ggplot_rs/scale/
manual.rs

1use crate::aes::Aesthetic;
2use crate::data::Value;
3
4use super::color::RGBAColor;
5use super::Scale;
6
7/// Manual color scale — maps named levels to user-specified colors.
8#[derive(Clone, Debug)]
9pub struct ScaleManual {
10    aesthetic: Aesthetic,
11    name: String,
12    levels: Vec<String>,
13    colors: Vec<RGBAColor>,
14}
15
16impl ScaleManual {
17    pub fn new(aesthetic: Aesthetic, values: Vec<(&str, RGBAColor)>) -> Self {
18        let levels: Vec<String> = values.iter().map(|(k, _)| k.to_string()).collect();
19        let colors: Vec<RGBAColor> = values.iter().map(|(_, c)| *c).collect();
20        ScaleManual {
21            aesthetic,
22            name: String::new(),
23            levels,
24            colors,
25        }
26    }
27}
28
29impl Scale for ScaleManual {
30    fn aesthetic(&self) -> Aesthetic {
31        self.aesthetic.clone()
32    }
33
34    fn train(&mut self, values: &[Value]) {
35        for v in values {
36            let key = v.to_group_key();
37            if !self.levels.contains(&key) {
38                self.levels.push(key);
39            }
40        }
41    }
42
43    fn map(&self, value: &Value) -> f64 {
44        let key = value.to_group_key();
45        self.levels
46            .iter()
47            .position(|l| l == &key)
48            .map(|i| i as f64)
49            .unwrap_or(0.0)
50    }
51
52    fn breaks(&self) -> Vec<(f64, String)> {
53        self.levels
54            .iter()
55            .enumerate()
56            .map(|(i, label)| (i as f64, label.clone()))
57            .collect()
58    }
59
60    fn name(&self) -> &str {
61        &self.name
62    }
63
64    fn set_name(&mut self, name: &str) {
65        self.name = name.to_string();
66    }
67
68    fn is_discrete(&self) -> bool {
69        true
70    }
71
72    fn map_to_color(&self, value: &Value) -> Option<(u8, u8, u8)> {
73        let key = value.to_group_key();
74        let idx = self.levels.iter().position(|l| l == &key).unwrap_or(0);
75        if idx < self.colors.len() {
76            let c = self.colors[idx];
77            Some((c.r, c.g, c.b))
78        } else {
79            // Wrap around
80            let c = self.colors[idx % self.colors.len()];
81            Some((c.r, c.g, c.b))
82        }
83    }
84
85    fn clone_box(&self) -> Box<dyn Scale> {
86        Box::new(self.clone())
87    }
88
89    fn reset_training(&mut self) {
90        self.levels.clear();
91    }
92}
ggplot_rs/scale/manual.rs

ggplot_rs/scale/
manual.rs
