Minor refactors to system-specific helpers in `MainForm`

src/BizHawk.Client.EmuHawk/MainForm.Events.cs

@@ -1288,19 +1288,13 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void NesPpuViewerMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<NesPPU>();
-			Tools.Load<NesPPU>();
-		}
 
 		private void NesNametableViewerMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<NESNameTableViewer>();
-			Tools.Load<NESNameTableViewer>();
-		}
 
 		private void MusicRipperMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<NESMusicRipper>();
-			Tools.Load<NESMusicRipper>();
-		}
 
 		private DialogResult OpenNesHawkGraphicsSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1315,20 +1309,16 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void NesGraphicSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				NES => OpenNesHawkGraphicsSettingsDialog(GetSettingsAdapterForLoadedCore<NES>()),
 				SubNESHawk => OpenNesHawkGraphicsSettingsDialog(GetSettingsAdapterForLoadedCore<SubNESHawk>()),
 				QuickNES => OpenQuickNesGraphicsSettingsDialog(GetSettingsAdapterForLoadedCore<QuickNES>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void NesSoundChannelsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<NESSoundConfig>();
-			Tools.Load<NESSoundConfig>();
-		}
 
 		private DialogResult OpenNesHawkVSSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1337,14 +1327,12 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void VsSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				NES { IsVS: true } => OpenNesHawkVSSettingsDialog(GetSettingsAdapterForLoadedCore<NES>()),
 				SubNESHawk { IsVs: true } => OpenNesHawkVSSettingsDialog(GetSettingsAdapterForLoadedCore<SubNESHawk>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void FdsEjectDiskMenuItem_Click(object sender, EventArgs e)
 		{
@@ -1389,15 +1377,13 @@ namespace BizHawk.Client.EmuHawk
 				ignoreSettings: true);
 
 		private void NesControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				NES => OpenNesHawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<NES>()),
 				SubNESHawk => OpenNesHawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<SubNESHawk>()),
 				QuickNES => OpenQuickNesGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<QuickNES>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenNesHawkAdvancedSettingsDialog(ISettingsAdapter settable, bool hasMapperProperties)
 		{
@@ -1406,24 +1392,18 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void MovieSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				NES nesHawk => OpenNesHawkAdvancedSettingsDialog(GetSettingsAdapterForLoadedCore<NES>(), nesHawk.HasMapperProperties),
 				SubNESHawk subNESHawk => OpenNesHawkAdvancedSettingsDialog(GetSettingsAdapterForLoadedCore<SubNESHawk>(), subNESHawk.HasMapperProperties),
 				_ => DialogResult.None
 			};
-		}
 
 		private void BarcodeReaderMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<BarcodeEntry>();
-			Tools.Load<BarcodeEntry>();
-		}
 
 		private void Ti83KeypadMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<TI83KeyPad>();
-			Tools.Load<TI83KeyPad>();
-		}
 
 		private void Ti83LoadTIFileMenuItem_Click(object sender, EventArgs e)
 		{
@@ -1436,16 +1416,21 @@ namespace BizHawk.Client.EmuHawk
 			try
 			{
 				ti83.LinkPort.SendFileToCalc(File.OpenRead(result), true);
+				return;
 			}
 			catch (IOException ex)
 			{
-				var message =
+				if (this.ShowMessageBox3(
-					$"Invalid file format. Reason: {ex.Message} \nForce transfer? This may cause the calculator to crash.";
+					owner: null,
-				if (this.ShowMessageBox3(owner: null, message, "Upload Failed", EMsgBoxIcon.Question) == true)
+					icon: EMsgBoxIcon.Question,
+					caption: "Upload Failed",
+					text: $"Invalid file format. Reason: {ex.Message} \nForce transfer? This may cause the calculator to crash.")
+						is not true)
 				{
-					ti83.LinkPort.SendFileToCalc(File.OpenRead(result), false);
+					return;
 				}
 			}
+			ti83.LinkPort.SendFileToCalc(File.OpenRead(result), false);
 		}
 
