The \l{widgets/wiggly}{Wiggly} - example shows how to use QBasicTimer. -*/ |