TASStudio can fail to paste copied in inputs

[greysondn]

Summary

So, if you have a text file with input mneumonics (similar to the log inside a .bk2 archive), and you try to copy-paste that input stream into TASStudio, the behavior exhibited by TASStudio appears to be inconsistent and, well, usually not what is expected or good.

If you copy from before the first character to just after the last drawn character of the inputs, TASStudio will see there was a last line of input but paste it as an empty frame.

There is some inconsistency with including the newline character afterwards where TASStudio will either work as expected or else refuse to let you paste the input.

Please see the short video I recorded for the TASVideos Discord, here, for a visual reproduction of this:

2022-12-28.13-01-53-1.mp4

The game likely does not matter, and this likely extends back at least as far as 2.3.2. (I say this because during my recording of the Mario Paint TAS, I was complaining about my tooling missing one input all the time. It never occurred to me to check TASStudio itself.)

Repro

It's basically explained (and even shown in video) above, sorry.

Output

N/A

Host env.

• Windows 10 Home x64
• Bizhawk 2.8

[vadosnaprimer]

Does this also fail if you copy it from one tastudio to another? I've never tested copypaste to/from a text file when implementing multi-instance tastudio copypaste.

BTW mnemonics don't matter, only char order does. tastudio just checks if it's a dot or not, and sets the mnemonic in its place if it's not.

[greysondn]

Does this also fail if you copy it from one tastudio to another?

Running an analogue for the same test from a 2.8 TASStudio to another 2.8 TASStudio shows consistent, and expected, behavior.

2022-12-28.19-59-45-1.mp4

BTW mnemonics don't matter, only char order does. tastudio just checks if it's a dot or not, and sets the mnemonic in its place if it's not.

Pasting a single four button frame from TAStudio for the arbitrary example platform (in this case, SMS), I see:

|..|UDLR..|......|

These positions match the first video's example. Genuinely, it was just removing as many variables as possible from the given example.

---

Unrelated, always good to see you ever since working together on that Java bug 🙃

[Morilli]

As far as I can see, there are two separate issues here:

1. Pasting excludes the latest line if it isn't followed by a newline
2. Sometimes, trying to paste input doesn't work

The relevant code is

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

Lines 453 to 493 in 9bc1646

	{
	if (TasView.Focused && TasView.AnyRowsSelected)
	{
	// TODO: if highlighting 2 rows and pasting 3, only paste 2 of them
	// FCEUX Taseditor doesn't do this, but I think it is the expected behavior in editor programs
	// TODO: copy paste from PasteInsertMenuItem_Click!
	IDataObject data = Clipboard.GetDataObject();
	if (data != null && data.GetDataPresent(DataFormats.StringFormat))
	{
	string input = (string)data.GetData(DataFormats.StringFormat);
	if (!string.IsNullOrWhiteSpace(input))
	{
	string[] lines = input.Split('\n');
	if (lines.Length > 0)
	{
	_tasClipboard.Clear();
	for (int i = 0; i < lines.Length - 1; i++)
	{
	var line = ControllerFromMnemonicStr(lines[i]);
	if (line == null)
	{
	return;
	}
	_tasClipboard.Add(new TasClipboardEntry(i, line));
	}
	var rollbackFrame = CurrentTasMovie.CopyOverInput(TasView.SelectionStartIndex ?? 0, _tasClipboard.Select(static x => x.ControllerState));
	if (rollbackFrame > 0)
	{
	GoToLastEmulatedFrameIfNecessary(rollbackFrame);
	DoAutoRestore();
	}
	FullRefresh();
	}
	}
	}
	}
	}

Notice how the for loop is iterating over lines.Length - 1 lines (from the clipboard), effectively always excluding the last time, whether it's empty or contains a full input line.
One way this could be improved is for example by doing this:

-for (int i = 0; i < lines.Length - 1; i++)
+for (int i = 0; i < lines.Length; i++)
 {
+	if (lines[i].Length is 0 && i == lines.Length - 1) continue;
 	var line = ControllerFromMnemonicStr(lines[i]);
 	if (line == null)
 	{
 		return;
 	}
 
 	_tasClipboard.Add(new TasClipboardEntry(i, line));
 }

The second issue has to do with the fact that seeking past the end of the tasproj's current length (clicking below any displayed frame numbers ḯ̵̡̻̒͑̒͘n̶̨̰̿͜t̵̫͊̑̈́̽͘o̴̢̲͔̱͗̈́̀̕ ̶͎̬̣͕̎t̵͔͕͎͌h̸̛͙́̑̒̓ȩ̷̫̝̈̋͋͘ ̵̫͋̀͆̕v̴͚̳͕͒̎̀o̴̬͚͔͍̠͋ḯ̴͕̟͊͐̽ͅd̶̡̢̻͚̯͝) will not select that frame, which you can notice by the frame getting highlighted in light blue color instead of dark blue color. No idea how to resolve this at the moment but it's probably a matter of just selecting the line instead of nothing.

[Morilli]

About 2:
The issue here is that on MouseDown, a SelectCell call is issued, which promptly early-returns here:

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

Lines 1786 to 1789 in 5544bc5

	private void SelectCell(Cell cell, bool toggle = false)
	{
	if (cell.RowIndex.HasValue && cell.RowIndex < RowCount)
	{

because of the failing condition cell.RowIndex < RowCount.
Removing this condition works... sometimes. (?)
Another way to fix this could be to select the current row in the StopSeeking function, although I'm not 100% sure that will always be the correct thing to do. For example, shift+clicking will currently cause a seek to the selected frame, but not select it. I am also unsure whether that is intentional and/or useful.

[vadosnaprimer]

Regarding 1, I think it's okay to not require that the last line is complete. You can't partially select columns in tastudio, but you can in a text editor. Even though an obvious suggestion would be using macros, text editor is fine as long as it works without breaking anything else.