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 200.8.0 or later is installed.

4. The Qt 6.8.2 software development framework or later 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.

Open a Qt Creator project

1. Open the project you created by completing the Display a map tutorial.
2. Continue with the following instructions to use a URL to access and display a feature layer in a map.

Update the header file

1. In the Projects window, open the Headers folder. Double-click the file Display_a_map.h to open it. Remove the unnecessary declaration for the setViewpoint() function.

   Display_a_map.h

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   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;
   
   };

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

   Display_a_map.h

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   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.

1. In the Projects window, open the Sources folder and then open the Display_a_map.cpp file. Remove the following unneeded include statements.

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   #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>

2. Add the following new include statements.

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   #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.

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

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   void Display_a_map::setupViewpoint()
   {
   
       const Point center(-118.80543, 34.02700, SpatialReference::wgs84());
       const Viewpoint viewpoint(center, 100000.0);
       m_mapView->setViewpointAsync(viewpoint);
   
   }

2. Finally, we will remove the call to the setupViewpoint() method from within the setMapView(MapQuickView* mapView) function.

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   // 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. The location is displayed as an overlay in the map view.

1. 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.

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   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.

2. Within the setMapView method, add the call to the new startLocation() method.

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   // 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.

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ARCGIS_RUNTIME_VERSION = 200.8.0
include($$PWD/arcgisruntime.pri)

# TODO: You need to replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# resides on your system, example: C:/arcgis-maps-sdk-toolkit-qt/uitools/toolkitcpp/toolkitcpp.pri
# This block determines whether you've cloned your toolkit
PATH_TO_TOOLKIT = "<path_to_toolkit_repo>/uitools/toolkitcpp/toolkitcpp.pri"

exists($${PATH_TO_TOOLKIT}) {
  message("Toolkit found")
  DEFINES += TOOLKIT_FOUND

  # include the toolkitcpp.pri, which contains all the toolkit resources
  include($${PATH_TO_TOOLKIT})

  qtHaveModule(webenginequick) {
    QT += webenginequick
  }
} else {
  message("Toolkit not found in provided path. Either set PATH_TO_TOOLKIT or use an API Key")
}

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{

#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

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

2. Open the .pro project file in Qt Creator.

Since the downloaded solution does not contain authentication credentials, 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

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ARCGIS_RUNTIME_VERSION = 200.8.0
include($$PWD/arcgisruntime.pri)

# TODO: You need to replace the <path_to_toolkit_repo> with a valid location where the Qt Toolkit
# resides on your system, example: C:/arcgis-maps-sdk-toolkit-qt/uitools/toolkitcpp/toolkitcpp.pri
# This block determines whether you've cloned your toolkit
PATH_TO_TOOLKIT = "<path_to_toolkit_repo>/uitools/toolkitcpp/toolkitcpp.pri"

exists($${PATH_TO_TOOLKIT}) {
  message("Toolkit found")
  DEFINES += TOOLKIT_FOUND

  # include the toolkitcpp.pri, which contains all the toolkit resources
  include($${PATH_TO_TOOLKIT})

  qtHaveModule(webenginequick) {
    QT += webenginequick
  }
} else {
  message("Toolkit not found in provided path. Either set PATH_TO_TOOLKIT or use an API Key")
}

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{

#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.