Command Line Writer Async Example

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 ** Copyright (C) 2013 Laszlo Papp <lpapp@kde.org>
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 ** This file is part of the QtSerialPort module of the Qt Toolkit.
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 #include "serialportwriter.h"

 #include <QCoreApplication>

 SerialPortWriter::SerialPortWriter(QSerialPort *serialPort, QObject *parent) :
     QObject(parent),
     m_serialPort(serialPort),
     m_standardOutput(stdout)
 {
     m_timer.setSingleShot(true);
     connect(m_serialPort, &QSerialPort::bytesWritten,
             this, &SerialPortWriter::handleBytesWritten);
     connect(m_serialPort, &QSerialPort::errorOccurred,
             this, &SerialPortWriter::handleError);
     connect(&m_timer, &QTimer::timeout, this, &SerialPortWriter::handleTimeout);
 }

 void SerialPortWriter::handleBytesWritten(qint64 bytes)
 {
     m_bytesWritten += bytes;
     if (m_bytesWritten == m_writeData.size()) {
         m_bytesWritten = 0;
         m_standardOutput << QObject::tr("Data successfully sent to port %1")
                             .arg(m_serialPort->portName()) << endl;
         QCoreApplication::quit();
     }
 }

 void SerialPortWriter::handleTimeout()
 {
     m_standardOutput << QObject::tr("Operation timed out for port %1, error: %2")
                         .arg(m_serialPort->portName())
                         .arg(m_serialPort->errorString())
                      << endl;
     QCoreApplication::exit(1);
 }

 void SerialPortWriter::handleError(QSerialPort::SerialPortError serialPortError)
 {
     if (serialPortError == QSerialPort::WriteError) {
         m_standardOutput << QObject::tr("An I/O error occurred while writing"
                                         " the data to port %1, error: %2")
                             .arg(m_serialPort->portName())
                             .arg(m_serialPort->errorString())
                          << endl;
         QCoreApplication::exit(1);
     }
 }

 void SerialPortWriter::write(const QByteArray &writeData)
 {
     m_writeData = writeData;

     const qint64 bytesWritten = m_serialPort->write(writeData);

     if (bytesWritten == -1) {
         m_standardOutput << QObject::tr("Failed to write the data to port %1, error: %2")
                             .arg(m_serialPort->portName())
                             .arg(m_serialPort->errorString())
                          << endl;
         QCoreApplication::exit(1);
     } else if (bytesWritten != m_writeData.size()) {
         m_standardOutput << QObject::tr("Failed to write all the data to port %1, error: %2")
                             .arg(m_serialPort->portName())
                             .arg(m_serialPort->errorString())
                          << endl;
         QCoreApplication::exit(1);
     }

     m_timer.start(5000);
 }