1 /*
2  * Copyright (C) 2010 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.location.provider;
18 
19 import java.io.FileDescriptor;
20 import java.io.FileOutputStream;
21 import java.io.PrintWriter;
22 
23 import android.content.Context;
24 import android.location.ILocationManager;
25 import android.location.Location;
26 import android.location.LocationManager;
27 import android.os.Bundle;
28 import android.os.IBinder;
29 import android.os.RemoteException;
30 import android.os.ServiceManager;
31 import android.os.WorkSource;
32 import android.util.Log;
33 
34 import com.android.internal.location.ILocationProvider;
35 import com.android.internal.location.ProviderProperties;
36 import com.android.internal.location.ProviderRequest;
37 import com.android.internal.util.FastPrintWriter;
38 
39 /**
40  * Base class for location providers implemented as unbundled services.
41  *
42  * <p>The network location provider must export a service with action
43  * "com.android.location.service.v2.NetworkLocationProvider"
44  * and a valid minor version in a meta-data field on the service, and
45  * then return the result of {@link #getBinder()} on service binding.
46  *
47  * <p>The fused location provider must export a service with action
48  * "com.android.location.service.FusedLocationProvider"
49  * and a valid minor version in a meta-data field on the service, and
50  * then return the result of {@link #getBinder()} on service binding.
51  *
52  * <p>IMPORTANT: This class is effectively a public API for unbundled
53  * applications, and must remain API stable. See README.txt in the root
54  * of this package for more information.
55  */
56 public abstract class LocationProviderBase {
57     private final String TAG;
58 
59     protected final ILocationManager mLocationManager;
60     private final ProviderProperties mProperties;
61     private final IBinder mBinder;
62 
63     /**
64      * Bundle key for a version of the location containing no GPS data.
65      * Allows location providers to flag locations as being safe to
66      * feed to LocationFudger.
67      */
68     public static final String EXTRA_NO_GPS_LOCATION = Location.EXTRA_NO_GPS_LOCATION;
69 
70     /**
71      * Name of the Fused location provider.
72      *
73      * <p>This provider combines inputs for all possible location sources
74      * to provide the best possible Location fix.
75      */
76     public static final String FUSED_PROVIDER = LocationManager.FUSED_PROVIDER;
77 
78     private final class Service extends ILocationProvider.Stub {
79         @Override
enable()80         public void enable() {
81             onEnable();
82         }
83         @Override
disable()84         public void disable() {
85             onDisable();
86         }
87         @Override
setRequest(ProviderRequest request, WorkSource ws)88         public void setRequest(ProviderRequest request, WorkSource ws) {
89             onSetRequest(new ProviderRequestUnbundled(request), ws);
90         }
91         @Override
getProperties()92         public ProviderProperties getProperties() {
93             return mProperties;
94         }
95         @Override
getStatus(Bundle extras)96         public int getStatus(Bundle extras) {
97             return onGetStatus(extras);
98         }
99         @Override
getStatusUpdateTime()100         public long getStatusUpdateTime() {
101             return onGetStatusUpdateTime();
102         }
103         @Override
sendExtraCommand(String command, Bundle extras)104         public boolean sendExtraCommand(String command, Bundle extras) {
105             return onSendExtraCommand(command, extras);
106         }
107         @Override
dump(FileDescriptor fd, String[] args)108         public void dump(FileDescriptor fd, String[] args) {
109             PrintWriter pw = new FastPrintWriter(new FileOutputStream(fd));
110             onDump(fd, pw, args);
111             pw.flush();
112         }
113     }
114 
LocationProviderBase(String tag, ProviderPropertiesUnbundled properties)115     public LocationProviderBase(String tag, ProviderPropertiesUnbundled properties) {
116         TAG = tag;
117         IBinder b = ServiceManager.getService(Context.LOCATION_SERVICE);
118         mLocationManager = ILocationManager.Stub.asInterface(b);
119         mProperties = properties.getProviderProperties();
120         mBinder = new Service();
121     }
122 
getBinder()123     public IBinder getBinder() {
124         return mBinder;
125     }
126 
127     /**
128      * Used by the location provider to report new locations.
129      *
130      * @param location new Location to report
131      *
132      * Requires the android.permission.INSTALL_LOCATION_PROVIDER permission.
133      */
reportLocation(Location location)134     public final void reportLocation(Location location) {
135         try {
136             mLocationManager.reportLocation(location, false);
137         } catch (RemoteException e) {
138             Log.e(TAG, "RemoteException", e);
139         } catch (Exception e) {
140             // never crash provider, might be running in a system process
141             Log.e(TAG, "Exception", e);
142         }
143     }
144 
145     /**
146      * Enable the location provider.
147      * <p>The provider may initialize resources, but does
148      * not yet need to report locations.
149      */
onEnable()150     public abstract void onEnable();
151 
152     /**
153      * Disable the location provider.
154      * <p>The provider must release resources, and stop
155      * performing work. It may no longer report locations.
156      */
onDisable()157     public abstract void onDisable();
158 
159     /**
160      * Set the {@link ProviderRequest} requirements for this provider.
161      * <p>Each call to this method overrides all previous requests.
162      * <p>This method might trigger the provider to start returning
163      * locations, or to stop returning locations, depending on the
164      * parameters in the request.
165      */
onSetRequest(ProviderRequestUnbundled request, WorkSource source)166     public abstract void onSetRequest(ProviderRequestUnbundled request, WorkSource source);
167 
168     /**
169      * Dump debug information.
170      */
onDump(FileDescriptor fd, PrintWriter pw, String[] args)171     public void onDump(FileDescriptor fd, PrintWriter pw, String[] args) {
172     }
173 
174     /**
175      * Returns a information on the status of this provider.
176      * <p>{@link android.location.LocationProvider#OUT_OF_SERVICE} is returned if the provider is
177      * out of service, and this is not expected to change in the near
178      * future; {@link android.location.LocationProvider#TEMPORARILY_UNAVAILABLE} is returned if
179      * the provider is temporarily unavailable but is expected to be
180      * available shortly; and {@link android.location.LocationProvider#AVAILABLE} is returned
181      * if the provider is currently available.
182      *
183      * <p>If extras is non-null, additional status information may be
184      * added to it in the form of provider-specific key/value pairs.
185      */
onGetStatus(Bundle extras)186     public abstract int onGetStatus(Bundle extras);
187 
188     /**
189      * Returns the time at which the status was last updated. It is the
190      * responsibility of the provider to appropriately set this value using
191      * {@link android.os.SystemClock#elapsedRealtime SystemClock.elapsedRealtime()}.
192      * there is a status update that it wishes to broadcast to all its
193      * listeners. The provider should be careful not to broadcast
194      * the same status again.
195      *
196      * @return time of last status update in millis since last reboot
197      */
onGetStatusUpdateTime()198     public abstract long onGetStatusUpdateTime();
199 
200     /**
201      * Implements addditional location provider specific additional commands.
202      *
203      * @param command name of the command to send to the provider.
204      * @param extras optional arguments for the command (or null).
205      * The provider may optionally fill the extras Bundle with results from the command.
206      *
207      * @return true if the command succeeds.
208      */
onSendExtraCommand(String command, Bundle extras)209     public boolean onSendExtraCommand(String command, Bundle extras) {
210         // default implementation
211         return false;
212     }
213 }
214