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Venugopal Shivashankar authored
- Removed redundant qdoc pages on supported platforms, getting source, and building from source. - Added a module page to list the C++ classes - Removed unnecessary \module commands in several pages - Made a few language edits to class documentation - Updated the index page with some introductory content - Fixed broken links to the examples Change-Id: Ia7bd74b383f344426814db736f7bc4cd77c13992 Reviewed-by:Laszlo Papp <lpapp@kde.org>
d424c1ee
terminal.qdoc 5.74 KiB
/******************************************************************************** Copyright (C) 2011 - 2012 Denis Shienkov <denis.shienkov@gmail.com>** Contact: http://www.qt-project.org/legal**** This file is part of the documentation of the Qt Toolkit.**** $QT_BEGIN_LICENSE:FDL$** Commercial License Usage** Licensees holding valid commercial Qt licenses may use this file in** accordance with the commercial license agreement provided with the** Software or, alternatively, in accordance with the terms contained in** a written agreement between you and Digia. For licensing terms and** conditions see http://qt.digia.com/licensing. For further information** use the contact form at http://qt.digia.com/contact-us.**** GNU Free Documentation License Usage** 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. Please review the following information to ensure** the GNU Free Documentation License version 1.3 requirements** will be met: http://www.gnu.org/copyleft/fdl.html.** $QT_END_LICENSE$******************************************************************************//*! \example terminal \title Terminal Example \ingroup qtserialport-examples The Terminal example shows how to create a terminal for a simple serial interface by using Qt Serial Port. \image terminal-example.png Screenshot of the Terminal example This example shows the main features of the QSerialPort class, like configuration, I/O implementation and so forth. Also, the class QSerialPortInfo is invoked to display information about the serial ports available in the system. QSerialPort supports two general programming approaches: \list \li \e{The asynchronous (non-blocking) approach.} Operations are scheduled and performed when the control returns to Qt's event loop. QSerialPort emits a signal when the operation is finished. For example, QSerialPort::write() returns immediately. When the data is sent to the serial port, QSerialPort emits \l{QIODevice::bytesWritten()}{bytesWritten()}. \li \e{The synchronous (blocking) approach.} In non-GUI and multithreaded applications, the \c waitFor...() functions can be called (i.e. QSerialPort::waitForReadyRead()) to suspend the calling thread until the operation has completed. \endlist In this example, the asynchronous approach is demonstrated. The \l{blockingslave}{Blocking Slave} example illustrates the synchronous approach. Our example contains some GUI widgets: \list \li \l{terminal/mainwindow.cpp}{MainWindow} - is the main application window that contains all the working logic for the serial port programming, including configuration, I/O processing and so forth, while inheriting the7172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140
QMainWindow.
\li \l{terminal/console.cpp}{Console} - is the central widget of the
main window, displaying the transmitted or received data. The widget is
derived from the QPlainTextEdit class.
\li \l{terminal/settingsdialog.cpp}{SettingsDialog} - is a dialog for
configuring the serial port, as well as for displaying the available serial
ports and information about them.
\endlist
The serial port is instantiated in the \l{terminal/mainwindow.cpp}{MainWindow}
constructor. The main widget is passed as the parent, so the object deletion
happens automatically according to the the parent and child mechanism in Qt:
\snippet terminal/mainwindow.cpp 0
\dots
\snippet terminal/mainwindow.cpp 1
The only QSerialPort signal invoked in this example is
\l{QIODevice::readyRead()}{readyRead()}, which shows that new data has been
received and hence available:
\dots
\snippet terminal/mainwindow.cpp 2
\dots
\snippet terminal/mainwindow.cpp 3
Clicking on the \b{Connect} button invokes the \c openSerialPort() slot:
\snippet terminal/mainwindow.cpp 4
In this slot, the settings are read from \l{terminal/settingsdialog.cpp}
{SettingsDialog} and an attempt is made to open and initialize the serial
port accordingly. If successful, the status bar displays a message that the
opening was successful with the given configuration; otherwise, a messagebox
is displayed with the appropriate error code and message. If the serial port
settings have never been called
\l{terminal/settingsdialog.cpp}{SettingsDialog}, then the terminal
attempts to open the port with the default settings: 9600 8N1.
Clicking on the \b{Disconnect} button invokes the \c closeSerialPort()
slot:
\snippet terminal/mainwindow.cpp 5
In this case, handled by the closure of the serial port.
Typing characters in the console invokes the \c writeData() slot:
\snippet terminal/mainwindow.cpp 6
This slot sends the characters typed in the given
\l{terminal/console.cpp}{Console} widget to the serial port.
When the serial port receives new data, the signal
\l{QTcpSocket::readyRead()}{readyRead()} is emitted, and that signal is
connected to the \c MainWindow::readData() slot:
\snippet terminal/mainwindow.cpp 7
This slot reads the data from the serial port and displays that in the
\l{terminal/console.cpp}{Console} widget.
Clicking on the \b{Configure} button invokes the \c show() slot which
belongs to the \l{terminal/settingsdialog.cpp}{SettingsDialog}
widget.
This method displays the \l{terminal/settingsdialog.cpp}{SettingsDialog}
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in which the user can choose the desired serial port, see the information
about the selected port, and set the desired parameters of the given serial
port.
\sa {Blocking Slave Example}
*/