Add helpers for getting selected radio button of group

BizHawk.Client.EmuHawk/config/DisplayConfig.Designer.cs

@@ -190,6 +190,7 @@
 			// 
 			this.rbDispMethodOpenGL.Checked = true;
 			this.rbDispMethodOpenGL.Name = "rbDispMethodOpenGL";
+			this.rbDispMethodOpenGL.Tag = BizHawk.Client.Common.EDispMethod.OpenGL;
 			this.rbDispMethodOpenGL.Text = "OpenGL";
 			// 
 			// lblDispMethodOpenGL
@@ -427,6 +428,7 @@
 			// rbARSquare
 			// 
 			this.rbARSquare.Name = "rbARSquare";
+			this.rbARSquare.Tag = BizHawk.Client.Common.EDispManagerAR.None;
 			this.rbARSquare.Text = "Use 1:1 pixel size (for crispness or debugging)";
 			this.rbARSquare.CheckedChanged += new System.EventHandler(this.rbARSquare_CheckedChanged);
 			// 
@@ -438,6 +440,7 @@
 			// rbARBySystem
 			// 
 			this.rbARBySystem.Name = "rbARBySystem";
+			this.rbARBySystem.Tag = BizHawk.Client.Common.EDispManagerAR.System;
 			this.rbARBySystem.Text = "Use system\'s recommendation";
 			this.rbARBySystem.CheckedChanged += new System.EventHandler(this.rbARBySystem_CheckedChanged);
 			// 
@@ -452,6 +455,7 @@
 			// rbARCustomSize
 			// 
 			this.rbARCustomSize.Name = "rbARCustomSize";
+			this.rbARCustomSize.Tag = BizHawk.Client.Common.EDispManagerAR.Custom;
 			this.rbARCustomSize.Text = "Use custom size:";
 			// 
 			// txtARCustomWidth
@@ -480,6 +484,7 @@
 			// rbARCustomRatio
 			// 
 			this.rbARCustomRatio.Name = "rbARCustomRatio";
+			this.rbARCustomRatio.Tag = BizHawk.Client.Common.EDispManagerAR.CustomRatio;
 			this.rbARCustomRatio.Text = "Use custom AR:";
 			// 
 			// txtARCustomRatioH
@@ -616,6 +621,7 @@
 			// 
 			this.rbDispMethodD3D.Checked = true;
 			this.rbDispMethodD3D.Name = "rbDispMethodD3D";
+			this.rbDispMethodD3D.Tag = BizHawk.Client.Common.EDispMethod.SlimDX9;
 			this.rbDispMethodD3D.Text = "Direct3D9";
 			// 
 			// lblDispMethodD3D
@@ -649,6 +655,7 @@
 			// 
 			this.rbDispMethodGDIPlus.Checked = true;
 			this.rbDispMethodGDIPlus.Name = "rbDispMethodGDIPlus";
+			this.rbDispMethodGDIPlus.Tag = BizHawk.Client.Common.EDispMethod.GdiPlus;
 			this.rbDispMethodGDIPlus.Text = "GDI+";
 			// 
 			// lblDispMethodGDIPlus

BizHawk.Client.EmuHawk/config/DisplayConfig.cs

@@ -130,14 +130,7 @@ namespace BizHawk.Client.EmuHawk
 			if (rbDispFeaturesMinimal.Checked) _config.DispSpeedupFeatures = 1;
 			if (rbDispFeaturesNothing.Checked) _config.DispSpeedupFeatures = 0;
 
-			if (rbARSquare.Checked)
+			_config.DispManagerAR = grpAspectRatio.Tracker.GetSelectionTagAs<EDispManagerAR>() ?? throw new InvalidOperationException();
-				_config.DispManagerAR = EDispManagerAR.None;
-			else if (rbARBySystem.Checked)
-				_config.DispManagerAR = EDispManagerAR.System;
-			else if (rbARCustomSize.Checked)
-				_config.DispManagerAR = EDispManagerAR.Custom;
-			else if (rbARCustomRatio.Checked)
-				_config.DispManagerAR = EDispManagerAR.CustomRatio;
 
 			if (string.IsNullOrWhiteSpace(txtARCustomWidth.Text))
 			{
@@ -188,12 +181,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 
 			var oldDisplayMethod = _config.DispMethod;
-			if(rbDispMethodOpenGL.Checked)
+			_config.DispMethod = grpDispMethod.Tracker.GetSelectionTagAs<EDispMethod>() ?? throw new InvalidOperationException();
-				_config.DispMethod = EDispMethod.OpenGL;
-			if(rbDispMethodGDIPlus.Checked)
-				_config.DispMethod = EDispMethod.GdiPlus;
-			if(rbDispMethodD3D.Checked)
-				_config.DispMethod = EDispMethod.SlimDX9;
 
 			if (int.TryParse(txtCropLeft.Text, out int dispCropLeft))
 			{

BizHawk.Client.EmuHawk/config/EmuHawkOptions.Designer.cs

@@ -478,11 +478,13 @@
 			// rbKopiLua
 			// 
 			this.rbKopiLua.Name = "rbKopiLua";
+			this.rbKopiLua.Tag = BizHawk.Client.Common.ELuaEngine.NLuaPlusKopiLua;
 			this.rbKopiLua.Text = "NLua+KopiLua - Reliable but slower";
 			// 
 			// rbLuaInterface
 			// 
 			this.rbLuaInterface.Name = "rbLuaInterface";
+			this.rbLuaInterface.Tag = BizHawk.Client.Common.ELuaEngine.LuaPlusLuaInterface;
 			this.rbLuaInterface.Text = "Lua+LuaInterface - Faster but memory leaks,  use at your own risk!";
 			// 
 			// flpDialogButtons