 		private DialogResult OpenTI83PaletteSettingsDialog(ISettingsAdapter settable)
@@ -1466,11 +1451,8 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void A7800SubMenu_DropDownOpened(object sender, EventArgs e)
-		{
+			=> A7800ControllerSettingsMenuItem.Enabled = A7800FilterSettingsMenuItem.Enabled
-			A7800ControllerSettingsMenuItem.Enabled
-				= A7800FilterSettingsMenuItem.Enabled
 				= MovieSession.Movie.NotActive();
-		}
 
 		private DialogResult OpenA7800HawkGamepadSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1479,13 +1461,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void A7800ControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				A7800Hawk => OpenA7800HawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<A7800Hawk>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenA7800HawkFilterSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1494,13 +1474,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void A7800FilterSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				A7800Hawk => OpenA7800HawkFilterSettingsDialog(GetSettingsAdapterForLoadedCore<A7800Hawk>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenGambatteSettingsDialog(ISettingsAdapter settable)
 			=> GBPrefs.DoGBPrefsDialog(Config, this, Game, MovieSession, settable);
@@ -1515,8 +1493,7 @@ namespace BizHawk.Client.EmuHawk
 			=> OpenGenericCoreConfigFor<SubGBHawk>(CoreNames.SubGbHawk + " Settings");
 
 		private void GbCoreSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				Gameboy => OpenGambatteSettingsDialog(GetSettingsAdapterForLoadedCore<Gameboy>()),
 				GBHawk => OpenGBHawkSettingsDialog(),
@@ -1524,7 +1501,6 @@ namespace BizHawk.Client.EmuHawk
 				SubGBHawk => OpenSubGBHawkSettingsDialog(),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenSameBoyPaletteSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1533,28 +1509,20 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void SameboyColorChooserMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				Sameboy => OpenSameBoyPaletteSettingsDialog(GetSettingsAdapterForLoadedCore<Sameboy>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void GbGpuViewerMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<GbGpuView>();
-			Tools.Load<GbGpuView>();
-		}
 
 		private void GbPrinterViewerMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<GBPrinterView>();
-			Tools.Load<GBPrinterView>();
-		}
 
 		private void PsxSubMenu_DropDownOpened(object sender, EventArgs e)
-		{
+			=> PSXControllerSettingsMenuItem.Enabled = MovieSession.Movie.NotActive();
-			PSXControllerSettingsMenuItem.Enabled = MovieSession.Movie.NotActive();
-		}
 
 		private DialogResult OpenOctoshockGamepadSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1563,13 +1531,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void PsxControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				Octoshock => OpenOctoshockGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<Octoshock>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenOctoshockSettingsDialog(ISettingsAdapter settable, OctoshockDll.eVidStandard vidStandard, Size vidSize)
 			=> PSXOptions.DoSettingsDialog(Config, this, settable, vidStandard, vidSize);
@@ -1585,9 +1551,7 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void PsxDiscControlsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<VirtualpadTool>().ScrollToPadSchema("Console");
-			Tools.Load<VirtualpadTool>().ScrollToPadSchema("Console");
-		}
 
 		private void PsxHashDiscsMenuItem_Click(object sender, EventArgs e)
 		{
@@ -1597,9 +1561,7 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void SnesSubMenu_DropDownOpened(object sender, EventArgs e)
-		{
+			=> SNESControllerConfigurationMenuItem.Enabled = MovieSession.Movie.NotActive();
-			SNESControllerConfigurationMenuItem.Enabled = MovieSession.Movie.NotActive();
-		}
 
 		private DialogResult OpenOldBSNESGamepadSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1614,20 +1576,16 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void SNESControllerConfigurationMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				LibsnesCore => OpenOldBSNESGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<LibsnesCore>()),
 				BsnesCore => OpenBSNESGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<BsnesCore>()),
 				SubBsnesCore => OpenBSNESGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<SubBsnesCore>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void SnesGfxDebuggerMenuItem_Click(object sender, EventArgs e)
-		{
+			=> Tools.Load<SNESGraphicsDebugger>();
-			Tools.Load<SNESGraphicsDebugger>();
-		}
 
