Bug 1624322 - Add a method to get the default device for a side in CubebDeviceEnumerator. r=achronop

Differential Revision: https://phabricator.services.mozilla.com/D68083

--HG--
extra : moz-landing-system : lando

dom/media/webrtc/CubebDeviceEnumerator.cpp

@@ -243,9 +243,9 @@ already_AddRefed<AudioDeviceInfo> CubebDeviceEnumerator::DeviceInfoFromID(
   if (mInputDevices.IsEmpty() || mManualInputInvalidation) {
     EnumerateAudioDevices(Side::INPUT);
   }
-  for (uint32_t i = 0; i < mInputDevices.Length(); i++) {
-    if (mInputDevices[i]->DeviceID() == aID) {
-      RefPtr<AudioDeviceInfo> other = mInputDevices[i];
+  for (RefPtr<AudioDeviceInfo>& device : mInputDevices) {
+    if (device->DeviceID() == aID) {
+      RefPtr<AudioDeviceInfo> other = device;
       return other.forget();
     }
   }
@@ -253,9 +253,9 @@ already_AddRefed<AudioDeviceInfo> CubebDeviceEnumerator::DeviceInfoFromID(
   if (mOutputDevices.IsEmpty() || mManualOutputInvalidation) {
     EnumerateAudioDevices(Side::OUTPUT);
   }
-  for (uint32_t i = 0; i < mOutputDevices.Length(); i++) {
-    if (mOutputDevices[i]->DeviceID() == aID) {
-      RefPtr<AudioDeviceInfo> other = mOutputDevices[i];
+  for (RefPtr<AudioDeviceInfo>& device : mOutputDevices) {
+    if (device->DeviceID() == aID) {
+      RefPtr<AudioDeviceInfo> other = device;
       return other.forget();
     }
   }
@@ -283,9 +283,30 @@ already_AddRefed<AudioDeviceInfo> CubebDeviceEnumerator::DeviceInfoFromName(
   if (devices.IsEmpty() || manualInvalidation) {
     EnumerateAudioDevices(aSide);
   }
-  for (uint32_t i = 0; i < devices.Length(); i++) {
-    if (devices[i]->Name().Equals(aName)) {
-      RefPtr<AudioDeviceInfo> other = devices[i];
+  for (RefPtr<AudioDeviceInfo>& device : devices) {
+    if (device->Name().Equals(aName)) {
+      RefPtr<AudioDeviceInfo> other = device;
+      return other.forget();
+    }
+  }
+
+  return nullptr;
+}
+
+RefPtr<AudioDeviceInfo> CubebDeviceEnumerator::DefaultDevice(Side aSide) {
+  MutexAutoLock lock(mMutex);
+
+  nsTArray<RefPtr<AudioDeviceInfo>>& devices =
+      (aSide == Side::INPUT) ? mInputDevices : mOutputDevices;
+  bool manualInvalidation = (aSide == Side::INPUT) ? mManualInputInvalidation
+                                                   : mManualOutputInvalidation;
+
+  if (devices.IsEmpty() || manualInvalidation) {
+    EnumerateAudioDevices(aSide);
+  }
+  for (RefPtr<AudioDeviceInfo>& device : devices) {
+    if (device->Preferred()) {
+      RefPtr<AudioDeviceInfo> other = device;
       return other.forget();
     }
   }

dom/media/webrtc/CubebDeviceEnumerator.h

@@ -54,6 +54,9 @@ class CubebDeviceEnumerator final {
     return mOnOutputDeviceListChange;
   }
 
+  // Return the default device for a particular side.
+  RefPtr<AudioDeviceInfo> DefaultDevice(Side aSide);
+
  private:
   CubebDeviceEnumerator();
   ~CubebDeviceEnumerator();