Refactor IControlMainform handling in Mainform (#3935)

This allows any loaded tool to control any aspect of `IControlMainform` independently of others. Also improves rewinder handling when any tool `WantsToControlRewind`.

src/BizHawk.Client.EmuHawk/IMainFormForTools.cs

@@ -78,9 +78,6 @@ namespace BizHawk.Client.EmuHawk
 
 		bool BlockFrameAdvance { get; set; }
 
-		/// <remarks>only referenced from <see cref="TAStudio"/></remarks>
-		void RelinquishControl(IControlMainform master);
-
 		/// <remarks>only referenced from <see cref="TAStudio"/></remarks>
 		void SeekFrameAdvance();
 
@@ -88,9 +85,6 @@ namespace BizHawk.Client.EmuHawk
 
 		bool StartNewMovie(IMovie movie, bool record);
 
-		/// <remarks>only referenced from <see cref="TAStudio"/></remarks>
-		void TakeBackControl();
-
 		/// <remarks>only referenced from <see cref="BasicBot"/></remarks>
 		void Throttle();
 

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

@@ -100,9 +100,9 @@ namespace BizHawk.Client.EmuHawk
 
 		public void StopMovie(bool saveChanges = true)
 		{
-			if (IsSlave && Master.WantsToControlStopMovie)
+			if (ToolControllingStopMovie is { } tool)
 			{
-				Master.StopMovie(!saveChanges);
+				tool.StopMovie(!saveChanges);
 			}
 			else
 			{
@@ -113,7 +113,7 @@ namespace BizHawk.Client.EmuHawk
 
 		public bool RestartMovie()
 		{
-			if (IsSlave && Master.WantsToControlRestartMovie) return Master.RestartMovie();
+			if (ToolControllingRestartMovie is { } tool) return tool.RestartMovie();
 			if (!MovieSession.Movie.IsActive()) return false;
 			var success = StartNewMovie(MovieSession.Movie, false);
 			if (success) AddOnScreenMessage("Replaying movie file in read-only mode");
@@ -122,9 +122,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private void ToggleReadOnly()
 		{
-			if (IsSlave && Master.WantsToControlReadOnly)
+			if (ToolControllingReadOnly is { } tool)
 			{
-				Master.ToggleReadOnly();
+				tool.ToggleReadOnly();
 			}
 			else
 			{

src/BizHawk.Client.EmuHawk/MainForm.cs

@@ -1089,6 +1089,13 @@ namespace BizHawk.Client.EmuHawk
 
 		public readonly ToolManager Tools;
 
+		private IControlMainform ToolControllingSavestates => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlSavestates);
+		private IControlMainform ToolControllingRewind => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlRewind);
+		private IControlMainform ToolControllingReboot => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlReboot);
+		private IControlMainform ToolControllingStopMovie => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlStopMovie);
+		private IControlMainform ToolControllingRestartMovie => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlRestartMovie);
+		private IControlMainform ToolControllingReadOnly => Tools.FirstOrNull<IControlMainform>(tool => tool.WantsToControlReadOnly);
+
 		private DisplayManager DisplayManager;
 
 		private OSDManager OSD => DisplayManager.OSD;
@@ -1116,6 +1123,8 @@ namespace BizHawk.Client.EmuHawk
 
 		public void CreateRewinder()
 		{
+			if (ToolControllingRewind is not null) return;
+
 			Rewinder?.Dispose();
 			Rewinder = Emulator.HasSavestates() && Config.Rewind.Enabled && (!Emulator.AsStatable().AvoidRewind || Config.Rewind.AllowSlowStates)
 				? Config.Rewind.UseDelta
@@ -1274,9 +1283,9 @@ namespace BizHawk.Client.EmuHawk
 
 		public bool RebootCore()
 		{
-			if (IsSlave && Master.WantsToControlReboot)
+			if (ToolControllingReboot is { } tool)
 			{
-				Master.RebootCore();
+				tool.RebootCore();
 				return true;
 			}
 			else
@@ -3257,7 +3266,7 @@ namespace BizHawk.Client.EmuHawk
 					MovieSession.Movie.SwitchToRecord();
 				}
 
