Add qtserialport-based NMEA position plugin for Windows

GPS receivers typically come with USB-to-serial drivers for Windows.
This allows reading NMEA sentences via Qt Serial Port, thus providing
basic GPS positioning support for all desktop Windows versions.

Task-number: QTBUG-48082
Change-Id: Ie053dffaaf76bc08b2b6148104fd981b0f1ccc6b
Reviewed-by: Alex Blasche <alexander.blasche@theqtcompany.com>

1 files changed, 123 insertions, 0 deletions

diff --git a/src/plugins/position/serialnmea/qgeopositioninfosourcefactory_serialnmea.cpp b/src/plugins/position/serialnmea/qgeopositioninfosourcefactory_serialnmea.cpp
new file mode 100644
index 00000000..2b6b3ce6
--- /dev/null
+++ b/src/plugins/position/serialnmea/qgeopositioninfosourcefactory_serialnmea.cpp
@@ -0,0 +1,123 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtPositioning module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** 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 The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qgeopositioninfosourcefactory_serialnmea.h"
+#include <QtPositioning/qnmeapositioninfosource.h>
+#include <QtSerialPort/qserialport.h>
+#include <QtSerialPort/qserialportinfo.h>
+#include <QtCore/qloggingcategory.h>
+
+Q_LOGGING_CATEGORY(lcSerial, "qt.positioning.serialnmea")
+
+class NmeaSource : public QNmeaPositionInfoSource
+{
+public:
+    NmeaSource(QObject *parent);
+    bool isValid() const { return !m_port.isNull(); }
+
+private:
+    QScopedPointer<QSerialPort> m_port;
+};
+
+NmeaSource::NmeaSource(QObject *parent)
+    : QNmeaPositionInfoSource(RealTimeMode, parent),
+      m_port(new QSerialPort)
+{
+    QByteArray requestedPort = qgetenv("QT_NMEA_SERIAL_PORT");
+    if (requestedPort.isEmpty()) {
+        const QList<QSerialPortInfo> ports = QSerialPortInfo::availablePorts();
+        qCDebug(lcSerial) << "Found" << ports.count() << "serial ports";
+        if (ports.isEmpty()) {
+            qWarning("serialnmea: No serial ports found");
+            m_port.reset();
+            return;
+        }
+
+        // Try to find a well-known device.
+        QString portName;
+        for (int i = 0; i < ports.count(); ++i) {
+            const QString candidatePortName = ports[i].portName();
+            bool acceptThis = false;
+
+            // GlobalSat (BU-353S4 and probably others)
+            acceptThis |= ports[i].hasVendorIdentifier() && ports[i].vendorIdentifier() == 0x67b;
+
+            if (acceptThis) {
+                portName = candidatePortName;
+                break;
+            }
+        }
+
+        if (portName.isEmpty()) {
+            qWarning("serialnmea: No known GPS device found. Specify the COM port via QT_NMEA_SERIAL_PORT.");
+            m_port.reset();
+            return;
+        }
+
+        m_port->setPortName(portName);
+    } else {
+        m_port->setPortName(QString::fromUtf8(requestedPort));
+    }
+
+    m_port->setBaudRate(4800);
+
+    qCDebug(lcSerial) << "Opening serial port" << m_port->portName();
+
+    if (!m_port->open(QIODevice::ReadOnly)) {
+        qWarning("serialnmea: Failed to open %s", qPrintable(m_port->portName()));
+        m_port.reset();
+        return;
+    }
+
+    setDevice(m_port.data());
+
+    qCDebug(lcSerial) << "Opened successfully";
+}
+
+QGeoPositionInfoSource *QGeoPositionInfoSourceFactorySerialNmea::positionInfoSource(QObject *parent)
+{
+    QScopedPointer<NmeaSource> src(new NmeaSource(parent));
+    return src->isValid() ? src.take() : Q_NULLPTR;
+}
+
+QGeoSatelliteInfoSource *QGeoPositionInfoSourceFactorySerialNmea::satelliteInfoSource(QObject *parent)
+{
+    Q_UNUSED(parent);
+    return Q_NULLPTR;
+}
+
+QGeoAreaMonitorSource *QGeoPositionInfoSourceFactorySerialNmea::areaMonitor(QObject *parent)
+{
+    Q_UNUSED(parent);
+    return Q_NULLPTR;
+}