3ef3c662fe
Change-Id: Ie1fe516f75ca8c1b2233dc6bb2b887b55593e730 Reviewed-by: Martin Smith <martin.smith@nokia.com>
75 lines
2.6 KiB
Plaintext
75 lines
2.6 KiB
Plaintext
/****************************************************************************
|
|
**
|
|
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
|
|
** Contact: http://www.qt-project.org/
|
|
**
|
|
** This file is part of the documentation of the Qt Toolkit.
|
|
**
|
|
** $QT_BEGIN_LICENSE:FDL$
|
|
** 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.
|
|
**
|
|
** Other Usage
|
|
** Alternatively, this file may be used in accordance with the terms
|
|
** and conditions contained in a signed written agreement between you
|
|
** and Nokia.
|
|
**
|
|
**
|
|
**
|
|
**
|
|
**
|
|
** $QT_END_LICENSE$
|
|
**
|
|
****************************************************************************/
|
|
|
|
/*!
|
|
\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 widgets/digitalclock/digitalclock.h 0
|
|
|
|
\section1 DigitalClock Class Implementation
|
|
|
|
\snippet 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 widgets/digitalclock/digitalclock.cpp 1
|
|
\snippet 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.
|
|
*/
|