scrin 0.1.83

A terminal UI toolkit with panes, widgets, overlays, animations, and Aisling-powered effects/loaders.
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

use crate::core::buffer::Buffer;
use crate::core::color::Color;
use crate::core::rect::Rect;
use crate::widgets::Widget;

#[derive(Debug, Clone, Copy, PartialEq)]
pub enum ScrollBarOrientation {
    Vertical,
    Horizontal,
}

#[derive(Debug, Clone)]
pub struct ScrollBar {
    pub position: usize,
    pub total: usize,
    pub viewport: usize,
    pub orientation: ScrollBarOrientation,
    pub track_color: Color,
    pub thumb_color: Color,
    pub arrow_color: Color,
}

impl ScrollBar {
    pub fn new(orientation: ScrollBarOrientation) -> Self {
        Self {
            position: 0,
            total: 100,
            viewport: 10,
            orientation,
            track_color: Color::rgb(48, 54, 61),
            thumb_color: Color::rgb(88, 166, 255),
            arrow_color: Color::rgb(139, 148, 158),
        }
    }

    pub fn with_position(mut self, pos: usize) -> Self {
        self.position = pos;
        self
    }

    pub fn with_total(mut self, total: usize) -> Self {
        self.total = total;
        self
    }

    pub fn with_viewport(mut self, vp: usize) -> Self {
        self.viewport = vp;
        self
    }

    pub fn thumb_position(&self) -> usize {
        if self.total <= self.viewport {
            return 0;
        }
        let track_len = if self.orientation == ScrollBarOrientation::Vertical {
            10
        } else {
            20
        };
        let thumb_len = ((self.viewport as f64 / self.total as f64) * track_len as f64) as usize;
        let max_pos = self.total.saturating_sub(self.viewport);
        if max_pos == 0 {
            0
        } else {
            let pos =
                (self.position as f64 / max_pos as f64 * (track_len - thumb_len) as f64) as usize;
            pos.min(track_len.saturating_sub(thumb_len))
        }
    }
}

impl Widget for ScrollBar {
    fn render(&self, buffer: &mut Buffer, area: Rect) {
        match self.orientation {
            ScrollBarOrientation::Vertical => self.render_vertical(buffer, area),
            ScrollBarOrientation::Horizontal => self.render_horizontal(buffer, area),
        }
    }
}

impl ScrollBar {
    fn render_vertical(&self, buffer: &mut Buffer, area: Rect) {
        let h = area.height as usize;
        let thumb_len = ((self.viewport as f64 / self.total as f64) * h as f64).max(1.0) as usize;
        let thumb_pos = self.thumb_position();

        for i in 0..h {
            let x = area.x as usize;
            let y = area.y as usize + i;
            let is_thumb = i >= thumb_pos && i < thumb_pos + thumb_len;
            let ch = if is_thumb { '█' } else { '░' };
            let fg = if is_thumb {
                self.thumb_color
            } else {
                self.track_color
            };
            buffer.set(
                x,
                y,
                crate::core::buffer::Cell {
                    ch,
                    fg,
                    bg: None,
                    bold: false,
                    italic: false,
                    underlined: false,
                },
            );
        }
    }

    fn render_horizontal(&self, buffer: &mut Buffer, area: Rect) {
        let w = area.width as usize;
        let thumb_len = ((self.viewport as f64 / self.total as f64) * w as f64).max(1.0) as usize;
        let thumb_pos = self.thumb_position();

        for i in 0..w {
            let x = area.x as usize + i;
            let y = area.y as usize;
            let is_thumb = i >= thumb_pos && i < thumb_pos + thumb_len;
            let ch = if is_thumb { '█' } else { '░' };
            let fg = if is_thumb {
                self.thumb_color
            } else {
                self.track_color
            };
            buffer.set(
                x,
                y,
                crate::core::buffer::Cell {
                    ch,
                    fg,
                    bg: None,
                    bold: false,
                    italic: false,
                    underlined: false,
                },
            );
        }
    }
}