1 /* clang-format off */
2 #include "jni.h"
3 #include <assert.h>
4 #include "cubeb-jni-instances.h"
5 /* clang-format on */
6
7 #define AUDIO_STREAM_TYPE_MUSIC 3
8
9 struct cubeb_jni {
10 jobject s_audio_manager_obj = nullptr;
11 jclass s_audio_manager_class = nullptr;
12 jmethodID s_get_output_latency_id = nullptr;
13 };
14
15 extern "C" cubeb_jni *
cubeb_jni_init()16 cubeb_jni_init()
17 {
18 jobject ctx_obj = cubeb_jni_get_context_instance();
19 JNIEnv * jni_env = cubeb_get_jni_env_for_thread();
20 if (!jni_env || !ctx_obj) {
21 return nullptr;
22 }
23
24 cubeb_jni * cubeb_jni_ptr = new cubeb_jni;
25 assert(cubeb_jni_ptr);
26
27 // Find the audio manager object and make it global to call it from another
28 // method
29 jclass context_class = jni_env->FindClass("android/content/Context");
30 jfieldID audio_service_field = jni_env->GetStaticFieldID(
31 context_class, "AUDIO_SERVICE", "Ljava/lang/String;");
32 jstring jstr = (jstring)jni_env->GetStaticObjectField(context_class,
33 audio_service_field);
34 jmethodID get_system_service_id =
35 jni_env->GetMethodID(context_class, "getSystemService",
36 "(Ljava/lang/String;)Ljava/lang/Object;");
37 jobject audio_manager_obj =
38 jni_env->CallObjectMethod(ctx_obj, get_system_service_id, jstr);
39 cubeb_jni_ptr->s_audio_manager_obj =
40 reinterpret_cast<jobject>(jni_env->NewGlobalRef(audio_manager_obj));
41
42 // Make the audio manager class a global reference in order to preserve method
43 // id
44 jclass audio_manager_class = jni_env->FindClass("android/media/AudioManager");
45 cubeb_jni_ptr->s_audio_manager_class =
46 reinterpret_cast<jclass>(jni_env->NewGlobalRef(audio_manager_class));
47 cubeb_jni_ptr->s_get_output_latency_id =
48 jni_env->GetMethodID(audio_manager_class, "getOutputLatency", "(I)I");
49
50 jni_env->DeleteLocalRef(ctx_obj);
51 jni_env->DeleteLocalRef(context_class);
52 jni_env->DeleteLocalRef(jstr);
53 jni_env->DeleteLocalRef(audio_manager_obj);
54 jni_env->DeleteLocalRef(audio_manager_class);
55
56 return cubeb_jni_ptr;
57 }
58
59 extern "C" int
cubeb_get_output_latency_from_jni(cubeb_jni * cubeb_jni_ptr)60 cubeb_get_output_latency_from_jni(cubeb_jni * cubeb_jni_ptr)
61 {
62 assert(cubeb_jni_ptr);
63 JNIEnv * jni_env = cubeb_get_jni_env_for_thread();
64 return jni_env->CallIntMethod(
65 cubeb_jni_ptr->s_audio_manager_obj,
66 cubeb_jni_ptr->s_get_output_latency_id,
67 AUDIO_STREAM_TYPE_MUSIC); // param: AudioManager.STREAM_MUSIC
68 }
69
70 extern "C" void
cubeb_jni_destroy(cubeb_jni * cubeb_jni_ptr)71 cubeb_jni_destroy(cubeb_jni * cubeb_jni_ptr)
72 {
73 assert(cubeb_jni_ptr);
74
75 JNIEnv * jni_env = cubeb_get_jni_env_for_thread();
76 assert(jni_env);
77
78 jni_env->DeleteGlobalRef(cubeb_jni_ptr->s_audio_manager_obj);
79 jni_env->DeleteGlobalRef(cubeb_jni_ptr->s_audio_manager_class);
80
81 delete cubeb_jni_ptr;
82 }
83