zoom over specific route google map

Question

I have a list of random latitude and longitude points and I am drawing a route between them. My question is how to bound this route within google map I made below utility method

public static void drawRouteIntoMap(final List<? extends MapHelper> position, final GoogleMap googleMap) {
    /*List<MapHelper> position = new ArrayList<MapHelper>();
    for (int i = lastPosition; i < maps.size(); i++) {
        position.add(maps.get(i));
    }*/
    if (position.size() > 0 && Validator.isNotNull(googleMap)) {
        googleMap.clear();
        List<PolylineOptions> polylineOptionses = new ArrayList<PolylineOptions>();
        PolylineOptions option = null;
        Boolean lastPause = null;
        for (MapHelper map : position) {
            if (map.isPause()) {
                if (Validator.isNull(lastPause) || !lastPause) {
                    option = new PolylineOptions().width(5).color(Color.rgb(255, 0, 155)).geodesic(true);
                    polylineOptionses.add(option);
                }
                option.add(new LatLng(map.getLatitude(), map.getLongitude()));
            } else {
                if (Validator.isNull(lastPause) || lastPause) {
                    option = new PolylineOptions().width(5).color(Color.rgb(0, 179, 253)).geodesic(true);
                    polylineOptionses.add(option);
                }
                option.add(new LatLng(map.getLatitude(), map.getLongitude()));
            }
            lastPause = map.isPause();
        }
        for (PolylineOptions options : polylineOptionses) {
            googleMap.addPolyline(options);
        }
        if(Validator.isNotNull(option)){
            //List<LatLng> points = option.getPoints();
            final LatLngBounds.Builder mapBounds = new LatLngBounds.Builder();

            googleMap.setOnMapLoadedCallback(new GoogleMap.OnMapLoadedCallback() {
                @Override
                public void onMapLoaded() {
                    LatLng startPoint = new LatLng(position.get(0).getLatitude(), position.get(0).getLongitude());
                    googleMap.addMarker(new MarkerOptions().position(startPoint).title("start").icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_GREEN)));
                    mapBounds.include(startPoint);
                    LatLng endPoint = new LatLng(position.get(position.size() - 1).getLatitude(), position.get(position.size() - 1).getLongitude());
                    mapBounds.include(endPoint);
                    googleMap.addMarker(new MarkerOptions().position(endPoint).title("finish").icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_RED)));
                    googleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(mapBounds.build(), 10));
                   /* googleMap.animateCamera(CameraUpdateFactory.newLatLngBounds(mapBounds.build(), 10));
                    googleMap.moveCamera(CameraUpdateFactory.zoomOut());*/

                }
            });
        }

    }
}

here last pause is boolean indicating whether it is paused point for indicating red color polyline.

but it is not working.Any help is appreciated.

Answer 1

Try implementing this way

/**
 * Zooms a Route (given a List of LalLng) at the greatest possible zoom level.
 *
 * @param googleMap: instance of GoogleMap
 * @param lstLatLngRoute: list of LatLng forming Route
 */
public void zoomRoute(GoogleMap googleMap, List<LatLng> lstLatLngRoute) {

    if (googleMap == null || lstLatLngRoute == null || lstLatLngRoute.isEmpty()) return;

    LatLngBounds.Builder boundsBuilder = new LatLngBounds.Builder();
    for (LatLng latLngPoint : lstLatLngRoute)
        boundsBuilder.include(latLngPoint);

    int routePadding = 100;
    LatLngBounds latLngBounds = boundsBuilder.build();

    googleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(latLngBounds, routePadding));
}

UPDATE

After looking at the image, there are layouts above map. So it would require you to set Variable Padding. You can do it as

googleMap.setPadding(left, top, right, bottom);

Note: While setting variable padding, you can initialize routePadding = 0; In your case, approximations are: left = right = 10, bottom=100, top=200. Once set, you can calibrate'em as per your requirement.

Recommendation: You can calculate the height of those (top and bottom) layouts in pixels and then set padding accordingly.

Answer 2

The reason, why zooming in is not working might be because map has not been inflated yet at the time of calling the method:

moveCamera(com.google.android.gms.maps.CameraUpdate)

Try adding ViewTreeObserver.OnGlobalLayoutListener to the map:

ViewTreeObserver vto = googleMap.getViewTreeObserver();
ViewTreeObserver.OnGlobalLayoutListener globalLayoutListener = new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
            googleMap.getViewTreeObserver().removeOnGlobalLayoutListener(this);
        } else {
            googleMap.getViewTreeObserver().removeGlobalOnLayoutListener(this);
        }
        googleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(mapBounds.build(), 10));
    }
};
vto.addOnGlobalLayoutListener(globalLayoutListener);

If the method above does not work GoogleMap has it's own listener for layout, you might use that:

googleMap.setOnCameraChangeListener(new OnCameraChangeListener() {

    @Override
    public void onCameraChange(CameraPosition arg0) {
        googleMap.moveCamera(CameraUpdateFactory.newLatLngBounds(mapBounds.build(), 10));
        googleMap.setOnCameraChangeListener(null);
    }
});

However, as of play-services-maps 9.4.0 version of the API the method above is deprecated. Use one of:

• GoogleMap.OnCameraMoveStartedListener

• GoogleMap.OnCameraMoveListener

• GoogleMap.OnCameraIdleListener