ntui 0.1.0

An Ink-style TUI library for Rust: components, hooks, flexbox layout, and fullscreen rendering.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143

//! Shared helpers for emitting styled cells as ANSI to a writer.

use std::io::{self, Write};

use crossterm::{queue, style};

use crate::buffer::Cell;
use crate::style::{Attrs, Color};

pub(crate) fn to_ct(c: Color) -> style::Color {
    match c {
        Color::Reset => style::Color::Reset,
        Color::Black => style::Color::Black,
        Color::Red => style::Color::Red,
        Color::Green => style::Color::Green,
        Color::Yellow => style::Color::Yellow,
        Color::Blue => style::Color::Blue,
        Color::Magenta => style::Color::Magenta,
        Color::Cyan => style::Color::Cyan,
        Color::White => style::Color::White,
        Color::DarkGrey => style::Color::DarkGrey,
        Color::Rgb(r, g, b) => style::Color::Rgb { r, g, b },
        Color::Ansi(n) => style::Color::AnsiValue(n),
    }
}

pub(crate) fn ct_attrs(a: Attrs) -> style::Attributes {
    let mut attrs = style::Attributes::default();
    if a.bold {
        attrs.set(style::Attribute::Bold);
    }
    if a.dim {
        attrs.set(style::Attribute::Dim);
    }
    if a.italic {
        attrs.set(style::Attribute::Italic);
    }
    if a.underline {
        attrs.set(style::Attribute::Underlined);
    }
    attrs
}

/// Write one styled cell at the current cursor position.
pub(crate) fn write_cell(out: &mut impl Write, cell: &Cell) -> io::Result<()> {
    queue!(
        out,
        style::SetAttribute(style::Attribute::Reset),
        style::SetAttributes(ct_attrs(cell.attrs)),
        style::SetForegroundColor(to_ct(cell.fg)),
        style::SetBackgroundColor(to_ct(cell.bg)),
        style::Print(cell.ch),
    )
}

/// Write a row of cells at the current cursor position, trimming trailing
/// blank cells and resetting style at the end. Used for scrollback / live rows.
pub(crate) fn write_row(out: &mut impl Write, cells: &[Cell]) -> io::Result<()> {
    let end = cells
        .iter()
        .rposition(|c| *c != Cell::default())
        .map(|i| i + 1)
        .unwrap_or(0);
    for cell in &cells[..end] {
        write_cell(out, cell)?;
    }
    queue!(out, style::SetAttribute(style::Attribute::Reset))
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn to_ct_maps_every_color_variant() {
        assert_eq!(to_ct(Color::Reset), style::Color::Reset);
        assert_eq!(to_ct(Color::Black), style::Color::Black);
        assert_eq!(to_ct(Color::Red), style::Color::Red);
        assert_eq!(to_ct(Color::Green), style::Color::Green);
        assert_eq!(to_ct(Color::Yellow), style::Color::Yellow);
        assert_eq!(to_ct(Color::Blue), style::Color::Blue);
        assert_eq!(to_ct(Color::Magenta), style::Color::Magenta);
        assert_eq!(to_ct(Color::Cyan), style::Color::Cyan);
        assert_eq!(to_ct(Color::White), style::Color::White);
        assert_eq!(to_ct(Color::DarkGrey), style::Color::DarkGrey);
        assert_eq!(
            to_ct(Color::Rgb(1, 2, 3)),
            style::Color::Rgb { r: 1, g: 2, b: 3 }
        );
        assert_eq!(to_ct(Color::Ansi(42)), style::Color::AnsiValue(42));
    }

    #[test]
    fn write_cell_emits_every_attribute() {
        let mut out = Vec::new();
        write_cell(
            &mut out,
            &Cell {
                ch: 'x',
                fg: Color::Red,
                bg: Color::Blue,
                attrs: Attrs {
                    bold: true,
                    dim: true,
                    italic: true,
                    underline: true,
                },
            },
        )
        .unwrap();
        assert!(String::from_utf8(out).unwrap().contains('x'));
    }

    #[test]
    fn write_row_all_blank_emits_only_reset() {
        let mut out = Vec::new();
        write_row(&mut out, &[Cell::default(), Cell::default()]).unwrap();
        // Trimmed to zero cells; still succeeds (emits a trailing style reset).
        assert!(!String::from_utf8(out).unwrap().contains('x'));
    }

    #[test]
    fn write_row_trims_trailing_blanks() {
        let mut out = Vec::new();
        let cells = [
            Cell {
                ch: 'h',
                ..Cell::default()
            },
            Cell {
                ch: 'i',
                ..Cell::default()
            },
            Cell::default(),
            Cell::default(),
        ];
        write_row(&mut out, &cells).unwrap();
        let s = String::from_utf8(out).unwrap();
        assert!(s.contains('h') && s.contains('i'));
        // trailing blanks trimmed → only two Print payloads
        assert_eq!(s.matches('h').count() + s.matches('i').count(), 2);
    }
}