1 // Copyright 2016 The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 //
15 
16 // Main loop of the brillo audio service.
17 
18 #ifndef BRILLO_AUDIO_AUDIOSERVICE_AUDIO_DAEMON_H_
19 #define BRILLO_AUDIO_AUDIOSERVICE_AUDIO_DAEMON_H_
20 
21 #include <memory>
22 #include <stack>
23 #include <vector>
24 
25 #include <base/files/file.h>
26 #include <base/memory/weak_ptr.h>
27 #include <brillo/binder_watcher.h>
28 #include <brillo/daemons/daemon.h>
29 #include <media/IAudioPolicyService.h>
30 
31 #include "audio_device_handler.h"
32 #include "audio_volume_handler.h"
33 #include "brillo_audio_service.h"
34 
35 namespace brillo {
36 
37 class AudioDaemon : public Daemon {
38  public:
AudioDaemon()39   AudioDaemon() {}
40   virtual ~AudioDaemon();
41 
42  protected:
43   // Initialize the audio daemon handlers and start pollig the files in
44   // /dev/input.
45   int OnInit() override;
46 
47  private:
48   friend class AudioDaemonTest;
49   FRIEND_TEST(AudioDaemonTest, RegisterService);
50   FRIEND_TEST(AudioDaemonTest, TestAPSConnectInitializesHandlersOnlyOnce);
51   FRIEND_TEST(AudioDaemonTest, TestDeviceCallbackInitializesBASIfNULL);
52 
53   // Callback function for input events. Events are handled by the audio device
54   // handler.
55   void EventCallback(base::File* file);
56 
57   // Callback function for device state changes. Events are handler by the
58   // audio service.
59   //
60   // |mode| is kDevicesConnected when |devices| are connected.
61   // |devices| is a vector of integers representing audio_devices_t.
62   void DeviceCallback(AudioDeviceHandler::DeviceConnectionState,
63                       const std::vector<int>& devices);
64 
65   // Callback function when volume changes.
66   //
67   // |stream| is an audio_stream_type_t representing the stream.
68   // |previous_index| is the volume index before the key press.
69   // |current_index| is the volume index after the key press.
70   void VolumeCallback(audio_stream_type_t stream,
71                       int previous_index,
72                       int current_index);
73 
74   // Callback function for audio policy service death notification.
75   void OnAPSDisconnected();
76 
77   // Connect to the audio policy service and register a callback to be invoked
78   // if the audio policy service dies.
79   void ConnectToAPS();
80 
81   // Register the brillo audio service with the service manager.
82   void InitializeBrilloAudioService();
83 
84   // Initialize all audio daemon handlers.
85   //
86   // Note: This can only occur after we have connected to the audio policy
87   // service.
88   virtual void InitializeHandlers();
89 
90   // Store the file objects that are created during initialization for the files
91   // being polled. This is done so these objects can be freed when the
92   // AudioDaemon object is destroyed.
93   std::stack<base::File> files_;
94   // Handler for audio device input events.
95   std::shared_ptr<AudioDeviceHandler> audio_device_handler_;
96   // Handler for volume key press input events.
97   std::shared_ptr<AudioVolumeHandler> audio_volume_handler_;
98   // Used to generate weak_ptr to AudioDaemon for use in base::Bind.
99   base::WeakPtrFactory<AudioDaemon> weak_ptr_factory_{this};
100   // Pointer to the audio policy service.
101   android::sp<android::IAudioPolicyService> aps_;
102   // Flag to indicate whether the handlers have been initialized.
103   bool handlers_initialized_ = false;
104   // Binder watcher to watch for binder messages.
105   BinderWatcher binder_watcher_;
106   // Brillo audio service. Used for scheduling callbacks to clients.
107   android::sp<BrilloAudioService> brillo_audio_service_;
108 };
109 
110 }  // namespace brillo
111 
112 #endif  // BRILLO_AUDIO_AUDIOSERVICE_AUDIO_DAEMON_H_
113