From 69af966a2d90e87d1e87f3bb34454f6c6efbcfeb Mon Sep 17 00:00:00 2001
From: SuuperW <SuuperW@gmail.com>
Date: Fri, 15 Jan 2021 11:16:23 -0600
Subject: [PATCH] TAStudio undo history form: make use of TAStudio methods, so
 that rewinds necessary to stay inside the greenzone happen. (also refresh
 after "to here" un/redo)

---
 .../tools/TAStudio/UndoHistoryForm.cs         | 60 +++++++++----------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/src/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs b/src/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
index bf25b973da..2f4750d9df 100644
--- a/src/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
+++ b/src/BizHawk.Client.EmuHawk/tools/TAStudio/UndoHistoryForm.cs
@@ -75,13 +75,13 @@ namespace BizHawk.Client.EmuHawk
 
 		private void UndoButton_Click(object sender, EventArgs e)
 		{
-			Log.Undo();
+			_tastudio.UndoExternal();
 			_tastudio.RefreshDialog();
 		}
 
 		private void RedoButton_Click(object sender, EventArgs e)
 		{
-			Log.Redo();
+			_tastudio.RedoExternal();
 			_tastudio.RefreshDialog();
 		}
 
@@ -89,20 +89,27 @@ namespace BizHawk.Client.EmuHawk
 			? HistoryView.SelectedRows.First()
 			: -1;
 
-		private void HistoryView_DoubleClick(object sender, EventArgs e)
+		private void UndoToHere(int index)
 		{
-			if (Log.UndoIndex <= SelectedItem)
+			int earliestFrame = int.MaxValue;
+			while (Log.UndoIndex > index)
 			{
-				return;
+				int frame = Log.Undo();
+				if (frame < earliestFrame)
+					earliestFrame = frame;
 			}
 
-			do
-			{
-				Log.Undo();
-			}
-			while (Log.UndoIndex > SelectedItem);
-
 			UpdateValues();
+
+			// potentially rewind, then update display for TAStudio
+			if (_tastudio.Emulator.Frame > earliestFrame)
+				_tastudio.GoToFrame(earliestFrame);
+			_tastudio.RefreshDialog();
+		}
+
+		private void HistoryView_DoubleClick(object sender, EventArgs e)
+		{
+			UndoToHere(SelectedItem);
 		}
 
 		private void HistoryView_MouseUp(object sender, MouseEventArgs e)
@@ -130,34 +137,25 @@ namespace BizHawk.Client.EmuHawk
 
 		private void UndoHereMenuItem_Click(object sender, EventArgs e)
 		{
-			if (SelectedItem == -1 || Log.UndoIndex < SelectedItem)
-			{
-				return;
-			}
-
-			do
-			{
-				Log.Undo();
-			}
-			while (Log.UndoIndex >= SelectedItem);
-
-			UpdateValues();
+			UndoToHere(SelectedItem);
 		}
 
 		private void RedoHereMenuItem_Click(object sender, EventArgs e)
 		{
-			if (SelectedItem == -1 || Log.UndoIndex >= SelectedItem)
+			int earliestFrame = int.MaxValue;
+			while (Log.UndoIndex < SelectedItem)
 			{
-				return;
+				int frame = Log.Redo();
+				if (earliestFrame < frame)
+					earliestFrame = frame;
 			}
 
-			do
-			{
-				Log.Redo();
-			}
-			while (Log.UndoIndex < SelectedItem);
-
 			UpdateValues();
+
+			// potentially rewind, then update display for TAStudio
+			if (_tastudio.Emulator.Frame > earliestFrame)
+				_tastudio.GoToFrame(earliestFrame);
+			_tastudio.RefreshDialog();
 		}
 
 		private void ClearHistoryToHereMenuItem_Click(object sender, EventArgs e)