google maps - Visualize progress on GoogleMaps Android -

i'm creating small test application visualise progress on google map using google maps android api. (api: here)

my backend serves me data polylines between 2 given coordinates. android application decodes data , draw polylines on googlemaps view.

i'd visualise route i've done. (so grey out parts/polylines i've driven on. i've tried coloring polylines i've passed calculating closest distance polyline given treshold. seem unable color polyline with:

• setcolor() - polyline
• color() - polylineoptions

there seems no way update existing polyline. if remove markers, polylines, .. , redraw polylines updated values on every location change, laggy.

i wondering if there better/alternative ways visualise progress on map.

private void drawpolyline() {     if (polylines == null) polylines = new arraylist<polyline>();     if (mrouteinformation == null) return;      log.i("navigationactivity", "drawing polyline");      (int = 0; < mrouteinformation.getrouteguidance().size(); i++) {         routepart part = mrouteinformation.getrouteguidance().get(i);          if (part != null && part.getroutevisualization() != null) {             list<polylineoptions> options = mapsutils.decodepolylines(mrouteinformation.getrouteguidance().get(i).getroutevisualization());             if (options != null && options.size() > 0 && mgooglemap != null) {                  //add polylines maps.                 (polylineoptions polylineoptions : options) {                     if (!isfinishing()) {                         polylines.add(mgooglemap.addpolyline(polylineoptions));                     }                 }             }         }     } }