Add passive location provider.

The passive location provider allows receiving location updates without
actually triggering them.  This allows an application to receive location
updates that are being generated due to other clients of the location manager.

Change-Id: Ibf7a96b089c56875d4f62d3210252ae8d9f32768
Signed-off-by: Mike Lockwood <lockwood@android.com>

9 files changed, 200 insertions, 16 deletions

diff --git a/api/current.xml b/api/current.xml
index c3a7b26..444b002 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -78725,6 +78725,17 @@
  visibility="public"
 >
 </field>
+<field name="PASSIVE_PROVIDER"
+ type="java.lang.String"
+ transient="false"
+ volatile="false"
+ value="&quot;passive&quot;"
+ static="true"
+ final="true"
+ deprecated="not deprecated"
+ visibility="public"
+>
+</field>
 </class>
 <class name="LocationProvider"
  extends="java.lang.Object"
diff --git a/location/java/android/location/ILocationManager.aidl b/location/java/android/location/ILocationManager.aidl
index 8c24ee1..2c0399e 100644
--- a/location/java/android/location/ILocationManager.aidl
+++ b/location/java/android/location/ILocationManager.aidl
@@ -59,8 +59,10 @@ interface ILocationManager
 
     Location getLastKnownLocation(String provider);
 
-    /* used by location providers to tell the location manager when it has a new location */
-    void reportLocation(in Location location);
+    // Used by location providers to tell the location manager when it has a new location.
+    // Passive is true if the location is coming from the passive provider, in which case
+    // it need not be shared with other providers.
+    void reportLocation(in Location location, boolean passive);
 
     String getFromLocation(double latitude, double longitude, int maxResults,
         in GeocoderParams params, out List<Address> addrs);
diff --git a/location/java/android/location/LocationManager.java b/location/java/android/location/LocationManager.java
index 9027fc2..da760a1 100644
--- a/location/java/android/location/LocationManager.java
+++ b/location/java/android/location/LocationManager.java
@@ -81,6 +81,19 @@ public class LocationManager {
     public static final String GPS_PROVIDER = "gps";
 
     /**
+     * A special location provider for receiving locations without actually initiating
+     * a location fix. This provider can be used to passively receive location updates
+     * when other applications or services request them without actually requesting
+     * the locations yourself.  This provider will return locations generated by other
+     * providers.  You can query the {@link Location#getProvider()} method to determine
+     * the origin of the location update.
+     *
+     * Requires the permission android.permission.ACCESS_FINE_LOCATION, although if the GPS
+     * is not enabled this provider might only return coarse fixes.
+     */
+    public static final String PASSIVE_PROVIDER = "passive";
+
+    /**
      * Key used for the Bundle extra holding a boolean indicating whether
      * a proximity alert is entering (true) or exiting (false)..
      */
diff --git a/location/java/android/location/LocationProvider.java b/location/java/android/location/LocationProvider.java
index 3faba58..bb3e2a5 100644
--- a/location/java/android/location/LocationProvider.java
+++ b/location/java/android/location/LocationProvider.java
@@ -71,6 +71,10 @@ public abstract class LocationProvider {
      * false otherwise.
      */
     public boolean meetsCriteria(Criteria criteria) {
+        // We do not want to match the special passive provider based on criteria.
+        if (LocationManager.PASSIVE_PROVIDER.equals(mName)) {
+            return false;
+        }
         if ((criteria.getAccuracy() != Criteria.NO_REQUIREMENT) && 
             (criteria.getAccuracy() < getAccuracy())) {
             return false;
diff --git a/location/java/android/location/provider/LocationProvider.java b/location/java/android/location/provider/LocationProvider.java
index 0d028c0..4163def 100644
--- a/location/java/android/location/provider/LocationProvider.java
+++ b/location/java/android/location/provider/LocationProvider.java
@@ -156,7 +156,7 @@ public abstract class LocationProvider {
      */
     public void reportLocation(Location location) {
         try {
-            mLocationManager.reportLocation(location);
+            mLocationManager.reportLocation(location, false);
         } catch (RemoteException e) {
             Log.e(TAG, "RemoteException in reportLocation: ", e);
         }
diff --git a/location/java/com/android/internal/location/GpsLocationProvider.java b/location/java/com/android/internal/location/GpsLocationProvider.java
index dce3b27..8e84106 100755
--- a/location/java/com/android/internal/location/GpsLocationProvider.java
+++ b/location/java/com/android/internal/location/GpsLocationProvider.java
@@ -863,7 +863,7 @@ public class GpsLocationProvider implements LocationProviderInterface {
             }
 
