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
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
/// One of the 8 base colors.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum BaseColor {
/// Black color
///
/// Color #0
Black,
/// Red color
///
/// Color #1
Red,
/// Green color
///
/// Color #2
Green,
/// Yellow color (Red + Green)
///
/// Color #3
Yellow,
/// Blue color
///
/// Color #4
Blue,
/// Magenta color (Red + Blue)
///
/// Color #5
Magenta,
/// Cyan color (Green + Blue)
///
/// Color #6
Cyan,
/// White color (Red + Green + Blue)
///
/// Color #7
White,
}
impl BaseColor {
/// Returns the regular (dark) version of this base color.
pub fn dark(self) -> Color {
Color::Dark(self)
}
/// Returns the light version of this base color.
pub fn light(self) -> Color {
Color::Light(self)
}
}
impl From<u8> for BaseColor {
fn from(n: u8) -> Self {
match n % 8 {
0 => BaseColor::Black,
1 => BaseColor::Red,
2 => BaseColor::Green,
3 => BaseColor::Yellow,
4 => BaseColor::Blue,
5 => BaseColor::Magenta,
6 => BaseColor::Cyan,
7 => BaseColor::White,
_ => unreachable!(),
}
}
}
/// Represents a color used by the theme.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum Color {
/// Represents a color, preset by terminal.
TerminalDefault,
/// One of the 8 base colors.
///
/// Note: the actual color used depends on the terminal configuration.
Dark(BaseColor),
/// Lighter version of a base color.
///
/// Note: the actual color used depends on the terminal configuration.
Light(BaseColor),
/// True-color, 24-bit.
Rgb(u8, u8, u8),
/// Low-resolution
///
/// Each value should be `<= 5` (you'll get panics otherwise).
///
/// These 216 possible colors are part of the default color palette.
RgbLowRes(u8, u8, u8),
}
impl Color {
/// Creates a color from its ID in the 256 colors list.
///
/// * Colors 0-7 are base dark colors.
/// * Colors 8-15 are base light colors.
/// * Colors 16-231 are rgb colors with 6 values per channel (216 colors).
/// * Colors 232-255 are grayscale colors.
pub fn from_256colors(n: u8) -> Self {
if n < 8 {
Color::Dark(BaseColor::from(n))
} else if n < 16 {
Color::Light(BaseColor::from(n))
} else if n >= 232 {
let n = n - 232;
let value = 8 + 10 * n;
// TODO: returns a Grayscale value?
Color::Rgb(value, value, value)
} else {
let n = n - 16;
// We support 6*6*6 = 216 colors here
assert!(n < 216);
let r = n / 36;
let g = (n % 36) / 6;
let b = n % 6;
// Each color is in the range [0, 5] (6 possible values)
assert!(r < 6);
assert!(g < 6);
assert!(b < 6);
Color::RgbLowRes(r, g, b)
}
}
/// Parse a string into a color.
///
/// Examples:
/// * `"red"` becomes `Color::Dark(BaseColor::Red)`
/// * `"light green"` becomes `Color::Light(BaseColor::Green)`
/// * `"default"` becomes `Color::TerminalDefault`
/// * `"#123456"` becomes `Color::Rgb(0x12, 0x34, 0x56)`
pub fn parse(value: &str) -> Option<Self> {
Some(match value {
"black" => Color::Dark(BaseColor::Black),
"red" => Color::Dark(BaseColor::Red),
"green" => Color::Dark(BaseColor::Green),
"yellow" => Color::Dark(BaseColor::Yellow),
"blue" => Color::Dark(BaseColor::Blue),
"magenta" => Color::Dark(BaseColor::Magenta),
"cyan" => Color::Dark(BaseColor::Cyan),
"white" => Color::Dark(BaseColor::White),
"light black" => Color::Light(BaseColor::Black),
"light red" => Color::Light(BaseColor::Red),
"light green" => Color::Light(BaseColor::Green),
"light yellow" => Color::Light(BaseColor::Yellow),
"light blue" => Color::Light(BaseColor::Blue),
"light magenta" => Color::Light(BaseColor::Magenta),
"light cyan" => Color::Light(BaseColor::Cyan),
"light white" => Color::Light(BaseColor::White),
"default" => Color::TerminalDefault,
value => return Color::parse_special(value),
})
}
fn parse_special(value: &str) -> Option<Color> {
if value.starts_with('#') {
let value = &value[1..];
// Compute per-color length, and amplitude
let (l, multiplier) = match value.len() {
6 => (2, 1),
3 => (1, 17),
_ => panic!("Cannot parse color: {}", value),
};
let r = load_hex(&value[0..l]) * multiplier;
let g = load_hex(&value[l..2 * l]) * multiplier;
let b = load_hex(&value[2 * l..3 * l]) * multiplier;
Some(Color::Rgb(r as u8, g as u8, b as u8))
} else if value.len() == 3 {
// RGB values between 0 and 5 maybe?
// Like 050 for green
let rgb: Vec<_> =
value.chars().map(|c| c as i16 - '0' as i16).collect();
assert_eq!(rgb.len(), 3);
if rgb.iter().all(|&i| i >= 0 && i < 6) {
Some(Color::RgbLowRes(
rgb[0] as u8,
rgb[1] as u8,
rgb[2] as u8,
))
} else {
None
}
} else {
None
}
}
}
/// Loads a hexadecimal code
fn load_hex(s: &str) -> u16 {
let mut sum = 0;
for c in s.chars() {
sum *= 16;
sum += match c {
n @ '0'..='9' => n as i16 - '0' as i16,
n @ 'a'..='f' => n as i16 - 'a' as i16 + 10,
n @ 'A'..='F' => n as i16 - 'A' as i16 + 10,
_ => 0,
};
}
sum as u16
}
#[cfg(test)]
mod tests {
#[test]
fn test_256_colors() {
// Make sure Color::from_256colors never panics
use super::Color;
// TODO: use inclusive range when it gets stable
for i in 0..256u16 {
Color::from_256colors(i as u8);
}
}
}