-				if (isRewinding && !IsRewindSlave && MovieSession.Movie.IsRecording())
+				if (isRewinding && ToolControllingRewind is null && MovieSession.Movie.IsRecording())
 				{
 					MovieSession.Movie.Truncate(Emulator.Frame);
 				}
@@ -4175,7 +4184,6 @@ namespace BizHawk.Client.EmuHawk
 				Emulator.Dispose();
 				Emulator = new NullEmulator();
 				Game = GameInfo.NullInstance;
-				CreateRewinder();
 				Tools.Restart(Config, Emulator, Game);
 				RewireSound();
 				ClearHolds();
@@ -4248,25 +4256,6 @@ namespace BizHawk.Client.EmuHawk
 			Rewinder = null;
 		}
 
-		// TODO: move me
-		public IControlMainform Master { get; private set; }
-
-		private bool IsSlave => Master != null;
-
-		private bool IsSavestateSlave => IsSlave && Master.WantsToControlSavestates;
-
-		private bool IsRewindSlave => IsSlave && Master.WantsToControlRewind;
-
-		public void RelinquishControl(IControlMainform master)
-		{
-			Master = master;
-		}
-
-		public void TakeBackControl()
-		{
-			Master = null;
-		}
-
 		private int SlotToInt(string slot)
 		{
 			return int.Parse(slot.Substring(slot.Length - 1, 1));
@@ -4282,7 +4271,7 @@ namespace BizHawk.Client.EmuHawk
 		public bool LoadState(string path, string userFriendlyStateName, bool suppressOSD = false) // Move to client.common
 		{
 			if (!Emulator.HasSavestates()) return false;
-			if (IsSavestateSlave) return Master.LoadState();
+			if (ToolControllingSavestates is { } tool) return tool.LoadState();
 
 			if (!new SavestateFile(Emulator, MovieSession, MovieSession.UserBag).Load(path, this))
 			{
@@ -4311,7 +4300,7 @@ namespace BizHawk.Client.EmuHawk
 
 			//we don't want to analyze how to intermix movies, rewinding, and states
 			//so purge rewind history when loading a state while doing a movie
-			if (!IsRewindSlave && MovieSession.Movie.IsActive())
+			if (ToolControllingRewind is null && MovieSession.Movie.IsActive())
 			{
 				Rewinder?.Clear();
 			}
@@ -4337,7 +4326,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 			if (handled) return true; // not sure
 
-			if (IsSavestateSlave) return Master.LoadQuickSave(SlotToInt(quickSlotName));
+			if (ToolControllingSavestates is { } tool) return tool.LoadQuickSave(SlotToInt(quickSlotName));
 
 			var path = $"{SaveStatePrefix()}.{quickSlotName}.State";
 			if (!File.Exists(path))
@@ -4356,9 +4345,9 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				Master.SaveState();
+				tool.SaveState();
 				return;
 			}
 
@@ -4409,9 +4398,9 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				Master.SaveQuickSave(SlotToInt(quickSlotName));
+				tool.SaveQuickSave(SlotToInt(quickSlotName));
 				return;
 			}
 
@@ -4482,9 +4471,9 @@ namespace BizHawk.Client.EmuHawk
 				Tools.TAStudio.NamedStatePending = true;
 			}
 
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				Master.SaveStateAs();
+				tool.SaveStateAs();
 				return;
 			}
 
@@ -4512,7 +4501,7 @@ namespace BizHawk.Client.EmuHawk
 		private bool LoadStateAs()
 		{
 			if (!Emulator.HasSavestates()) return false;
-			if (IsSavestateSlave) return Master.LoadStateAs();
+			if (ToolControllingSavestates is { } tool) return tool.LoadStateAs();
 
 			var result = this.ShowFileOpenDialog(
 				discardCWDChange: true,
@@ -4525,9 +4514,9 @@ namespace BizHawk.Client.EmuHawk
 		private void SelectSlot(int slot)
 		{
 			if (!Emulator.HasSavestates()) return;
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				var handled = Master.SelectSlot(slot);
+				bool handled = tool.SelectSlot(slot);
 				if (handled) return;
 			}
 			Config.SaveSlot = slot;
@@ -4538,9 +4527,9 @@ namespace BizHawk.Client.EmuHawk
 		private void PreviousSlot()
 		{
 			if (!Emulator.HasSavestates()) return;
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				var handled = Master.PreviousSlot();
+				bool handled = tool.PreviousSlot();
 				if (handled) return;
 			}
 			Config.SaveSlot--;
@@ -4552,9 +4541,9 @@ namespace BizHawk.Client.EmuHawk
 		private void NextSlot()
 		{
 			if (!Emulator.HasSavestates()) return;
-			if (IsSavestateSlave)
+			if (ToolControllingSavestates is { } tool)
 			{
-				var handled = Master.NextSlot();
+				bool handled = tool.NextSlot();
 				if (handled) return;
 			}
 			Config.SaveSlot++;
@@ -4565,9 +4554,9 @@ namespace BizHawk.Client.EmuHawk
 
