cubeb-jni.cpp - mozsearch

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/* clang-format off */

#include "jni.h"

#include <assert.h>

#include "cubeb-jni-instances.h"

/* clang-format on */

#define AUDIO_STREAM_TYPE_MUSIC 3

struct cubeb_jni {

  jobject s_audio_manager_obj = nullptr;

  jclass s_audio_manager_class = nullptr;

  jmethodID s_get_output_latency_id = nullptr;

};

extern "C" cubeb_jni *

cubeb_jni_init()

  jobject ctx_obj = cubeb_jni_get_context_instance();

  JNIEnv * jni_env = cubeb_get_jni_env_for_thread();

  if (!jni_env || !ctx_obj) {

    return nullptr;

  cubeb_jni * cubeb_jni_ptr = new cubeb_jni;

  assert(cubeb_jni_ptr);

  // Find the audio manager object and make it global to call it from another

  // method

  jclass context_class = jni_env->FindClass("android/content/Context");

  jfieldID audio_service_field = jni_env->GetStaticFieldID(

      context_class, "AUDIO_SERVICE", "Ljava/lang/String;");

  jstring jstr = (jstring)jni_env->GetStaticObjectField(context_class,

                                                        audio_service_field);

  jmethodID get_system_service_id =

      jni_env->GetMethodID(context_class, "getSystemService",

                           "(Ljava/lang/String;)Ljava/lang/Object;");

  jobject audio_manager_obj =

      jni_env->CallObjectMethod(ctx_obj, get_system_service_id, jstr);

  cubeb_jni_ptr->s_audio_manager_obj =

      reinterpret_cast<jobject>(jni_env->NewGlobalRef(audio_manager_obj));

  // Make the audio manager class a global reference in order to preserve method

  // id

  jclass audio_manager_class = jni_env->FindClass("android/media/AudioManager");

  cubeb_jni_ptr->s_audio_manager_class =

      reinterpret_cast<jclass>(jni_env->NewGlobalRef(audio_manager_class));

  cubeb_jni_ptr->s_get_output_latency_id =

      jni_env->GetMethodID(audio_manager_class, "getOutputLatency", "(I)I");

  jni_env->DeleteLocalRef(ctx_obj);

  jni_env->DeleteLocalRef(context_class);

  jni_env->DeleteLocalRef(jstr);

  jni_env->DeleteLocalRef(audio_manager_obj);

  jni_env->DeleteLocalRef(audio_manager_class);

  return cubeb_jni_ptr;

extern "C" int

cubeb_get_output_latency_from_jni(cubeb_jni * cubeb_jni_ptr)

  assert(cubeb_jni_ptr);

  JNIEnv * jni_env = cubeb_get_jni_env_for_thread();

  return jni_env->CallIntMethod(

      cubeb_jni_ptr->s_audio_manager_obj,

      cubeb_jni_ptr->s_get_output_latency_id,

      AUDIO_STREAM_TYPE_MUSIC); // param: AudioManager.STREAM_MUSIC

extern "C" void

cubeb_jni_destroy(cubeb_jni * cubeb_jni_ptr)

  assert(cubeb_jni_ptr);

  JNIEnv * jni_env = cubeb_get_jni_env_for_thread();

  assert(jni_env);

  jni_env->DeleteGlobalRef(cubeb_jni_ptr->s_audio_manager_obj);

  jni_env->DeleteGlobalRef(cubeb_jni_ptr->s_audio_manager_class);

  delete cubeb_jni_ptr;