Android Question Gmap issue

Hirogens · Aug 10, 2018

Hello I ask again for some help with GPS map tracking.
My app log all the GPS points like this (.txt)
When I want to trace all the point I use this:

Code:

If gmap.IsInitialized Then
        If File.ExternalWritable = False Then
            Msgbox("No rights to write"," ")
            Return
        Else
            shared = Starter.rp.GetSafeDirDefaultExternal("GPS_Location")
            Starter.rp.CheckAndRequest(Starter.rp.PERMISSION_READ_EXTERNAL_STORAGE)
            Starter.rp.CheckAndRequest(Starter.rp.PERMISSION_WRITE_EXTERNAL_STORAGE)
            Wait For Activity_PermissionResult(Permission As String, Result As Boolean)
            If Result Then SaveStringExample
        End If

        Dim pl As Polyline = gmap.AddPolyline

        pl.Points = File.ReadList(shared, "PositionsGPScycling.txt")
        pl.Color=Colors.Blue
        pl.ZIndex=3
    Else
        Log("Gmap not initialize llll")
    End If

The SaveStringExample check if the file already exist, and if it exist I try to parse this file to get the position.
I have an error with the parsing : " pl.Points = File.ReadList(shared, "PositionsGPScycling.txt")"
This is the error:

Code:

Map is not ready yet.
** Activity (page_statistique) Resume **
Map is not ready yet.
Isinit=> true
Gmap isinit:> true
File exist
Error occurred on line: 242 (page_statistique)
java.lang.ClassCastException: java.lang.String cannot be cast to com.google.android.gms.maps.model.LatLng
    at anywheresoftware.b4a.objects.MapFragmentWrapper$PolylineWrapper.setPoints(MapFragmentWrapper.java:496)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:710)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:339)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
    at anywheresoftware.b4a.shell.DebugResumableSub$RemoteResumableSub.resume(DebugResumableSub.java:19)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:132)
    at anywheresoftware.b4a.BA$2.run(BA.java:360)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6121)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)

How can I resolve this issue ? And it's enough to recreate my journey ?

Thanks =)

Erel · Aug 12, 2018

File.ReadList returns a list with string elements. You need to create a new list where each item in that list is a LatLng object.

Hirogens · Aug 13, 2018

Erel said:
File.ReadList returns a list with string elements. You need to create a new list where each item in that list is a LatLng object.

When you say list is a LatLng Object, I give this List to a Polyline object and just do this

Code:

pl.Points = File.ReadList(shared, "PositionsGPScycling.txt")
        pl.Color=Colors.Blue
        pl.ZIndex=3

Or I need to use something different ?

Thanks !

Erel · Aug 13, 2018

Hirogens said:
pl.Points = File.ReadList(shared, "PositionsGPScycling.txt")

This cannot work. File.ReadList returns a List with string elements.
You need to create a new list with LatLng elements.

Hirogens · Aug 13, 2018

Erel said:
This cannot work. File.ReadList returns a List with string elements.
You need to create a new list with LatLng elements.

So if I log all my Long/lat in a file every seconde. When I finish my journey I parse this file and recup' all my value in the Object, it can works ?
Sorry I don't realy know how work this Object :/

marcick · Aug 13, 2018

Something like this:

Code:

Dim Points as list

forEach ....
Dim ll As LatLng
ll.Initialize(lat, lon)
Points.Add(ll)
Next

pl.Points = Points

You need to scan your file, for each row retrieve the lat/lon values (float), create the ll objects and put it in Points list.

Hirogens · Aug 13, 2018

marcick said:
Something like this:

Code:

Dim Points as list forEach .... Dim ll As LatLng ll.Initialize(lat, lon) Points.Add(ll) Next pl.Points = Points

You need to scan your file, for each row retrieve the lat/lon values (float), create the ll objects and put it in Points list.

Hello, I do this

Code:

Dim pl As Polyline = gmap.AddPolyline
        
        For Each k As Int In Starter.gmaps 'an array
            Dim ll As LatLng
            Dim lat_lng As String
            Dim lat As Double
            Dim lng As Double
            lat_lng = Starter.gmaps.GetValueAt(k)
            lat = lat_lng.SubString2(0, lat_lng.IndexOf(","))
            lng = lat_lng.SubString2(lat_lng.IndexOf(","), lat_lng.Length)
            ll.Initialize(lat, lng)       
        Next
        pl.Points = ll
        pl.Color=Colors.Blue
        pl.ZIndex=3

my gmaps value is a Map which contain a string with that : "Lattitude,longitude"

marcick · Aug 13, 2018

you're missing a list.

