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diff --git a/doc/src/examples/digitalclock.qdoc b/doc/src/examples/digitalclock.qdoc new file mode 100644 index 0000000000..027abc754a --- /dev/null +++ b/doc/src/examples/digitalclock.qdoc @@ -0,0 +1,74 @@ +/**************************************************************************** +** +** 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 documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** 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 Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example widgets/digitalclock + \title Digital Clock Example + + The Digital Clock example shows how to use QLCDNumber to display a + number with LCD-like digits. + + \image digitalclock-example.png Screenshot of the Digital Clock example + + This example also demonstrates how QTimer can be used to update a widget + at regular intervals. + + \section1 DigitalClock Class Definition + + The \c DigitalClock class provides a clock widget showing the time with + hours and minutes separated by a blinking colon. We subclass QLCDNumber + and implement a private slot called \c showTime() to update the clock + display: + + \snippet examples/widgets/digitalclock/digitalclock.h 0 + + \section1 DigitalClock Class Implementation + + \snippet examples/widgets/digitalclock/digitalclock.cpp 0 + + In the constructor, we first change the look of the LCD numbers. The + QLCDNumber::Filled style produces raised segments filled with the + foreground color (typically black). We also set up a one-second timer + to keep track of the current time, and we connect + its \l{QTimer::timeout()}{timeout()} signal to the private \c showTime() slot + so that the display is updated every second. Then, we + call the \c showTime() slot; without this call, there would be a one-second + delay at startup before the time is shown. + + \snippet examples/widgets/digitalclock/digitalclock.cpp 1 + \snippet examples/widgets/digitalclock/digitalclock.cpp 2 + + The \c showTime() slot is called whenever the clock display needs + to be updated. + + The current time is converted into a string with the format "hh:mm". + When QTime::second() is a even number, the colon in the string is + replaced with a space. This makes the colon appear and vanish every + other second. + + Finally, we call QLCDNumber::display() to update the widget. +*/ |