mainwindow.cpp Example File

can/mainwindow.cpp
/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the QtSerialBus module.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
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#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "connectdialog.h"

#include <QCanBusFrame>
#include <QCanBus>
#include <QCloseEvent>
#include <QTimer>

#include <QtCore/qbytearray.h>
#include <QtCore/qvariant.h>
#include <QtCore/qdebug.h>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    m_ui(new Ui::MainWindow),
    m_canDevice(nullptr)
{
    m_ui->setupUi(this);

    m_connectDialog = new ConnectDialog;

    m_status = new QLabel;
    m_ui->statusBar->addWidget(m_status);

    m_ui->sendMessagesBox->setEnabled(false);

    initActionsConnections();
    QTimer::singleShot(50, m_connectDialog, &ConnectDialog::show);

    connect(m_ui->sendButton, &QPushButton::clicked, this, &MainWindow::sendMessage);
}

MainWindow::~MainWindow()
{
    delete m_canDevice;

    delete m_connectDialog;
    delete m_ui;
}

void MainWindow::showStatusMessage(const QString &message)
{
    m_status->setText(message);
}

void MainWindow::initActionsConnections()
{
    m_ui->actionConnect->setEnabled(true);
    m_ui->actionDisconnect->setEnabled(false);
    m_ui->actionQuit->setEnabled(true);

    connect(m_ui->actionConnect, &QAction::triggered, m_connectDialog, &ConnectDialog::show);
    connect(m_connectDialog, &QDialog::accepted, this, &MainWindow::connectDevice);
    connect(m_ui->actionDisconnect, &QAction::triggered, this, &MainWindow::disconnectDevice);
    connect(m_ui->actionQuit, &QAction::triggered, this, &QWidget::close);
    connect(m_ui->actionAboutQt, &QAction::triggered, qApp, &QApplication::aboutQt);
}

void MainWindow::receiveError(QCanBusDevice::CanBusError error) const
{
    switch (error) {
    case QCanBusDevice::ReadError:
    case QCanBusDevice::WriteError:
    case QCanBusDevice::ConnectionError:
    case QCanBusDevice::ConfigurationError:
    case QCanBusDevice::UnknownError:
        qWarning() << m_canDevice->errorString();
    default:
        break;
    }
}

void MainWindow::connectDevice()
{
    const ConnectDialog::Settings p = m_connectDialog->settings();

    m_canDevice = QCanBus::instance()->createDevice(p.backendName.toLocal8Bit(), p.deviceInterfaceName);
    if (!m_canDevice) {
        showStatusMessage(tr("Error creating device: %1").arg(p.backendName));
        return;
    }

    connect(m_canDevice, &QCanBusDevice::errorOccurred,
            this, &MainWindow::receiveError);
    connect(m_canDevice, &QCanBusDevice::framesReceived,
            this, &MainWindow::checkMessages);
    connect(m_canDevice, &QCanBusDevice::framesWritten,
            this, &MainWindow::framesWritten);

    if (p.useConfigurationEnabled) {
        foreach (const ConnectDialog::ConfigurationItem &item, p.configurations)
            m_canDevice->setConfigurationParameter(item.first, item.second);
    }

    if (!m_canDevice->connectDevice()) {
        showStatusMessage(tr("Connection error: %1").arg(m_canDevice->errorString()));

        delete m_canDevice;
        m_canDevice = nullptr;
    } else {
        m_ui->actionConnect->setEnabled(false);
        m_ui->actionDisconnect->setEnabled(true);

        m_ui->sendMessagesBox->setEnabled(true);

        QVariant bitRate = m_canDevice->configurationParameter(QCanBusDevice::BitRateKey);
        if (bitRate.isValid()) {
            showStatusMessage(tr("Backend: %1, connected to %2 at %3 kBit/s")
                    .arg(p.backendName).arg(p.deviceInterfaceName)
                    .arg(bitRate.toInt() / 1000));
        } else {
            showStatusMessage(tr("Backend: %1, connected to %2")
                    .arg(p.backendName).arg(p.deviceInterfaceName));
        }
    }
}

void MainWindow::disconnectDevice()
{
    if (!m_canDevice)
        return;

    m_canDevice->disconnectDevice();
    delete m_canDevice;
    m_canDevice = nullptr;

    m_ui->actionConnect->setEnabled(true);
    m_ui->actionDisconnect->setEnabled(false);

    m_ui->sendMessagesBox->setEnabled(false);

    showStatusMessage(tr("Disconnected"));
}

void MainWindow::framesWritten(qint64 count)
{
    qDebug() << "Number of frames written:" << count;
}

void MainWindow::closeEvent(QCloseEvent *event)
{
    m_connectDialog->close();
    event->accept();
}

static QByteArray dataToHex(const QByteArray &data)
{
    QByteArray result = data.toHex().toUpper();

    for (int i = 0; i < result.size(); i += 3)
        result.insert(i, ' ');

    return result;
}

void MainWindow::checkMessages()
{
    if (!m_canDevice)
        return;

    const QCanBusFrame frame = m_canDevice->readFrame();

    const qint8 dataLength = frame.payload().size();

    const qint32 id = frame.frameId();

    QString view;
    if (frame.frameType() == QCanBusFrame::ErrorFrame) {
        interpretError(view, frame);
    } else {
        const char *format =
                frame.hasExtendedFrameFormat() ? "Id: %08X" : "Id:      %03X";
        view += QString::asprintf(format, static_cast<uint>(id));
        view += QLatin1String(" bytes: ");
        view += QString::number(dataLength, 10);
        if (frame.frameType() != QCanBusFrame::RemoteRequestFrame) {
            view += QLatin1String(" data: ");
            view += dataToHex(frame.payload());
        }
    }

    if (frame.frameType() == QCanBusFrame::RemoteRequestFrame) {
        m_ui->requestList->addItem(view);
        m_ui->requestList->scrollToBottom();
    } else if (frame.frameType() == QCanBusFrame::ErrorFrame) {
        m_ui->errorList->addItem(view);
        m_ui->errorList->scrollToBottom();
    } else {
        m_ui->receiveList->addItem(view);
        m_ui->receiveList->scrollToBottom();
    }
}

static QByteArray dataFromHex(const QString &hex)
{
    QByteArray line = hex.toLatin1();
    line.replace(' ', QByteArray());
    return QByteArray::fromHex(line);
}

void MainWindow::sendMessage() const
{
    if (!m_canDevice)
        return;

    QByteArray writings = dataFromHex(m_ui->lineEdit->displayText());

    QCanBusFrame frame;
    const int maxPayload = m_ui->fdBox->checkState() ? 64 : 8;
    int size = writings.size();
    if (size > maxPayload)
        size = maxPayload;
    writings = writings.left(size);
    frame.setPayload(writings);

    qint32 id = m_ui->idEdit->displayText().toInt(nullptr, 16);
    if (!m_ui->effBox->checkState() && id > 2047) //11 bits
        id = 2047;

    frame.setFrameId(id);
    frame.setExtendedFrameFormat(m_ui->effBox->checkState());

    if (m_ui->remoteFrame->isChecked())
        frame.setFrameType(QCanBusFrame::RemoteRequestFrame);
    else if (m_ui->errorFrame->isChecked())
        frame.setFrameType(QCanBusFrame::ErrorFrame);
    else
        frame.setFrameType(QCanBusFrame::DataFrame);

    m_canDevice->writeFrame(frame);
}

void MainWindow::interpretError(QString &view, const QCanBusFrame &frame)
{
    if (!m_canDevice)
        return;

    view = m_canDevice->interpretErrorFrame(frame);
}

© 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.