Using a Mock Location in Navigation App

2019-01-13 19:40发布

问题:

I'm trying to develop an application that will simulate a route through Google's Navigation application. I found some excellent examples of how to implement a mock location provider in some other posts on this website ( Android mock location on device? ).
With a simple modification to the source code http://www.cowlumbus.nl/forum/MockGpsProvider.zip, my mock location shows up in Google's Maps application. (The only change is the mock provider name to LocationManager.GPS_PROVIDER).
My problem is that when I open the Navigation app, it says "Searching for GPS signal." I still see my location moving across the map; however, it doesn't generate a route to the destination. I was wondering if anyone knows what I need to do to fake Navigation into see my mock location as the GPS signal.
Thanks.

public class MockGpsProviderActivity extends Activity implements LocationListener {

private MockGpsProvider mMockGpsProviderTask = null;
private Integer mMockGpsProviderIndex = 0;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
    String mocLocationProvider = LocationManager.GPS_PROVIDER;
    locationManager.addTestProvider(mocLocationProvider, false, false,
            false, false, true, false, false, 0, 5);
    locationManager.setTestProviderEnabled(mocLocationProvider, true);
    locationManager.requestLocationUpdates(mocLocationProvider, 0, 0, this);

    try {

        List<String> data = new ArrayList<String>();

        InputStream is = getAssets().open("test.csv");
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));

        String line = null;
        while ((line = reader.readLine()) != null) {
            data.add(line);
        }

        // convert to a simple array so we can pass it to the AsyncTask
        String[] coordinates = new String[data.size()];
        data.toArray(coordinates);

        // create new AsyncTask and pass the list of GPS coordinates
        mMockGpsProviderTask = new MockGpsProvider();
        mMockGpsProviderTask.execute(coordinates);
    } 
    catch (Exception e) {}
}

@Override
public void onDestroy() {
    super.onDestroy();

    // stop the mock GPS provider by calling the 'cancel(true)' method
    try {
        mMockGpsProviderTask.cancel(true);
        mMockGpsProviderTask = null;
    }
    catch (Exception e) {}

    // remove it from the location manager
    try {
        LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
        locationManager.removeTestProvider(MockGpsProvider.GPS_MOCK_PROVIDER);
    }
    catch (Exception e) {}
}

@Override
public void onLocationChanged(Location location) {
    // show the received location in the view
    TextView view = (TextView) findViewById(R.id.text);
    view.setText( "index:" + mMockGpsProviderIndex
            + "\nlongitude:" + location.getLongitude() 
            + "\nlatitude:" + location.getLatitude() 
            + "\naltitude:" + location.getAltitude() );     
}

@Override
public void onProviderDisabled(String provider) {
    // TODO Auto-generated method stub      
}


@Override
public void onProviderEnabled(String provider) {
    // TODO Auto-generated method stub      
}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
    // TODO Auto-generated method stub      
}


/** Define a mock GPS provider as an asynchronous task of this Activity. */
private class MockGpsProvider extends AsyncTask<String, Integer, Void> {
    public static final String LOG_TAG = "GpsMockProvider";
    public static final String GPS_MOCK_PROVIDER = "GpsMockProvider";

    /** Keeps track of the currently processed coordinate. */
    public Integer index = 0;

    @Override
    protected Void doInBackground(String... data) {         
        // process data
        for (String str : data) {
            // skip data if needed (see the Activity's savedInstanceState functionality)
            if(index < mMockGpsProviderIndex) {
                index++;
                continue;
            }               

            // let UI Thread know which coordinate we are processing
            publishProgress(index);

            // retrieve data from the current line of text
            Double latitude = null;
            Double longitude = null;
            Double altitude= null;
            try {
                String[] parts = str.split(",");
                latitude = Double.valueOf(parts[0]);
                longitude = Double.valueOf(parts[1]);
                altitude = Double.valueOf(parts[2]);
            }
            catch(NullPointerException e) { break; }        // no data available
            catch(Exception e) { continue; }                // empty or invalid line

            // translate to actual GPS location
            Location location = new Location(LocationManager.GPS_PROVIDER);
            location.setLatitude(latitude);
            location.setLongitude(longitude);
            location.setAltitude(altitude);
            location.setTime(System.currentTimeMillis());

            // show debug message in log
            Log.d(LOG_TAG, location.toString());

            // provide the new location
            LocationManager locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
            locationManager.setTestProviderLocation(LocationManager.GPS_PROVIDER, location);

            // sleep for a while before providing next location
            try {
                Thread.sleep(200);

                // gracefully handle Thread interruption (important!)
                if(Thread.currentThread().isInterrupted())
                    throw new InterruptedException("");
            } catch (InterruptedException e) {
                break;
            }

            // keep track of processed locations
            index++;
        }

        return null;
    }

    @Override
    protected void onProgressUpdate(Integer... values) {
        Log.d(LOG_TAG, "onProgressUpdate():"+values[0]);
        mMockGpsProviderIndex = values[0];
    }
}
}

回答1:

Here is what I was missing:

location.setLatitude(latitude);
location.setLongitude(longitude);
location.setAccuracy(16F);
location.setAltitude(0D);
location.setTime(System.currentTimeMillis());
location.setBearing(0F);

Also, it is important to calcaulte the bearing for navigation. Otherwise, the route updates will be inaccurate.