BizHawk.Client.EmuHawk/config/EmuHawkOptions.cs

@@ -118,14 +118,7 @@ namespace BizHawk.Client.EmuHawk
 			_config.MoviesInAwe = cbMoviesInAWE.Checked;
 
 			var prevLuaEngine = _config.LuaEngine;
-			if (rbLuaInterface.Checked)
+			_config.LuaEngine = grpLuaEngine.Tracker.GetSelectionTagAs<ELuaEngine>() ?? throw new InvalidOperationException();
-			{
-				_config.LuaEngine = ELuaEngine.LuaPlusLuaInterface;
-			}
-			else if (rbKopiLua.Checked)
-			{
-				_config.LuaEngine = ELuaEngine.NLuaPlusKopiLua;
-			}
 
 			_mainForm.AddOnScreenMessage("Custom configurations saved.");
 			if (prevLuaEngine != _config.LuaEngine)

BizHawk.Client.EmuHawk/config/SoundConfig.Designer.cs

@@ -288,18 +288,21 @@
 			// rbSoundMethodDirectSound
 			// 
 			this.rbSoundMethodDirectSound.Name = "rbSoundMethodDirectSound";
+			this.rbSoundMethodDirectSound.Tag = BizHawk.Client.Common.ESoundOutputMethod.DirectSound;
 			this.rbSoundMethodDirectSound.Text = "DirectSound";
 			this.rbSoundMethodDirectSound.CheckedChanged += new System.EventHandler(this.rbSoundMethodAllRadios_CheckedChanged);
 			// 
 			// rbSoundMethodXAudio2
 			// 
 			this.rbSoundMethodXAudio2.Name = "rbSoundMethodXAudio2";
+			this.rbSoundMethodXAudio2.Tag = BizHawk.Client.Common.ESoundOutputMethod.XAudio2;
 			this.rbSoundMethodXAudio2.Text = "XAudio2";
 			this.rbSoundMethodXAudio2.CheckedChanged += new System.EventHandler(this.rbSoundMethodAllRadios_CheckedChanged);
 			// 
 			// rbSoundMethodOpenAL
 			// 
 			this.rbSoundMethodOpenAL.Name = "rbSoundMethodOpenAL";
+			this.rbSoundMethodOpenAL.Tag = BizHawk.Client.Common.ESoundOutputMethod.OpenAL;
 			this.rbSoundMethodOpenAL.Text = "OpenAL";
 			this.rbSoundMethodOpenAL.CheckedChanged += new System.EventHandler(this.rbSoundMethodAllRadios_CheckedChanged);
 			// 

BizHawk.Client.EmuHawk/config/SoundConfig.cs

@@ -62,9 +62,7 @@ namespace BizHawk.Client.EmuHawk
 			_config.SoundEnabledNormal = cbFullSpeedEnable.Checked;
 			_config.SoundEnabledRWFF = cbRewindFFWEnable.Checked;
 			_config.MuteFrameAdvance = cbMuteFrameAdvance.Checked;
-			if (rbSoundMethodDirectSound.Checked) _config.SoundOutputMethod = ESoundOutputMethod.DirectSound;
+			_config.SoundOutputMethod = grpSoundMethod.Tracker.GetSelectionTagAs<ESoundOutputMethod>() ?? ESoundOutputMethod.Dummy;
-			if (rbSoundMethodXAudio2.Checked) _config.SoundOutputMethod = ESoundOutputMethod.XAudio2;
-			if (rbSoundMethodOpenAL.Checked) _config.SoundOutputMethod = ESoundOutputMethod.OpenAL;
 			_config.SoundBufferSizeMs = (int)nudBufferSize.Value;
 			_config.SoundVolume = tbFullSpeedVolume.Value;
 			_config.SoundVolumeRWFF = tbRewindFFWVolume.Value;

BizHawk.WinForms.Controls/GroupBoxEx/ITrackedRadioButton.cs

@@ -7,6 +7,8 @@ namespace BizHawk.WinForms.Controls
 
 		string Name { get; }
 
+		object Tag { get; }
+
 		void UncheckFromTracker();
 	}
 }

BizHawk.WinForms.Controls/GroupBoxEx/RadioButtonGroupTracker.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.Windows.Forms;
 
@@ -12,6 +13,20 @@ namespace BizHawk.WinForms.Controls
 	/// <inheritdoc cref="IRadioButtonReadOnlyTracker"/>
 	public sealed class RadioButtonGroupTracker : List<ITrackedRadioButton>, IRadioButtonReadOnlyTracker
 	{
+		/// <value>The selected radio button, or <see langword="null"/> if no button is selected or if the collection is empty.</value>
+		public ITrackedRadioButton? Selection
+		{
+			get
+			{
+				if (Count == 0) return null;
+				foreach (var rb in this) if (rb.Checked) return rb;
+				return null;
+			}
+		}
+
+		/// <returns>The <see cref="Control.Tag"/> of the selected radio button, cast to <typeparamref name="T"/><c>?</c>, or <see langword="null"/> if no button is selected or if the collection is empty.</returns>
+		public T? GetSelectionTagAs<T>() where T : struct, Enum => (T?) Selection?.Tag;
+
 		public void UpdateDeselected(string name)
 		{
 			foreach (var rb in this) if (rb.Name != name) rb.UncheckFromTracker();