Geolocation with TeaVM

Browsers let you ask the user their location, giving you their exact latitude and longitude. To get the lat/lon via TeaVM, use the following code:

        HTMLBodyElement body = document.getBody();

        final HTMLElement p = document.createElement("p");
        body.appendChild(p);

        if (Navigator.isGeolocationAvailable()) {
          Navigator.getGeolocation().getCurrentPosition(new PositionHandler() {
            @Override
            public void handlePosition(Position position) {
              final Coordinates coords = position.getCoords();
              p.appendChild(document.createTextNode("Lat/Lon: " + coords.getLatitude() + "/" + coords.getLongitude() + " accuracy=" + coords.getAccuracy() + " heading=" + coords.getHeading()));
            }
          }, new PositionErrorHandler() {
            @Override
            public void handlePositionError(PositionError positionError) {
              // Handle errors by looking at positionError.getCode()
            }
          });
        } else {
          p.appendChild(document.createTextNode("This browser doesn't support geolocation"));
        }

Be sure to use a recent build of TeaVM from bintray that includes the geolocation API.

Next Steps

Once you have the user's location, what useful things can you do?

Show their location on a map
Tag photos or postings with a location
Pair them up with other nearby users

Last modified on 27 Nov 2018 by AO