Android map: how to make polyline animation on map?

When I draw polylines on the map from point a - > b, I need to animate polylines. It seems that I continue to draw polylines from a - > B

I have used the following link as a reference:

https://github.com/amalChandran/google-maps-route-animation

Using this solution, I can animate the polyline, but the polyline itself is not appropriate. It does not pass through the road. The original APK of the solution also has the same error

Can someone help me provide the right solution

resolvent:

Invalid Sign

Valueanimator - used to animate overlays and polylines

ValueAnimator tAnimator = ValueAnimator.ofFloat(0, 1);
       tAnimator.setRepeatCount(ValueAnimator.INFINITE);
       tAnimator.setRepeatMode(ValueAnimator.RESTART);
       tAnimator.setInterpolator(new LinearInterpolator());
       tAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
           @Override
           public void onAnimationUpdate(ValueAnimator valueAnimator) {
              // animate here
           }
       });

Polyline - used to draw lines on the map

 PolylineOptions greyOptions = new PolylineOptions();
        greyOptions.width(10);
        greyOptions.color(Color.GRAY);
        greyOptions.startCap(new SquareCap());
        greyOptions.endCap(new SquareCap());
        greyOptions.jointType(ROUND);
        greyPolyLine = mMap.addPolyline(greyOptions);