Android set GoolgeMap bounds from database of points

Question

Using Google Maps Android API v2, I am trying to set the bounds of the map using LatLngBounds.Builder() with points from a database. I think I am close, however the activity is crashing because I don't think I am properly loading the points. I may be just a couple of lines away.

//setup map
private void setUpMap() {

    //get all cars from the datbase with getter method
    List<Car> K = db.getAllCars();

    //loop through cars in the database
    for (Car cn : K) {

        //add a map marker for each car, with description as the title using getter methods
        mapView.addMarker(new MarkerOptions().position(new LatLng(cn.getLatitude(), cn.getLongitude())).title(cn.getDescription()));

        //use .include to put add each point to be included in the bounds   
        bounds = new LatLngBounds.Builder().include(new LatLng(cn.getLatitude(), cn.getLongitude())).build();

       //set bounds with all the map points
       mapView.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds, 50));
    }
}

I think there may be an error in how I arranged the for loop to get all the cars, if I remove the bounds statements the map point are plotted correctly as I expected but not bounding the map properly.

Answer 1

you are creating a new LatLngBounds.Builder() everytime in the loop. try this

private LatLngBounds.Builder bounds;
//setup map
private void setUpMap() {

    bounds = new LatLngBounds.Builder();   
    //get all cars from the datbase with getter method
    List<Car> K = db.getAllCars();

    //loop through cars in the database
    for (Car cn : K) {

        //add a map marker for each car, with description as the title using getter methods
        mapView.addMarker(new MarkerOptions().position(new LatLng(cn.getLatitude(), cn.getLongitude())).title(cn.getDescription()));

        //use .include to put add each point to be included in the bounds   
        bounds.include(new LatLng(cn.getLatitude(), cn.getLongitude()));


    }
    //set bounds with all the map points
    mapView.moveCamera(CameraUpdateFactory.newLatLngBounds(bounds.build(), 50));
}