change TAStudio layout when rotation changes

- addresses #3708

src/BizHawk.Client.EmuHawk/CustomControls/InputRoll/InputRoll.cs

@@ -477,6 +477,10 @@ namespace BizHawk.Client.EmuHawk
 		[Description("Occurs when a cell is dragged and then dropped into a new cell, old cell is the cell that was being dragged, new cell is its new destination")]
 		public event CellDroppedEvent CellDropped;
 
+		[Category("Property Changed")]
+		[Description("Fires after rotation has been changed.")]
+		public event EventHandler RotationChanged;
+
 		/// <summary>
 		/// Retrieve the text for a cell
 		/// </summary>
@@ -1568,6 +1572,7 @@ namespace BizHawk.Client.EmuHawk
 
 		private void OrientationChanged()
 		{
+			RotationChanged?.Invoke(this, EventArgs.Empty);
 			// TODO scroll to correct positions
 			ColumnChangedCallback();
 			Refresh();

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

@@ -895,6 +895,7 @@ namespace BizHawk.Client.EmuHawk
 			this.TasView.RightMouseScrolled += new BizHawk.Client.EmuHawk.InputRoll.RightMouseScrollEventHandler(this.TasView_MouseWheel);
 			this.TasView.ColumnReordered += new BizHawk.Client.EmuHawk.InputRoll.ColumnReorderedEventHandler(this.TasView_ColumnReordered);
 			this.TasView.CellDropped += new BizHawk.Client.EmuHawk.InputRoll.CellDroppedEvent(this.TasView_CellDropped);
+			this.TasView.RotationChanged += new System.EventHandler(this.HandleRotationChanged);
 			this.TasView.KeyDown += new System.Windows.Forms.KeyEventHandler(this.TasView_KeyDown);
 			this.TasView.MouseDoubleClick += new System.Windows.Forms.MouseEventHandler(this.TasView_MouseDoubleClick);
 			this.TasView.MouseDown += new System.Windows.Forms.MouseEventHandler(this.TasView_MouseDown);

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

@@ -1019,7 +1019,6 @@ namespace BizHawk.Client.EmuHawk
 		private void RotateMenuItem_Click(object sender, EventArgs e)
 		{
 			TasView.HorizontalOrientation = !TasView.HorizontalOrientation;
-			CurrentTasMovie.FlagChanges();
 		}
 
 		private void HideLagFramesX_Click(object sender, EventArgs e)

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

@@ -180,16 +180,7 @@ namespace BizHawk.Client.EmuHawk
 				return;
 			}
 
-			if (TasView.Rotatable)
-			{
-				RightClickMenu.Items.AddRange(TasView.GenerateContextMenuItems()
-					.ToArray());
-
-				RightClickMenu.Items
-					.OfType<ToolStripMenuItem>()
-					.First(t => t.Name == "RotateMenuItem")
-					.Click += (o, ov) => { CurrentTasMovie.FlagChanges(); };
-			}
+			RightClickMenu.Items.AddRange(TasView.GenerateContextMenuItems().ToArray());
 
 			TasView.ScrollSpeed = Settings.ScrollSpeed;
 			TasView.AlwaysScroll = Settings.FollowCursorAlwaysScroll;
@@ -1251,5 +1242,20 @@ namespace BizHawk.Client.EmuHawk
 				}
 			}
 		}
+
+		private void HandleRotationChanged(object sender, EventArgs e)
+		{
+			CurrentTasMovie.FlagChanges();
+			if (TasView.HorizontalOrientation)
+			{
+				BranchesMarkersSplit.Orientation = Orientation.Vertical;
+				BranchesMarkersSplit.SplitterDistance = 200;
+			}
+			else
+			{
+				BranchesMarkersSplit.Orientation = Orientation.Horizontal;
+				BranchesMarkersSplit.SplitterDistance = _defaultBranchMarkerSplitDistance;
+			}
+		}
 	}
 }