 		private void CaptureRewind(bool suppressCaptureRewind)
 		{
-			if (IsRewindSlave)
+			if (ToolControllingRewind is { } tool)
 			{
-				Master.CaptureRewind();
+				tool.CaptureRewind();
 			}
 			else if (!suppressCaptureRewind && Rewinder?.Active == true)
 			{
@@ -4581,7 +4570,7 @@ namespace BizHawk.Client.EmuHawk
 
 			returnToRecording = false;
 
-			if (IsRewindSlave)
+			if (ToolControllingRewind is { } rewindTool)
 			{
 				if (InputManager.ClientControls["Rewind"] || PressRewind)
 				{
@@ -4620,7 +4609,7 @@ namespace BizHawk.Client.EmuHawk
 					if (isRewinding)
 					{
 						runFrame = Emulator.Frame > 1; // TODO: the master should be deciding this!
-						Master.Rewind();
+						rewindTool.Rewind();
 					}
 				}
 				else

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

@@ -68,7 +68,7 @@
 			}
 		}
 
-		public bool WantsToControlRewind => true;
+		public bool WantsToControlRewind { get; private set; } = true;
 
 		public void CaptureRewind()
 		{

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

@@ -281,7 +281,6 @@ namespace BizHawk.Client.EmuHawk
 			MainForm.AddOnScreenMessage("TAStudio engaged");
 			SetTasMovieCallbacks(CurrentTasMovie);
 			UpdateWindowTitle();
-			MainForm.RelinquishControl(this);
 			_originalEndAction = Config.Movies.MovieEndAction;
 			MainForm.DisableRewind();
 			Config.Movies.MovieEndAction = MovieEndAction.Record;
@@ -732,8 +731,8 @@ namespace BizHawk.Client.EmuHawk
 			_engaged = false;
 			MainForm.PauseOnFrame = null;
 			MainForm.AddOnScreenMessage("TAStudio disengaged");
-			MainForm.TakeBackControl();
 			Config.Movies.MovieEndAction = _originalEndAction;
+			WantsToControlRewind = false;
 			MainForm.EnableRewind(true);
 			MainForm.SetMainformMovieInfo();
 		}

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

@@ -473,6 +473,25 @@ namespace BizHawk.Client.EmuHawk
 			return Load<T>(false);
 		}
 
+		/// <summary>
+		/// Returns the first tool of type <typeparamref name="T"/> that fulfills the given condition
+		/// </summary>
+		/// <param name="condition">The condition to check for</param>
+		/// <typeparam name="T">Type of tools to check</typeparam>
+		/// <returns></returns>
+		public T FirstOrNull<T>(Predicate<T> condition) where T : class
+		{
+			foreach (var tool in _tools)
+			{
+				if (tool.IsActive && tool is T specialTool && condition(specialTool))
+				{
+					return specialTool;
+				}
+			}
+
+			return null;
+		}
+
 		/// <summary>
 		/// returns the instance of <paramref name="toolType"/>, regardless of whether it's loaded,<br/>
 		/// but doesn't create and load a new instance if it's not found
@@ -482,7 +501,7 @@ namespace BizHawk.Client.EmuHawk
 		/// you may pass any class or interface
 		/// </remarks>
 		public IToolForm/*?*/ LazyGet(Type toolType)
-			=> _tools.Find(t => toolType.IsAssignableFrom(t.GetType()));
+			=> _tools.Find(toolType.IsInstanceOfType);
 
 		internal static readonly IDictionary<Type, (Image/*?*/ Icon, string Name)> IconAndNameCache = new Dictionary<Type, (Image/*?*/ Icon, string Name)>
 		{