Allow left/right modifier keys to be used separately (no UI)

Should allow for any key to be used as a modifier (see #2981), simply by
populating `Config.ModifierKeys`. Flip the assignment on `Input.cs:45` to try
out this change specifically.

src/BizHawk.Client.Common/config/Config.cs

@@ -5,6 +5,8 @@ using BizHawk.Common;
 using BizHawk.Common.PathExtensions;
 using BizHawk.Emulation.Common;
 using BizHawk.Emulation.Cores;
+
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
 namespace BizHawk.Client.Common
@@ -332,5 +334,12 @@ namespace BizHawk.Client.Common
 		public EHostInputMethod HostInputMethod { get; set; } = HostCapabilityDetector.HasDirectX ? EHostInputMethod.DirectInput : EHostInputMethod.OpenTK;
 
 		public bool UseStaticWindowTitles { get; set; }
+
+		public List<string> ModifierKeys { get; set; } = new();
+
+		[JsonIgnore]
+		public IReadOnlyList<string> ModifierKeysEffective;
+
+		public bool MergeLAndRModifierKeys { get; set; } = true;
 	}
 }

src/BizHawk.Client.Common/input/InputEvent.cs

@@ -1,6 +1,8 @@
 #nullable enable
 
 using System;
+using System.Collections.Generic;
+using System.Text;
 
 namespace BizHawk.Client.Common
 {
@@ -29,25 +31,31 @@ namespace BizHawk.Client.Common
 		Press, Release
 	}
 
-	public readonly struct LogicalButton
+	public struct LogicalButton
 	{
+		public const uint MASK_ALT = 1U << 2;
+
+		public const uint MASK_CTRL = 1U << 1;
+
+		public const uint MASK_SHIFT = 1U << 3;
+
+		public const uint MASK_WIN = 1U << 0;
+
 		public static bool operator ==(LogicalButton lhs, LogicalButton rhs)
 			=> lhs.Button == rhs.Button && lhs.Modifiers == rhs.Modifiers;
 
 		public static bool operator !=(LogicalButton lhs, LogicalButton rhs) => !(lhs == rhs);
 
-		public bool Alt => (Modifiers & ModifierKey.Alt) != 0;
+		/// <remarks>pretty sure these are always consumed during the same iteration of the main program loop, but ¯\_(ツ)_/¯ better safe than sorry --yoshi</remarks>
+		private readonly Func<IReadOnlyList<string>> _getEffectiveModListCallback;
 
 		public readonly string Button;
 
-		public bool Control => (Modifiers & ModifierKey.Control) != 0;
+		public readonly uint Modifiers;
 
-		public readonly ModifierKey Modifiers;
+		public LogicalButton(string button, uint modifiers, Func<IReadOnlyList<string>> getEffectiveModListCallback)
-
-		public bool Shift => (Modifiers & ModifierKey.Shift) != 0;
-
-		public LogicalButton(string button, ModifierKey modifiers)
 		{
+			_getEffectiveModListCallback = getEffectiveModListCallback;
 			Button = button;
 			Modifiers = modifiers;
 		}
@@ -58,12 +66,19 @@ namespace BizHawk.Client.Common
 
 		public override readonly string ToString()
 		{
-			var ret = "";
+			if (Modifiers is 0U) return Button;
-			if (Control) ret += "Ctrl+";
+			var allMods = _getEffectiveModListCallback();
-			if (Alt) ret += "Alt+";
+			StringBuilder ret = new();
-			if (Shift) ret += "Shift+";
+			for (var i = 0; i < allMods.Count; i++)
-			ret += Button;
+			{
-			return ret;
+				var b = 1U << i;
+				if ((Modifiers & b) is not 0U)
+				{
+					ret.Append(allMods[i]);
+					ret.Append('+');
+				}
+			}
+			return ret + Button;
 		}
 	}
 }

