1 // Copyright (c) 2012 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 CONTENT_PUBLIC_BROWSER_MEDIA_OBSERVER_H_ 6 #define CONTENT_PUBLIC_BROWSER_MEDIA_OBSERVER_H_ 7 8 #include "base/callback_forward.h" 9 #include "content/public/browser/media_request_state.h" 10 #include "content/public/common/media_stream_request.h" 11 12 namespace content { 13 14 // An embedder may implement MediaObserver and return it from 15 // ContentBrowserClient to receive callbacks as media events occur. 16 class MediaObserver { 17 public: 18 // Called when a audio capture device is plugged in or unplugged. 19 virtual void OnAudioCaptureDevicesChanged() = 0; 20 21 // Called when a video capture device is plugged in or unplugged. 22 virtual void OnVideoCaptureDevicesChanged() = 0; 23 24 // Called when a media request changes state. 25 virtual void OnMediaRequestStateChanged( 26 int render_process_id, 27 int render_view_id, 28 int page_request_id, 29 const GURL& security_origin, 30 const MediaStreamDevice& device, 31 MediaRequestState state) = 0; 32 33 // Called when an audio stream is being created. 34 virtual void OnCreatingAudioStream(int render_process_id, 35 int render_frame_id) = 0; 36 37 // Called when an audio stream transitions into a playing state. 38 // |power_read_callback| is a thread-safe callback, provided for polling the 39 // current audio signal power level, and any copies/references to it must be 40 // destroyed when OnAudioStreamStopped() is called. 41 // 42 // The callback returns the current power level (in dBFS units) and the clip 43 // status (true if any part of the audio signal has clipped since the last 44 // callback run). See media/audio/audio_power_monitor.h for more info. 45 typedef base::Callback<std::pair<float, bool>()> ReadPowerAndClipCallback; 46 virtual void OnAudioStreamPlaying( 47 int render_process_id, 48 int render_frame_id, 49 int stream_id, 50 const ReadPowerAndClipCallback& power_read_callback) = 0; 51 52 // Called when an audio stream has stopped. 53 virtual void OnAudioStreamStopped( 54 int render_process_id, 55 int render_frame_id, 56 int stream_id) = 0; 57 58 protected: 59 virtual ~MediaObserver() {} 60 }; 61 62 } // namespace content 63 64 #endif // CONTENT_PUBLIC_BROWSER_MEDIA_OBSERVER_H_ 65
