Android Question Open Street Map viewer - GPS

davelew1s · Jul 12, 2022

I downloaded this https://www.b4x.com/android/forum/threads/127827/#content last week This worked initially but after a few runs I just blue lines
in all the tiles no map.
I tried changing the server, i tried running it on a tablet and phone, i tried compiling it on a desktop and laptop, i used wifi and phone data with the same results.
Any help?
Thanks Dave.

drgottjr · Jul 13, 2022

you mean these blue lines?

so annoying.
there seems to be some issue with the osmfoundation ("ResponseError. Reason: , Response: Access denied. See https://operations.osmfoundation.org/policies/tiles/").
you'll have to wait for the app's author to follow up. i can think of a number of possible explanations.

TILogistic · Jul 13, 2022

This problem is caused by the query limit.

Open Street Map viewer - GPS

Hi, This b4Xlib contains a custom view (cvMap) which can display Open Street Map. The tiles are retrieved from the internet and cached in a database. You can add shapes and images on the map. UI : - Lat/lng Center of the map - Zoom Level - Compass Direction with rotation - Scale - Button...

www.b4x.com

you need to change the tile server and user agent.

Check the servers available at:

Tile servers - OpenStreetMap Wiki

wiki.openstreetmap.org

example:

B4X:

'Get Tile from internet openstreemap website
public Sub getTileFromInternet(aZ As Int,aX As Int,aY As Int) As ResumableSub
    Dim j As HttpJob
    Dim bmp As B4XBitmap
    Try
        j.Initialize("", Me)
'        j.Download($"https://a.tile.openstreetmap.org/${aZ}/${aX}/${aY}.png"$)
        j.Download($"https://a.tile.openstreetmap.fr/osmfr/${aZ}/${aX}/${aY}.png"$) 'see server tiles
        j.GetRequest.SetHeader("User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0") 'see user gent
        Wait For (j) JobDone(j As HttpJob)
        If j.Success Then
            Try
                bmp=j.GetBitmap
            Catch
                Log($"getTileFromInternet: ${LastException.Message}"$)
            End Try
        End If
    Catch
        Log($"getTileFromInternet: ${LastException.Message}"$)
    End Try
    If j.IsInitialized Then
        j.Release
    End If
    Return bmp
End Sub

see:

TILogistic · Jul 13, 2022

test: google maps

Change:

B4X:

j.Download($"https://mt1.google.com/vt/lyrs=r&x=${aX}&y=${aY}&z=${aZ}"$)

davelew1s · Jul 13, 2022

Thanks '

drgottjr and

Omar Parra A.

for the replies.
I think it's solved but i'm still playing with it.
I changed the server and the user agent, initially it didn't work as expected so i emptied the database now it seem fine.
I also tried Google Maps that works aswell.
As said i am still playing around with it.
Dave.

TILogistic · Jul 13, 2022

I changed the server and the user agent, initially it didn't work as expected so i emptied the database now it seem fine.

You are right, it uses a database as a tile cache.

Note that this database stores images and is relatively large in size.

Lakhtin_V · Jun 28, 2023

How should the code be redone so that the map is displayed based on a previously downloaded file with the OCM extension. I don't have internet access during the map rendering process and I want to use one locality OSM file that I downloaded earlier via export from mapsource main site

Android Question Open Street Map viewer - GPS

davelew1s

Active Member

drgottjr

Expert

TILogistic

Expert

Open Street Map viewer - GPS

Tile servers - OpenStreetMap Wiki

TILogistic

Expert

davelew1s

Active Member

drgottjr and

Omar Parra A.

TILogistic

Expert

Lakhtin_V

Active Member

Similar Threads

Android Question Open Street Map viewer - GPS

Active Member

Expert

Expert

Expert

Active Member

drgottjr and​

Omar Parra A.​

Expert

Active Member

Similar Threads

Privacy & Transparency

Privacy & Transparency

drgottjr and

Omar Parra A.