Googleマップで現在地の変更イベントを取得する方法Android API v2？
v1では、場所変更イベントを処理するために次のことができます。
public class MyLocationOverlay extends com.google.Android.maps.MyLocationOverlay {
/**
* Listener
*/
public interface Listener {
void onLocationChanged(Android.location.Location location);
}
private Listener listener;
public MyLocationOverlay(Context context, MapView mapView, Listener listener) {
super(context, mapView);
this.listener = listener;
}
@Override
public synchronized void onLocationChanged(Location location) {
super.onLocationChanged(location);
// fire listener
if (listener != null)
listener.onLocationChanged(location);
}
}
[〜＃〜] update [〜＃〜]：Googleが新しい LocationClient を導入し、関連付けられました- LocationListener （OnMyLocationChangeListenerインターフェースは廃止されました）。
これを行うには、my-locationレイヤーのカスタムLocationSourceを作成します。以下は、GoogleマップのMyLocationOverlayによって提供された機能と同様に、カメラを現在の場所（「現在地」）に自動的に中心合わせする例ですAndroid API v1。
したがって、このコード行を単に置き換えることができます
mMap.animateCamera(CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude())));
場所が変わったときに実行する必要がある機能を備えています。
public class PlaceMapFragment extends SupportMapFragment {
// Note that this may be null if the Google Play services APK is not available.
private GoogleMap mMap;
protected PlaceActivity activity;
private FollowMeLocationSource followMeLocationSource;
private Context mContext;
/* We need the Context in order to get a reference to the Location Manager
* (when instantiating this fragment from your activity use:
* PlaceMapFragment mapFragment = new PlaceMapFragment(this); ) */
public PlaceMapFragment(Context context) {
this.mContext = context;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
activity = (PlaceActivity)getActivity();
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// creates our custom LocationSource and initializes some of its members
followMeLocationSource = new FollowMeLocationSource();
/* We can't be guaranteed that the map is available because Google Play services might not be available.
* (un-comment the following line when using this code in a FragmentActivity / Activity
* to try get a reference to the map here !) */
//setUpMapIfNeeded();
}
@Override
public void onResume() {
super.onResume();
/* We query for the best Location Provider everytime this fragment is displayed
* just in case a better provider might have become available since we last displayed it */
followMeLocationSource.getBestAvailableProvider();
// Get a reference to the map/GoogleMap object
setUpMapIfNeeded();
/* Enable the my-location layer (this causes our LocationSource to be automatically activated.)
* While enabled, the my-location layer continuously draws an indication of a user's
* current location and bearing, and displays UI controls that allow a user to interact
* with their location (for example, to enable or disable camera tracking of their location and bearing).*/
mMap.setMyLocationEnabled(true);
}
@Override
public void onPause() {
/* Disable the my-location layer (this causes our LocationSource to be automatically deactivated.) */
mMap.setMyLocationEnabled(false);
super.onPause();
}
/**
* Sets up the map if it is possible to do so (i.e., the Google Play services APK is correctly
* installed) and the map has not already been instantiated. This will ensure that we only ever
* manipulate the map once when it {@link #mMap} is not null.
* <p>
* If it isn't installed {@link SupportMapFragment} (and {@link com.google.Android.gms.maps.MapView
* MapView}) will show a Prompt for the user to install/update the Google Play services APK on their device.
*/
private void setUpMapIfNeeded() {
// Do a null check to confirm that we have not already instantiated the map.
if (mMap == null) {
mMap = getMap();
// Check if we were successful in obtaining the map.
if (mMap != null) {
// The Map is verified. It is now safe to manipulate the map:
// Replace the (default) location source of the my-location layer with our custom LocationSource
mMap.setLocationSource(followMeLocationSource);
// Set default zoom
mMap.moveCamera(CameraUpdateFactory.zoomTo(15f));
}
}
}
/* Our custom LocationSource.
* We register this class to receive location updates from the Location Manager
* and for that reason we need to also implement the LocationListener interface. */
private class FollowMeLocationSource implements LocationSource, LocationListener {
private OnLocationChangedListener mListener;
private LocationManager locationManager;
private final Criteria criteria = new Criteria();
private String bestAvailableProvider;
/* Updates are restricted to one every 10 seconds, and only when
* movement of more than 10 meters has been detected.*/
private final int minTime = 10000; // minimum time interval between location updates, in milliseconds
private final int minDistance = 10; // minimum distance between location updates, in meters
private FollowMeLocationSource() {
// Get reference to Location Manager
locationManager = (LocationManager) mContext.getSystemService(Context.LOCATION_SERVICE);
// Specify Location Provider criteria
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setPowerRequirement(Criteria.POWER_LOW);
criteria.setAltitudeRequired(true);
criteria.setBearingRequired(true);
criteria.setSpeedRequired(true);
criteria.setCostAllowed(true);
}
private void getBestAvailableProvider() {
/* The preffered way of specifying the location provider (e.g. GPS, NETWORK) to use
* is to ask the Location Manager for the one that best satisfies our criteria.
* By passing the 'true' boolean we ask for the best available (enabled) provider. */
bestAvailableProvider = locationManager.getBestProvider(criteria, true);
}
/* Activates this provider. This provider will notify the supplied listener
* periodically, until you call deactivate().
* This method is automatically invoked by enabling my-location layer. */
@Override
public void activate(OnLocationChangedListener listener) {
// We need to keep a reference to my-location layer's listener so we can Push forward
// location updates to it when we receive them from Location Manager.
mListener = listener;
// Request location updates from Location Manager
if (bestAvailableProvider != null) {
locationManager.requestLocationUpdates(bestAvailableProvider, minTime, minDistance, this);
} else {
// (Display a message/dialog) No Location Providers currently available.
}
}
/* Deactivates this provider.
* This method is automatically invoked by disabling my-location layer. */
@Override
public void deactivate() {
// Remove location updates from Location Manager
locationManager.removeUpdates(this);
mListener = null;
}
@Override
public void onLocationChanged(Location location) {
/* Push location updates to the registered listener..
* (this ensures that my-location layer will set the blue dot at the new/received location) */
if (mListener != null) {
mListener.onLocationChanged(location);
}
/* ..and Animate camera to center on that location !
* (the reason for we created this custom Location Source !) */
mMap.animateCamera(CameraUpdateFactory.newLatLng(new LatLng(location.getLatitude(), location.getLongitude())));
}
@Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
@Override
public void onProviderEnabled(String s) {
}
@Override
public void onProviderDisabled(String s) {
}
}
}
現在、これを行う方法はありません： http://code.google.com/p/gmaps-api-issues/issues/detail?id=4644
私は同じ問題に遭遇しました...私の解決策は今までに：
数回位置を取得するようハンドラーに要求するスレッドを作成します。 getMyLocationメソッドはGUIスレッドからのみ呼び出すことができるため、ハンドラーを使用する必要があります。
private class MyLocationThread extends Thread{
@Override
public void run() {
int loops = 0;
// we give the location search a minute
while(loops < 60){
// we have to try it over a handler, because getMyLocation() has to be called from GUI Thread -_-
_getMyLocationHandler.sendEmptyMessage(0);
if(isInterrupted()){
return;
}
// take a short nap before next try
try {Thread.sleep(1000);} catch(Exception e){}
loops++;
}
}
}
ハンドラーが行うことは次のとおりです。
private Handler _getMyLocationHandler = new Handler(){
public void handleMessage(Android.os.Message msg) {
if(getMap().isMyLocationEnabled() && getMap().getMyLocation() != null){
_locationWatcher.interrupt();
drawCurrentImagePositions();
}
}
};