After discovering several problems in the operation of GPS and GNSS libraries on SDK32 and SDK33, I decided to make one library that will be compatible with almost all versions of android (from SDK less than 24 to SDK33 and above). This library combines deprecated GPS classes with still up-to-date GNSS classes and, based on the android version, decides which one to use. Basically, if used on SDK less than 24, library will use GPS set of classes, otherwise GNSS set of classes. This allows developers to use one library to create an application which will work on almost all android SDK versions.
The working principle of this library is almost exactly the same as that of the native GPS library. The library contains the same methods and the same events. Of course, there are a few additional methods, properties and events, but the basic ones have remained unchanged.
The only major change is that instead of the "Location" class that is part of the GPS library, this library uses the "ALocation" class that is in a separate library called "ALocation" which is packaged together with the GPSGNSS library. The "ALocation" library must be checked together with the GPSGNSS library (picture below). This was done to avoid accidental class conflicts with the GPS or GNSS libraries. So your old project that uses the GPS library needs to be reworked so that wherever class "Location" is used, just put an "A" in front of "Location" = "ALocation". It shouldn't be that hard
.
Also, the "GPSEnabled" property has been replaced with "IsLocationEnabledInSettings" relative to the GPS library. Everything else is the same with a few added methods, events and properties.
An addition in this library compared to the old ones is a class called NETPOS (NETwork POSitioning). This class uses the network provider to determine the location (can be used when the GPS or GNSS signal is weak or unavailable). Both classes can be used in parallel so that locating is always available. The NETPOS class uses the same methods and properties as the GPSGNSS class, with the exception of events such as GpsStatus and NMEA, which are unavailable when using a network provider.
The METHODS contained in the GPSGNSS and NETPOS classes are:
The PROPERTIES contained in the GPSGNSS and NETPOS classes are:
The EVENTS contained in the GPSGNSS and NETPOS classes are:
This library was tested on devices with SDK23, SDK27, SDK28, SDK29, SDK31 and SDK33.
If this library makes your work easier and saves time in creating your application, please make a donation.
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The working principle of this library is almost exactly the same as that of the native GPS library. The library contains the same methods and the same events. Of course, there are a few additional methods, properties and events, but the basic ones have remained unchanged.
The only major change is that instead of the "Location" class that is part of the GPS library, this library uses the "ALocation" class that is in a separate library called "ALocation" which is packaged together with the GPSGNSS library. The "ALocation" library must be checked together with the GPSGNSS library (picture below). This was done to avoid accidental class conflicts with the GPS or GNSS libraries. So your old project that uses the GPS library needs to be reworked so that wherever class "Location" is used, just put an "A" in front of "Location" = "ALocation". It shouldn't be that hard
.Also, the "GPSEnabled" property has been replaced with "IsLocationEnabledInSettings" relative to the GPS library. Everything else is the same with a few added methods, events and properties.
An addition in this library compared to the old ones is a class called NETPOS (NETwork POSitioning). This class uses the network provider to determine the location (can be used when the GPS or GNSS signal is weak or unavailable). Both classes can be used in parallel so that locating is always available. The NETPOS class uses the same methods and properties as the GPSGNSS class, with the exception of events such as GpsStatus and NMEA, which are unavailable when using a network provider.
The METHODS contained in the GPSGNSS and NETPOS classes are:
- GetCurrentLocation (new method) - This method asynchronously determines the current location. At the end of the procedure, the "CurrentLocationResult (Location1 As ALocation)" event is activated.
- Initialize (the same as in GPS library).
- IsInitialized (the same as in GPS library).
- Start (the same as in GPS library).
- Stop (the same as in GPS library).
The PROPERTIES contained in the GPSGNSS and NETPOS classes are:
- IsLocationEnabledInSettings (Equivalent to the GPSEnabled property in the GPS library).
- IsStarted (new property) - returns true if GPSGNSS or NETPOS is started and listening for events, otherwise false.
- LastKnownLocation (new property) - returns the last remembered location without calculating the current location.
- LocationSettingsIntent (the same as in GPS library).
The EVENTS contained in the GPSGNSS and NETPOS classes are:
- LocationChanged (Location1 As ALocation) - (the same as in GPS library).
- LocationChanged2 (Locations() As ALocation) 'Works on SDK31 and up - (new event).
- UserEnabled (Enabled As Boolean) - (the same as in GPS library).
- GpsStatus (Satellites As List) - (the same as in GPS library) available only in GPSGNSS class.
- NMEA (TimeStamp As Long, Sentence As String) - (the same as in GPS library) available only in GPSGNSS class.
- Started - (new event) will bi fired when GPSGNSS or NETPOS is started and starts to listening for events (Start method called).
- Stopped - (new event) will bi fired when GPSGNSS or NETPOS stops to listening for events (Stop method called).
- CurrentLocationResult (Location1 As ALocation) - (new event) will bi fired after calling GetCurrentLocation method.
