src/location/qlocationutils.cpp
changeset 0 876b1a06bc25
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/location/qlocationutils.cpp	Wed Aug 25 15:49:42 2010 +0300
@@ -0,0 +1,354 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the Qt Mobility Components.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "qlocationutils_p.h"
+#include "qgeopositioninfo.h"
+
+#include <QTime>
+#include <QList>
+#include <QByteArray>
+#include <QDebug>
+
+#include <math.h>
+
+QTM_BEGIN_NAMESPACE
+
+// converts e.g. 15306.0235 from NMEA sentence to 153.100392
+static double qlocationutils_nmeaDegreesToDecimal(double nmeaDegrees)
+{
+    double deg;
+    double min = 100.0 * modf(nmeaDegrees / 100.0, &deg);
+    return deg + (min / 60.0);
+}
+
+static void qlocationutils_readGga(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    QByteArray sentence(data, size);
+    QList<QByteArray> parts = sentence.split(',');
+    QGeoCoordinate coord;
+
+    if (hasFix && parts.count() > 6 && parts[6].count() > 0)
+        *hasFix = parts[6].toInt() > 0;
+
+    if (parts.count() > 1 && parts[1].count() > 0) {
+        QTime time;
+        if (QLocationUtils::getNmeaTime(parts[1], &time))
+            info->setTimestamp(QDateTime(QDate(), time, Qt::UTC));
+    }
+
+    if (parts.count() > 5 && parts[3].count() == 1 && parts[5].count() == 1) {
+        double lat;
+        double lng;
+        if (QLocationUtils::getNmeaLatLong(parts[2], parts[3][0], parts[4], parts[5][0], &lat, &lng)) {
+            coord.setLatitude(lat);
+            coord.setLongitude(lng);
+        }
+    }
+
+    if (parts.count() > 9 && parts[9].count() > 0) {
+        bool hasAlt = false;
+        double alt = parts[9].toDouble(&hasAlt);
+        if (hasAlt)
+            coord.setAltitude(alt);
+    }
+
+    if (coord.type() != QGeoCoordinate::InvalidCoordinate)
+        info->setCoordinate(coord);
+}
+
+static void qlocationutils_readGll(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    QByteArray sentence(data, size);
+    QList<QByteArray> parts = sentence.split(',');
+    QGeoCoordinate coord;
+
+    if (hasFix && parts.count() > 6 && parts[6].count() > 0)
+        *hasFix = (parts[6][0] == 'A');
+
+    if (parts.count() > 5 && parts[5].count() > 0) {
+        QTime time;
+        if (QLocationUtils::getNmeaTime(parts[5], &time))
+            info->setTimestamp(QDateTime(QDate(), time, Qt::UTC));
+    }
+
+    if (parts.count() > 4 && parts[2].count() == 1 && parts[4].count() == 1) {
+        double lat;
+        double lng;
+        if (QLocationUtils::getNmeaLatLong(parts[1], parts[2][0], parts[3], parts[4][0], &lat, &lng)) {
+            coord.setLatitude(lat);
+            coord.setLongitude(lng);
+        }
+    }
+
+    if (coord.type() != QGeoCoordinate::InvalidCoordinate)
+        info->setCoordinate(coord);
+}
+
+static void qlocationutils_readRmc(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    QByteArray sentence(data, size);
+    QList<QByteArray> parts = sentence.split(',');
+    QGeoCoordinate coord;
+    QDate date;
+    QTime time;
+
+    if (hasFix && parts.count() > 2 && parts[2].count() > 0)
+        *hasFix = (parts[2][0] == 'A');
+
+    if (parts.count() > 9 && parts[9].count() == 6) {
+        date = QDate::fromString(parts[9], "ddMMyy");
+        if (date.isValid())
+            date = date.addYears(100);     // otherwise starts from 1900
