Camera: Add new hidden API for camera open/close callback

The hidden API is used by SystemUI process to adjust the system UI based
on when a certain camera is opened or closed.

Test: Manually observe callbacks in SystemUI when running camera CTS
Bug: 150540299
Change-Id: I04cae782d96f0e32be8ef588dcd328f84b32887a
Merged-In: I04cae782d96f0e32be8ef588dcd328f84b32887a

core/java/android/hardware/camera2/CameraManager.java

@@ -701,6 +701,33 @@ public final class CameraManager {
         public void onCameraAccessPrioritiesChanged() {
             // default empty implementation
         }
+
+        /**
+         * A camera device has been opened by an application.
+         *
+         * <p>The default implementation of this method does nothing.</p>
+         *
+         * @param cameraId The unique identifier of the new camera.
+         * @param packageId The package Id of the application opening the camera.
+         *
+         * @see #onCameraClosed
+         */
+        /** @hide */
+        public void onCameraOpened(@NonNull String cameraId, @NonNull String packageId) {
+            // default empty implementation
+        }
+
+        /**
+         * A previously-opened camera has been closed.
+         *
+         * <p>The default implementation of this method does nothing.</p>
+         *
+         * @param cameraId The unique identifier of the closed camera.
+         */
+        /** @hide */
+        public void onCameraClosed(@NonNull String cameraId) {
+            // default empty implementation
+        }
     }
 
     /**
@@ -1139,6 +1166,38 @@ public final class CameraManager {
             }
         }
 
+        private void postSingleCameraOpenedUpdate(final AvailabilityCallback callback,
+                final Executor executor, final String id, final String packageId) {
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                executor.execute(
+                    new Runnable() {
+                        @Override
+                        public void run() {
+                            callback.onCameraOpened(id, packageId);
+                        }
+                    });
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+
+        private void postSingleCameraClosedUpdate(final AvailabilityCallback callback,
+                final Executor executor, final String id) {
+            final long ident = Binder.clearCallingIdentity();
+            try {
+                executor.execute(
+                    new Runnable() {
+                        @Override
+                        public void run() {
+                            callback.onCameraClosed(id);
+                        }
+                    });
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+
         private void postSingleUpdate(final AvailabilityCallback callback, final Executor executor,
                 final String id, final int status) {
             if (isAvailable(status)) {
@@ -1401,6 +1460,32 @@ public final class CameraManager {
             }
         }
 
+        @Override
+        public void onCameraOpened(String cameraId, String clientPackageId) {
+            synchronized (mLock) {
+                final int callbackCount = mCallbackMap.size();
+                for (int i = 0; i < callbackCount; i++) {
+                    Executor executor = mCallbackMap.valueAt(i);
+                    final AvailabilityCallback callback = mCallbackMap.keyAt(i);
+
+                    postSingleCameraOpenedUpdate(callback, executor, cameraId, clientPackageId);
+                }
+            }
+        }
+
+        @Override
+        public void onCameraClosed(String cameraId) {
+            synchronized (mLock) {
+                final int callbackCount = mCallbackMap.size();
+                for (int i = 0; i < callbackCount; i++) {
+                    Executor executor = mCallbackMap.valueAt(i);
+                    final AvailabilityCallback callback = mCallbackMap.keyAt(i);
+
+                    postSingleCameraClosedUpdate(callback, executor, cameraId);
+                }
+            }
+        }
+
         /**
          * Try to connect to camera service after some delay if any client registered camera
          * availability callback or torch status callback.

core/res/AndroidManifest.xml

@@ -1267,6 +1267,14 @@
         android:description="@string/permdesc_camera"
         android:protectionLevel="dangerous|instant" />
 
+    <!-- Allows receiving the camera service notifications when a camera is opened
+            (by a certain application package) or closed.
+        @hide -->
+    <permission android:name="android.permission.CAMERA_OPEN_CLOSE_LISTENER"
+        android:permissionGroup="android.permission-group.UNDEFINED"
+        android:label="@string/permlab_cameraOpenCloseListener"
+        android:description="@string/permdesc_cameraOpenCloseListener"
+        android:protectionLevel="signature" />
 
     <!-- ====================================================================== -->
     <!-- Permissions for accessing the device sensors                           -->

core/res/res/values/strings.xml

@@ -1151,6 +1151,11 @@
     <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->
     <string name="permdesc_camera">This app can take pictures and record videos using the camera at any time.</string>
 
+    <!-- Title of an application permission, listed so the user can choose whether they want to allow the application to do this. [CHAR_LIMIT=NONE] -->
+    <string name="permlab_cameraOpenCloseListener">Allow an application or service to receive callbacks about camera devices being opened or closed.</string>
+    <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. [CHAR_LIMIT=NONE] -->
+    <string name="permdesc_cameraOpenCloseListener">This signature app can receive callbacks when any camera device is being opened (by what application package) or closed.</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_vibrate">control vibration</string>
     <!-- Description of an application permission, listed so the user can choose whether they want to allow the application to do this. -->

data/etc/com.android.systemui.xml

@@ -60,5 +60,6 @@
         <permission name="android.permission.WRITE_SECURE_SETTINGS"/>
         <permission name="android.permission.WRITE_EMBEDDED_SUBSCRIPTIONS"/>
         <permission name="android.permission.CONTROL_DISPLAY_COLOR_TRANSFORMS" />
+        <permission name="android.permission.CAMERA_OPEN_CLOSE_LISTENER" />
     </privapp-permissions>
 </permissions>

media/tests/MediaFrameworkTest/src/com/android/mediaframeworktest/integration/CameraBinderTest.java

@@ -313,6 +313,15 @@ public class CameraBinderTest extends AndroidTestCase {
         public void onCameraAccessPrioritiesChanged() {
             Log.v(TAG, "Camera access permission change");
         }
+        @Override
+        public void onCameraOpened(String cameraId, String clientPackageName) {
+            Log.v(TAG, String.format("Camera %s is opened by client package %s",
+                    cameraId, clientPackageName));
+        }
+        @Override
+        public void onCameraClosed(String cameraId) {
+            Log.v(TAG, String.format("Camera %s is closed", cameraId));
+        }
     }
 
     /**

packages/SystemUI/AndroidManifest.xml

@@ -151,6 +151,7 @@
     <uses-permission android:name="android.permission.CONFIGURE_WIFI_DISPLAY" />
 
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.CAMERA_OPEN_CLOSE_LISTENER" />
 
     <!-- Screen Capturing -->
     <uses-permission android:name="android.permission.MANAGE_MEDIA_PROJECTION" />