Display device location

Before starting this tutorial:

1. You need an ArcGIS Location Platform or ArcGIS Online account.

2. Your system meets the system requirements.

3. The ArcGIS Maps SDK for Qt, version 300.1.0 or later is installed.

4. The Qt 6.8.2 software development framework or later is installed.

5. The CMake build system is installed.

Option 1: Develop the code

To start the tutorial, complete the Display a map tutorial. This creates a map to display the Santa Monica Mountains in California using the topographic basemap from the ArcGIS Basemap Styles service The ArcGIS Basemap Styles service, also referred to as the Basemap Styles service, is a location service that provides basemap styles and data for the world. It returns styles as Mapbox styles and web maps, and data as vector tiles and/or map tiles. It supports all of the styles in the ArcGIS Basemap style and Open Basemap style family. An ArcGIS Location Platform or ArcGIS Online account is required to use the service. Learn more .

Open a Qt Creator project

Open the project you created by completing the Display a map tutorial.

Continue with the following instructions to use a URL to access and display a feature layer in a map.

Update the header file

In the project Display_a_map > Display_a_map > Header Files folder of Qt Creator, double-click the Display_a_map.h file to open it. Remove the unnecessary declaration for the setViewpoint() function.

private:
    Esri::ArcGISRuntime::MapQuickView* mapView() const;
    void setMapView(Esri::ArcGISRuntime::MapQuickView* mapView);

    void setupViewpoint();

    Esri::ArcGISRuntime::Map* m_map = nullptr;

    Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;

};

Add the new method declaration for the startLocation() method under the private: section. Then save the file.

private:
    Esri::ArcGISRuntime::MapQuickView* mapView() const;
    void setMapView(Esri::ArcGISRuntime::MapQuickView* mapView);

    void startLocation();

    Esri::ArcGISRuntime::Map* m_map = nullptr;

    Esri::ArcGISRuntime::MapQuickView* m_mapView = nullptr;

};

Update include statements

To create this app you will need to remove some and add additional include statements in the class header file.

In the project Display_a_map > Display_a_map > Source Files folder of Qt Creator, double-click the Display_a_map.cpp file to open it. Remove the following unneeded include statements.

#include "Display_a_map.h"
#include "Map.h"

#include "MapTypes.h"

#include "MapQuickView.h"

#include "Point.h"
#include "Viewpoint.h"
#include "SpatialReference.h"

#include <QFuture>

Add the following new include statements. Then save the file.

#include "Display_a_map.h"
#include "Map.h"

#include "MapTypes.h"

#include "MapQuickView.h"

#include <QFuture>

#include "LocationDisplay.h"
#include "MapViewTypes.h"

Remove remaining unneeded code

At this point we will remove the remainder of the unnecessary code before add the logic to display the device’s location on the map.

Continuing on the Display_a_map.cpp file, remove the setupViewpoint() method.

void Display_a_map::setupViewpoint()
{

    const Point center(-118.80543, 34.02700, SpatialReference::wgs84());
    const Viewpoint viewpoint(center, 100000.0);
    m_mapView->setViewpointAsync(viewpoint);

}

Also remove the call to the setupViewpoint() method from within the setMapView(MapQuickView* mapView) function. Then save the file.

// Set the view (created in QML)
void Display_a_map::setMapView(MapQuickView* mapView)
{
    if (!mapView || mapView == m_mapView)
    {
        return;
    }

    m_mapView = mapView;

    m_mapView->setMap(m_map);

    setupViewpoint();

    emit mapViewChanged();
}

Show the current location

Each map view has its own instance of a LocationDisplay for showing the current location (point) of the device A device is nearly any kind of computer, including desktops, laptops, mobile phones, and tablets. Learn more . The location is displayed as an overlay in the map view A map view is a user interface that displays map layers and graphics in 2D. It controls the area (extent) of the map that is visible and supports user interactions such as pan and zoom. Learn more .