 		private DialogResult OpenOldBSNESSettingsDialog(ISettingsAdapter settable)
 			=> SNESOptions.DoSettingsDialog(this, settable);
@@ -1636,15 +1594,13 @@ namespace BizHawk.Client.EmuHawk
 			=> BSNESOptions.DoSettingsDialog(this, settable);
 
 		private void SnesOptionsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				LibsnesCore => OpenOldBSNESSettingsDialog(GetSettingsAdapterForLoadedCore<LibsnesCore>()),
 				BsnesCore => OpenBSNESSettingsDialog(GetSettingsAdapterForLoadedCore<BsnesCore>()),
 				SubBsnesCore => OpenBSNESSettingsDialog(GetSettingsAdapterForLoadedCore<SubBsnesCore>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void ColecoSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
@@ -1686,28 +1642,23 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void ColecoControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				ColecoVision => OpenColecoHawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<ColecoVision>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void N64SubMenu_DropDownOpened(object sender, EventArgs e)
 		{
-			N64PluginSettingsMenuItem.Enabled =
+			N64PluginSettingsMenuItem.Enabled = N64ControllerSettingsMenuItem.Enabled
-				N64ControllerSettingsMenuItem.Enabled =
+				= N64ExpansionSlotMenuItem.Enabled
-				N64ExpansionSlotMenuItem.Enabled =
+				= MovieSession.Movie.NotActive();
-				MovieSession.Movie.NotActive();
-
 			N64CircularAnalogRangeMenuItem.Checked = Config.N64UseCircularAnalogConstraint;
-
+			var mupen = (N64) Emulator;
-			var s = ((N64)Emulator).GetSettings();
+			var s = mupen.GetSettings();
 			MupenStyleLagMenuItem.Checked = s.UseMupenStyleLag;
-
+			N64ExpansionSlotMenuItem.Checked = mupen.UsingExpansionSlot;
-			N64ExpansionSlotMenuItem.Checked = ((N64)Emulator).UsingExpansionSlot;
+			N64ExpansionSlotMenuItem.Enabled = !mupen.IsOverridingUserExpansionSlotSetting;
-			N64ExpansionSlotMenuItem.Enabled = !((N64)Emulator).IsOverridingUserExpansionSlotSetting;
 		}
 
 		private DialogResult OpenMupen64PlusGraphicsSettingsDialog(ISettingsAdapter settable)
@@ -1732,13 +1683,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void N64ControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				N64 => OpenMupen64PlusGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<N64>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void N64CircularAnalogRangeMenuItem_Click(object sender, EventArgs e)
 			=> Config.N64UseCircularAnalogConstraint = !Config.N64UseCircularAnalogConstraint;
@@ -1777,13 +1726,11 @@ namespace BizHawk.Client.EmuHawk
 			=> GBLPrefs.DoGBLPrefsDialog(Config, this, Game, MovieSession, settable);
 
 		private void GblSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				GambatteLink => OpenGambatteLinkSettingsDialog(GetSettingsAdapterForLoadedCore<GambatteLink>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenGenericCoreConfigFor<T>(string title)
 			where T : IEmulator
@@ -1799,13 +1746,11 @@ namespace BizHawk.Client.EmuHawk
 			=> OpenGenericCoreConfigFor<AppleII>(CoreNames.Virtu + " Settings");
 
 		private void AppleIISettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				AppleII => OpenVirtuSettingsDialog(),
 				_ => DialogResult.None
 			};
-		}
 
 		private void AppleSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
@@ -1869,13 +1814,11 @@ namespace BizHawk.Client.EmuHawk
 			=> OpenGenericCoreConfigFor<C64>(CoreNames.C64Hawk + " Settings");
 
