Android google maps add to marker own tag

Question

I have such code:

protected void onPostExecute(final ArrayList<HashMap<String, String>> adapter) {

                for (final HashMap<String, String> a : adapter) {
                    LatLng pos = new LatLng(Double.valueOf(a.get(TAG_latitude)), Double.valueOf(a.get(TAG_longitude)));
                    Log.e("pppppos", String.valueOf(pos.latitude));
                    Marker m = map.addMarker(new MarkerOptions().position(pos)
                            .title(a.get(TAG_NAME))
                            .snippet("Kiel is cool"));

                    map.setOnInfoWindowClickListener(
                              new OnInfoWindowClickListener(){
                                    public void onInfoWindowClick(Marker marker){
                                      Intent nextScreen = new Intent(SearchExchangerActivity.this, BankExchangersListActivity.class);
                                        nextScreen.putExtra("exchanger_id", id);    
                                        startActivityForResult(nextScreen, 0);
                                    }
                                  });
                }

But i need to set invisible to user field for example Tag_id for each marker, and use this id then when sending extra info to other activity, something like:

protected void onPostExecute(final ArrayList<HashMap<String, String>> adapter) {

            for (final HashMap<String, String> a : adapter) {
                LatLng pos = new LatLng(Double.valueOf(a.get(TAG_latitude)), Double.valueOf(a.get(TAG_longitude)));
                Marker m = map.addMarker(new MarkerOptions().position(pos)
                        .title(a.get(TAG_NAME))
                        .snippet("Kiel is cool")
                                                    .Tag_id(TAG_ID));

                map.setOnInfoWindowClickListener(
                          new OnInfoWindowClickListener(){
                                public void onInfoWindowClick(Marker marker){
                                  Intent nextScreen = new Intent(SearchExchangerActivity.this, BankExchangersListActivity.class);
                                    nextScreen.putExtra("exchanger_id", marker.get(TAG_ID));    
                                    startActivityForResult(nextScreen, 0);
                                }
                              });
            }

Is it real to do? Just how can i in my listener get what marker i'm clicking?

Also it could be done via title field... But i'm getting error's when writing marker.getTitle()...

upd

for (final HashMap<String, String> a : adapter) {
                LatLng pos = new LatLng(Double.valueOf(a.get(TAG_latitude)), Double.valueOf(a.get(TAG_longitude)));
                Log.e("pppppos", String.valueOf(pos.latitude));
                HashMap<Marker, String> m = new HashMap<Marker, String>();
                        m.put( map.addMarker(new MarkerOptions().position(pos)
                        .title(a.get(TAG_NAME))
                        .snippet("Kiel is cool")), "1");                    

            }

            map.setOnInfoWindowClickListener(
              new OnInfoWindowClickListener(){
                    public void onInfoWindowClick(HashMap<Marker, String> marker){
                      Intent nextScreen = new Intent(SearchExchangerActivity.this, BankExchangersListActivity.class);
                        nextScreen.putExtra("exchanger_id", "1");   
                        startActivityForResult(nextScreen, 0);
                    }
                  });

Answer 1

That is currently formally available, the setTag and getTag have been added to the Marker API.

The following was taken from the "associate data with a marker" section from the official doc:

/**
 * A demo class that stores and retrieves data objects with each marker.
 */
public class MarkerDemoActivity extends FragmentActivity implements
        OnMarkerClickListener,
        OnMapReadyCallback {

    private static final LatLng PERTH = new LatLng(-31.952854, 115.857342);
    private static final LatLng SYDNEY = new LatLng(-33.87365, 151.20689);
    private static final LatLng BRISBANE = new LatLng(-27.47093, 153.0235);

    private Marker mPerth;
    private Marker mSydney;
    private Marker mBrisbane;

    private GoogleMap mMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.marker_demo);

        SupportMapFragment mapFragment =
                (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    /** Called when the map is ready. */
    @Override
    public void onMapReady(GoogleMap map) {
        mMap = map;

        // Add some markers to the map, and add a data object to each marker.
        mPerth = mMap.addMarker(new MarkerOptions()
                .position(PERTH)
                .title("Perth");
        mPerth.setTag(0);

        mSydney = mMap.addMarker(new MarkerOptions()
                .position(SYDNEY)
                .title("Sydney");
        mSydney.setTag(0);

        mBrisbane = mMap.addMarker(new MarkerOptions()
                .position(BRISBANE)
                .title("Brisbane");
        mBrisbane.setTag(0);

        // Set a listener for marker click.
        mMap.setOnMarkerClickListener(this);
    }

    /** Called when the user clicks a marker. */
    @Override
    public boolean onMarkerClick(final Marker marker) {

        // Retrieve the data from the marker.
        Integer clickCount = (Integer) marker.getTag();

        // Check if a click count was set, then display the click count.
        if (clickCount != null) {
            clickCount = clickCount + 1;
            marker.setTag(clickCount);
            Toast.makeText(this,
                           marker.getTitle() +
                           " has been clicked " + clickCount + " times.",
                           Toast.LENGTH_SHORT).show();
        }

        // Return false to indicate that we have not consumed the event and that we wish
        // for the default behavior to occur (which is for the camera to move such that the
        // marker is centered and for the marker's info window to open, if it has one).
        return false;
    }
}

Answer 2

1. You may use Map<Marker, String> and keep your data there or
2. use Android Maps Extensions which adds getData and setData functions to Marker class.

Btw. You should not set InfoWindowAdapter in a loop. It makes no sense. Only the last survives.