GPSFollowMovement (Function)

ONLINE HELP
WINDEV, WEBDEV AND WINDEV MOBILE

Version:

Home | Sign in | English

This content has been translated automatically. Click here to view the French version.

Retrieved properties
Notes
Operating mode in iPhone/iPad
Required permissions
Required application feature
Browsers allowing the geolocation

WINDEV

WEBDEV

WINDEV Mobile

Others

See also

GPSFollowMovement (Function)

In french: GPSSuitDéplacement

Asks to be regularly notified about the current device position.

Versions 16 and later

This function is now available in Browser code.

New in version 16

This function is now available in Browser code.

Versions 17 and later

This function is now available for iPhone/iPad applications.

New in version 17

This function is now available for iPhone/iPad applications.

Versions 18 and later

This function is now available in Android Widget mode.

New in version 18

This function is now available in Android Widget mode.

Versions 21 and later

This function is now available in Universal Windows 10 App mode.

New in version 21

This function is now available in Universal Windows 10 App mode.

Versions 22 and later

This function is now available for WINDEV applications.

New in version 22

This function is now available for WINDEV applications.

Example

// Branche une procédure pour recevoir régulièrement la position du périphérique
GPSFollowMovement(ProcDeplacement)

// Procédure
PROCÉDURE ProcDeplacement(pos is géoPosition)

Info(" Latitude: " + pos.Latitude)
Info(" Longitude: " + pos.Longitude)

Syntax

Enabling the notification mechanism (in a mobile) Hide the details

GPSFollowMovement(<WLanguage procedure> [, <Timeout> [, <Distance>]])

<WLanguage procedure>: Procedure name

Name of WLanguage procedure called at each notification.
This procedure has the following format:

PROCEDURE <Nom de la Procédure>(<Position>)

<Position> is a geoPosition variable containing information about the device position at the time of notification.

<Timeout>: Optional integer or optional Duration

Minimum timeout (in hundredths of a second) between two notifications. If this parameter is not specified, the minimum time-out will be set to 60 seconds.
Remark: This parameter can correspond to:
an integer corresponding to the number of hundredths of a second,
a Duration variable,
Versions 23 and later
direct indication of the time (e.g. 1 s or 10 ms).
New in version 23
direct indication of the time (e.g. 1 s or 10 ms).
direct indication of the time (e.g. 1 s or 10 ms).
This parameter is ignored.

<Distance>: Optional real

Minimum distance (in meters) between two notifications.
If this parameter is not specified, the minimum distance will be set to 5 meters.

Enabling the notification mechanism in browser code Hide the details

GPSFollowMovement(<WLanguage procedure>)

<WLanguage procedure>: Procedure name

Name of WLanguage procedure called at each notification. This procedure has the following format:

PROCEDURE <Nom de la Procédure>(<Position>, <Erreur>)

where:
<Position> is a geoPosition variable containing information about the device position at the time of notification. To find out whether the Speed, Accuracy, Direction or Altitude properties of a geoPosition variable have been filled when retrieving the position, use SpeedValid, AccuracyValid, DirectionValid and AltitudeValid.
<Error> is an Integer constant corresponding to the error code and that can take the following values:
gpsErrorOK No error was detected.
gpsErrorRights The browser has no sufficient rights to use geolocation.
gpsErrorPosition Unable to define the position (internal error of provider for example).
gpsErrorTimeout The position could not be retrieved within the timeout.

Disabling the notification mechanism

GPSFollowMovement()

Remarks

Retrieved properties

To find out whether the Speed, Accuracy, Direction or Altitude properties of a geoPosition variable have been filled when retrieving the position, use SpeedValid, AccuracyValid, DirectionValid and AltitudeValid.
To reinitialize a geoPosition variable, use VariableReset.
It is recommended to initialize the location provider settings using the GPSInitParameter function before retrieving a position.
The positioning information that was retrieved corresponds to the last known device position: therefore, they may not correspond to the current device position if the device was moved while the GPS signal was not valid for example. It is possible to know the date and time at which the position was calculated thanks to the Property MeasurementDate of the Variable geoPosition.
Speed, Accuracy, Direction and Altitude will be specified only if the location provider allows it (otherwise, these properties will take their default value).
The location provider can be set using the GPSInitParameter function.

Notes

Geolocation functions can consume a lot of resources on the device (battery, bandwidth, etc.). Therefore, we advise you not de define very small values for the minimum time-out and for the minimum distance between two notifications.
Versions 21 and later
It is possible to perform geolocation tracking in the background without consuming resources via the functions geoTrackingEnable, geoTrackingDisable, geoTrackingStatus and geoTrackingProcedure. For more details, see Location tracking.
New in version 21
It is possible to perform geolocation tracking in the background without consuming resources via the functions geoTrackingEnable, geoTrackingDisable, geoTrackingStatus and geoTrackingProcedure. For more details, see Location tracking.
It is possible to perform geolocation tracking in the background without consuming resources via the functions geoTrackingEnable, geoTrackingDisable, geoTrackingStatus and geoTrackingProcedure. For more details, see Location tracking.
When generating the application, it is possible to allow the GPSFollowMovement function to be called when the application is in the background (option "Allow GPSSuitDevice and BeaconPreciseDetect to be called when the application is in the background" in the "Configuration" step of the wizard).. In this case, the geolocation will continue when the application runs in the background or when the device is in standby mode. See Generating an iOS application for more details.
To stop receiving notifications, call GPSFollowMovement without parameter or call GPSEnd.

