map_manager.cpp

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#include "map_management/map_manager.h"
 
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QtNetwork>
#include <vector>
 
namespace MapManagement
{
 
    //"GetMap" retrieves map data from geonorges WMS service. It sets up a
    // network
    // request to fetch the map image and processes the response to store the
    // data.
    void
    MapManager::GetMap(Core::UTMCoordinate coord, int size)
    {
        // Create a QNetworkAccessManager object for making network requests
        QNetworkAccessManager* manager = new QNetworkAccessManager(nullptr);
 
        // Set the URL endpoint for the map service
        QString endpoint =
            "https://openwms.statkart.no/skwms1/wms.norges_grunnkart";
        QUrl url(endpoint);
        QUrlQuery query;
 
        // Calculate the corner coordinates of the map based on the UTM
        // coordinate and size
        MapManager::CalculateCornerCoordinates(coord, size);
 
        // Add query parameters
        query.addQueryItem("service", "WMS");
        query.addQueryItem("version", "1.3.0");
        query.addQueryItem("request", "GetMap");
        query.addQueryItem("layers",
                           "hoyde,Arealtyper,fjellskygge,helning,Vann_og_"
                           "vassdrag,Samferdsel,Bygninger");
        query.addQueryItem("styles", "default");
        query.addQueryItem("format", "image/png");
        query.addQueryItem("crs", "EPSG:25833");
        // Set the bounding box query parameter using the map area that was
        // calulated with the CalculateCornerCoordinates function
        query.addQueryItem("bbox", Instance().m_Area);
        // Set the width and height query parameters based on the image
        // resolution
        query.addQueryItem("width",
                           QString::number(Instance().m_ImageResolution));
        query.addQueryItem("height",
                           QString::number(Instance().m_ImageResolution));
        url.setQuery(query);
        QNetworkRequest request(url);
 
        // Emit a signal to indicate that an image request is being made
        emit Instance().RequestImage();
        QNetworkReply* reply = manager->get(request);
 
        // Connect a lambda function to the finished signal of the network reply
        // and check if the reply has no error. If it has no error it read the
        // response data from the reply.
        QObject::connect(reply, &QNetworkReply::finished, [=]() {
            if (reply->error() == QNetworkReply::NoError) {
                QByteArray data = reply->readAll();
                Instance().m_Data = data;
                // Emit a signal to indicate that the image has been received
                emit Instance().GotImage();
            }
        });
    };
 
    // CalculateCornerCoordinates calculates the corner coordinate of the map,
    // ensuring that the origin is centered in the middle and the sides of the
    // map are equal in length to the specified size. This is added to a QString
    // variable, which will be used in the HTTP request within the "getMap"
    // function.
    void
    MapManager::CalculateCornerCoordinates(Core::UTMCoordinate coord, int size)
    {
        double minX = coord.Easting - (size / 2);
        double minY = coord.Northing - (size / 2);
        double maxX = coord.Easting + (size / 2);
        double maxY = coord.Northing + (size / 2);
 
        const QStringList wmsRequestCoordsList{
            QString::number(minX),
            QString::number(long(minY)),
            QString::number(maxX),
            QString::number(long(maxY)),
        };
        Instance().m_Area = wmsRequestCoordsList.join(",");
    };
 
} // namespace MapManagement