Question

I’m creating a cluster feature for maps (v2). I group location into clusters and then display the clusters as custom markers:

This works great, but I would like to create an animation when clusters get created and split up. I successfully did this with iOS by creating a UIView Animation on the markers (annotations). I couldn’t find any code / hints online for android.

I managed to get a simple ImageView as overlay to resemble a cluster and then use a TranslateAnimation to get the desired animation. At the end I removed this view and added the marker.

Is there a better way to animate a marker?

Answer 1

I found a solution that works:

final LatLng target = NEW_LOCATION;

final long duration = 400;
final Handler handler = new Handler();
final long start = SystemClock.uptimeMillis();
Projection proj = map.getProjection();

Point startPoint = proj.toScreenLocation(marker.getPosition());
final LatLng startLatLng = proj.fromScreenLocation(startPoint);

final Interpolator interpolator = new LinearInterpolator();
handler.post(new Runnable() {
    @Override
    public void run() {
        long elapsed = SystemClock.uptimeMillis() - start;
        float t = interpolator.getInterpolation((float) elapsed / duration);
        double lng = t * target.longitude + (1 - t) * startLatLng.longitude;
        double lat = t * target.latitude + (1 - t) * startLatLng.latitude;
        marker.setPosition(new LatLng(lat, lng));
        if (t < 1.0) {
            // Post again 10ms later.
            handler.postDelayed(this, 10);
        } else {
            // animation ended
        }
    }
});

It’s a bit slow with about 20 simultaneously, maybe there is a better way?