Cherry-pick: Add callback-based support for HW Activity Recognition.

Add a callback-based mechanism for GmsCore to connect to Hardware Activity
Recognition. This allows GmsCore to stop polling to identify if the Android
platform supports the functionality or not.

Bug: 17112184
Change-Id: I8f9459cbd15eecd70f6919c6551e6f7a663c732f

3 files changed, 88 insertions, 14 deletions

diff --git a/location/lib/java/com/android/location/provider/ActivityRecognitionProvider.java b/location/lib/java/com/android/location/provider/ActivityRecognitionProvider.java
index da33464..f4943d5 100644
--- a/location/lib/java/com/android/location/provider/ActivityRecognitionProvider.java
+++ b/location/lib/java/com/android/location/provider/ActivityRecognitionProvider.java
@@ -31,8 +31,7 @@ import java.util.HashSet;
  */
 public final class ActivityRecognitionProvider {
     private final IActivityRecognitionHardware mService;
-    private final HashSet<Sink> mSinkSet = new HashSet<Sink>();
-    private final SinkTransport mSinkTransport = new SinkTransport();
+    private final HashSet<Sink> mSinkSet = new HashSet<>();
 
     // the following constants must remain in sync with activity_recognition.h
 
@@ -60,7 +59,7 @@ public final class ActivityRecognitionProvider {
             throws RemoteException {
         Preconditions.checkNotNull(service);
         mService = service;
-        mService.registerSink(mSinkTransport);
+        mService.registerSink(new SinkTransport());
     }
 
     public String[] getSupportedActivities() throws RemoteException {
@@ -102,26 +101,23 @@ public final class ActivityRecognitionProvider {
 
     private final class SinkTransport extends IActivityRecognitionHardwareSink.Stub {
         @Override
-        public void onActivityChanged(
-                android.hardware.location.ActivityChangedEvent activityChangedEvent) {
+        public void onActivityChanged(android.hardware.location.ActivityChangedEvent event) {
             Collection<Sink> sinks;
             synchronized (mSinkSet) {
                 if (mSinkSet.isEmpty()) {
                     return;
                 }
-
-                sinks = new ArrayList<Sink>(mSinkSet);
+                sinks = new ArrayList<>(mSinkSet);
             }
 
             // translate the event from platform internal and GmsCore types
-            ArrayList<ActivityRecognitionEvent> gmsEvents =
-                    new ArrayList<ActivityRecognitionEvent>();
-            for (android.hardware.location.ActivityRecognitionEvent event
-                    : activityChangedEvent.getActivityRecognitionEvents()) {
+            ArrayList<ActivityRecognitionEvent> gmsEvents = new ArrayList<>();
+            for (android.hardware.location.ActivityRecognitionEvent reportingEvent
+                    : event.getActivityRecognitionEvents()) {
                 ActivityRecognitionEvent gmsEvent = new ActivityRecognitionEvent(
-                        event.getActivity(),
-                        event.getEventType(),
-                        event.getTimestampNs());
+                        reportingEvent.getActivity(),
+                        reportingEvent.getEventType(),
+                        reportingEvent.getTimestampNs());
                 gmsEvents.add(gmsEvent);
             }
             ActivityChangedEvent gmsEvent = new ActivityChangedEvent(gmsEvents);
diff --git a/location/lib/java/com/android/location/provider/ActivityRecognitionProviderClient.java b/location/lib/java/com/android/location/provider/ActivityRecognitionProviderClient.java
new file mode 100644
index 0000000..0b878d7
--- /dev/null
+++ b/location/lib/java/com/android/location/provider/ActivityRecognitionProviderClient.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2015 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.location.provider;
+
+import android.annotation.NonNull;
+import android.hardware.location.IActivityRecognitionHardware;
+import android.hardware.location.IActivityRecognitionHardwareClient;
+import android.os.Binder;
+import android.os.IBinder;
+import android.os.Process;
+import android.os.RemoteException;
+import android.util.Log;
+
+/**
+ * A client class for interaction with an Activity-Recognition provider.
+ */
+public abstract class ActivityRecognitionProviderClient {
+    private static final String TAG = "ArProviderClient";
+
+    protected ActivityRecognitionProviderClient() {}
+
+    private IActivityRecognitionHardwareClient.Stub mClient =
+            new IActivityRecognitionHardwareClient.Stub() {
+                @Override
+                public void onAvailabilityChanged(
+                        boolean isSupported,
+                        IActivityRecognitionHardware instance) {
+                    int callingUid = Binder.getCallingUid();
+                    if (callingUid != Process.SYSTEM_UID) {
+                        Log.d(TAG, "Ignoring calls from non-system server. Uid: " + callingUid);
+                        return;
+                    }
+                    ActivityRecognitionProvider provider;
+                    try {
+                        provider = isSupported ? new ActivityRecognitionProvider(instance) : null;
+                    } catch (RemoteException e) {
+                        Log.e(TAG, "Error creating Hardware Activity-Recognition Provider.", e);
+                        return;
+                    }
+                    onProviderChanged(isSupported, provider);
+                }
+            };
+
+    /**
+     * Gets the binder needed to interact with proxy provider in the platform.
+     */
+    @NonNull
+    public IBinder getBinder() {
+        return mClient;
+    }
+
+    /**
+     * Called when a change in the availability of {@link ActivityRecognitionProvider} is detected.
+     *
+     * @param isSupported whether the platform supports the provider natively
+     * @param instance the available provider's instance
+     */
+    public abstract void onProviderChanged(
+            boolean isSupported,
+            ActivityRecognitionProvider instance);
+}
diff --git a/location/lib/java/com/android/location/provider/ActivityRecognitionProviderWatcher.java b/location/lib/java/com/android/location/provider/ActivityRecognitionProviderWatcher.java
index 03dd042..7139025 100644
--- a/location/lib/java/com/android/location/provider/ActivityRecognitionProviderWatcher.java
+++ b/location/lib/java/com/android/location/provider/ActivityRecognitionProviderWatcher.java
@@ -28,7 +28,10 @@ import android.util.Log;
 
 /**
  * A watcher class for Activity-Recognition instances.
+ *
+ * @deprecated use {@link ActivityRecognitionProviderClient} instead.
  */
+@Deprecated
 public class ActivityRecognitionProviderWatcher {
     private static final String TAG = "ActivityRecognitionProviderWatcher";