feat: Keep volume level across audio devices

SoundSwitch.Audio.Manager/AudioSwitcher.cs

@@ -177,6 +177,58 @@ public void SwitchForegroundProcessTo(string deviceId, ERole role, EDataFlow flo
             SwitchProcessTo(deviceId, role, flow, processId);
         }
 
+        /// <summary>
+        /// Set the same master volume level from the default audio device to the next device
+        /// </summary>
+        /// <param name="deviceId">Id of the device</param>
+        /// <param name="role">Which role to switch</param>
+        /// <param name="flow">Which flow to switch</param>
+        /// <summary>
+        /// Get the current default endpoint
+        /// </summary>
+        /// <param name="flow"></param>
+        /// <param name="role"></param>
+        /// <returns>Null if no default device is defined</returns>
+        private MMDevice? GetMmDefaultAudioEndpoint(EDataFlow flow, ERole role) => ComThread.Invoke(() => EnumeratorClient.GetDefaultEndpoint(flow, role));
+
+        /// <summary>
+        /// Set the same master volume level from the default audio device to the next device
+        /// </summary>
+        /// <param name="device"></param>
+        public void SetVolumeFromDefaultDevice(DeviceInfo device)
+        {
+            var currentDefault = GetMmDefaultAudioEndpoint((EDataFlow)device.Type, ERole.eConsole);
+            if (currentDefault == null)
+                return;
+            var audioInfo = InteractWithMmDevice(currentDefault, mmDevice =>
+            {
+                var defaultDeviceAudioEndpointVolume = mmDevice.AudioEndpointVolume;
+                return defaultDeviceAudioEndpointVolume == null ? default : (Volume: defaultDeviceAudioEndpointVolume.MasterVolumeLevelScalar, IsMuted: defaultDeviceAudioEndpointVolume.Mute);
+            });
+
+            if (audioInfo == default)
+                return;
+
+            var nextDevice = GetDevice(device.Id);
+
+            if(nextDevice == null)
+                return;
+
+            InteractWithMmDevice(nextDevice, mmDevice =>
+            {
+                if (mmDevice is not { State: DeviceState.Active })
+                    return nextDevice;
+
+                if (mmDevice.AudioEndpointVolume == null)
+                    return nextDevice;
+
+                mmDevice.AudioEndpointVolume.MasterVolumeLevelScalar = audioInfo.Volume;
+                mmDevice.AudioEndpointVolume.Mute = audioInfo.IsMuted;
+                return mmDevice;
+            });
+        }
+
+
         /// <summary>
         /// Is the given deviceId the default audio device in the system
         /// </summary>

SoundSwitch/Framework/Configuration/ISoundSwitchConfiguration.cs

@@ -91,5 +91,10 @@ public interface ISoundSwitchConfiguration : IConfiguration
         /// Is the quick menu showed when using a hotkey
         /// </summary>
         bool QuickMenuEnabled { get; set; }
+
+        /// <summary>
+        /// Is keep volume enabled
+        /// </summary>
+        bool KeepVolumeEnabled { get; set; }
     }
 }

SoundSwitch/Framework/Configuration/SoundSwitchConfiguration.cs

@@ -126,6 +126,11 @@ public SoundSwitchConfiguration()
         /// </summary>
         public bool QuickMenuEnabled { get; set; } = false;
 
+        /// <summary>
+        /// Is keep volume enabled
+        /// </summary>
+        public bool KeepVolumeEnabled { get; set; } = false;
+
         // Needed by Interface
         [JsonIgnore]
         public string FileLocation { get; set; }

SoundSwitch/Framework/DeviceCyclerManager/DeviceCycler/ADeviceCycler.cs

@@ -79,6 +79,11 @@ private DeviceInfo GetNextDevice(DeviceInfo[] audioDevices, DataFlow type)
         /// <param name="device"></param>
         public bool SetActiveDevice(DeviceInfo device)
         {
+            if (device.Type != DataFlow.Capture && AppModel.Instance.KeepVolumeEnabled)
+            {
+                AudioSwitcher.Instance.SetVolumeFromDefaultDevice(device);
+            }
+
             Log.Information("Set Default device: {Device}", device);
             if (!AppModel.Instance.SetCommunications)
             {

SoundSwitch/Localization/SettingsStrings.resx

@@ -477,14 +477,20 @@ Restore the state of the system when the application is closed.</value>
   <data name="telemetry" xml:space="preserve">
     <value>Telemetry</value>
   </data>
+  <data name="telemetry.desc" xml:space="preserve">
+    <value>Gather anonymously which version of SoundSwitch is in use. Only shared with the developer of SoundSwitch.</value>
+  </data>
   <data name="quickMenu" xml:space="preserve">
     <value>Quick Menu on hotkey</value>
   </data>
   <data name="quickMenu.desc" xml:space="preserve">
     <value>Show a quick menu like Windows language when using a hotkey</value>
   </data>
-  <data name="telemetry.desc" xml:space="preserve">
-    <value>Gather anonymously which version of SoundSwitch is in use. Only shared with the developer of SoundSwitch.</value>
+  <data name="keepVolume" xml:space="preserve">
+    <value>Keep volume level across devices</value>
+  </data>
+  <data name="keepVolume.desc" xml:space="preserve">
+    <value>Keep the same volume level when switching playback devices</value>
   </data>
   <data name="devices.AutoAddNewDevice" xml:space="preserve">
     <value>Auto select new devices</value>

SoundSwitch/Model/AppModel.cs

@@ -181,6 +181,15 @@ public bool QuickMenuEnabled
             }
         }
 
+        public bool KeepVolumeEnabled
+        {
+            get => AppConfigs.Configuration.KeepVolumeEnabled;
+            set
+            {
+                AppConfigs.Configuration.KeepVolumeEnabled = value;
+                AppConfigs.Configuration.Save();
+            }
+        }
 
         public DeviceCollection<DeviceInfo> SelectedDevices
         {

SoundSwitch/Model/IAppModel.cs

@@ -110,6 +110,7 @@ public interface IAppModel : IDisposable
 
         bool Telemetry { get; set; }
         bool QuickMenuEnabled { get; set; }
+        bool KeepVolumeEnabled { get; set; }
         bool AutoAddNewDevice { get; set; }
 
         #endregion