src/BizHawk.Client.Common/input/MiscInputEnums.cs

@@ -1,5 +1,3 @@
-using System;
-
 namespace BizHawk.Client.Common
 {
 	public enum AllowInput
@@ -8,19 +6,4 @@ namespace BizHawk.Client.Common
 		All = 1,
 		OnlyController = 2
 	}
-
-	[Flags]
-	public enum ModifierKey
-	{
-		/// <summary>The bitmask to extract modifiers from a key value.</summary>
-		Modifiers = -65536,
-		/// <summary>No key pressed.</summary>
-		None = 0,
-		/// <summary>The SHIFT modifier key.</summary>
-		Shift = 65536,
-		/// <summary>The CTRL modifier key.</summary>
-		Control = 131072,
-		/// <summary>The ALT modifier key.</summary>
-		Alt = 262144,
-	}
 }

src/BizHawk.Client.EmuHawk/Input/Input.cs

@@ -8,6 +8,7 @@ using BizHawk.Bizware.DirectX;
 using BizHawk.Bizware.OpenTK3;
 using BizHawk.Common;
 using BizHawk.Client.Common;
+using BizHawk.Common.CollectionExtensions;
 
 namespace BizHawk.Client.EmuHawk
 {
@@ -33,15 +34,20 @@ namespace BizHawk.Client.EmuHawk
 
 		public readonly IHostInputAdapter Adapter;
 
+		private Config _currentConfig;
+
 		private readonly Func<Config> _getConfigCallback;
 
 		internal Input(IntPtr mainFormHandle, Func<Config> getConfigCallback, Func<bool, AllowInput> mainFormInputAllowedCallback)
 		{
 			_getConfigCallback = getConfigCallback;
+			_currentConfig = _getConfigCallback();
+			_currentConfig.MergeLAndRModifierKeys = true; // for debugging
+			UpdateModifierKeysEffective();
+
 			MainFormInputAllowedCallback = mainFormInputAllowedCallback;
 
-			var config = _getConfigCallback();
+			Adapter = _currentConfig.HostInputMethod switch
-			Adapter = config.HostInputMethod switch
 			{
 				EHostInputMethod.OpenTK => new OpenTKInputAdapter(),
 				_ when OSTailoredCode.IsUnixHost => new OpenTKInputAdapter(),
@@ -49,7 +55,7 @@ namespace BizHawk.Client.EmuHawk
 				_ => throw new Exception()
 			};
 			Console.WriteLine($"Using {Adapter.Desc} for host input (keyboard + gamepads)");
-			Adapter.UpdateConfig(config);
+			Adapter.UpdateConfig(_currentConfig);
 			Adapter.FirstInitAll(mainFormHandle);
 			_updateThread = new Thread(UpdateThreadProc)
 			{
@@ -66,26 +72,36 @@ namespace BizHawk.Client.EmuHawk
 		private bool _trackDeltas;
 		private bool _ignoreEventsNextPoll;
 