GPSGNSS example code:
Sub Class_Globals
Private Root As B4XView
Private GPS As GPSGNSS
Private rp As RuntimePermissions
Private lblNumOfSattelites As Label
Private lblAverageSignal As Label
Private lblLatitude As Label
Private lblLongitude As Label
End Sub
Public Sub Initialize
B4XPages.GetManager.LogEvents = True
End Sub
'This event will be called once, before the page becomes visible.
Private Sub B4XPage_Created (Root1 As B4XView)
Root = Root1
Root.LoadLayout("MainPage")
'Requesting Location's runtime permissions
rp.CheckAndRequest(rp.PERMISSION_ACCESS_COARSE_LOCATION)
Wait For B4XPage_PermissionResult (Permission As String, Result As Boolean)
If Result=False Then
ExitApplication
End If
rp.CheckAndRequest(rp.PERMISSION_ACCESS_FINE_LOCATION)
Wait For B4XPage_PermissionResult (Permission As String, Result As Boolean)
If Result=False Then
ExitApplication
End If
If GPS.IsInitialized=False Then
GPS.Initialize("GPS")
End If
End Sub
Private Sub B4XPage_Disappear
If GPS.IsInitialized Then
If GPS.IsStarted Then
GPS.Stop
End If
End If
ExitApplication
End Sub
Private Sub btnStartGPSGNSS_Click
If GPS.IsStarted=False Then
GPS.Start(0,0)
End If
End Sub
Private Sub btnStopGPSGNSS_Click
If GPS.IsStarted=True Then
GPS.Stop
End If
End Sub
Private Sub Msgbox_Result (Result As Int)
End Sub
Private Sub btnGetLastKnownLocation_Click
Dim loc As ALocation=GPS.LastKnownLocation
If loc.IsInitialized Then
MsgboxAsync("Your last known location is:" & CRLF & "Latitude=" & loc.Latitude & CRLF & "Longitude=" & loc.Longitude,"Last Known Location")
End If
End Sub
Private Sub btnCurrentLocation_Click
ProgressDialogShow("Collecting information...")
Sleep(20)
GPS.GetCurrentLocation
Wait For GPS_CurrentLocationResult (Location1 As ALocation)
ProgressDialogHide
If Location1.IsInitialized Then
MsgboxAsync("Your current location is:" & CRLF & "Latitude=" & Location1.Latitude & CRLF & "Longitude=" & Location1.Longitude,"Current Location")
End If
End Sub
Private Sub GPS_GpsStatus (Satellites As List)
If GPS.IsStarted Then
Dim NumOfSat As Int=0
Dim Signal As Float=0
For Each sat As GPSSatellite In Satellites
If sat.UsedInFix Then
' Log("--------SATTELITE " & Satellites.IndexOf(sat) & "-----------------------")
' Log("Azimuth=" & sat.Azimuth)
' Log("Elevation=" & sat.Elevation)
' Log("Prn=" & sat.Prn)
' Log("Snr=" & sat.Snr)
' Log("HasAlmanac=" & sat.HasAlmanac)
' Log("HasEphemeris=" & sat.HasEphemeris)
' Log("UsedInFix=" & sat.UsedInFix)
' Log("-------------------------------------------------------------------------")
NumOfSat=NumOfSat+1
Signal=Signal+sat.Snr
End If
Next
lblNumOfSattelites.Text="Satelites in use: " & NumOfSat
lblAverageSignal.Text="Average signal: " & Round2(Signal/NumOfSat,2)
End If
End Sub
Private Sub GPS_LocationChanged (Location1 As ALocation)
If GPS.IsStarted Then
lblLatitude.Text="Latitude: " & Round2(Location1.Latitude,8)
lblLongitude.Text="Longitude: " & Round2(Location1.Longitude,8)
End If
End Sub
Private Sub GPS_UserEnabled (Enabled As Boolean)
Log("LocationEnabled = " & Enabled)
' If Enabled=False Then
' StartActivity(GPS.LocationSettingsIntent)
' End If
End Sub
Private Sub GPS_NMEA (TimeStamp As Long, Sentence As String)
'Log("NMEA: Sentence=" & Sentence & " TimeStamp=" & TimeStamp)
End Sub
Private Sub GPS_LocationChanged2 (Locations() As ALocation) 'Works on SDK31 and up
'Log(Locations.Length)
End Sub
Private Sub GPS_Started
Log("GPS_Started GPS.IsStarted=" & GPS.IsStarted)
lblNumOfSattelites.Text="Satelites in use: calculting"
lblAverageSignal.Text="Average signal: calculting"
lblLatitude.Text="Latitude: calculting"
lblLongitude.Text="Longitude: calculting"
End Sub
Private Sub GPS_Stopped
Log("GPS_Stopped GPS.IsStarted=" & GPS.IsStarted)
lblNumOfSattelites.Text="Satelites in use: unknown"
lblAverageSignal.Text="Average signal: unknown"
lblLatitude.Text="Latitude: unknown"
lblLongitude.Text="Longitude: unknown"
End SubThis library was tested on devices with SDK23, SDK27, SDK28, SDK29, SDK31 and SDK33.
If this library makes your work easier and saves time in creating your application, please make a donation.
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