audiopolicy: Add notification when default effects are updated

 * In M, we now have the ability to define a default set of audio effect
   on a per-stream basis. This allows us to get around the problem of
   apps not sending the control intents so we can implement smart
   global effects for specific media types.
 * We still need a session id in order to get a handle and configure them
   from an app like AudioFX, so we'll need to add some plumbing in
   order to send an event to interested applications.
 * This patch implements the native side of this. The Java layer will
   call down thru AudioSystem and register a callback which will be
   invoked by the audio policy when default effects are updated on
   a stream. This callback will receive both the stream type as well
   as the session id.
 * Attaching this listener requires that the caller hold the
   MODIFY_AUDIO_ROUTING permission.

Change-Id: I142b15f2585ffca6a953c3e828e2a7c07b24f56c

4 files changed, 14 insertions, 0 deletions

diff --git a/include/media/AudioPolicy.h b/include/media/AudioPolicy.h
index feed402..5a82bae 100644
--- a/include/media/AudioPolicy.h
+++ b/include/media/AudioPolicy.h
@@ -42,6 +42,7 @@ namespace android {
 //   AudioSystem's implementation of the AudioPolicyClient interface
 // keep in sync with AudioSystem.java
 #define DYNAMIC_POLICY_EVENT_MIX_STATE_UPDATE 0
+#define AUDIO_OUTPUT_SESSION_EFFECTS_UPDATE 10
 
 #define MIX_STATE_DISABLED -1
 #define MIX_STATE_IDLE 0
diff --git a/include/media/AudioSystem.h b/include/media/AudioSystem.h
index 26a0bb2..35b06ba 100644
--- a/include/media/AudioSystem.h
+++ b/include/media/AudioSystem.h
@@ -31,6 +31,8 @@ namespace android {
 
 typedef void (*audio_error_callback)(status_t err);
 typedef void (*dynamic_policy_callback)(int event, String8 regId, int val);
+typedef void (*effect_session_callback)(int event,
+        audio_stream_type_t stream, audio_unique_id_t sessionId, bool added);
 
 class IAudioFlinger;
 class IAudioPolicyService;
@@ -92,6 +94,7 @@ public:
 
     static void setErrorCallback(audio_error_callback cb);
     static void setDynPolicyCallback(dynamic_policy_callback cb);
+    static status_t setEffectSessionCallback(effect_session_callback cb);
 
     // helper function to obtain AudioFlinger service handle
     static const sp<IAudioFlinger> get_audio_flinger();
@@ -419,6 +422,9 @@ private:
         virtual void onAudioPortListUpdate();
         virtual void onAudioPatchListUpdate();
         virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state);
+        virtual void onOutputSessionEffectsUpdate(audio_stream_type_t stream,
+                                                  audio_unique_id_t sessionId,
+                                                  bool added);
 
     private:
         Mutex                               mLock;
@@ -438,6 +444,7 @@ private:
     static sp<IAudioFlinger> gAudioFlinger;
     static audio_error_callback gAudioErrorCallback;
     static dynamic_policy_callback gDynPolicyCallback;
+    static effect_session_callback gEffectSessionCallback;
 
     static size_t gInBuffSize;
     // previous parameters for recording buffer size queries
diff --git a/include/media/IAudioPolicyService.h b/include/media/IAudioPolicyService.h
index 6b93f6f..3a7bd68 100644
--- a/include/media/IAudioPolicyService.h
+++ b/include/media/IAudioPolicyService.h
@@ -165,6 +165,8 @@ public:
                                       const audio_attributes_t *attributes,
                                       audio_io_handle_t *handle) = 0;
     virtual status_t stopAudioSource(audio_io_handle_t handle) = 0;
+
+    virtual status_t setEffectSessionCallbacksEnabled(bool enabled) = 0;
 };
 
 
diff --git a/include/media/IAudioPolicyServiceClient.h b/include/media/IAudioPolicyServiceClient.h
index a7f2cc3..3bdeb5a 100644
--- a/include/media/IAudioPolicyServiceClient.h
+++ b/include/media/IAudioPolicyServiceClient.h
@@ -37,6 +37,10 @@ public:
     virtual void onAudioPatchListUpdate() = 0;
     // Notifies a change in the mixing state of a specific mix in a dynamic audio policy
     virtual void onDynamicPolicyMixStateUpdate(String8 regId, int32_t state) = 0;
+    // Notifies when a default effect set is attached to a session/stream
+    virtual void onOutputSessionEffectsUpdate(audio_stream_type_t stream,
+                                              audio_unique_id_t sessionId,
+                                              bool added) = 0;
 };