Staying within the Display_a_map.cpp file, add the following new method, startLocation(). This code enables LocationDisplay for the map view and assigns a LocationDisplayAutoPanMode that centers the map at the device location.

MapQuickView* Display_a_map::mapView() const
{
    return m_mapView;
}

void Display_a_map::startLocation()
{
    // start location display
    m_mapView->locationDisplay()->start();
    // center the location display around the device location
    m_mapView->locationDisplay()->setAutoPanMode(LocationDisplayAutoPanMode::Recenter);
}

The setMapView method appearing later in this file gets a handle to the MapView object that was declared in QML code and sets the Map on the MapView for display. This code is installed by the templates that ArcGIS provides when creating a new project in Qt.

Within the setMapView method, add the call to the new startLocation() method. Then save the file.

// Set the view (created in QML)
void Display_a_map::setMapView(MapQuickView* mapView)
{
    if (!mapView || mapView == m_mapView)
    {
        return;
    }

    m_mapView = mapView;

    m_mapView->setMap(m_map);

    startLocation();

    emit mapViewChanged();
}

Set developer credentials

For the final steps of this tutorial, click the tab below that corresponds to the authentication type (API key authentication or User authentication) that you chose when you completed the Display a map tutorial.

Be sure to also provide the same authentication (API key or user authentication Client ID/Redirect URL) that you used for the Display a map tutorial.

    // The following methods grant an access token:

    // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
    // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
    // organization in ArcGIS Online or ArcGIS Enterprise.

    // 2. API key authentication: Get a long-lived access token that gives your application access to
    // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
    // Copy the API Key access token.

    const QString accessToken = QString("");

    if (accessToken.isEmpty())
    {
        qWarning()
            << "Use of ArcGIS location services, such as the basemap styles service, requires"
            << "you to authenticate with an ArcGIS account or set the API Key property.";
    }
    else
    {
        ArcGISRuntimeEnvironment::setApiKey(accessToken);
    }

# TODO: Replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# root directory resides on your system, example: C:/applications/arcgis-maps-sdk-toolkit-qt
# The code also sets the TOOLKIT_FOUND variable which is used by other parts of the tutorial.

set(ARCGIS_TOOLKIT_REPOSITORY "<path_to_toolkit_repo>")

{

#ifdef TOOLKIT_FOUND

    // Define the Redirect URL string obtained when creating the OAuth credentials.
    // TODO: You need to replace the "REDIRECT_URL" with your own valid string,
    // ex: "urn:ietf:wg:oauth:2.0:oob"

    const auto qStringRedirectUrl = QString{"REDIRECT_URL"};

    // Define the URL of the portal to authenticate with.
    const QUrl qUrlPortal = QUrl{"https://www.arcgis.com/"};

    // Define a unique identifier associated with an application registered with the
    // portal that assists with client/server OAuth authentication.
    // TODO: You need to replace the "CLIENT_ID" with your own valid string.

    const QString qStringClientId = QString{"CLIENT_ID"};

    // Create a new OAuth user configuration using: the Url to mapping web service, the Client ID
    // string, and the Redirect Url string.
    auto* oAuthUserConfiguration = new OAuthUserConfiguration(qUrlPortal, qStringClientId,
                                                              qStringRedirectUrl, this);

    // Call the Toolkit's OAuthUserConfigurationManager static `addConfiguration`
    // method to use the OAuth dialog. This will tell the Authenticator to use OAuth for the provided configuration.
    Toolkit::OAuthUserConfigurationManager::addConfiguration(oAuthUserConfiguration);
#endif // TOOLKIT_FOUND

Press Ctrl + R to run the app.

You should see your current location displayed on the map. Different location symbols are used depending on the auto pan mode and whether a location is acquired. See LocationDisplayAutoPanMode for details.

By default, a round blue symbol is used to display the device’s location. The location data source tries to get the most accurate location available but depending upon signal strength, satellite positions, and other factors, the location reported could be an approximation. A semi-transparent circle around the location symbol indicates the range of accuracy. As the device moves and location updates are received, the location symbol will be repositioned on the map.

