Add prop FormBase.BlocksInputWhenFocused to simplify some logic

src/BizHawk.Client.EmuHawk/FormBase.cs

@@ -12,6 +12,8 @@ namespace BizHawk.Client.EmuHawk
 	{
 		private string? _windowTitleStatic;
 
+		public virtual bool BlocksInputWhenFocused { get; } = true;
+
 		public Config? Config { get; set; }
 
 		[DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -392,39 +392,18 @@ namespace BizHawk.Client.EmuHawk
 				Sound?.StartSound();
 			};
 
-			Input.Instance.MainFormInputAllowedCallback = yieldAlt => {
-				// the main form gets input
-				if (ActiveForm == this)
-				{
-					return Input.AllowInput.All;
-				}
-
-				// even more special logic for TAStudio:
-				// TODO - implement by event filter in TAStudio
-				if (ActiveForm is TAStudio maybeTAStudio)
-				{
-					if (yieldAlt || maybeTAStudio.IsInMenuLoop)
-					{
-						return Input.AllowInput.None;
-					}
-				}
-
-				// modals that need to capture input for binding purposes get input, of course
-				if (ActiveForm is HotkeyConfig
-					|| ActiveForm is ControllerConfig
-					|| ActiveForm is TAStudio
-					|| ActiveForm is VirtualpadTool)
-				{
-					return Input.AllowInput.All;
-				}
-
-				// if no form is active on this process, then the background input setting applies
-				if (ActiveForm == null && Config.AcceptBackgroundInput)
-				{
-					return Config.AcceptBackgroundInputControllerOnly ? Input.AllowInput.OnlyController : Input.AllowInput.All;
-				}
-
-				return Input.AllowInput.None;
+			Input.Instance.MainFormInputAllowedCallback = yieldAlt => ActiveForm switch
+			{
+				null => Config.AcceptBackgroundInput // none of our forms are focused, check the background input config
+					? Config.AcceptBackgroundInputControllerOnly
+						? Input.AllowInput.OnlyController
+						: Input.AllowInput.All
+					: Input.AllowInput.None,
+				TAStudio _ when yieldAlt => Input.AllowInput.None,
+				FormBase f when !f.BlocksInputWhenFocused => Input.AllowInput.All,
+				ControllerConfig _ => Input.AllowInput.All,
+				HotkeyConfig _ => Input.AllowInput.All,
+				_ => Input.AllowInput.None
 			};
 			Input.Instance.Adapter.FirstInitAll(Handle);
 			InitControls();
@@ -627,6 +606,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private readonly bool _suppressSyncSettingsWarning;
 
+		public override bool BlocksInputWhenFocused { get; } = false;
+
 		public int ProgramRunLoop()
 		{
 			CheckMessages(); // can someone leave a note about why this is needed?

src/BizHawk.Client.EmuHawk/tools/TAStudio/TAStudio.cs

@@ -15,6 +15,8 @@ namespace BizHawk.Client.EmuHawk
 {
 	public partial class TAStudio : ToolFormBase, IToolFormAutoConfig, IControlMainform
 	{
+		public override bool BlocksInputWhenFocused => IsInMenuLoop;
+
 		// TODO: UI flow that conveniently allows to start from savestate
 		public ITasMovie CurrentTasMovie => MovieSession.Movie as ITasMovie;
 

src/BizHawk.Client.EmuHawk/tools/VirtualPads/VirtualpadsTool.cs

@@ -22,6 +22,8 @@ namespace BizHawk.Client.EmuHawk
 		
 		private bool _readOnly;
 
+		public override bool BlocksInputWhenFocused { get; } = false;
+
 		private List<VirtualPad> Pads =>
 			ControllerPanel.Controls
 				.OfType<VirtualPad>()