Add CameraService to system server.

- Adds a camera service to system server that forwards events to the
  mediaserver camera service.
- Notify the camera service when the device user changes.

Bug: 19186859
Change-Id: I172a2ce46c8e8a131ae7e8dd99d60c5f4f0d6668

core/java/android/hardware/ICameraService.aidl

@@ -75,4 +75,11 @@ interface ICameraService
                     out BinderHolder device);
 
     int setTorchMode(String CameraId, boolean enabled, IBinder clientBinder);
+
+    /**
+     * Notify the camera service of a system event.  Should only be called from system_server.
+     *
+     * Callers require the android.permission.CAMERA_SEND_SYSTEM_EVENTS permission.
+     */
+    oneway void notifySystemEvent(int eventId, int arg0);
 }

core/res/AndroidManifest.xml

@@ -1220,6 +1220,14 @@
         android:label="@string/permlab_cameraDisableTransmitLed"
         android:description="@string/permdesc_cameraDisableTransmitLed" />
 
+    <!-- Allows sending the camera service notifications about system-wide events.
+        @hide -->
+    <permission android:name="android.permission.CAMERA_SEND_SYSTEM_EVENTS"
+        android:permissionGroup="android.permission-group.CAMERA"
+        android:protectionLevel="signature|system"
+        android:label="@string/permdesc_cameraSendSystemEvent"
+        android:description="@string/permdesc_cameraSendSystemEvent" />
+
     <!-- =========================================== -->
     <!-- Permissions associated with telephony state -->
     <!-- =========================================== -->

core/res/res/values/strings.xml

@@ -1758,6 +1758,8 @@
     <string name="permlab_cameraDisableTransmitLed">disable transmit indicator LED when camera is in use</string>
     <!-- Description of a camera app permission, listed so the user can choose whether or not they want to allow it to disable the may-transmit light indicator. -->
     <string name="permdesc_cameraDisableTransmitLed">Allows a pre-installed system application to disable the camera use indicator LED.</string>
+    <!-- Description of a camera app permission, listed so that the user can send the camera service notifications about system-wide events. -->
+    <string name="permdesc_cameraSendSystemEvent">Allows a pre-installed system application to send the camera service system events.</string>
 
     <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permlab_brick" product="tablet">permanently disable tablet</string>

services/core/java/com/android/server/camera/CameraService.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 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.server.camera;
+
+import android.content.Context;
+import android.hardware.ICameraService;
+import android.os.IBinder;
+import android.os.RemoteException;
+
+import com.android.server.SystemService;
+
+/**
+ * CameraService is the system_server analog to the camera service running in mediaserver.
+ *
+ * @hide
+ */
+public class CameraService extends SystemService {
+
+    /**
+     * This must match the ICameraService.aidl definition
+     */
+    private static final String CAMERA_SERVICE_BINDER_NAME = "media.camera";
+
+    // Event arguments to use with the camera service notifySystemEvent call:
+    public static final int NO_EVENT = 0; // NOOP
+    public static final int USER_SWITCHED = 1; // User changed, argument is the new user handle
+
+    public CameraService(Context context) {
+        super(context);
+    }
+
+    @Override
+    public void onStart() {}
+
+    @Override
+    public void onSwitchUser(int userHandle) {
+        super.onSwitchUser(userHandle);
+
+        /**
+         * Forward the user switch event to the native camera service running in mediaserver.
+         */
+        IBinder cameraServiceBinder = getBinderService(CAMERA_SERVICE_BINDER_NAME);
+        if (cameraServiceBinder == null) {
+            return; // Camera service not active, there is no need to evict user clients.
+        }
+        ICameraService cameraServiceRaw = ICameraService.Stub.asInterface(cameraServiceBinder);
+        try {
+            cameraServiceRaw.notifySystemEvent(USER_SWITCHED, userHandle);
+        } catch (RemoteException e) {
+            // Do nothing, if camera service is dead, there is no need to evict user clients.
+        }
+    }
+}

services/java/com/android/server/SystemServer.java

@@ -53,6 +53,7 @@ import com.android.server.accessibility.AccessibilityManagerService;
 import com.android.server.accounts.AccountManagerService;
 import com.android.server.am.ActivityManagerService;
 import com.android.server.audio.AudioService;
+import com.android.server.camera.CameraService;
 import com.android.server.clipboard.ClipboardService;
 import com.android.server.content.ContentService;
 import com.android.server.devicepolicy.DevicePolicyManagerService;
@@ -408,6 +409,7 @@ public final class SystemServer {
         AudioService audioService = null;
         MmsServiceBroker mmsService = null;
         EntropyMixer entropyMixer = null;
+        CameraService cameraService = null;
 
         boolean disableStorage = SystemProperties.getBoolean("config.disable_storage", false);
         boolean disableBluetooth = SystemProperties.getBoolean("config.disable_bluetooth", false);
@@ -436,6 +438,9 @@ public final class SystemServer {
 
             mContentResolver = context.getContentResolver();
 
+            Slog.i(TAG, "Camera Service");
+            mSystemServiceManager.startService(CameraService.class);
+
             // The AccountManager must come before the ContentService
             try {
                 // TODO: seems like this should be disable-able, but req'd by ContentService