chrome/browser/media/audio_stream_indicator.h

   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 CHROME_BROWSER_MEDIA_AUDIO_STREAM_INDICATOR_H_
   6 #define CHROME_BROWSER_MEDIA_AUDIO_STREAM_INDICATOR_H_
   7
   8 #include <map>
   9 #include <vector>
  10
  11 #include "base/memory/ref_counted.h"
  12
  13 namespace content {
  14 class WebContents;
  15 }
  16
  17 class AudioStreamIndicator
  18     : public base::RefCountedThreadSafe<AudioStreamIndicator> {
  19  public:
  20   AudioStreamIndicator();
  21
  22   // This method should be called on the IO thread.
  23   void UpdateWebContentsStatus(int render_process_id,
  24                                int render_view_id,
  25                                int stream_id,
  26                                bool is_playing,
  27                                float power_dbfs,
  28                                bool clipped);
  29
  30   // This method should be called on the UI thread.
  31   bool IsPlayingAudio(const content::WebContents* contents);
  32
  33   // Returns the audible |level| in the range [0.0,1.0], where 0.0 means the
  34   // audio signal is imperceivably silent and 1.0 means it is at maximum
  35   // volume.  |signal_has_clipped| is set to true if any part of the audio
  36   // signal has clipped since the last call to this method.
  37   //
  38   // This method should be called on the UI thread.
  39   void CurrentAudibleLevel(const content::WebContents* contents,
  40                            float* level, bool* signal_has_clipped);
  41
  42  private:
  43   // <render process ID, render view ID>
  44   // Note: Using std::pair<> to reduce binary-size bloat.
  45   typedef std::pair<int, int> RenderViewId;
  46   struct StreamPowerLevel {
  47     int stream_id;
  48     float power_dbfs;
  49     bool clipped;
  50   };
  51   typedef std::vector<StreamPowerLevel> StreamPowerLevels;
  52   // Container for the power levels of streams playing from each render view.
  53   typedef std::map<RenderViewId, StreamPowerLevels> RenderViewStreamMap;
  54
  55   friend class base::RefCountedThreadSafe<AudioStreamIndicator>;
  56   virtual ~AudioStreamIndicator();
  57
  58   void UpdateWebContentsStatusOnUIThread(int render_process_id,
  59                                          int render_view_id,
  60                                          int stream_id,
  61                                          bool is_playing,
  62                                          float power_dbfs,
  63                                          bool clipped);
  64
  65   RenderViewStreamMap audio_streams_;
  66 };
  67
  68 #endif  // CHROME_BROWSER_MEDIA_AUDIO_STREAM_INDICATOR_H_