Option 2: Download the solution

Click the Download solution link on this page under the Solution title and unzip the file to a location on your machine.

In Qt Creator, choose File > Open File or Project… from them menus. In the Open file dialog, navigate to the CMakeLists.txt file for the solution you unzipped and click the Open button.

The Configure Project window will appear for you to specify the Qt Kit to use to compile the project. Check on the Qt Kit called Desktop Qt 6.8.2 MSVC2022 64bit before clicking the Configure Project button at the bottom of the page.

Since the downloaded solution does not contain authentication credentials (API Key or User authentication), you must set up authentication to create the developer credentials and add them to the project.

For the final steps of this tutorial, click the tab below that corresponds to the authentication type (API key authentication or User authentication) that you chose when you completed the Display a map tutorial.

Be sure to also provide the same authentication (API key or user authentication Client ID/Redirect URL) that you used for the Display a map tutorial.

Set developer credentials in the solution

    // The following methods grant an access token:

    // 1. User authentication: Grants a temporary access token associated with a user's ArcGIS account.
    // To generate a token, a user logs in to the app with an ArcGIS account that is part of an
    // organization in ArcGIS Online or ArcGIS Enterprise.

    // 2. API key authentication: Get a long-lived access token that gives your application access to
    // ArcGIS location services. Go to the tutorial at https://links.esri.com/create-an-api-key.
    // Copy the API Key access token.

    const QString accessToken = QString("");

    if (accessToken.isEmpty())
    {
        qWarning()
            << "Use of ArcGIS location services, such as the basemap styles service, requires"
            << "you to authenticate with an ArcGIS account or set the API Key property.";
    }
    else
    {
        ArcGISRuntimeEnvironment::setApiKey(accessToken);
    }

# TODO: Replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# root directory resides on your system, example: C:/applications/arcgis-maps-sdk-toolkit-qt
# The code also sets the TOOLKIT_FOUND variable which is used by other parts of the tutorial.

set(ARCGIS_TOOLKIT_REPOSITORY "<path_to_toolkit_repo>")

{

#ifdef TOOLKIT_FOUND

    // Define the Redirect URL string obtained when creating the OAuth credentials.
    // TODO: You need to replace the "REDIRECT_URL" with your own valid string,
    // ex: "urn:ietf:wg:oauth:2.0:oob"

    const auto qStringRedirectUrl = QString{"REDIRECT_URL"};

    // Define the URL of the portal to authenticate with.
    const QUrl qUrlPortal = QUrl{"https://www.arcgis.com/"};

    // Define a unique identifier associated with an application registered with the
    // portal that assists with client/server OAuth authentication.
    // TODO: You need to replace the "CLIENT_ID" with your own valid string.

    const QString qStringClientId = QString{"CLIENT_ID"};

    // Create a new OAuth user configuration using: the Url to mapping web service, the Client ID
    // string, and the Redirect Url string.
    auto* oAuthUserConfiguration = new OAuthUserConfiguration(qUrlPortal, qStringClientId,
                                                              qStringRedirectUrl, this);

    // Call the Toolkit's OAuthUserConfigurationManager static `addConfiguration`
    // method to use the OAuth dialog. This will tell the Authenticator to use OAuth for the provided configuration.
    Toolkit::OAuthUserConfigurationManager::addConfiguration(oAuthUserConfiguration);
#endif // TOOLKIT_FOUND

Run the app

Press Ctrl + R to run the app.

You should see your current location displayed on the map. Different location symbols are used depending on the auto pan mode and whether a location is acquired. See LocationDisplayAutoPanMode for details.

By default, a round blue symbol is used to display the device’s location. The location data source tries to get the most accurate location available but depending upon signal strength, satellite positions, and other factors, the location reported could be an approximation. A semi-transparent circle around the location symbol indicates the range of accuracy. As the device moves and location updates are received, the location symbol will be repositioned on the map.