 		private void C64SettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				C64 => OpenC64HawkSettingsDialog(),
 				_ => DialogResult.None
 			};
-		}
 
 		private void IntVSubMenu_DropDownOpened(object sender, EventArgs e)
 		{
@@ -1889,13 +1832,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void IntVControllerSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				Intellivision => OpenIntelliHawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<Intellivision>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenZXHawkGamepadSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1904,13 +1845,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void ZXSpectrumControllerConfigurationMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				ZXSpectrum => OpenZXHawkGamepadSettingsDialog(GetSettingsAdapterForLoadedCore<ZXSpectrum>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenZXHawkSyncSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1919,13 +1858,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void ZXSpectrumCoreEmulationSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				ZXSpectrum => OpenZXHawkSyncSettingsDialog(GetSettingsAdapterForLoadedCore<ZXSpectrum>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenZXHawkSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1934,13 +1871,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void ZXSpectrumNonSyncSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				ZXSpectrum => OpenZXHawkSettingsDialog(GetSettingsAdapterForLoadedCore<ZXSpectrum>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenZXHawkAudioSettingsDialog(ISettingsAdapter settable)
 		{
@@ -1949,13 +1884,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void ZXSpectrumAudioSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				ZXSpectrum => OpenZXHawkAudioSettingsDialog(GetSettingsAdapterForLoadedCore<ZXSpectrum>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void ZXSpectrumMediaMenuItem_DropDownOpened(object sender, EventArgs e)
 		{
@@ -2029,6 +1962,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 			catch (Exception)
 			{
+				// ignored
 			}
 		}
 
@@ -2039,13 +1973,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void AmstradCpcCoreEmulationSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				AmstradCPC => OpenCPCHawkSyncSettingsDialog(GetSettingsAdapterForLoadedCore<AmstradCPC>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private DialogResult OpenCPCHawkAudioSettingsDialog(ISettingsAdapter settable)
 		{
@@ -2054,13 +1986,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void AmstradCpcAudioSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				AmstradCPC => OpenCPCHawkAudioSettingsDialog(GetSettingsAdapterForLoadedCore<AmstradCPC>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void AmstradCpcMediaMenuItem_DropDownOpened(object sender, EventArgs e)
 		{
@@ -2124,13 +2054,11 @@ namespace BizHawk.Client.EmuHawk
 		}
 
 		private void AmstradCpcNonSyncSettingsMenuItem_Click(object sender, EventArgs e)
-		{
+			=> _ = Emulator switch
-			_ = Emulator switch
 			{
 				AmstradCPC => OpenCPCHawkSettingsDialog(GetSettingsAdapterForLoadedCore<AmstradCPC>()),
 				_ => DialogResult.None
 			};
-		}
 
 		private void HelpSubMenu_DropDownOpened(object sender, EventArgs e)
 		{

src/BizHawk.Client.EmuHawk/MainForm.Hotkey.cs

@@ -1,4 +1,6 @@
 using System.Linq;
+using System.Runtime.CompilerServices;
+
 using BizHawk.Emulation.Common;
 using BizHawk.Emulation.Cores.Consoles.Nintendo.NDS;
 using BizHawk.Emulation.Cores.Nintendo.Gameboy;
@@ -21,23 +23,6 @@ namespace BizHawk.Client.EmuHawk
 				Config.SaveSlot = slot;
 				UpdateStatusSlots();
 			}
-			void ToggleGambatteSyncSetting(
-				string name,
-				Func<Gameboy.GambatteSyncSettings, bool> getter,
-				Action<Gameboy.GambatteSyncSettings, bool> setter)
-			{
-				if (Emulator is not Gameboy gb) return;
-				if (gb.DeterministicEmulation)
-				{
-					AddOnScreenMessage($"{name} cannot be toggled during movie recording.");
-					return;
-				}
-				var ss = gb.GetSyncSettings();
-				var newState = !getter(ss);
-				setter(ss, newState);
-				gb.PutSyncSettings(ss);
-				AddOnScreenMessage($"{name} toggled {(newState ? "on" : "off")}");
-			}
 
