Control OSM map in QML qt - c++

Question

I am trying to control the map in Qt however I keep ending up with the following error:
QGeoTileRequestManager: Failed to fetch tile (291271,152514,19) 5 times, giving up. Last error message was: 'Permission denied'
I have functions in C++ that parse the messages and calculates the position:
Map.qml
import QtQuick 2.12
import QtQuick.Window 2.14
import QtQuick.Controls 2.15
import QtLocation 5.6
import QtPositioning 5.6
import QtQuick.Controls.Material 2.12
import QtQuick.Layouts 1.12
import Qt.labs.location 1.0
Page {
id: mainWindow
visible: true
function addMarker(latitude, longitude)
{
var Component = Qt.createComponent("qrc:/Marker.qml")
var item = Component.createObject(window, {
coordinate: QtPositioning.coordinate(latitude, longitude)
})
map.addMapItem(item)
}
Map {
id: map
width: mainWindow.width
height: mainWindow.height
plugin: mapPlugin
center: QtPositioning.coordinate(59.91, 10.75)
Component.onCompleted: addMarker(59.91, 10.75)
zoomLevel: 60
}
Plugin {
id: mapPlugin
name: "osm" // "mapboxgl", "esri", ...
// specify plugin parameters if necessary
PluginParameter {
name: "osm.mapping.providersrepository.disabled"
value: "true"
}
PluginParameter {
name: "osm.mapping.providersrepository.address"
value: "http://maps-redirect.qt.io/osm/5.6/"
}
}
}
Setting the coordinates is done through Q_PROPERTY:
#include <QObject>
class Data : public QObject
{
Q_OBJECT;
Q_PROPERTY(double gnss_log READ gnss_long WRITE set_gnss_long NOTIFY gnss_long_changed);
Q_PROPERTY(double gnss_lat READ gnss_lat WRITE set_gnss_lat NOTIFY gnss_lat_changed);
public: signals:
void gnss_long_changed();
void gnss_lat_changed();
public slots:
void set_gnss_long(double);
void set_gnss_lat(double);
public:
Data();
double gnss_long();
double gnss_lat();
private:
double m_gnss_long;
double m_gnss_lat;
};
void Data::set_gnss_long(double curr_long)
{
// Checks whether updated baud rate changed
if (curr_long == m_gnss_long)
return;
m_gnss_long = curr_long;
qDebug() << m_gnss_long;
//Emits signal indicating change
emit gnss_long_changed();
}
double Data::gnss_long()
{
return m_gnss_long;
}
I when I run this, I get a blank screen with a bunch of the errors mentioned above.

Answer 1

Since the OP has not provided an MRE my answer will only show a demo. The logic is to create a QProperty that exposes the position, then a binding must be done:
#include <QGeoCoordinate>
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include <QTimer>
#include <random>
class Data: public QObject{
Q_OBJECT
Q_PROPERTY(QGeoCoordinate gnssPosition READ gnssPosition WRITE setGnssPosition NOTIFY gnssPositionChanged)
public:
const QGeoCoordinate &gnssPosition() const{
return m_gnssPosition;
}
void setGnssLatitude(qreal latitude){
QGeoCoordinate coordinate(latitude, m_gnssPosition.longitude());
setGnssPosition(coordinate);
}
void setGnssLongitude(qreal longitude){
QGeoCoordinate coordinate(m_gnssPosition.latitude(), longitude);
setGnssPosition(coordinate);
}
void setGnssPosition(const QGeoCoordinate &newGnssPosition){
if (m_gnssPosition == newGnssPosition)
return;
m_gnssPosition = newGnssPosition;
emit gnssPositionChanged();
}
signals:
void gnssPositionChanged();
private:
QGeoCoordinate m_gnssPosition;
};
int main(int argc, char *argv[])
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
#endif
QGuiApplication app(argc, argv);
Data data_out;
data_out.setGnssPosition(QGeoCoordinate(59.91273, 10.74609));
QQmlApplicationEngine engine;
engine.rootContext()->setContextProperty("data_out", &data_out);
const QUrl url(QStringLiteral("qrc:/main.qml"));
QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
&app, [url](QObject *obj, const QUrl &objUrl) {
if (!obj && url == objUrl)
QCoreApplication::exit(-1);
}, Qt::QueuedConnection);
engine.load(url);
QTimer timer;
timer.setInterval(1000);
QObject::connect(&timer, &QTimer::timeout, &data_out, [&data_out](){
std::random_device rd;
std::mt19937 e2(rd());
std::uniform_real_distribution<> dist(-.05, .05);
QGeoCoordinate coord = data_out.gnssPosition();
coord.setLatitude(coord.latitude() + dist(e2));
coord.setLongitude(coord.longitude() + dist(e2));
data_out.setGnssPosition(coord);
// qDebug() << data_out.gnssPosition();
});
timer.start();
return app.exec();
}
#include "main.moc"
import QtQuick 2.15
import QtQuick.Window 2.15
import QtLocation 5.15
import QtPositioning 5.15
Window {
id: mainWindow
width: 640
height: 480
visible: true
title: qsTr("Hello World")
property Component markerProvider: MapQuickItem {
anchorPoint.x: rect.width / 2
anchorPoint.y: rect.height / 2
sourceItem: Rectangle{
id: rect
width: 40
height: 40
color: "salmon"
}
}
function addMarker(coordinate){
var marker = markerProvider.createObject()
console.log(marker)
marker.coordinate = coordinate
map.addMapItem(marker)
}
Map {
id: map
width: mainWindow.width
height: mainWindow.height
plugin: mapPlugin
center: data_out.gnssPosition
zoomLevel: 12
}
Plugin {
id: mapPlugin
name: "osm" // "mapboxgl", "esri", ...
// specify plugin parameters if necessary
PluginParameter {
name: "osm.mapping.providersrepository.disabled"
value: "true"
}
PluginParameter {
name: "osm.mapping.providersrepository.address"
value: "http://maps-redirect.qt.io/osm/5.6/"
}
}
Connections{
target: data_out
function onGnssPositionChanged(){
addMarker(data_out.gnssPosition)
}
}
}