CEC: Add listener for HDMI CEC volume control feature

Adds a listener to receive updates to the state of the HDMI CEC volume
control features.

Interested parties can register and unregister to get notified about
state updates which are sent on every change to the value.

Test: atest HdmiControlServiceTest
Bug: 152018314
Change-Id: I342d748114bae99b3c3f236502d73bfeac9e9ac5
Merged-In: I342d748114bae99b3c3f236502d73bfeac9e9ac5

core/java/android/hardware/hdmi/HdmiControlManager.java

@@ -18,6 +18,7 @@ package android.hardware.hdmi;
 
 import static com.android.internal.os.RoSystemProperties.PROPERTY_HDMI_IS_DEVICE_HDMI_CEC_SWITCH;
 
+import android.annotation.CallbackExecutor;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -30,6 +31,7 @@ import android.annotation.SystemApi;
 import android.annotation.SystemService;
 import android.content.Context;
 import android.content.pm.PackageManager;
+import android.os.Binder;
 import android.os.RemoteException;
 import android.os.SystemProperties;
 import android.util.ArrayMap;
@@ -40,6 +42,7 @@ import com.android.internal.annotations.GuardedBy;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.concurrent.Executor;
 
 /**
  * The {@link HdmiControlManager} class is used to send HDMI control messages
@@ -817,6 +820,24 @@ public final class HdmiControlManager {
     private final ArrayMap<HdmiControlStatusChangeListener, IHdmiControlStatusChangeListener>
             mHdmiControlStatusChangeListeners = new ArrayMap<>();
 
+    /**
+     * Listener used to get the status of the HDMI CEC volume control feature (enabled/disabled).
+     * @hide
+     */
+    public interface HdmiCecVolumeControlFeatureListener {
+        /**
+         * Called when the HDMI Control (CEC) volume control feature is enabled/disabled.
+         *
+         * @param enabled status of HDMI CEC volume control feature
+         * @see {@link HdmiControlManager#setHdmiCecVolumeControlEnabled(boolean)} ()}
+         **/
+        void onHdmiCecVolumeControlFeature(boolean enabled);
+    }
+
+    private final ArrayMap<HdmiCecVolumeControlFeatureListener,
+            IHdmiCecVolumeControlFeatureListener>
+            mHdmiCecVolumeControlFeatureListeners = new ArrayMap<>();
+
     /**
      * Listener used to get vendor-specific commands.
      */
@@ -979,4 +1000,76 @@ public final class HdmiControlManager {
         };
     }
 
+    /**
+     * Adds a listener to get informed of changes to the state of the HDMI CEC volume control
+     * feature.
+     *
+     * Upon adding a listener, the current state of the HDMI CEC volume control feature will be
+     * sent immediately.
+     *
+     * <p>To stop getting the notification,
+     * use {@link #removeHdmiCecVolumeControlFeatureListener(HdmiCecVolumeControlFeatureListener)}.
+     *
+     * @param listener {@link HdmiCecVolumeControlFeatureListener} instance
+     * @hide
+     * @see #removeHdmiCecVolumeControlFeatureListener(HdmiCecVolumeControlFeatureListener)
+     */
+    @RequiresPermission(android.Manifest.permission.HDMI_CEC)
+    public void addHdmiCecVolumeControlFeatureListener(@NonNull @CallbackExecutor Executor executor,
+            @NonNull HdmiCecVolumeControlFeatureListener listener) {
+        if (mService == null) {
+            Log.e(TAG, "HdmiControlService is not available");
+            return;
+        }
+        if (mHdmiCecVolumeControlFeatureListeners.containsKey(listener)) {
+            Log.e(TAG, "listener is already registered");
+            return;
+        }
+        IHdmiCecVolumeControlFeatureListener wrappedListener =
+                createHdmiCecVolumeControlFeatureListenerWrapper(executor, listener);
+        mHdmiCecVolumeControlFeatureListeners.put(listener, wrappedListener);
+        try {
+            mService.addHdmiCecVolumeControlFeatureListener(wrappedListener);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    /**
+     * Removes a listener to stop getting informed of changes to the state of the HDMI CEC volume
+     * control feature.
+     *
+     * @param listener {@link HdmiCecVolumeControlFeatureListener} instance to be removed
+     * @hide
+     */
+    @RequiresPermission(android.Manifest.permission.HDMI_CEC)
+    public void removeHdmiCecVolumeControlFeatureListener(
+            HdmiCecVolumeControlFeatureListener listener) {
+        if (mService == null) {
+            Log.e(TAG, "HdmiControlService is not available");
+            return;
+        }
+        IHdmiCecVolumeControlFeatureListener wrappedListener =
+                mHdmiCecVolumeControlFeatureListeners.remove(listener);
+        if (wrappedListener == null) {
+            Log.e(TAG, "tried to remove not-registered listener");
+            return;
+        }
+        try {
+            mService.removeHdmiCecVolumeControlFeatureListener(wrappedListener);
+        } catch (RemoteException e) {
+            throw e.rethrowFromSystemServer();
+        }
+    }
+
+    private IHdmiCecVolumeControlFeatureListener createHdmiCecVolumeControlFeatureListenerWrapper(
+            Executor executor, final HdmiCecVolumeControlFeatureListener listener) {
+        return new android.hardware.hdmi.IHdmiCecVolumeControlFeatureListener.Stub() {
+            @Override
+            public void onHdmiCecVolumeControlFeature(boolean enabled) {
+                Binder.clearCallingIdentity();
+                executor.execute(() -> listener.onHdmiCecVolumeControlFeature(enabled));
+            }
+        };
+    }
 }

core/java/android/hardware/hdmi/IHdmiCecVolumeControlFeatureListener.aidl

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2020 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 android.hardware.hdmi;
+
+/**
+ * Listener used to get the status of the HDMI CEC volume control feature (enabled/disabled).
+ * @hide
+ */
+oneway interface IHdmiCecVolumeControlFeatureListener {
+
+    /**
+     * Called when the HDMI Control (CEC) volume control feature is enabled/disabled.
+     *
+     * @param enabled status of HDMI CEC volume control feature
+     * @see {@link HdmiControlManager#setHdmiCecVolumeControlEnabled(boolean)} ()}
+     **/
+    void onHdmiCecVolumeControlFeature(boolean enabled);
+}

core/java/android/hardware/hdmi/IHdmiControlService.aidl

@@ -18,6 +18,7 @@ package android.hardware.hdmi;
 
 import android.hardware.hdmi.HdmiDeviceInfo;
 import android.hardware.hdmi.HdmiPortInfo;
+import android.hardware.hdmi.IHdmiCecVolumeControlFeatureListener;
 import android.hardware.hdmi.IHdmiControlCallback;
 import android.hardware.hdmi.IHdmiControlStatusChangeListener;
 import android.hardware.hdmi.IHdmiDeviceEventListener;
@@ -44,6 +45,8 @@ interface IHdmiControlService {
     void queryDisplayStatus(IHdmiControlCallback callback);
     void addHdmiControlStatusChangeListener(IHdmiControlStatusChangeListener listener);
     void removeHdmiControlStatusChangeListener(IHdmiControlStatusChangeListener listener);
+    void addHdmiCecVolumeControlFeatureListener(IHdmiCecVolumeControlFeatureListener listener);
+    void removeHdmiCecVolumeControlFeatureListener(IHdmiCecVolumeControlFeatureListener listener);
     void addHotplugEventListener(IHdmiHotplugEventListener listener);
     void removeHotplugEventListener(IHdmiHotplugEventListener listener);
     void addDeviceEventListener(IHdmiDeviceEventListener listener);