ggplot_rs/scale/
manual.rs

1use crate::aes::Aesthetic;
2use crate::data::Value;
3use indexmap::IndexSet;
4
5use super::color::RGBAColor;
6use super::Scale;
7
8/// Manual color scale — maps named levels to user-specified colors.
9#[derive(Clone, Debug)]
10pub struct ScaleManual {
11    aesthetic: Aesthetic,
12    name: String,
13    levels: IndexSet<String>,
14    colors: Vec<RGBAColor>,
15}
16
17impl ScaleManual {
18    pub fn new(aesthetic: Aesthetic, values: Vec<(&str, RGBAColor)>) -> Self {
19        let levels: IndexSet<String> = values.iter().map(|(k, _)| k.to_string()).collect();
20        let colors: Vec<RGBAColor> = values.iter().map(|(_, c)| *c).collect();
21        ScaleManual {
22            aesthetic,
23            name: String::new(),
24            levels,
25            colors,
26        }
27    }
28}
29
30impl Scale for ScaleManual {
31    fn aesthetic(&self) -> Aesthetic {
32        self.aesthetic.clone()
33    }
34
35    fn train(&mut self, values: &[Value]) {
36        for v in values {
37            let key = v.key_str();
38            if !self.levels.contains(key.as_ref()) {
39                self.levels.insert(key.into_owned());
40            }
41        }
42    }
43
44    fn map(&self, value: &Value) -> f64 {
45        let key = value.key_str();
46        self.levels
47            .get_index_of(key.as_ref())
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        // No values supplied (`scale_color_manual(vec![])`): no mapping, so
74        // the geom falls back to its default colour instead of panicking.
75        if self.colors.is_empty() {
76            return None;
77        }
78        let key = value.key_str();
79        let idx = self.levels.get_index_of(key.as_ref()).unwrap_or(0);
80        // Wrap around when there are more levels than colours.
81        let c = self.colors[idx % self.colors.len()];
82        Some((c.r, c.g, c.b))
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