             try {
-                mLocationManager.reportLocation(mLocation);
+                mLocationManager.reportLocation(mLocation, false);
             } catch (RemoteException e) {
                 Log.e(TAG, "RemoteException calling reportLocation");
             }
diff --git a/location/java/com/android/internal/location/MockProvider.java b/location/java/com/android/internal/location/MockProvider.java
index 2f6fdee..bc1893e 100644
--- a/location/java/com/android/internal/location/MockProvider.java
+++ b/location/java/com/android/internal/location/MockProvider.java
@@ -143,7 +143,7 @@ public class MockProvider implements LocationProviderInterface {
         mLocation.set(l);
         mHasLocation = true;
         try {
-            mLocationManager.reportLocation(mLocation);
+            mLocationManager.reportLocation(mLocation, false);
         } catch (RemoteException e) {
             Log.e(TAG, "RemoteException calling reportLocation");
         }
diff --git a/location/java/com/android/internal/location/PassiveProvider.java b/location/java/com/android/internal/location/PassiveProvider.java
new file mode 100644
index 0000000..7eb711d
--- /dev/null
+++ b/location/java/com/android/internal/location/PassiveProvider.java
@@ -0,0 +1,139 @@
+/*
+ * Copyright (C) 2010 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 com.android.internal.location;
+
+import android.location.ILocationManager;
+import android.location.Location;
+import android.location.LocationManager;
+import android.location.LocationProvider;
+import android.location.LocationProviderInterface;
+import android.net.NetworkInfo;
+import android.os.Bundle;
+import android.os.RemoteException;
+import android.util.Log;
+
+/**
+ * A passive location provider reports locations received from other providers
+ * for clients that want to listen passively without actually triggering
+ * location updates.
+ *
+ * {@hide}
+ */
+public class PassiveProvider implements LocationProviderInterface {
+
+    private static final String TAG = "PassiveProvider";
+
+    private final ILocationManager mLocationManager;
+    private boolean mTracking;
+
+    public PassiveProvider(ILocationManager locationManager) {
+        mLocationManager = locationManager;
+    }
+
+    public String getName() {
+        return LocationManager.PASSIVE_PROVIDER;
+    }
+
+    public boolean requiresNetwork() {
+        return false;
+    }
+
+    public boolean requiresSatellite() {
+        return false;
+    }
+
+    public boolean requiresCell() {
+        return false;
+    }
+
+    public boolean hasMonetaryCost() {
+        return false;
+    }
+
+    public boolean supportsAltitude() {
+        return false;
+    }
+
+    public boolean supportsSpeed() {
+        return false;
+    }
+
+    public boolean supportsBearing() {
+        return false;
+    }
+
+    public int getPowerRequirement() {
+        return -1;
+    }
+
+    public int getAccuracy() {
+        return -1;
+    }
+
+    public boolean isEnabled() {
+        return true;
+    }
+
+    public void enable() {
+    }
+
+    public void disable() {
+    }
+
+    public int getStatus(Bundle extras) {
+        if (mTracking) {
+            return LocationProvider.AVAILABLE;
+        } else {
+            return LocationProvider.TEMPORARILY_UNAVAILABLE;
+        }
+    }
+
+    public long getStatusUpdateTime() {
+        return -1;
+    }
+
+    public void enableLocationTracking(boolean enable) {
+        mTracking = enable;
+    }
+
+    public void setMinTime(long minTime) {
+    }
+
+    public void updateNetworkState(int state, NetworkInfo info) {
+    }
+
+    public void updateLocation(Location location) {
+        if (mTracking) {
+            try {
+                // pass the location back to the location manager
+                mLocationManager.reportLocation(location, true);
+            } catch (RemoteException e) {
+                Log.e(TAG, "RemoteException calling reportLocation");
+            }
+        }
+    }
+
+    public boolean sendExtraCommand(String command, Bundle extras) {
+        return false;
+    }
+
+    public void addListener(int uid) {
+    }
+
+    public void removeListener(int uid) {
+    }
+}
diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index e12f2e1..9068966 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -71,6 +71,7 @@ import com.android.internal.location.GpsLocationProvider;
 import com.android.internal.location.GpsNetInitiatedHandler;
 import com.android.internal.location.LocationProviderProxy;
 import com.android.internal.location.MockProvider;
+import com.android.internal.location.PassiveProvider;
 
