/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.webkit;
import android.app.ActivityThread;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.location.LocationProvider;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebView;
import android.webkit.WebViewCore;
/**
* Implements the Java side of GeolocationServiceAndroid.
*/
final class GeolocationService implements LocationListener {
// Log tag
private static final String TAG = "geolocationService";
private long mNativeObject;
private LocationManager mLocationManager;
private boolean mIsGpsEnabled;
private boolean mIsRunning;
private boolean mIsNetworkProviderAvailable;
private boolean mIsGpsProviderAvailable;
/**
* Constructor
* @param context The context from which we obtain the system service.
* @param nativeObject The native object to which this object will report position updates and
* errors.
*/
public GeolocationService(Context context, long nativeObject) {
mNativeObject = nativeObject;
// Register newLocationAvailable with platform service.
mLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
if (mLocationManager == null) {
Log.e(TAG, "Could not get location manager.");
}
}
/**
* Start listening for location updates.
*/
public boolean start() {
registerForLocationUpdates();
mIsRunning = true;
return mIsNetworkProviderAvailable || mIsGpsProviderAvailable;
}
/**
* Stop listening for location updates.
*/
public void stop() {
unregisterFromLocationUpdates();
mIsRunning = false;
}
/**
* Sets whether to use the GPS.
* @param enable Whether to use the GPS.
*/
public void setEnableGps(boolean enable) {
if (mIsGpsEnabled != enable) {
mIsGpsEnabled = enable;
if (mIsRunning) {
// There's no way to unregister from a single provider, so we can
// only unregister from all, then reregister with all but the GPS.
unregisterFromLocationUpdates();
registerForLocationUpdates();
// Check that the providers are still available after we re-register.
maybeReportError("The last location provider is no longer available");
}
}
}
/**
* LocationListener implementation.
* Called when the location has changed.
* @param location The new location, as a Location object.
*/
public void onLocationChanged(Location location) {
// Callbacks from the system location sevice are queued to this thread, so it's possible
// that we receive callbacks after unregistering. At this point, the native object will no
// longer exist.
if (mIsRunning) {
nativeNewLocationAvailable(mNativeObject, location);
}
}
/**
* LocationListener implementation.
* Called when the provider status changes.
* @param provider The name of the provider.
* @param status The new status of the provider.
* @param extras an optional Bundle with provider specific data.
*/
public void onStatusChanged(String providerName, int status, Bundle extras) {
boolean isAvailable = (status == LocationProvider.AVAILABLE);
if (LocationManager.NETWORK_PROVIDER.equals(providerName)) {
mIsNetworkProviderAvailable = isAvailable;
} else if (LocationManager.GPS_PROVIDER.equals(providerName)) {
mIsGpsProviderAvailable = isAvailable;
}
maybeReportError("The last location provider is no longer available");
}
/**
* LocationListener implementation.
* Called when the provider is enabled.
* @param provider The name of the location provider that is now enabled.
*/
public void onProviderEnabled(String providerName) {
// No need to notify the native side. It's enough to start sending
// valid position fixes again.
if (LocationManager.NETWORK_PROVIDER.equals(providerName)) {
mIsNetworkProviderAvailable = true;
} else if (LocationManager.GPS_PROVIDER.equals(providerName)) {
mIsGpsProviderAvailable = true;
}
}
/**
* LocationListener implementation.
* Called when the provider is disabled.
* @param provider The name of the location provider that is now disabled.
*/
public void onProviderDisabled(String providerName) {
if (LocationManager.NETWORK_PROVIDER.equals(providerName)) {
mIsNetworkProviderAvailable = false;
} else if (LocationManager.GPS_PROVIDER.equals(providerName)) {
mIsGpsProviderAvailable = false;
}
maybeReportError("The last location provider was disabled");
}
/**
* Registers this object with the location service.
*/
private void registerForLocationUpdates() {
try {
// Registration may fail if providers are not present on the device.
try {
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, this);
mIsNetworkProviderAvailable = true;
} catch(IllegalArgumentException e) { }
if (mIsGpsEnabled) {
try {
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
mIsGpsProviderAvailable = true;
} catch(IllegalArgumentException e) { }
}
} catch(SecurityException e) {
Log.e(TAG, "Caught security exception registering for location updates from system. " +
"This should only happen in DumpRenderTree.");
}
}
/**
* Unregisters this object from the location service.
*/
private void unregisterFromLocationUpdates() {
mLocationManager.removeUpdates(this);
mIsNetworkProviderAvailable = false;
mIsGpsProviderAvailable = false;
}
/**
* Reports an error if neither the network nor the GPS provider is available.
*/
private void maybeReportError(String message) {
// Callbacks from the system location sevice are queued to this thread, so it's possible
// that we receive callbacks after unregistering. At this point, the native object will no
// longer exist.
if (mIsRunning && !mIsNetworkProviderAvailable && !mIsGpsProviderAvailable) {
nativeNewErrorAvailable(mNativeObject, message);
}
}
// Native functions
private static native void nativeNewLocationAvailable(long nativeObject, Location location);
private static native void nativeNewErrorAvailable(long nativeObject, String message);
}