terminal "goes dead" after quitting a TUI application

[ExpandingMan]

Any time a break a loop (and I don't mean through an error, just normally), the terminal "goes dead" meaning that it no longer appears to accept any user input. I figured this was coming from somewhere in TUI.cleanup() (since the programs themselves seemed to work normally) but this seems to happen even if TUI.cleanup() is not called, so something seems to be going wrong before this.

This is happening on alacritty. I happened to have gnome-terminal on this machine so I checked that, and I get the same behavior, so it probably isn't terminal specific.

[kdheepak]

Do you mean after hitting Ctrl+C?

[ExpandingMan]

Nope, just normal exiting. In one of your examples, it's q to break the loop, even hitting q lands me in this issue.

[kdheepak]

Are you calling TUI.initialize()?

TerminalUserInterfaces.jl/src/utils.jl

Lines 202 to 217 in 4217d1a

	function initialize()
	backup_termios()
	tui_mode()
	hide_cursor()
	enable_raw_mode()
	clear_screen()
	move_cursor_home()
	end
	function cleanup()
	move_cursor_home()
	clear_screen()
	disable_raw_mode()
	show_cursor()
	default_mode()
	end

TUI.initialize() does the following:

1. Backs up termios settings for restore
2. Switches to tui_mode(), i.e. switches to the alternate terminal buffer
3. Hides the cursor
4. Enables the raw mode
5. Clears the alternate terminal buffer screen
6. Moves the cursor to the first row first column

One TUI.initialize() is called, since you are in raw mode, it'll consume all key presses without echoing them back. TUI.cleanup() undoes the above, you should should now be in the same state as you were before calling TUI.initialize().

I'm not surprised that that when you don't call TUI.cleanup(), you are seeing a "dead" terminal. You can call any of those functions in the cleanup manually too btw.

When you hit q and call TUI.cleanup(), does the cursor show? Are you still in the alternate buffer?

[ExpandingMan]

Yup, I'm literally just running your examples. Yes, I do see the cursor after quitting normally with q and call TUI.cleanup(). Note that this issue does not seem to depend on how I exit, in the list example, it happens even if I choose an option. I do indeed see the normal output as expected, everything looks normal, I just can't do anything. (So presumably I'm no longer in the alternate buffer.)

Note that I have just tried this on a different computer, just for the hell of it. Both are in alacritty in linux, but figured I'd try it for the hell of it.

If I had to guess, I'd say this isn't getting out of raw mode for some reason, but I have no idea why.

[kdheepak]

Yeah it does seem like a bug in the termios restore. I’m just trying to figure out what that is. When you are in that “dead” state, what happens if you type reset and hit Enter?

[kdheepak]

Note for myself, this is potentially related to this issue: kdheepak/TERMIOS.jl#6

[ExpandingMan]

Typing reset and then enter in the "dead" state does not seem to do anything.

[rfourquet]

I think I'm hitting the same problem. More specifically, when running an example like julia examples/barchart.jl on the command line, there is no problem, but when I include the file from within the Julia REPL, my whole screen goes "dead" (after quitting the TUI app with q), and I have to kill the julia process. Do you know of a trick to get out of the dead state without having to kill julia?

[Cyrannosaurus]

copying the code examples straight from GitHub and pasting in the REPL also leads to the REPL freezing/dying. Everything works while in the example until using 'q'. The program exits, I'm back in REPL, and cannot do anything but terminate the process.

[kdheepak]

Can you tell me what terminal / operating system?

[kdheepak]

Can someone who has had this issue try it again in v0.3.0:

https://github.com/kdheepak/TerminalUserInterfaces.jl/releases/tag/v0.3.0

It should be resolved now (I've updated the examples too, there's no longer a TUI.initialize()).