tui_scrollbar/
glyphs.rs

1//! Glyph configuration for scrollbar rendering.
2
3/// Glyphs used to render the track, arrows, and thumb.
4///
5/// Arrays use indices 0..=7 to represent 1/8th through full coverage.
6#[derive(Debug, Clone, PartialEq, Eq)]
7pub struct GlyphSet {
8    /// Track glyph for vertical scrollbars.
9    pub track_vertical: char,
10    /// Track glyph for horizontal scrollbars.
11    pub track_horizontal: char,
12    /// Arrow glyph for the start of a vertical scrollbar (top).
13    pub arrow_vertical_start: char,
14    /// Arrow glyph for the end of a vertical scrollbar (bottom).
15    pub arrow_vertical_end: char,
16    /// Arrow glyph for the start of a horizontal scrollbar (left).
17    pub arrow_horizontal_start: char,
18    /// Arrow glyph for the end of a horizontal scrollbar (right).
19    pub arrow_horizontal_end: char,
20    /// Thumb glyphs for vertical lower fills (1/8th through full).
21    pub thumb_vertical_lower: [char; 8],
22    /// Thumb glyphs for vertical upper fills (1/8th through full).
23    pub thumb_vertical_upper: [char; 8],
24    /// Thumb glyphs for horizontal left fills (1/8th through full).
25    pub thumb_horizontal_left: [char; 8],
26    /// Thumb glyphs for horizontal right fills (1/8th through full).
27    pub thumb_horizontal_right: [char; 8],
28}
29
30impl GlyphSet {
31    /// Minimal glyphs: no visible track by default.
32    ///
33    /// This uses a space character for the track so the scrollbar is "all thumb", with the
34    /// background color coming from `track_style`.
35    ///
36    /// ```plain
37    /// [██      ]
38    /// [🮋█▏     ]
39    /// [🮊█▎     ]
40    /// [🮉█▍     ]
41    /// [▐█▌     ]
42    /// [🮈█▋     ]
43    /// [🮇█▊     ]
44    /// [▕█▉     ]
45    /// [ ██     ]
46    /// ```
47    pub const fn minimal() -> Self {
48        let mut glyphs = Self::symbols_for_legacy_computing();
49        glyphs.track_vertical = ' ';
50        glyphs.track_horizontal = ' ';
51        glyphs
52    }
53
54    /// Glyphs that include box-drawing line symbols for the track.
55    ///
56    /// ```plain
57    /// [██──────]
58    /// [🮋█▏─────]
59    /// [🮊█▎─────]
60    /// [🮉█▍─────]
61    /// [▐█▌─────]
62    /// [🮈█▋─────]
63    /// [🮇█▊─────]
64    /// [▕█▉─────]
65    /// [─██─────]
66    /// ```
67    pub const fn box_drawing() -> Self {
68        Self::symbols_for_legacy_computing()
69    }
70
71    /// Glyphs that mix standard block elements with legacy supplement glyphs.
72    ///
73    /// Use this to get full 1/8th coverage for upper and right edges that the standard block set
74    /// lacks; these glyphs come from [Symbols for Legacy Computing].
75    ///
76    /// ```plain
77    /// [██──────]
78    /// [🮋█▏─────]
79    /// [🮊█▎─────]
80    /// [🮉█▍─────]
81    /// [▐█▌─────]
82    /// [🮈█▋─────]
83    /// [🮇█▊─────]
84    /// [▕█▉─────]
85    /// [─██─────]
86    /// ```
87    ///
88    /// [Symbols for Legacy Computing]: https://en.wikipedia.org/wiki/Symbols_for_Legacy_Computing
89    pub const fn symbols_for_legacy_computing() -> Self {
90        let vertical_lower = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
91        let vertical_upper = ['▔', '🮂', '🮃', '▀', '🮄', '🮅', '🮆', '█'];
92        let horizontal_left = ['▏', '▎', '▍', '▌', '▋', '▊', '▉', '█'];
93        let horizontal_right = ['▕', '🮇', '🮈', '▐', '🮉', '🮊', '🮋', '█'];
94        Self {
95            track_vertical: '│',
96            track_horizontal: '─',
97            arrow_vertical_start: '▲',
98            arrow_vertical_end: '▼',
99            arrow_horizontal_start: '◀',
100            arrow_horizontal_end: '▶',
101            thumb_vertical_lower: vertical_lower,
102            thumb_vertical_upper: vertical_upper,
103            thumb_horizontal_left: horizontal_left,
104            thumb_horizontal_right: horizontal_right,
105        }
106    }
107
108    /// Glyphs using only standard Unicode block elements.
109    ///
110    /// Use this if your font lacks the legacy glyphs.
111    ///
112    /// The standard block set does not include 1/8th upper or right fills (those come from
113    /// [Symbols for Legacy Computing]), so this set approximates upper and right partials by
114    /// rounding to coarse blocks:
115    ///
116    /// - ~1/4: `▔` / `▕`
117    /// - ~1/2 and ~3/4: `▀` / `▐`
118    /// - ~7/8 and full: `█`
119    ///
120    /// ```plain
121    /// [██──────]
122    /// [██▏─────]
123    /// [▐█▎─────]
124    /// [▐█▍─────]
125    /// [▐█▌─────]
126    /// [▐█▋─────]
127    /// [▕█▊─────]
128    /// [▕█▉─────]
129    /// [─██─────]
130    /// ```
131    pub const fn unicode() -> Self {
132        let vertical_lower = ['▁', '▂', '▃', '▄', '▅', '▆', '▇', '█'];
133        let vertical_upper = ['▔', '▔', '▀', '▀', '▀', '▀', '█', '█'];
134        let horizontal_left = ['▏', '▎', '▍', '▌', '▋', '▊', '▉', '█'];
135        let horizontal_right = ['▕', '▕', '▐', '▐', '▐', '▐', '█', '█'];
136        Self {
137            track_vertical: '│',
138            track_horizontal: '─',
139            arrow_vertical_start: '▲',
140            arrow_vertical_end: '▼',
141            arrow_horizontal_start: '◀',
142            arrow_horizontal_end: '▶',
143            thumb_vertical_lower: vertical_lower,
144            thumb_vertical_upper: vertical_upper,
145            thumb_horizontal_left: horizontal_left,
146            thumb_horizontal_right: horizontal_right,
147        }
148    }
149}
150
151impl Default for GlyphSet {
152    fn default() -> Self {
153        Self::minimal()
154    }
155}
tui_scrollbar/glyphs.rs

tui_scrollbar/
glyphs.rs