 			switch (trigger)
 			{
@@ -488,22 +473,13 @@ namespace BizHawk.Client.EmuHawk
 
 				// GB
 				case "GB Toggle BG":
-					ToggleGambatteSyncSetting(
+					GB_ToggleBackgroundLayer();
-						"BG",
-						static ss => ss.DisplayBG,
-						static (ss, newState) => ss.DisplayBG = newState);
 					break;
 				case "GB Toggle Obj":
-					ToggleGambatteSyncSetting(
+					GB_ToggleObjectLayer();
-						"OBJ",
-						static ss => ss.DisplayOBJ,
-						static (ss, newState) => ss.DisplayOBJ = newState);
 					break;
 				case "GB Toggle Window":
-					ToggleGambatteSyncSetting(
+					GB_ToggleWindowLayer();
-						"WIN",
-						static ss => ss.DisplayWindow,
-						static (ss, newState) => ss.DisplayWindow = newState);
 					break;
 
 				// Analog
@@ -534,64 +510,89 @@ namespace BizHawk.Client.EmuHawk
 
 				// DS
 				case "Next Screen Layout":
-					IncrementDSLayout(1);
+					NDS_IncrementLayout(1);
 					break;
 				case "Previous Screen Layout":
-					IncrementDSLayout(-1);
+					NDS_IncrementLayout(-1);
 					break;
 				case "Screen Rotate":
-					IncrementDSScreenRotate();
+					NDS_IncrementScreenRotate();
 					break;
 			}
 
 			return true;
 		}
 
-		private void IncrementDSScreenRotate()
+		[MethodImpl(MethodImplOptions.AggressiveInlining)]
+		private void GB_ToggleGambatteSyncSetting(
+			string name,
+			Func<Gameboy.GambatteSyncSettings, bool> getter,
+			Action<Gameboy.GambatteSyncSettings, bool> setter)
 		{
-			if (Emulator is NDS ds)
+			if (Emulator is not Gameboy gb) return;
+			if (gb.DeterministicEmulation)
 			{
-				var settings = ds.GetSettings();
+				AddOnScreenMessage($"{name} cannot be toggled during movie recording.");
-				settings.ScreenRotation = settings.ScreenRotation switch
+				return;
-				{
-					NDS.ScreenRotationKind.Rotate0 => settings.ScreenRotation = NDS.ScreenRotationKind.Rotate90,
-					NDS.ScreenRotationKind.Rotate90 => settings.ScreenRotation = NDS.ScreenRotationKind.Rotate180,
-					NDS.ScreenRotationKind.Rotate180 => settings.ScreenRotation = NDS.ScreenRotationKind.Rotate270,
-					NDS.ScreenRotationKind.Rotate270 => settings.ScreenRotation = NDS.ScreenRotationKind.Rotate0,
-					_ => settings.ScreenRotation
-				};
-				ds.PutSettings(settings);
-				AddOnScreenMessage($"Screen rotation to {settings.ScreenRotation}");
-				FrameBufferResized();
 			}
+			var ss = gb.GetSyncSettings();
+			var newState = !getter(ss);
+			setter(ss, newState);
+			gb.PutSyncSettings(ss);
+			AddOnScreenMessage($"{name} toggled {(newState ? "on" : "off")}");
 		}
 
