Start proof of concept of an IControlManinform interface. Mainform now has RelinguishControl and TakeControl methods. Tools that implement IControlMainform can override mainform actions. TAstudio implements this, currently the only ability is to override Read only toggle. The intend of this is to allow TAStudio and debuggers to take control of relevant mainform actions

BizHawk.Client.EmuHawk/BizHawk.Client.EmuHawk.csproj

@@ -497,6 +497,7 @@
     <Compile Include="Input\GamePad.cs" Condition=" '$(OS)' == 'Windows_NT' " />
     <Compile Include="Input\GamePad360.cs" />
     <Compile Include="Input\Input.cs" />
+    <Compile Include="IControlMainform.cs" />
     <Compile Include="JumpLists.cs" />
     <Compile Include="LogConsole.cs" />
     <Compile Include="LogWindow.cs">

BizHawk.Client.EmuHawk/IControlMainform.cs

@@ -0,0 +1,7 @@
+namespace BizHawk.Client.EmuHawk
+{
+	public interface IControlMainform
+	{
+		void ToggleReadOnly();
+	}
+}

BizHawk.Client.EmuHawk/MainForm.cs

@@ -1894,16 +1894,23 @@ namespace BizHawk.Client.EmuHawk
 			Global.Config.DisplayInput ^= true;
 		}
 
-		private static void ToggleReadOnly()
+		private void ToggleReadOnly()
 		{
-			if (Global.MovieSession.Movie.IsActive)
+			if (IsSlave)
 			{
-				Global.MovieSession.ReadOnly ^= true;
-				GlobalWin.OSD.AddMessage(Global.MovieSession.ReadOnly ? "Movie read-only mode" : "Movie read+write mode");
+				_master.ToggleReadOnly();
 			}
 			else
 			{
-				GlobalWin.OSD.AddMessage("No movie active");
+				if (Global.MovieSession.Movie.IsActive)
+				{
+					Global.MovieSession.ReadOnly ^= true;
+					GlobalWin.OSD.AddMessage(Global.MovieSession.ReadOnly ? "Movie read-only mode" : "Movie read+write mode");
+				}
+				else
+				{
+					GlobalWin.OSD.AddMessage("No movie active");
+				}
 			}
 		}
 
@@ -3304,7 +3311,21 @@ namespace BizHawk.Client.EmuHawk
 			ProfileFirstBootLabel.Visible = false;
 		}
 
-		
+		// TODO: move me
+		private IControlMainform _master;
+		public void RelinquishControl(IControlMainform master)
+		{
+			_master = master;
+		}
 
+		private bool IsSlave
+		{
+			get { return _master != null; }
+		}
+
+		public void TakeControl()
+		{
+			_master = null;
+		}
 	}
 }

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

@@ -10,7 +10,7 @@ using BizHawk.Client.Common.MovieConversionExtensions;
 
 namespace BizHawk.Client.EmuHawk
 {
-	public partial class TAStudio : Form, IToolForm
+	public partial class TAStudio : Form, IToolForm, IControlMainform
 	{
 		// TODO: UI flow that conveniently allows to start from savestate
 		private const string MarkerColumnName = "MarkerColumn";
@@ -129,6 +129,15 @@ namespace BizHawk.Client.EmuHawk
 
 		#endregion
 
+		#region IControlMainform implementation
+
+		public void ToggleReadOnly()
+		{
+			GlobalWin.OSD.AddMessage("TAStudio does not allow manual readonly toggle");
+		}
+
+		#endregion
+
 		private void TasView_QueryItemBkColor(int index, int column, ref Color color)
 		{
 			var record = _tas[index];
@@ -227,12 +236,14 @@ namespace BizHawk.Client.EmuHawk
 		{
 			GlobalWin.OSD.AddMessage("TAStudio engaged");
 			_tas = Global.MovieSession.Movie as TasMovie;
+			GlobalWin.MainForm.RelinquishControl(this);
 		}
 
 		private void DisengageTastudio()
 		{
 			GlobalWin.OSD.AddMessage("TAStudio disengaged");
 			Global.MovieSession.Movie = MovieService.DefaultInstance;
+			GlobalWin.MainForm.TakeControl();
 		}
 
 		private void NewTasMovie()