+		private static readonly IReadOnlyList<string> ModifierKeysBase = new[] { "Win", "Ctrl", "Alt", "Shift" };
+
+		private static readonly IReadOnlyList<string> ModifierKeysBaseUnmerged = new[] { "Win", "Ctrl", "Alt", "Shift", "LeftWin", "RightWin", "LeftCtrl", "RightCtrl", "LeftAlt", "RightAlt", "LeftShift", "RightShift" };
+
+		public void UpdateModifierKeysEffective()
+			=> _currentConfig.ModifierKeysEffective = (_currentConfig.MergeLAndRModifierKeys ? ModifierKeysBase : ModifierKeysBaseUnmerged)
+				.Concat(_currentConfig.ModifierKeys)
+				.Take(32).ToArray();
+
+		private readonly IReadOnlyDictionary<string, string> _modifierKeyPreMap = new Dictionary<string, string>
+		{
+			["LeftWin"] = "Win",
+			["RightWin"] = "Win",
+			["LeftCtrl"] = "Ctrl",
+			["RightCtrl"] = "Ctrl",
+			["LeftAlt"] = "Alt",
+			["RightAlt"] = "Alt",
+			["LeftShift"] = "Shift",
+			["RightShift"] = "Shift",
+		};
+
 		private void HandleButton(string button, bool newState, ClientInputFocus source)
 		{
-			var currentModifier = button switch
+			if (!(_currentConfig.MergeLAndRModifierKeys &&_modifierKeyPreMap.TryGetValue(button, out var button1))) button1 = button;
-			{
+			var modIndex = _currentConfig.ModifierKeysEffective.IndexOf(button1);
-//				"LeftWin" => ModifierKey.Win,
+			var currentModifier = modIndex is -1 ? 0U : 1U << modIndex;
-//				"RightWin" => ModifierKey.Win,
+			if (EnableIgnoreModifiers && currentModifier is not 0U) return;
-				"LeftShift" => ModifierKey.Shift,
+			if (newState == _lastState[button1]) return;
-				"RightShift" => ModifierKey.Shift,
-				"LeftCtrl" => ModifierKey.Control,
-				"RightCtrl" => ModifierKey.Control,
-				"LeftAlt" => ModifierKey.Alt,
-				"RightAlt" => ModifierKey.Alt,
-				_ => ModifierKey.None
-			};
-			if (EnableIgnoreModifiers && currentModifier != ModifierKey.None) return;
-			if (_lastState[button] == newState) return;
 
-			// apply
+			if (currentModifier is not 0U)
-			// NOTE: this is not quite right. if someone held leftshift+rightshift it would be broken. seems unlikely, though.
-			if (currentModifier != ModifierKey.None)
 			{
 				if (newState)
 					_modifiers |= currentModifier;
@@ -94,17 +110,17 @@ namespace BizHawk.Client.EmuHawk
 			}
 
 			// don't generate events for things like Ctrl+LeftControl
-			ModifierKey mods = _modifiers;
+			var mods = _modifiers;
-			if (currentModifier != ModifierKey.None)
+			if (currentModifier is not 0U)
 				mods &= ~currentModifier;
 
 			var ie = new InputEvent
 				{
 					EventType = newState ? InputEventType.Press : InputEventType.Release,
-					LogicalButton = new LogicalButton(button, mods),
+					LogicalButton = new(button1, mods, () => _getConfigCallback().ModifierKeysEffective),
 					Source = source
 				};
-			_lastState[button] = newState;
+			_lastState[button1] = newState;
 
 			// track the pressed events with modifiers that we send so that we can send corresponding unpresses with modifiers
 			// this is an interesting idea, which we may need later, but not yet.
@@ -115,11 +131,11 @@ namespace BizHawk.Client.EmuHawk
 			// so, i am adding it as of 11-sep-2011
 			if (newState)
 			{
-				_modifierState[button] = ie.LogicalButton;
+				_modifierState[button1] = ie.LogicalButton;
 			}
 			else
 			{
-				if (_modifierState.TryGetValue(button, out var buttonModifierState))
+				if (_modifierState.TryGetValue(button1, out var buttonModifierState))
 				{
 					if (buttonModifierState != ie.LogicalButton && !_ignoreEventsNextPoll)
 					{
@@ -131,7 +147,7 @@ namespace BizHawk.Client.EmuHawk
 								Source = source
 							});
 					}
-					_modifierState.Remove(button);
+					_modifierState.Remove(button1);
 				}
 			}
 
@@ -147,7 +163,7 @@ namespace BizHawk.Client.EmuHawk
 			_axisValues[axis] = newValue;
 		}
 