 /**
  * The service class that manages LocationProviders and issues location
@@ -452,6 +453,11 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
             mGpsLocationProvider = gpsProvider;
         }
 
+        // create a passive location provider, which is always enabled
+        PassiveProvider passiveProvider = new PassiveProvider(this);
+        addProvider(passiveProvider);
+        mEnabledProviders.add(passiveProvider.getName());
+
         // initialize external network location and geocoder services
         Resources resources = mContext.getResources();
         String serviceName = resources.getString(
@@ -538,7 +544,8 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
     }
 
     private void checkPermissionsSafe(String provider) {
-        if (LocationManager.GPS_PROVIDER.equals(provider)
+        if ((LocationManager.GPS_PROVIDER.equals(provider)
+                 || LocationManager.PASSIVE_PROVIDER.equals(provider))
             && (mContext.checkCallingOrSelfPermission(ACCESS_FINE_LOCATION)
                 != PackageManager.PERMISSION_GRANTED)) {
             throw new SecurityException("Requires ACCESS_FINE_LOCATION permission");
@@ -1343,7 +1350,7 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
         }
     }
 
-    public void reportLocation(Location location) {
+    public void reportLocation(Location location, boolean passive) {
         if (mContext.checkCallingOrSelfPermission(INSTALL_LOCATION_PROVIDER)
                 != PackageManager.PERMISSION_GRANTED) {
             throw new SecurityException("Requires INSTALL_LOCATION_PROVIDER permission");
@@ -1351,6 +1358,7 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
 
         mLocationHandler.removeMessages(MESSAGE_LOCATION_CHANGED, location);
         Message m = Message.obtain(mLocationHandler, MESSAGE_LOCATION_CHANGED, location);
+        m.arg1 = (passive ? 1 : 0);
         mLocationHandler.sendMessageAtFrontOfQueue(m);
     }
 
@@ -1415,8 +1423,8 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
         return true;
     }
 
-    private void handleLocationChangedLocked(Location location) {
-        String provider = location.getProvider();
+    private void handleLocationChangedLocked(Location location, boolean passive) {
+        String provider = (passive ? LocationManager.PASSIVE_PROVIDER : location.getProvider());
         ArrayList<UpdateRecord> records = mRecordsByProvider.get(provider);
         if (records == null || records.size() == 0) {
             return;
@@ -1502,17 +1510,20 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
                     synchronized (mLock) {
                         Location location = (Location) msg.obj;
                         String provider = location.getProvider();
-
-                        // notify other providers of the new location
-                        for (int i = mProviders.size() - 1; i >= 0; i--) {
-                            LocationProviderInterface p = mProviders.get(i);
-                            if (!provider.equals(p.getName())) {
-                                p.updateLocation(location);
+                        boolean passive = (msg.arg1 == 1);
+
+                        if (!passive) {
+                            // notify other providers of the new location
+                            for (int i = mProviders.size() - 1; i >= 0; i--) {
+                                LocationProviderInterface p = mProviders.get(i);
+                                if (!provider.equals(p.getName())) {
+                                    p.updateLocation(location);
+                                }
                             }
                         }
 
                         if (isAllowedBySettingsLocked(provider)) {
-                            handleLocationChangedLocked(location);
+                            handleLocationChangedLocked(location, passive);
                         }
                     }
                 }
@@ -1687,6 +1698,10 @@ public class LocationManagerService extends ILocationManager.Stub implements Run
         boolean supportsSpeed, boolean supportsBearing, int powerRequirement, int accuracy) {
         checkMockPermissionsSafe();
 
+        if (LocationManager.PASSIVE_PROVIDER.equals(name)) {
+            throw new IllegalArgumentException("Cannot mock the passive location provider");
+        }
+
         long identity = Binder.clearCallingIdentity();
         synchronized (mLock) {
             MockProvider provider = new MockProvider(name, this,