Tab characters not shown in TUI

[osa1]

@Kabouik reported on IRC that tiny doesn't show tab characters. Haven't check the code yet but I wouldn't be surprised if we just completely ignore tab characters in termbox.

[Kabouik]

Thanks for opening the issue @osa1. To illustrate the problem, if I use $EDITOR (Kakoune in my case) to post this in Tiny:

<div>
	<p>
		aaa
	</p>
	<p>
		bbb
	</p>
</div>

<div>
    <p>
        Let's see if it's related to my editor using \t instead of spaces.
    </p>
</div>

I get this:

And it seems others using other clients see the indentation even when I use only tabs, but they didn't tell me which client they were using. @sarnold in the #tiny channel showed that irssi users see that:

irssi in tmux in mosh in urxvt. The capital Is are inverse video tabs.

Fri 05 14:58:53 < Kabouik> <div>
Fri 05 14:58:53 < Kabouik> I<p>
Fri 05 14:58:53 < Kabouik> IIaaa
Fri 05 14:58:55 < Kabouik> I</p>
Fri 05 14:58:55 < Kabouik> I<p>
Fri 05 14:58:57 < Kabouik> IIbbb
Fri 05 14:58:57 < Kabouik> I</p>
Fri 05 14:58:59 < Kabouik> </div>
Fri 05 14:58:59 < Kabouik>  
Fri 05 14:59:01 < Kabouik> <div>
Fri 05 14:59:01 < Kabouik>     <p>
Fri 05 14:59:03 < Kabouik>         Let's see if it's related to my editor using \t instead of spaces.
Fri 05 14:59:03 < Kabouik>     </p>
Fri 05 14:59:05 < Kabouik> </div>
Fri 05 14:59:33 < Kabouik> Yeah, I can see space-identation, not tab-identation
Fri 05 14:59:48 < Kabouik> But apparently others using other IRC clients could see tab-identation too

[osa1]

termbox's tab handling is fine. Here's an example:

use term_input::{Event, Input, Key};
use termbox_simple::*;
use tokio::stream::StreamExt;

fn main() {
    let mut tui = Termbox::init().unwrap();

    draw(&mut tui);

    let runtime = tokio::runtime::Builder::new_current_thread()
        .enable_all()
        .build()
        .unwrap();
    let local = tokio::task::LocalSet::new();

    local.block_on(&runtime, async move {
        let mut input = Input::new();
        while let Some(mb_ev) = input.next().await {
            match mb_ev {
                Err(_) => {}
                Ok(Event::Key(Key::Esc)) => {
                    return;
                }
                Ok(_) => {}
            }
            draw(&mut tui);
        }
    });
}

fn draw(tui: &mut Termbox) {
    tui.clear();

    tui.change_cell(0, 0, '\t', 0, 1);
    tui.change_cell(1, 0, 'x', 0, 1);

    tui.present();
}

When I run this I see

        x

so the tab is rendered as 8 spaces.

[osa1]

This must be where we drop the tab character, as it's considered a "control" character:

tiny/libtiny_tui/src/utils.rs

Lines 92 to 135 in e82046a

	/// Translate IRC color codes using the callback, and remove ASCII control chars from the input.
	pub(crate) fn translate_irc_control_chars(
	str: &str,
	push_color: fn(ret: &mut String, fg: u8, bg: Option<u8>),
	) -> String {
	let mut ret = String::with_capacity(str.len());
	let mut iter = str.chars().peekable();
	while let Some(char) = iter.next() {
	if char == '\x03' {
	match parse_color_code(&mut iter) {
	None => {
	// just skip the control char
	}
	Some(fg) => {
	if let Some(char) = iter.peek().cloned() {
	if char == ',' {
	iter.next(); // consume ','
	match parse_color_code(&mut iter) {
	None => {
	// comma was not part of the color code,
	// add it to the new string
	push_color(&mut ret, fg, None);
	ret.push(char);
	}
	Some(bg) => {
	push_color(&mut ret, fg, Some(bg));
	}
	}
	} else {
	push_color(&mut ret, fg, None);
	}
	} else {
	push_color(&mut ret, fg, None);
	}
	}
	}
	} else if !char.is_ascii_control() {
	ret.push(char);
	}
	}
	ret
	}

[osa1]

Fixed.

Note that we don't handle entering wide characters (characters that take more than one row on screen, e.g. Ｈ) in the input widget yet. I'll create another issue for that.

[osa1]

Note that we don't handle entering wide characters (characters that take more than one row on screen, e.g. Ｈ) in the input widget yet. I'll create another issue for that.

Tracked in #306.