chrome/common/extensions/api/audio.idl

// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// The <code>chrome.audio</code> API is provided to allow users to
// get information about and control the audio devices attached to the
// system. This API is currently only implemented for ChromeOS.
namespace audio {

  dictionary OutputDeviceInfo {
    // The unique identifier of the audio output device.
    DOMString id;
    // The user-friendly name (e.g. "Bose Amplifier").
    DOMString name;
    // True if this is the current active device.
    boolean isActive;
    // True if this is muted.
    boolean isMuted;
    // The output volume ranging from 0.0 to 1.0.
    double volume;
  };

  dictionary InputDeviceInfo {
    // The unique identifier of the audio input device.
    DOMString id;
    // The user-friendly name (e.g. "USB Microphone").
    DOMString name;
    // True if this is the current active device.
    boolean isActive;
    // True if this is muted.
    boolean isMuted;
    // The input gain ranging from 0.0 to 1.0.
    double gain;
  };

  dictionary DeviceProperties {
    // True if this is muted.
    boolean isMuted;
    // If this is an output device then this field indicates the output volume.
    // If this is an input device then this field is ignored.
    double? volume;
    // If this is an input device then this field indicates the input gain.
    // If this is an output device then this field is ignored.
    double? gain;
  };

  callback GetInfoCallback = void(OutputDeviceInfo[] outputInfo,
                                  InputDeviceInfo[] inputInfo);
  callback SetActiveDevicesCallback = void();
  callback SetPropertiesCallback = void();

  interface Functions {
    // Get the information of all audio output and input devices.
    static void getInfo(GetInfoCallback callback);

    // Select a subset of audio devices as active.
    static void setActiveDevices(DOMString[] ids,
                                 SetActiveDevicesCallback callback);

    // Sets the properties for the input or output device.
    static void setProperties(DOMString id,
                              DeviceProperties properties,
                              SetPropertiesCallback callback);
  };

  interface Events {
    // Fired when anything changes to the audio device configuration.
    static void onDeviceChanged();
  };
};