Code:

Dim pl As Polyline = gmap.AddPolyline
Dim lat_lng As String
Dim lat, lng As Double
Dim Points as list
For Each k As Int In Starter.gmaps 'an array
  lat_lng = Starter.gmaps.GetValueAt(k)
  lat = lat_lng.SubString2(0, lat_lng.IndexOf(","))
  lng = lat_lng.SubString2(lat_lng.IndexOf(","), lat_lng.Length)
  Dim ll As LatLng
  ll.Initialize(lat, lng)      
  Points.add (ll)
Next
pl.Points = Points
pl.Color=Colors.Blue
pl.ZIndex=3

Hirogens · Aug 13, 2018

marcick said:

you're missing a list.

Code:

Dim pl As Polyline = gmap.AddPolyline
Dim lat_lng As String
Dim lat, lng As Double
Dim Points as list
For Each k As Int In Starter.gmaps 'an array
  lat_lng = Starter.gmaps.GetValueAt(k)
  lat = lat_lng.SubString2(0, lat_lng.IndexOf(","))
  lng = lat_lng.SubString2(lat_lng.IndexOf(","), lat_lng.Length)
  Dim ll As LatLng
  ll.Initialize(lat, lng)    
  Points.add (ll)
Next
pl.Points = Points
pl.Color=Colors.Blue
pl.ZIndex=3

Well I do want you said but I have this

Code:

Error occurred on line: 251 (page_statistique)
java.lang.RuntimeException: Object should first be initialized (List).
    at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:50)
    at anywheresoftware.b4a.objects.collections.List.Add(List.java:76)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.shell.Shell.runVoidMethod(Shell.java:755)
    at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:345)
    at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:249)
    at java.lang.reflect.Method.invoke(Native Method)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:139)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:166)
    at anywheresoftware.b4a.shell.DebugResumableSub$RemoteResumableSub.resume(DebugResumableSub.java:19)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:240)
    at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:132)
    at anywheresoftware.b4a.BA$2.run(BA.java:360)
    at android.os.Handler.handleCallback(Handler.java:751)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6121)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)

Edit: My bad forgot to initialize Points

Hirogens · Aug 13, 2018

Well, nothing is draw on my map :/ only empty Gmap :/ Any solutions ?

marcick · Aug 13, 2018

Try to log your latlng points, maybe you’re not extracting them correctly

Hirogens · Aug 13, 2018

marcick said:
Try to log your latlng points, maybe you’re not extracting them correctly

So when I finish my activity I use File.WriteMap to create a .txt file with the values (pb: I would like to stock in Key order like 0,1,2,3,etc but actually it's stock randomly :/)
My lat/long are like this

marcick · Aug 13, 2018

That is.
I don’t know where do you live but it’s evident in the file that the coordinates are not correct.
Double check it, especially just before creating the latlng object.

Hirogens · Aug 13, 2018

marcick said:
That is.
I don’t know where do you live but it’s evident in the file that the coordinates are not correct.
Double check it, especially just before creating the latlng object.

I live in France, but when I get the postion I do this

Code:

If gmaps.IsInitialized Then
        gmaps.Put(Key, Round(Location1.Latitude*11930464.7111) & "," & Round(Location1.Longitude*11930464.7111))
        Key = Key + 1
        Log("+1")
    End If

Edit: Now I have that but no map design: Lat: 49 Longi: 6

marcick · Aug 13, 2018

????
I don’t understand what that calculation is for.
Just store latitude and longitude as they’re.
You can use Format to store them as string with fixed number of digit eventually

Hirogens · Aug 13, 2018

marcick said:
????
I don’t understand what that calculation is for.
Just store latitude and longitude as they’re.
You can use Format to store them as string with fixed number of digit eventually

Now I have something better but still no map :/
(Lat 49 long:6) Values rounds

marcick · Aug 13, 2018

No maps or no polyline?
If no maps, please start with Google Maps tutorial

Hirogens · Aug 13, 2018

No Point on the map :/ I check if everything are initialize, I put a break point on pl.Points = Points I pass here but nothing appear on my map :/

marcick · Aug 13, 2018

Add log(ll) before
Points.add (ll) and report here

Hirogens · Aug 13, 2018

marcick said:
Add log(ll) before
Points.add (ll) and report here

(LatLng) lat/lng: (49.0,6.0) I have this

Android Question Gmap issue

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