extensions/common/api/audio.idl

   1 // Copyright (c) 2013 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 // The <code>chrome.audio</code> API is provided to allow users to
   6 // get information about and control the audio devices attached to the
   7 // system. This API is currently only implemented for ChromeOS.
   8 namespace audio {
   9
  10   dictionary OutputDeviceInfo {
  11     // The unique identifier of the audio output device.
  12     DOMString id;
  13     // The user-friendly name (e.g. "Bose Amplifier").
  14     DOMString name;
  15     // True if this is the current active device.
  16     boolean isActive;
  17     // True if this is muted.
  18     boolean isMuted;
  19     // The output volume ranging from 0.0 to 100.0.
  20     double volume;
  21   };
  22
  23   dictionary InputDeviceInfo {
  24     // The unique identifier of the audio input device.
  25     DOMString id;
  26     // The user-friendly name (e.g. "USB Microphone").
  27     DOMString name;
  28     // True if this is the current active device.
  29     boolean isActive;
  30     // True if this is muted.
  31     boolean isMuted;
  32     // The input gain ranging from 0.0 to 100.0.
  33     double gain;
  34   };
  35
  36   dictionary DeviceProperties {
  37     // True if this is muted.
  38     boolean isMuted;
  39     // If this is an output device then this field indicates the output volume.
  40     // If this is an input device then this field is ignored.
  41     double? volume;
  42     // If this is an input device then this field indicates the input gain.
  43     // If this is an output device then this field is ignored.
  44     double? gain;
  45   };
  46
  47   callback GetInfoCallback = void(OutputDeviceInfo[] outputInfo,
  48                                   InputDeviceInfo[] inputInfo);
  49   callback SetActiveDevicesCallback = void();
  50   callback SetPropertiesCallback = void();
  51
  52   interface Functions {
  53     // Gets the information of all audio output and input devices.
  54     static void getInfo(GetInfoCallback callback);
  55
  56   // Sets the active nodes to the nodes specified by |ids|.
  57   // It can pass in the "complete" active node id list of either input
  58   // nodes, or output nodes, or both. If only input node ids are passed in,
  59   // it will only change the input nodes' active status, output nodes will NOT
  60   // be changed; similarly for the case if only output nodes are passed.
  61   // If the nodes specified in |new_active_ids| are already active, they will
  62   // remain active. Otherwise, the old active nodes will be de-activated before
  63   // we activate the new nodes with the same type(input/output).
  64     static void setActiveDevices(DOMString[] ids,
  65                                  SetActiveDevicesCallback callback);
  66
  67     // Sets the properties for the input or output device.
  68     static void setProperties(DOMString id,
  69                               DeviceProperties properties,
  70                               SetPropertiesCallback callback);
  71      };
  72
  73   interface Events {
  74     // Fired when anything changes to the audio device configuration.
  75     static void onDeviceChanged();
  76
  77     // Fired when sound level changes for an active audio node.
  78     // |id|: id of the audio node.
  79     // |level|: new sound level of the node(volume for output, gain for input).
  80     static void OnLevelChanged(DOMString id, long level);
  81   };
  82 };