How to make the border text centralized

[jnmdf]

let mut t = Table::new(output); t.with(LineText::new("DescribeTargetHealth", Rows::first()).offset(2))
tabled version 0.17.0
Any other approach to set alignment center instead of calculating the offset manually

[zhiburt]

Hi @jnmdf

Ahhhhhhhhhhhhhhhhhhhhhhhh unfortunately there's no such a way.
And I can tell you it's pretty messy logic to do it right..... 😞

I think it well might be worth to be included in the lib.
If you wish you can contribute based on my example, just let me know.

But otherwise I may do it myself and release it in 0.18 which I am about to get done I wish.

You could do something like this

use std::iter::FromIterator;

use tabled::{
    grid::util::string::get_text_width,
    settings::{object::Rows, split::Split, style::LineText, Style},
    Table,
};

fn main() {
    let table = Table::from_iter(['a'..='z']);

    for layout in [2, 5, 7] {
        let mut table = table.clone();

        table.with(Split::column(layout));
        table.with(Style::modern());

        set_centered_text(&mut table, 0, "Alphabet");

        println!("{table}");
    }
}

fn set_centered_text(table: &mut Table, row: usize, text: &str) {
    let table_w = table.total_width();
    let text_w = get_text_width(text);

    let mut off = 0;
    if table_w > text_w {
        let center = table_w / 2;
        let text_center = text_w / 2;
        off = center.saturating_sub(text_center);
    }

    table.with(LineText::new(text, Rows::single(row)).offset(off));
}

Alphabet┐
│ a │ b │
├───┼───┤
│ c │ d │
├───┼───┤
│ e │ f │
├───┼───┤
│ g │ h │
├───┼───┤
│ i │ j │
├───┼───┤
│ k │ l │
├───┼───┤
│ m │ n │
├───┼───┤
│ o │ p │
├───┼───┤
│ q │ r │
├───┼───┤
│ s │ t │
├───┼───┤
│ u │ v │
├───┼───┤
│ w │ x │
├───┼───┤
│ y │ z │
└───┴───┘
┌───┬─Alphabet──┬───┐
│ a │ b │ c │ d │ e │
├───┼───┼───┼───┼───┤
│ f │ g │ h │ i │ j │
├───┼───┼───┼───┼───┤
│ k │ l │ m │ n │ o │
├───┼───┼───┼───┼───┤
│ p │ q │ r │ s │ t │
├───┼───┼───┼───┼───┤
│ u │ v │ w │ x │ y │
├───┼───┼───┼───┼───┤
│ z │   │   │   │   │
└───┴───┴───┴───┴───┘
┌───┬───┬─Alphabet──┬───┬───┐
│ a │ b │ c │ d │ e │ f │ g │
├───┼───┼───┼───┼───┼───┼───┤
│ h │ i │ j │ k │ l │ m │ n │
├───┼───┼───┼───┼───┼───┼───┤
│ o │ p │ q │ r │ s │ t │ u │
├───┼───┼───┼───┼───┼───┼───┤
│ v │ w │ x │ y │ z │   │   │
└───┴───┴───┴───┴───┴───┴───┘

[zhiburt]

OK I've done it.
On the next release you could just call .align(Alignment::center()).

test_table!(
    border_text_alignment_test_0,
    Matrix::table(2, 2)
         .with(LineText::new("TABLE", Rows::first()).align(Alignment::center())),
    "+---+------TABLE----------+"
    "| N | column 0 | column 1 |"
    "+---+----------+----------+"
    "| 0 |   0-0    |   0-1    |"
    "+---+----------+----------+"
    "| 1 |   1-0    |   1-1    |"
    "+---+----------+----------+"
);