-		private ModifierKey _modifiers;
+		private uint _modifiers;
 		private readonly List<InputEvent> _newEvents = new List<InputEvent>();
 
 		public void ClearEvents()
@@ -245,7 +261,8 @@ namespace BizHawk.Client.EmuHawk
 			};
 			while (true)
 			{
-				Adapter.UpdateConfig(_getConfigCallback());
+				_currentConfig = _getConfigCallback();
+				Adapter.UpdateConfig(_currentConfig);
 
 				var keyEvents = Adapter.ProcessHostKeyboards();
 				Adapter.PreprocessHostGamepads();
@@ -307,7 +324,7 @@ namespace BizHawk.Client.EmuHawk
 						foreach (var ie in _newEvents)
 						{
 							//events are swallowed in some cases:
-							if (ie.LogicalButton.Alt && ShouldSwallow(MainFormInputAllowedCallback(true), ie))
+							if ((ie.LogicalButton.Modifiers & LogicalButton.MASK_ALT) is not 0U && ShouldSwallow(MainFormInputAllowedCallback(true), ie))
 								continue;
 							if (ie.EventType == InputEventType.Press && ShouldSwallow(allowInput, ie))
 								continue;

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -992,9 +992,9 @@ namespace BizHawk.Client.EmuHawk
 				if (triggers.Count == 0)
 				{
 					// Maybe it is a system alt-key which hasn't been overridden
-					if (ie.EventType is InputEventType.Press)
+					if (ie.EventType is InputEventType.Press && (ie.LogicalButton.Modifiers & LogicalButton.MASK_ALT) is not 0U)
 					{
-						if (ie.LogicalButton.Alt && ie.LogicalButton.Button.Length == 1)
+						if (ie.LogicalButton.Button.Length == 1)
 						{
 							var c = ie.LogicalButton.Button.ToLower()[0];
 							if ((c >= 'a' && c <= 'z') || c == ' ')
@@ -1002,8 +1002,7 @@ namespace BizHawk.Client.EmuHawk
 								SendAltKeyChar(c);
 							}
 						}
-
+						else if (ie.LogicalButton.Button == "Space")
-						if (ie.LogicalButton.Alt && ie.LogicalButton.Button == "Space")
 						{
 							SendPlainAltKey(32);
 						}

src/BizHawk.Client.EmuHawk/config/ControllerConfig.cs

@@ -81,7 +81,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private Control CreateNormalPanel(Dictionary<string, string> settings, List<string> buttons, Size size)
 		{
-			var cp = new ControllerConfigPanel { Dock = DockStyle.Fill, AutoScroll = true, Tooltip = toolTip1 };
+			ControllerConfigPanel cp = new(_config.ModifierKeysEffective) { Dock = DockStyle.Fill, AutoScroll = true, Tooltip = toolTip1 };
 			cp.LoadSettings(settings, checkBoxAutoTab.Checked, buttons, size.Width, size.Height);
 			return cp;
 		}

src/BizHawk.Client.EmuHawk/config/ControllerConfig/ControllerConfigPanel.cs

@@ -4,6 +4,8 @@ using System.Drawing;
 using System.Linq;
 using System.Windows.Forms;
 
+using BizHawk.Client.Common;
+
 namespace BizHawk.Client.EmuHawk
 {
 	// this is a little messy right now because of remnants of the old config system
@@ -33,8 +35,11 @@ namespace BizHawk.Client.EmuHawk
 
 		private bool _autoTab;
 
-		public ControllerConfigPanel()
+		private readonly IReadOnlyList<string> _effectiveModList;
+
+		public ControllerConfigPanel(IReadOnlyList<string> effectiveModList)
 		{
+			_effectiveModList = effectiveModList;
 			InitializeComponent();
 		}
 
@@ -121,7 +126,7 @@ namespace BizHawk.Client.EmuHawk
 					x += columnWidth;
 				}
 
-				var iw = new InputCompositeWidget
+				var iw = new InputCompositeWidget(_effectiveModList)
 				{
 					Location = new Point(x, y),
 					Size = new Size(_inputSize, UIHelper.ScaleY(23)),

src/BizHawk.Client.EmuHawk/config/HotkeyConfig.cs

@@ -110,7 +110,7 @@ namespace BizHawk.Client.EmuHawk
 						Size = new Size(iwOffsetX - UIHelper.ScaleX(2), UIHelper.ScaleY(15))
 					};
 
