Issue with tab character in SelectView item

[julienXX]

This is a bug report

Problem description

When adding an item containing a tab character in a SelectView the text is truncated.

Some code to reproduce the issue:

extern crate native_tls;

use cursive::traits::*;
use cursive::views::{Dialog, SelectView};
use cursive::Cursive;

fn main() {
    let mut select = SelectView::new();

    select.add_item("there is a \ttab", 1);
    select.add_item("there is no tab", 2);

    let mut siv = Cursive::default();

    siv.add_layer(
        Dialog::around(select.fixed_size((20, 10)))
    );

    siv.run();
}

Here is the output I get:

Environment

• Operating system: Ubuntu 19.04
• Backend used: ncurses 6.1
• Current locale: en_US.UTF-8
• Cursive version: 0.12.0

[gyscos]

Hi, and thanks for the report! Indeed, tab characters are not very well handled. It's possible ncurses doesn't even support them?

tabs in general can be confusing as they would try to align to some column, independently of the current View offset. In general it's recommended to uses spaces and manual alignment.

[gyscos]

Possible way forward:

• Keep the current behaviour; document that some characters are not safe to print (tab, sometimes newlines, ...)
• Handle special characters in the view itself
  • Adds a potential cost only at view creation, but only protects builtin views, not custom views
• Handle special characters in the printer
  • Protects every print, but adds a potential cost per-print

I think the printer solution is probably the best long-term wise; especially if we start caching the screen state more extensively.