AudioVolumeGroup introspection & callback JAVA APIs
This CL adds introspection APIs for Audio Volume group
and callback notification on group volume change.
It allows to keep the same level of service available today
in CarAudioManager and is a starting point to get rid of Stream Alias
hard coded in AudioServer.
Bug: 124767636
Test: dumpsys media.audio_policy
Change-Id: I48909df93c146f071acd24cd3ecc608cb98b4d7e
Signed-off-by: François Gaffie <francois.gaffie@renault.com>
diff --git a/core/jni/android_media_AudioVolumeGroupCallback.cpp b/core/jni/android_media_AudioVolumeGroupCallback.cpp
new file mode 100644
index 0000000..cb4ddbd
--- /dev/null
+++ b/core/jni/android_media_AudioVolumeGroupCallback.cpp
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+
+//#define LOG_NDEBUG 0
+
+#define LOG_TAG "AudioVolumeGroupCallback-JNI"
+
+#include <utils/Log.h>
+#include <nativehelper/JNIHelp.h>
+#include "core_jni_helpers.h"
+
+#include "android_media_AudioVolumeGroupCallback.h"
+
+
+// ----------------------------------------------------------------------------
+using namespace android;
+
+static const char* const kAudioVolumeGroupChangeHandlerClassPathName =
+ "android/media/audiopolicy/AudioVolumeGroupChangeHandler";
+
+static struct {
+ jfieldID mJniCallback;
+} gAudioVolumeGroupChangeHandlerFields;
+
+static struct {
+ jmethodID postEventFromNative;
+} gAudioVolumeGroupChangeHandlerMethods;
+
+static Mutex gLock;
+
+JNIAudioVolumeGroupCallback::JNIAudioVolumeGroupCallback(JNIEnv* env,
+ jobject thiz,
+ jobject weak_thiz)
+{
+ jclass clazz = env->GetObjectClass(thiz);
+ if (clazz == NULL) {
+ ALOGE("Can't find class %s", kAudioVolumeGroupChangeHandlerClassPathName);
+ return;
+ }
+ mClass = (jclass)env->NewGlobalRef(clazz);
+
+ // We use a weak reference so the AudioVolumeGroupChangeHandler object can be garbage collected.
+ // The reference is only used as a proxy for callbacks.
+ mObject = env->NewGlobalRef(weak_thiz);
+}
+
+JNIAudioVolumeGroupCallback::~JNIAudioVolumeGroupCallback()
+{
+ // remove global references
+ JNIEnv *env = AndroidRuntime::getJNIEnv();
+ if (env == NULL) {
+ return;
+ }
+ env->DeleteGlobalRef(mObject);
+ env->DeleteGlobalRef(mClass);
+}
+
+void JNIAudioVolumeGroupCallback::onAudioVolumeGroupChanged(volume_group_t group, int flags)
+{
+ JNIEnv *env = AndroidRuntime::getJNIEnv();
+ if (env == NULL) {
+ return;
+ }
+ ALOGV("%s volume group id %d", __FUNCTION__, group);
+ env->CallStaticVoidMethod(mClass,
+ gAudioVolumeGroupChangeHandlerMethods.postEventFromNative,
+ mObject,
+ AUDIOVOLUMEGROUP_EVENT_VOLUME_CHANGED, group, flags, NULL);
+ if (env->ExceptionCheck()) {
+ ALOGW("An exception occurred while notifying an event.");
+ env->ExceptionClear();
+ }
+}
+
+void JNIAudioVolumeGroupCallback::onServiceDied()
+{
+ JNIEnv *env = AndroidRuntime::getJNIEnv();
+ if (env == NULL) {
+ return;
+ }
+ env->CallStaticVoidMethod(mClass,
+ gAudioVolumeGroupChangeHandlerMethods.postEventFromNative,
+ mObject,
+ AUDIOVOLUMEGROUP_EVENT_SERVICE_DIED, 0, 0, NULL);
+ if (env->ExceptionCheck()) {
+ ALOGW("An exception occurred while notifying an event.");
+ env->ExceptionClear();
+ }
+}
+
+static
+sp<JNIAudioVolumeGroupCallback> setJniCallback(JNIEnv* env,
+ jobject thiz,
+ const sp<JNIAudioVolumeGroupCallback>& callback)
+{
+ Mutex::Autolock l(gLock);
+ sp<JNIAudioVolumeGroupCallback> old = (JNIAudioVolumeGroupCallback*)env->GetLongField(
+ thiz, gAudioVolumeGroupChangeHandlerFields.mJniCallback);
+ if (callback.get()) {
+ callback->incStrong((void*)setJniCallback);
+ }
+ if (old != 0) {
+ old->decStrong((void*)setJniCallback);
+ }
+ env->SetLongField(thiz, gAudioVolumeGroupChangeHandlerFields.mJniCallback,
+ (jlong)callback.get());
+ return old;
+}
+
+static void
+android_media_AudioVolumeGroupChangeHandler_eventHandlerSetup(JNIEnv *env,
+ jobject thiz,
+ jobject weak_this)
+{
+ ALOGV("%s", __FUNCTION__);
+ sp<JNIAudioVolumeGroupCallback> callback =
+ new JNIAudioVolumeGroupCallback(env, thiz, weak_this);
+
+ if (AudioSystem::addAudioVolumeGroupCallback(callback) == NO_ERROR) {
+ setJniCallback(env, thiz, callback);
+ }
+}
+
+static void
+android_media_AudioVolumeGroupChangeHandler_eventHandlerFinalize(JNIEnv *env, jobject thiz)
+{
+ ALOGV("%s", __FUNCTION__);
+ sp<JNIAudioVolumeGroupCallback> callback = setJniCallback(env, thiz, 0);
+ if (callback != 0) {
+ AudioSystem::removeAudioVolumeGroupCallback(callback);
+ }
+}
+
+/*
+ * JNI registration.
+ */
+static const JNINativeMethod gMethods[] = {
+ {"native_setup", "(Ljava/lang/Object;)V",
+ (void *)android_media_AudioVolumeGroupChangeHandler_eventHandlerSetup},
+ {"native_finalize", "()V",
+ (void *)android_media_AudioVolumeGroupChangeHandler_eventHandlerFinalize},
+};
+
+int register_android_media_AudioVolumeGroupChangeHandler(JNIEnv *env)
+{
+ jclass audioVolumeGroupChangeHandlerClass =
+ FindClassOrDie(env, kAudioVolumeGroupChangeHandlerClassPathName);
+ gAudioVolumeGroupChangeHandlerMethods.postEventFromNative =
+ GetStaticMethodIDOrDie(env, audioVolumeGroupChangeHandlerClass, "postEventFromNative",
+ "(Ljava/lang/Object;IIILjava/lang/Object;)V");
+
+ gAudioVolumeGroupChangeHandlerFields.mJniCallback =
+ GetFieldIDOrDie(env, audioVolumeGroupChangeHandlerClass, "mJniCallback", "J");
+
+ env->DeleteLocalRef(audioVolumeGroupChangeHandlerClass);
+
+ return RegisterMethodsOrDie(env,
+ kAudioVolumeGroupChangeHandlerClassPathName,
+ gMethods,
+ NELEM(gMethods));
+}
+