Versions 17 and later

Operating mode in iPhone/iPad

When a GPS function is first run, the system requests geolocation permission from the user. If the user refuses, all the GPS functions used in the rest of the application will fail (fatal error).

To re-allow the use of GPS for this application, the system configuration of the application must be modified.

New in version 17

Operating mode in iPhone/iPad

When a GPS function is first run, the system requests geolocation permission from the user. If the user refuses, all the GPS functions used in the rest of the application will fail (fatal error).

To re-allow the use of GPS for this application, the system configuration of the application must be modified.

Operating mode in iPhone/iPad

When a GPS function is first run, the system requests geolocation permission from the user. If the user refuses, all the GPS functions used in the rest of the application will fail (fatal error).

To re-allow the use of GPS for this application, the system configuration of the application must be modified.

Required permissions

The call to this function modifies the permissions required by the application.
Required permission: ACCESS_FINE_LOCATION.

Android 10 specific case: Android 10 has implemented a new permission for the functions that allow locating the device: ACCESS_BACKGROUND_LOCATION.
This permission allows using the function when the application is in the background.
When this permission is added to the application, a window allows the user to:

allow access to the device location while the application is in the background,
allow access to the location only while the application is in use,
deny access to the location.

The user can also change these permissions at any time in the Android settings. Android 11 specific case: The use of this function requires the implementation of the Permission: ACCESS_BACKGROUND_LOCATION allowing the location of the device.
This permission allows using the function when the application is in the background.

If the application requires background localization, you must:

Manually add the Permission "ACCESS_BACKGROUND_LOCATION" in the wizard generation of the Android application.
Explicitly request the Permission location in the background from the user with the PermissionRequest function. For example:

PermissionRequest(permBackgroundLocation, Callback)
INTERNAL PROCÉDURE Callback(p is Permission)
IF p.Granted THEN
// Utilisation possible des fonctions nécessitant la localisation en arrière-plan
END
END

A window allows the user to:

allow access to the device location while the application is in the background,
allow access to the location only while the application is in use,
deny access to the location. The user can also change these permissions at any time in the Android settings.

Remarks:

Follow Google's specifications for applications that use location in the background. For more details, see https://support.google.com/googleplay/android-developer/answer/9799150. If these conditions are not met (including user information requirements), applications may not be authorized for publication on the Play Store.
The Permission background location request should only be made if the Permission location has been granted. Otherwise, the PermissionRequest function will fail.
If the user's choice when requesting Permission to locate in the background is more restrictive than the choice made when requesting Permission to locate, the application will automatically be restarted.
On devices below Android 10, if the Permission location has been granted to the application, the Permission background location request will be granted without displaying a window.

Versions 21 and later

Required application feature

When this function is used, an application feature is declared in the application generation wizard.

Required feature: Geolocation

This feature allows the applications to access the geolocation features found on the device or on the computer.

New in version 21

Required application feature

When this function is used, an application feature is declared in the application generation wizard.

Required feature: Geolocation

This feature allows the applications to access the geolocation features found on the device or on the computer.

Required application feature

When this function is used, an application feature is declared in the application generation wizard.

Required feature: Geolocation

This feature allows the applications to access the geolocation features found on the device or on the computer.

Browsers allowing the geolocation

Caution: Geolocation is only available on certain modern browsers:

FireFox from version 3.5,
Chrome from version 5.0.342.1,
Opera from version 10.6,
Safari from version 5.0.

During the call to a geolocation function, the browser requests a location authorization.Remark: From Chrome 50 (including on Android), GPSFollowMovement can only be used on the sites secured via an SSL certificate for example. If the site is not secured, the function returns a result that cannot be used. During the test in local (localhost), the function operates properly.

Related Examples:

Android (WINDEV Mobile): Android GPS

[ + ] This example presents the use of the GPS functions of WLanguage in an Android application.
It is used to retrieve at regular interval:
- The latitude
- The longitude
- The altitude
- The speed
- The direction

Cross-platform examples (WINDEV Mobile): WM Sports

[ + ] This example is a sport application used to save your performances.
The application calculates the distance, the time, the average speed and the number of calories spent according to the sport.
The run is displayed on a map control via markers and an itinerary.

The example also includes a server part used to synchronize the user data.
This webservice is available in the WEBDEV "WW_Sports" example.

Component: wd260java.dll