| // Copyright 2017 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef CHROMECAST_MEDIA_CMA_BACKEND_CAST_AUDIO_JSON_H_ |
| #define CHROMECAST_MEDIA_CMA_BACKEND_CAST_AUDIO_JSON_H_ |
| |
| #include "base/files/file_path.h" |
| #include "base/files/file_path_watcher.h" |
| #include "base/functional/callback.h" |
| #include "base/memory/scoped_refptr.h" |
| #include "base/threading/sequence_bound.h" |
| #include "base/values.h" |
| #include "third_party/abseil-cpp/absl/types/optional.h" |
| |
| namespace chromecast { |
| namespace media { |
| |
| class CastAudioJson { |
| public: |
| // Returns GetFilePathForTuning() if a file exists at that path, otherwise |
| // returns GetReadOnlyFilePath(). |
| static base::FilePath GetFilePath(); |
| static base::FilePath GetReadOnlyFilePath(); |
| static base::FilePath GetFilePathForTuning(); |
| }; |
| |
| // Provides an interface for reading CastAudioJson and registering for file |
| // updates. |
| class CastAudioJsonProvider { |
| public: |
| using TuningChangedCallback = |
| base::RepeatingCallback<void(absl::optional<base::Value::Dict> contents)>; |
| |
| virtual ~CastAudioJsonProvider() = default; |
| |
| // Returns the contents of cast_audio.json. |
| // If a file exists at CastAudioJson::GetFilePathForTuning() and is valid |
| // JSON, its contents will be returned. Otherwise, the contents of the file |
| // at CastAudioJson::GetReadOnlyFilePath() will be returned. |
| // This function will run on the thread on which it is called, and may |
| // perform blocking I/O. |
| virtual absl::optional<base::Value::Dict> GetCastAudioConfig() = 0; |
| |
| // |callback| will be called when a new cast_audio config is available. |
| // |callback| will always be called from the same thread, but not necessarily |
| // the same thread on which |SetTuningChangedCallback| is called. |
| virtual void SetTuningChangedCallback(TuningChangedCallback callback) = 0; |
| }; |
| |
| class CastAudioJsonProviderImpl : public CastAudioJsonProvider { |
| public: |
| CastAudioJsonProviderImpl(); |
| |
| CastAudioJsonProviderImpl(const CastAudioJsonProviderImpl&) = delete; |
| CastAudioJsonProviderImpl& operator=(const CastAudioJsonProviderImpl&) = |
| delete; |
| |
| ~CastAudioJsonProviderImpl() override; |
| |
| private: |
| class FileWatcher { |
| public: |
| FileWatcher(); |
| ~FileWatcher(); |
| |
| void SetTuningChangedCallback(TuningChangedCallback callback); |
| |
| private: |
| base::FilePathWatcher watcher_; |
| }; |
| |
| // CastAudioJsonProvider implementation: |
| absl::optional<base::Value::Dict> GetCastAudioConfig() override; |
| void SetTuningChangedCallback(TuningChangedCallback callback) override; |
| |
| base::SequenceBound<FileWatcher> cast_audio_watcher_; |
| }; |
| |
| } // namespace media |
| } // namespace chromecast |
| |
| #endif // CHROMECAST_MEDIA_CMA_BACKEND_CAST_AUDIO_JSON_H_ |