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1 // Copyright (c) 2015 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 #ifndef MEDIA_BASE_OUTPUT_DEVICE_H_ | |
6 #define MEDIA_BASE_OUTPUT_DEVICE_H_ | |
7 | |
8 #include <string> | |
9 | |
10 #include "base/callback.h" | |
11 #include "media/audio/audio_parameters.h" | |
12 #include "media/base/media_export.h" | |
13 #include "url/origin.h" | |
14 | |
15 namespace media { | |
16 | |
17 // Result of an audio output device switch operation | |
18 enum OutputDeviceStatus { | |
19 OUTPUT_DEVICE_STATUS_OK = 0, | |
20 OUTPUT_DEVICE_STATUS_ERROR_NOT_FOUND, | |
21 OUTPUT_DEVICE_STATUS_ERROR_NOT_AUTHORIZED, | |
22 OUTPUT_DEVICE_STATUS_ERROR_INTERNAL, | |
23 OUTPUT_DEVICE_STATUS_LAST = OUTPUT_DEVICE_STATUS_ERROR_INTERNAL, | |
24 }; | |
25 | |
26 typedef base::Callback<void(OutputDeviceStatus)> SwitchOutputDeviceCB; | |
27 | |
28 // OutputDevice is an interface that allows performing operations related | |
29 // audio output devices. | |
30 | |
31 class OutputDevice { | |
32 public: | |
33 // Attempts to switch the audio output device. | |
34 // Once the attempt is finished, |callback| is invoked with the | |
35 // result of the operation passed as a parameter. The result is a value from | |
36 // the media::SwitchOutputDeviceResult enum. | |
37 // There is no guarantee about the thread where |callback| will | |
38 // be invoked, so users are advised to use media::BindToCurrentLoop() to | |
39 // ensure that |callback| runs on the correct thread. | |
40 // Note also that copy constructors and destructors for arguments bound to | |
41 // |callback| may run on arbitrary threads as |callback| is moved across | |
42 // threads. It is advisable to bind arguments such that they are released by | |
43 // |callback| when it runs in order to avoid surprises. | |
44 virtual void SwitchOutputDevice(const std::string& device_id, | |
45 const url::Origin& security_origin, | |
46 const SwitchOutputDeviceCB& callback) = 0; | |
47 | |
48 // Returns the device's audio output parameters. | |
49 // The return value is undefined if the device status (as returned by | |
50 // GetDeviceStatus()) is different from OUTPUT_DEVICE_STATUS_OK. | |
51 // If the parameters are not available, this method may block until they | |
52 // become available. | |
53 // This method must never be called on the IO thread. | |
54 virtual AudioParameters GetOutputParameters() = 0; | |
55 | |
56 // Returns the status of output device. | |
57 // If the status is not available, this method may block until it becomes | |
58 // available. Must never be called on the IO thread. | |
59 virtual OutputDeviceStatus GetDeviceStatus() = 0; | |
60 | |
61 protected: | |
62 virtual ~OutputDevice() {} | |
63 }; | |
64 | |
65 } // namespace media | |
66 | |
67 #endif // MEDIA_BASE_OUTPUT_DEVICE_H_ | |
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