Make clickable polygons on Google Maps (for Android)

Question

I have continuous LatLngs of various areas in a city. Is there any way I can create clickable polygons with it. Once way to go about would be to

• Generate polygons with the available LatLngs.( I want to visually show the polygons on the map with color encoding)
• Set up setOnMapClickListener.
• Do a point inside polygon test.

I understand that this is very naive. What are the alternative approaches?

Answer 1

Here's how I did it.

    Polygon polygon = getMap().addPolygon(new PolygonOptions()
                    .add(new LatLng(12.780712, 77.770956), new LatLng(12.912006, 77.229738), new LatLng(12.412006, 77.629738), new LatLng(12.912006, 77.229738))
                    .strokeColor(0xFF00AA00)
                    .fillColor(0x2200FFFF)
                    .strokeWidth(2)
    );


    polygon.setClickable(true);

    getMap().setOnPolygonClickListener(new GoogleMap.OnPolygonClickListener() {
        public void onPolygonClick(Polygon polygon) {

            mClusterManager = new ClusterManager<MyItem>(getApplicationContext(), getMap());
            getMap().setOnCameraChangeListener(mClusterManager);
            getMap().moveCamera(CameraUpdateFactory.newLatLngZoom(getMap().getCameraPosition().target, getMap().getCameraPosition().zoom));

            try {
                readItems();
            } catch (JSONException e) {
                Toast.makeText(getApplicationContext(), "Problem reading list of markers.", Toast.LENGTH_LONG).show();
            }

        }
    });

Hope that helps.

Answer 2

you don't need to go crazy for having clickable polygon. I did it time ago but now, there is an api for that:

GoogleMap.setOnPolygonClickListener(OnPolygonClickListener)

You can use it easily:

GoogleMap mymap =....//init your map
mymap.setOnPolygonClickListener(new OnPolygonClickListener(){
 void onPolygonClick(Polygon polygon){
   //do whatever with polygon!
 }
});

Answer 3

In adding Polygon to the map. First create a PolygonOptions object and add some points to it. These points will form the outline of the polygon. You then add the polygon to the map by calling GoogleMap.addPolygon(PolygonOptions) which will return a Polygon object. This following code snippet show how to add polygon to a map.

// Instantiates a new Polygon object and adds points to define a rectangle PolygonOptions rectOptions = new PolygonOptions()
              .add(new LatLng(37.35, -122.0),
                   new LatLng(37.45, -122.0),
                   new LatLng(37.45, -122.2),
                   new LatLng(37.35, -122.2),
                   new LatLng(37.35, -122.0));

// Get back the mutable Polygon Polygon polygon = myMap.addPolygon(rectOptions);

By default, polygons are not clickable. You can enable and disable the clickability by calling Polygon.setClickable(boolean).

Like N Dorigatti said. In using OnPolygonClickListener to listen click events, call GoogleMap.setOnPolygonClickListener(OnPolygonClickListener).

When a user clicks on a polygon, you will receive an onPolygonClick(Polygon) callback. Check this document for more information.