+        else
+            date = QDate();
+    }
+
+    if (parts.count() > 1 && parts[1].count() > 0)
+        QLocationUtils::getNmeaTime(parts[1], &time);
+
+    if (parts.count() > 6 && parts[4].count() == 1 && parts[6].count() == 1) {
+        double lat;
+        double lng;
+        if (QLocationUtils::getNmeaLatLong(parts[3], parts[4][0], parts[5], parts[6][0], &lat, &lng)) {
+            coord.setLatitude(lat);
+            coord.setLongitude(lng);
+        }
+    }
+
+    bool parsed = false;
+    double value = 0.0;
+    if (parts.count() > 7 && parts[7].count() > 0) {
+        value = parts[7].toDouble(&parsed);
+        if (parsed)
+            info->setAttribute(QGeoPositionInfo::GroundSpeed, qreal(value * 1.852 / 3.6));    // knots -> m/s
+    }
+    if (parts.count() > 8 && parts[8].count() > 0) {
+        value = parts[8].toDouble(&parsed);
+        if (parsed)
+            info->setAttribute(QGeoPositionInfo::Direction, qreal(value));
+    }
+    if (parts.count() > 11 && parts[11].count() == 1
+            && (parts[11][0] == 'E' || parts[11][0] == 'W')) {
+        value = parts[10].toDouble(&parsed);
+        if (parsed) {
+            if (parts[11][0] == 'W')
+                value *= -1;
+            info->setAttribute(QGeoPositionInfo::MagneticVariation, qreal(value));
+        }
+    }
+
+    if (coord.type() != QGeoCoordinate::InvalidCoordinate)
+        info->setCoordinate(coord);
+
+    info->setTimestamp(QDateTime(date, time, Qt::UTC));
+}
+
+static void qlocationutils_readVtg(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    if (hasFix)
+        *hasFix = false;
+
+    QByteArray sentence(data, size);
+    QList<QByteArray> parts = sentence.split(',');
+
+    bool parsed = false;
+    double value = 0.0;
+    if (parts.count() > 1 && parts[1].count() > 0) {
+        value = parts[1].toDouble(&parsed);
+        if (parsed)
+            info->setAttribute(QGeoPositionInfo::Direction, qreal(value));
+    }
+    if (parts.count() > 7 && parts[7].count() > 0) {
+        value = parts[7].toDouble(&parsed);
+        if (parsed)
+            info->setAttribute(QGeoPositionInfo::GroundSpeed, qreal(value / 3.6));    // km/h -> m/s
+    }
+}
+
+static void qlocationutils_readZda(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    if (hasFix)
+        *hasFix = false;
+
+    QByteArray sentence(data, size);
+    QList<QByteArray> parts = sentence.split(',');
+    QDate date;
+    QTime time;
+
+    if (parts.count() > 1 && parts[1].count() > 0)
+        QLocationUtils::getNmeaTime(parts[1], &time);
+
+    if (parts.count() > 4 && parts[2].count() > 0 && parts[3].count() > 0
+            && parts[4].count() == 4) {     // must be full 4-digit year
+        int day = parts[2].toUInt();
+        int month = parts[3].toUInt();
+        int year = parts[4].toUInt();
+        if (day > 0 && month > 0 && year > 0)
+            date.setDate(year, month, day);
+    }
+
+    info->setTimestamp(QDateTime(date, time, Qt::UTC));
+}
+
+bool QLocationUtils::getPosInfoFromNmea(const char *data, int size, QGeoPositionInfo *info, bool *hasFix)
+{
+    if (!info)
+        return false;
+
+    if (hasFix)
+        *hasFix = false;
+    if (size < 6 || data[0] != '$' || !hasValidNmeaChecksum(data, size))
+        return false;
+
+    if (data[3] == 'G' && data[4] == 'G' && data[5] == 'A') {
+        // "$--GGA" sentence.
