I'm building a running tracker app and i want to save a screenshot of the map at the end of the run I'm using utsmannn's implementation of osmdroid in my app and was wondering if there's a way to do this using utsmannn library since i didn't find anything in their wiki, if not is there a way to do it using osmdroid directly ?

this is my base map composable

@Composable
fun TrackerMap(
    modifier: Modifier = Modifier,
    isRunFinished: Boolean,
    currentLocation: Location?,
    locations: List<List<LocationTimestamp>>,
    onSnapshot: (Bitmap) -> Unit
) {

    val context = LocalContext.current

    val cameraState = rememberCameraState {
        zoom = 17.0
    }

    LaunchedEffect(currentLocation, isRunFinished) {
        if (currentLocation != null && !isRunFinished) {
            cameraState.geoPoint = GeoPoint(currentLocation.lat, currentLocation.long)
        }
    }

    val overlayManagerState = rememberOverlayManagerState()

    var mapProperties by remember {
        mutableStateOf(DefaultMapProperties)
    }

    SideEffect {
        mapProperties = mapProperties
            .copy(isTilesScaledToDpi = true)
            .copy(tileSources = TileSourceFactory.MAPNIK)
            .copy(isEnableRotationGesture = false)
            .copy(isFlingEnable = false)
            .copy(zoomButtonVisibility = ZoomButtonVisibility.NEVER)
    }

    OpenStreetMap(
        modifier = modifier.fillMaxSize(),
        cameraState = cameraState,
        properties = mapProperties,
        overlayManagerState = overlayManagerState,
        onFirstLoadListener = {
            mapInstance = overlayManagerState.getMap()
            val copyright = CopyrightOverlay(context)
            overlayManagerState.overlayManager.add(copyright)
        }
    ) {
        RunikPolylines(locations = locations)
    }
}

I'm really new to android and may need your answer basically in baby terms !!

I'm building a running tracker app and i want to save a screenshot of the map at the end of the run I'm using utsmannn's implementation of osmdroid in my app and was wondering if there's a way to do this using utsmannn library since i didn't find anything in their wiki, if not is there a way to do it using osmdroid directly ?

this is my base map composable

@Composable
fun TrackerMap(
    modifier: Modifier = Modifier,
    isRunFinished: Boolean,
    currentLocation: Location?,
    locations: List<List<LocationTimestamp>>,
    onSnapshot: (Bitmap) -> Unit
) {

    val context = LocalContext.current

    val cameraState = rememberCameraState {
        zoom = 17.0
    }

    LaunchedEffect(currentLocation, isRunFinished) {
        if (currentLocation != null && !isRunFinished) {
            cameraState.geoPoint = GeoPoint(currentLocation.lat, currentLocation.long)
        }
    }

    val overlayManagerState = rememberOverlayManagerState()

    var mapProperties by remember {
        mutableStateOf(DefaultMapProperties)
    }

    SideEffect {
        mapProperties = mapProperties
            .copy(isTilesScaledToDpi = true)
            .copy(tileSources = TileSourceFactory.MAPNIK)
            .copy(isEnableRotationGesture = false)
            .copy(isFlingEnable = false)
            .copy(zoomButtonVisibility = ZoomButtonVisibility.NEVER)
    }

    OpenStreetMap(
        modifier = modifier.fillMaxSize(),
        cameraState = cameraState,
        properties = mapProperties,
        overlayManagerState = overlayManagerState,
        onFirstLoadListener = {
            mapInstance = overlayManagerState.getMap()
            val copyright = CopyrightOverlay(context)
            overlayManagerState.overlayManager.add(copyright)
        }
    ) {
        RunikPolylines(locations = locations)
    }
}

I'm really new to android and may need your answer basically in baby terms !!

• android
• android-jetpack-compose
• screenshot
• osmdroid

1 Answer 1

In OSMDroid, you can take a screenshot of the map view using the getDrawingCache() method of the MapView. Here's how you can do it in Kotlin:

Steps to Capture Screenshot in OSMDroid

1. Enable the drawing cache for the MapView.

2. Capture the bitmap from the MapView.

3. Save the bitmap to storage.
   Kotlin Code to Capture OSMDroid Map Screenshot

   import android.graphics.Bitmap
   import android.graphics.Canvas
   import android.os.Bundle
   import android.os.Environment
   import android.view.View
   import android.widget.Button
   import androidx.appcompat.app.AppCompatActivity
   import .osmdroid.config.Configuration
   import .osmdroid.tileprovider.tilesource.TileSourceFactory
   import .osmdroid.util.GeoPoint
   import .osmdroid.views.MapView
   import java.io.File
   import java.io.FileOutputStream
   
   class MainActivity : AppCompatActivity() {
       private lateinit var mapView: MapView
       private lateinit var btnCapture: Button
   
       override fun onCreate(savedInstanceState: Bundle?) {
           super.onCreate(savedInstanceState)
           Configuration.getInstance().load(applicationContext, getSharedPreferences("osmdroid", MODE_PRIVATE))
           setContentView(R.layout.activity_main)
   
           // Initialize MapView
           mapView = findViewById(R.id.mapView)
           btnCapture = findViewById(R.id.btnCapture)
   
           mapView.setTileSource(TileSourceFactory.MAPNIK)
           mapView.setMultiTouchControls(true)
           mapView.controller.setZoom(15.0)
           mapView.controller.setCenter(GeoPoint(37.7749, -122.4194)) // Example: San Francisco
   
           // Capture Screenshot on Button Click
           btnCapture.setOnClickListener {
               captureMapScreenshot()
           }
       }
   
       private fun captureMapScreenshot() {
           try {
               // Create bitmap
               val bitmap = Bitmap.createBitmap(mapView.width, mapView.height, Bitmap.Config.ARGB_8888)
               val canvas = Canvas(bitmap)
               mapView.draw(canvas) // Draw the map on canvas
   
               // Save the bitmap to file
               val file = File(getExternalFilesDir(Environment.DIRECTORY_PICTURES), "map_screenshot.png")
               val outputStream = FileOutputStream(file)
               bitmappress(Bitmap.CompressFormat.PNG, 100, outputStream)
               outputStream.flush()
               outputStream.close()
   
               // Screenshot saved successfully
               println("Screenshot saved at: ${file.absolutePath}")
   
           } catch (e: Exception) {
               e.printStackTrace()
           }
       }
   }
   
   

   XML Layout (activity_main.xml)

   <LinearLayout
       xmlns:android="http://schemas.android/apk/res/android"
       android:layout_width="match_parent"
       android:layout_height="match_parent"
       android:orientation="vertical">
   
       <.osmdroid.views.MapView
           android:id="@+id/mapView"
           android:layout_width="match_parent"
           android:layout_height="0dp"
           android:layout_weight="1"/>
   
       <Button
           android:id="@+id/btnCapture"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:text="Capture Screenshot"/>
   </LinearLayout>
   
   

   How It Works

   1. The captureMapScreenshot() method:

      • Creates a Bitmap with the size of MapView.

      • Draws the map onto the Canvas.

      • Saves the image to the device storage.

   2. The onClickListener for the button triggers the screenshot function.