Simplify logic behind chrome.audio.setActiveDevices

extensions/common/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 {
@@ skipping 49 matching lines @@
     // 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;
   };
 
+  dictionary DeviceIdLists {
+    // <p>IDs of all input devices that should be active.</p>
+    // <p>
+    //   Only <b>existing input</b> device IDs will be accepted. If this is not
+    //   the case, the method will fail without updating active devices.
+    // </p>
+    DOMString[]? input;
+
+    // <p>IDs of all output devices that should be active.</p>
+    // <p>
+    //   Only <b>existing output</b> device IDs will be accepted. If this is not
+    //   the case, the method will fail without updating active devices.
+    // </p>
+    DOMString[]? output;
+  };
+
   callback GetInfoCallback = void(OutputDeviceInfo[] outputInfo,
                                   InputDeviceInfo[] inputInfo);
-  callback SetActiveDevicesCallback = void();
-  callback SetPropertiesCallback = void();
+  callback EmptyCallback = void();
 
   interface Functions {
     // Gets the information of all audio output and input devices.
     static void getInfo(GetInfoCallback callback);
 
-  // Sets the active devices to the devices specified by |ids|.
-  // It can pass in the "complete" active device id list of either input
-  // devices, or output devices, or both. If only input device ids are passed
-  // in, it will only change the input devices' active status, output devices will
-  // NOT be changed; similarly for the case if only output devices are passed.
-  // If the devices specified in |new_active_ids| are already active, they will
-  // remain active. Otherwise, the old active devices will be de-activated
-  // before we activate the new devices with the same type(input/output).
-    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);
-     };
+                              EmptyCallback callback);
+
+    // Sets lists of active input and/or output devices.
+    // |ids|: Specifies IDs of devices that should be active. The device IDs
+    //     are split on basis of the device's audio stream type. If list
+    //     for a particular stream direction is not set, set of active devices
+    //     with that stream direction will not be affected.
+    static void setActiveDeviceLists(DeviceIdLists ids, EmptyCallback callback);

[Devlin, 2017/01/13 16:11:00]

Could we instead update the signature of the current method (setActiveDevices)
and add a hook in the bindings and update the function impl to allow both
versions to work?  It'd be nice to avoid having two methods here, and
"setActiveDevices" is a friendlier name. :)

[tbarzic, 2017/01/13 18:52:49]

Yes. Or even better, we could define the first argument as union.

+
+    // Sets the active devices to the devices specified by |ids|.
+    // It can pass in the "complete" active device id list of either input
+    // devices, or output devices, or both. If only input device ids are passed
+    // in, it will only change the input devices' active status, output devices
+    // will *not* be changed; similarly for the case if only output devices are
+    // passed.
+    // If the devices specified in |new_active_ids| are already active, they
+    // will remain active. Otherwise, the old active devices will be
+    // de-activated before we activate the new devices with the same
+    // type(input/output).
+    [deprecated="Use $(ref:setActiveDeviceLists)"]
+    static void setActiveDevices(DOMString[] ids, EmptyCallback callback);
+  };
 
   interface Events {
     // Fired when anything changes to the audio device configuration.
     static void onDeviceChanged();
 
     // Fired when sound level changes for an active audio device.
     // |id|: id of the audio device.
     // |level|: new sound level of device(volume for output, gain for input).
     static void OnLevelChanged(DOMString id, long level);
 
     // Fired when the mute state of the audio input or output changes.
     // |isInput|: true indicating audio input; false indicating audio output.
     // |isMuted|: new value of mute state.
     static void OnMuteChanged(boolean isInput, boolean isMuted);
 
     // Fired when audio devices change, either new devices being added, or
     // existing devices being removed.
     // |devices|: List of all present audio devices after the change.
     static void OnDevicesChanged(AudioDeviceInfo[] devices);
   };
 };