AudioServer: Give the AudioClient a way to keep track of the main mix volume

Author: https://github.com/benit8
Commit: https://github.com/SerenityOS/serenity/commit/60a7187db27
Pull-request: https://github.com/SerenityOS/serenity/pull/2845
Reviewed-by: https://github.com/awesomekling

Libraries/LibAudio/ClientConnection.cpp

@@ -116,4 +116,10 @@ void ClientConnection::handle(const Messages::AudioClient::MutedStateChanged& me
         on_muted_state_change(message.muted());
 }
 
+void ClientConnection::handle(const Messages::AudioClient::MainMixVolumeChanged& message)
+{
+    if (on_main_mix_volume_change)
+        on_main_mix_volume_change(message.volume());
+}
+
 }

Libraries/LibAudio/ClientConnection.h

@@ -59,10 +59,12 @@ public:
 
     Function<void(i32 buffer_id)> on_finish_playing_buffer;
     Function<void(bool muted)> on_muted_state_change;
+    Function<void(int volume)> on_main_mix_volume_change;
 
 private:
     virtual void handle(const Messages::AudioClient::FinishedPlayingBuffer&) override;
     virtual void handle(const Messages::AudioClient::MutedStateChanged&) override;
+    virtual void handle(const Messages::AudioClient::MainMixVolumeChanged&) override;
 };
 
 }

Services/AudioServer/AudioClient.ipc

@@ -2,4 +2,5 @@ endpoint AudioClient = 82
 {
     FinishedPlayingBuffer(i32 buffer_id) =|
     MutedStateChanged(bool muted) =|
+    MainMixVolumeChanged(i32 volume) =|
 }

Services/AudioServer/ClientConnection.cpp

@@ -76,6 +76,11 @@ void ClientConnection::did_change_muted_state(Badge<Mixer>, bool muted)
     post_message(Messages::AudioClient::MutedStateChanged(muted));
 }
 
+void ClientConnection::did_change_main_mix_volume(Badge<Mixer>, int volume)
+{
+    post_message(Messages::AudioClient::MainMixVolumeChanged(volume));
+}
+
 OwnPtr<Messages::AudioServer::GreetResponse> ClientConnection::handle(const Messages::AudioServer::Greet&)
 {
     return make<Messages::AudioServer::GreetResponse>(client_id());

Services/AudioServer/ClientConnection.h

@@ -48,6 +48,7 @@ public:
 
     void did_finish_playing_buffer(Badge<BufferQueue>, int buffer_id);
     void did_change_muted_state(Badge<Mixer>, bool muted);
+    void did_change_main_mix_volume(Badge<Mixer>, int volume);
 
     virtual void die() override;
 

Services/AudioServer/Mixer.cpp

@@ -132,6 +132,14 @@ void Mixer::mix()
     }
 }
 
+void Mixer::set_main_volume(int volume)
+{
+    m_main_volume = volume;
+    ClientConnection::for_each([volume](ClientConnection& client) {
+        client.did_change_main_mix_volume({}, volume);
+    });
+}
+
 void Mixer::set_muted(bool muted)
 {
     if (m_muted == muted)

Services/AudioServer/Mixer.h

@@ -118,7 +118,7 @@ public:
     NonnullRefPtr<BufferQueue> create_queue(ClientConnection&);
 
     int main_volume() const { return m_main_volume; }
-    void set_main_volume(int volume) { m_main_volume = volume; }
+    void set_main_volume(int volume);
 
     bool is_muted() const { return m_muted; }
     void set_muted(bool);