+        qlocationutils_readGga(data, size, info, hasFix);
+        return true;
+    }
+
+    if (data[3] == 'G' && data[4] == 'L' && data[5] == 'L') {
+        // "$--GLL" sentence.
+        qlocationutils_readGll(data, size, info, hasFix);
+        return true;
+    }
+
+    if (data[3] == 'R' && data[4] == 'M' && data[5] == 'C') {
+        // "$--RMC" sentence.
+        qlocationutils_readRmc(data, size, info, hasFix);
+        return true;
+    }
+
+    if (data[3] == 'V' && data[4] == 'T' && data[5] == 'G') {
+        // "$--VTG" sentence.
+        qlocationutils_readVtg(data, size, info, hasFix);
+        return true;
+    }
+
+    if (data[3] == 'Z' && data[4] == 'D' && data[5] == 'A') {
+        // "$--ZDA" sentence.
+        qlocationutils_readZda(data, size, info, hasFix);
+        return true;
+    }
+
+    return false;
+}
+
+bool QLocationUtils::hasValidNmeaChecksum(const char *data, int size)
+{
+    int asteriskIndex = -1;
+    for (int i = 0; i < size; i++) {
+        if (data[i] == '*') {
+            asteriskIndex = i;
+            break;
+        }
+    }
+
+    const int CSUM_LEN = 2;
+    if (asteriskIndex < 0 || asteriskIndex + CSUM_LEN >= size)
+        return false;
+
+    // XOR byte value of all characters between '$' and '*'
+    int result = 0;
+    for (int i = 1; i < asteriskIndex; i++)
+        result ^= data[i];
+    /*
+        char calc[CSUM_LEN + 1];
+        ::snprintf(calc, CSUM_LEN + 1, "%02x", result);
+        return ::strncmp(calc, &data[asteriskIndex+1], 2) == 0;
+        */
+
+    QString s;
+    s.sprintf("%02x", result);
+    return s.toAscii() == QByteArray(&data[asteriskIndex+1], 2);
+}
+
+bool QLocationUtils::getNmeaTime(const QByteArray &bytes, QTime *time)
+{
+    int dotIndex = bytes.indexOf('.');
+    QTime tempTime;
+
+    if (dotIndex < 0) {
+        tempTime = QTime::fromString(bytes, "hhmmss");
+    } else {
+        tempTime = QTime::fromString(bytes.mid(0, dotIndex), "hhmmss");
+        bool hasMsecs = false;
+        int midLen = qMin(3, bytes.size() - dotIndex - 1);
+        int msecs = bytes.mid(dotIndex + 1, midLen).toUInt(&hasMsecs);
+        if (hasMsecs)
+            tempTime = tempTime.addMSecs(msecs);
+    }
+
+    if (tempTime.isValid()) {
+        *time = tempTime;
+        return true;
+    }
+    return false;
+}
+
+bool QLocationUtils::getNmeaLatLong(const QByteArray &latString, char latDirection, const QByteArray &lngString, char lngDirection, double *lat, double *lng)
+{
+    if ((latDirection != 'N' && latDirection != 'S')
+            || (lngDirection != 'E' && lngDirection != 'W')) {
+        return false;
+    }
+
+    bool hasLat = false;
+    bool hasLong = false;
+    double tempLat = latString.toDouble(&hasLat);
+    double tempLng = lngString.toDouble(&hasLong);
+    if (hasLat && hasLong) {
+        tempLat = qlocationutils_nmeaDegreesToDecimal(tempLat);
+        if (latDirection == 'S')
+            tempLat *= -1;
+        tempLng = qlocationutils_nmeaDegreesToDecimal(tempLng);
+        if (lngDirection == 'W')
+            tempLng *= -1;
+
+        if (isValidLat(tempLat) && isValidLong(tempLng)) {
+            *lat = tempLat;
+            *lng = tempLng;
+            return true;
+        }
+    }
+    return false;
+}
+
+QTM_END_NAMESPACE
+