Google Maps Tile Layers in Kotlin

Question

I'm trying to implement Tile Layers using Google Maps SDK Android, but the official documentation only have code examples in Java, and my project is in Kotlin. I can't find any examples about how to doing the same in kotlin. Anyone know how to do it?

The documentation java example code:

private GoogleMap mMap;

TileProvider tileProvider = new UrlTileProvider(256, 256) {
  @Override
  public URL getTileUrl(int x, int y, int zoom) {

    /* Define the URL pattern for the tile images */
    String s = String.format("http://my.image.server/images/%d/%d/%d.png",
        zoom, x, y);

    if (!checkTileExists(x, y, zoom)) {
      return null;
    }

    try {
      return new URL(s);
    } catch (MalformedURLException e) {
        throw new AssertionError(e);
    }
  }

  /*
   * Check that the tile server supports the requested x, y and zoom.
   * Complete this stub according to the tile range you support.
   * If you support a limited range of tiles at different zoom levels, then you
   * need to define the supported x, y range at each zoom level.
   */
  private boolean checkTileExists(int x, int y, int zoom) {
    int minZoom = 12;
    int maxZoom = 16;

    if ((zoom < minZoom || zoom > maxZoom)) {
      return false;
    }

    return true;
  }
};

TileOverlay tileOverlay = mMap.addTileOverlay(new TileOverlayOptions()
    .tileProvider(tileProvider));

Any help with this will be appreciated

score 1 · Accepted Answer · answered Mar 05 '19 at 19:28

In the end I ended up doing it myself based in this response, I need just to instanciate the UrlTileProvider abstract class like this:

val tileProvider: TileProvider = object: UrlTileProvider(256, 256){ 
...
}

The Final result:

val tileProvider: TileProvider = object: UrlTileProvider(256, 256) {
  override fun getTileUrl(x: Int, y: Int, zoom: Int): URL? {

    /* Define the URL pattern for the tile images */
    val s: String = String.format("http://my.image.server/images/%d/%d/%d.png",
      zoom, x, y)

    if (!checkTileExists(x, y, zoom)) {
      return null;
    }

    try {
      return URL(s)
    } catch (e: MalformedURLException) {
      throw AssertionError(e)
    }
  }

  /*
 * Check that the tile server supports the requested x, y and zoom.
 * Complete this stub according to the tile range you support.
 * If you support a limited range of tiles at different zoom levels, then you
 * need to define the supported x, y range at each zoom level.
 */
  private fun checkTileExists(x: Int, y: Int, zoom: Int): Boolean {
    val minZoom: Int = 12
    val maxZoom: Int = 16

    if ((zoom < minZoom || zoom > maxZoom)) {
      return false
    }
    return true
  }
}

val tileOverlay: TileOverlay = mMap.addTileOverlay(TileOverlayOptions()
.tileProvider(tileProvider))

Hope It help someone else.

score 0 · Answer 2 · answered Mar 05 '19 at 21:08

Here you go Cheers !!

private var mMap:GoogleMap?=null

    val tileProvider = object: UrlTileProvider(256, 256) {
      override fun getTileUrl(x:Int,y:Int,zoom:Int):URL {

        /* Define the URL pattern for the tile images */
        val s = String.format("http://my.image.server/images/%d/%d/%d.png",
            zoom, x, y)

        if (!checkTileExists(x, y, zoom)) {
          return null
        }

        try {
          return URL(s)
        } catch (e:MalformedURLException) {
            throw AssertionError(e)
        }
      }

      /*
       * Check that the tile server supports the requested x, y and zoom.
       * Complete this stub according to the tile range you support.
       * If you support a limited range of tiles at different zoom levels, then you
       * need to define the supported x, y range at each zoom level.
       */
      private fun checkTileExists(x:Int,y:Int,zoom:Int):Boolean {
        val minZoom = 12
        val maxZoom = 16

        if ((zoom < minZoom || zoom > maxZoom)) {
          return false
        }

        return true
      }
    }

    val tileOverlay = mMap!!.addTileOverlay(TileOverlayOptions()
        .tileProvider(tileProvider))

Google Maps Tile Layers in Kotlin

2 Answers2