-		private void IncrementDSLayout(int delta)
+		private void GB_ToggleBackgroundLayer()
+			=> GB_ToggleGambatteSyncSetting(
+				"BG",
+				static ss => ss.DisplayBG,
+				static (ss, newState) => ss.DisplayBG = newState);
+
+		private void GB_ToggleObjectLayer()
+			=> GB_ToggleGambatteSyncSetting(
+				"OBJ",
+				static ss => ss.DisplayOBJ,
+				static (ss, newState) => ss.DisplayOBJ = newState);
+
+		private void GB_ToggleWindowLayer()
+			=> GB_ToggleGambatteSyncSetting(
+				"WIN",
+				static ss => ss.DisplayWindow,
+				static (ss, newState) => ss.DisplayWindow = newState);
+
+		private void NDS_IncrementScreenRotate()
 		{
-			bool decrement = delta == -1;
+			if (Emulator is not NDS ds) return;
-			if (Emulator is NDS ds)
+
+			var settings = ds.GetSettings();
+			var next = settings.ScreenRotation switch
 			{
-				var settings = ds.GetSettings();
+				NDS.ScreenRotationKind.Rotate0 => NDS.ScreenRotationKind.Rotate90,
-				var num = (int)settings.ScreenLayout;
+				NDS.ScreenRotationKind.Rotate90 => NDS.ScreenRotationKind.Rotate180,
-				if (decrement)
+				NDS.ScreenRotationKind.Rotate180 => NDS.ScreenRotationKind.Rotate270,
-				{
+				NDS.ScreenRotationKind.Rotate270 => NDS.ScreenRotationKind.Rotate0,
-					num--;
+				_ => settings.ScreenRotation
-				}
+			};
-				else
+			settings.ScreenRotation = next;
-				{
+			ds.PutSettings(settings);
-					num++;
+			AddOnScreenMessage($"Screen rotation to {next}");
-				}
+			FrameBufferResized();
+		}
 
-				var next = (NDS.ScreenLayoutKind)Enum.Parse(typeof(NDS.ScreenLayoutKind), num.ToString());
+		private void NDS_IncrementLayout(int delta)
-				if (typeof(NDS.ScreenLayoutKind).IsEnumDefined(next))
+		{
-				{
+			if (Emulator is not NDS ds) return;
-					settings.ScreenLayout = next;
 
-					ds.PutSettings(settings);
+			var settings = ds.GetSettings();
-					AddOnScreenMessage($"Screen layout to {next}");
+			var t = typeof(NDS.ScreenLayoutKind);
-					FrameBufferResized();
+			//TODO WTF is this --yoshi
-				}
+			var next = (NDS.ScreenLayoutKind) Enum.Parse(t, ((int) settings.ScreenLayout + delta).ToString());
-			}
+			if (!t.IsEnumDefined(next)) return;
+
+			settings.ScreenLayout = next;
+			ds.PutSettings(settings);
+			AddOnScreenMessage($"Screen layout to {next}");
+			FrameBufferResized();
 		}
 
 		// Determines if the value is a hotkey  that would be handled outside of the CheckHotkey method

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -1609,11 +1609,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void SNES_ToggleBg(int layer)
 		{
-			if (Emulator is not (BsnesCore or SubBsnesCore or LibsnesCore or Snes9x) || !1.RangeTo(4).Contains(layer))
+			if (layer is < 1 or > 4) return; // should this throw?
-			{
-				return;
-			}
-
 			bool result = false;
 			switch (Emulator)
 			{
@@ -1684,6 +1680,8 @@ namespace BizHawk.Client.EmuHawk
 					snes9X.PutSettings(s);
 					break;
 				}
+				default:
+					return;
 			}
 
 			AddOnScreenMessage($"BG {layer} Layer {(result ? "On" : "Off")}");
@@ -1691,11 +1689,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void SNES_ToggleObj(int layer)
 		{
-			if (!(Emulator is LibsnesCore || Emulator is Snes9x) || !1.RangeTo(4).Contains(layer))
+			if (layer is < 1 or > 4) return; // should this throw?
-			{
-				return;
-			}
-
 			bool result = false;
 			if (Emulator is LibsnesCore bsnes)
 			{
@@ -1727,6 +1721,10 @@ namespace BizHawk.Client.EmuHawk
 				snes9X.PutSettings(s);
 				AddOnScreenMessage($"Sprite {layer} Layer {(result ? "On" : "Off")}");
 			}
+			else
+			{
+				return;
+			}
 		}
 
 		public bool RunLibretroCoreChooser()