-					var w = new InputCompositeWidget
+					var w = new InputCompositeWidget(_config.ModifierKeysEffective)
 					{
 						Location = new Point(x + iwOffsetX, y + iwOffsetY),
 						AutoTab = AutoTabCheckBox.Checked,

src/BizHawk.Client.EmuHawk/config/InputCompositeWidget.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Windows.Forms;
 
 using BizHawk.Client.Common;
@@ -7,8 +8,12 @@ namespace BizHawk.Client.EmuHawk
 {
 	public partial class InputCompositeWidget : UserControl
 	{
-		public InputCompositeWidget()
+		private readonly IReadOnlyList<string> _effectiveModList;
+
+		public InputCompositeWidget(IReadOnlyList<string> effectiveModList)
 		{
+			_effectiveModList = effectiveModList;
+
 			InitializeComponent();
 			btnSpecial.Image = Properties.Resources.ArrowBlackDown;
 
@@ -82,24 +87,24 @@ namespace BizHawk.Client.EmuHawk
 
 		private void DropdownMenu_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
 		{
-			var mods = ModifierKey.None;
+			var mods = 0U;
 
 			if ((ModifierKeys & Keys.Shift) != 0)
 			{
-				mods |= ModifierKey.Shift;
+				mods |= LogicalButton.MASK_SHIFT;
 			}
 
 			if ((ModifierKeys & Keys.Control) != 0)
 			{
-				mods |= ModifierKey.Control;
+				mods |= LogicalButton.MASK_CTRL;
 			}
 
 			if ((ModifierKeys & Keys.Alt) != 0)
 			{
-				mods |= ModifierKey.Alt;
+				mods |= LogicalButton.MASK_ALT;
 			}
 
-			LogicalButton lb = new(e.ClickedItem.Text, mods);
+			LogicalButton lb = new(e.ClickedItem.Text, mods, () => _effectiveModList);
 
 			widget.SetBinding(lb.ToString());
 		}

src/BizHawk.Common/Extensions/CollectionExtensions.cs

@@ -120,6 +120,19 @@ namespace BizHawk.Common.CollectionExtensions
 			foreach (var item in collection) list.Add(item);
 		}
 
+		/// <inheritdoc cref="IList{T}.IndexOf"/>
+		/// <remarks>
+		/// (This is an extension method which reimplements <see cref="IList{T}.IndexOf"/> for other <see cref="IReadOnlyList{T}">collections</see>.
+		/// It defers to the existing <see cref="IList{T}.IndexOf">IndexOf</see> if the receiver's type is <see cref="IList{T}"/> or a subtype.)
+		/// </remarks>
+		public static int IndexOf<T>(this IReadOnlyList<T> list, T elem)
+			where T : IEquatable<T>
+		{
+			if (list is IList<T> listImpl) return listImpl.IndexOf(elem);
+			for (int i = 0, l = list.Count; i < l; i++) if (elem.Equals(list[i])) return i;
+			return -1;
+		}
+
 		public static T? FirstOrNull<T>(this IEnumerable<T> list, Func<T, bool> predicate)
 			where T : struct
 		{

src/BizHawk.Tests/Client.Common/config/SerializationStabilityTests.cs

@@ -33,6 +33,7 @@ namespace BizHawk.Tests.Client.Common.config
 			typeof(Dictionary<,>),
 			typeof(int),
 			typeof(JToken),
+			typeof(List<>),
 			typeof(Nullable<>),
 			typeof(object),
 			typeof(float),
@@ -78,6 +79,7 @@ namespace BizHawk.Tests.Client.Common.config
 				groupDesc ??= t.Name;
 				foreach (var mi in t.GetMembers(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
 				{
+					if (mi.GetCustomAttribute<JsonIgnoreAttribute>() is not null) continue;
 					if (mi is PropertyInfo pi) CheckMemberAndTypeParams(pi.PropertyType, groupDesc);
 					else if (mi is FieldInfo fi) CheckMemberAndTypeParams(fi.FieldType, groupDesc);
 				}