ggplot_rs/scale/
scale_set.rs

1use crate::aes::Aesthetic;
2use crate::data::{DataFrame, Value};
3use crate::render::backend::{Linetype, PointShape};
4use crate::scale::alpha::ScaleAlphaContinuous;
5use crate::scale::color::{ScaleColorContinuous, ScaleColorDiscrete};
6use crate::scale::continuous::ScaleContinuous;
7use crate::scale::datetime::ScaleDateTime;
8use crate::scale::discrete::ScaleDiscrete;
9use crate::scale::linetype::ScaleLinetypeDiscrete;
10use crate::scale::linewidth::ScaleLinewidthContinuous;
11use crate::scale::shape::ScaleShapeDiscrete;
12use crate::scale::size::ScaleSizeContinuous;
13
14use super::Scale;
15
16/// Registry of all scales for a plot. Handles auto-detection and training.
17pub struct ScaleSet {
18    scales: Vec<Box<dyn Scale>>,
19}
20
21impl ScaleSet {
22    pub fn new() -> Self {
23        ScaleSet { scales: Vec::new() }
24    }
25
26    /// Add a user-specified scale.
27    pub fn add(&mut self, scale: Box<dyn Scale>) {
28        // Replace existing scale for same aesthetic
29        let aes = scale.aesthetic();
30        self.scales.retain(|s| s.aesthetic() != aes);
31        self.scales.push(scale);
32    }
33
34    /// Give every scale the plot-level default locale (scales with their own
35    /// locale keep it; scales without numeric/date labels ignore it).
36    pub fn set_default_locale(&mut self, locale: &crate::locale::Locale) {
37        for s in &mut self.scales {
38            s.set_default_locale(locale);
39        }
40    }
41
42    /// Get a scale for a specific aesthetic.
43    pub fn get(&self, aes: &Aesthetic) -> Option<&dyn Scale> {
44        self.scales
45            .iter()
46            .find(|s| s.aesthetic() == *aes)
47            .map(|s| s.as_ref())
48    }
49
50    /// Get mutable scale for a specific aesthetic.
51    pub fn get_mut(&mut self, aes: &Aesthetic) -> Option<&mut Box<dyn Scale>> {
52        self.scales.iter_mut().find(|s| s.aesthetic() == *aes)
53    }
54
55    /// Ensure a scale exists for a given aesthetic. Auto-detect type from data.
56    pub fn ensure_scale(&mut self, aes: &Aesthetic, data: &DataFrame) {
57        if self.get(aes).is_some() {
58            return;
59        }
60        // OHLC values live on the y scale (via the geom's ymin/ymax extents);
61        // they get no scale of their own.
62        if matches!(
63            aes,
64            Aesthetic::Open
65                | Aesthetic::High
66                | Aesthetic::Low
67                | Aesthetic::Close
68                | Aesthetic::Slope
69                | Aesthetic::Intercept
70                // Reference-line intercepts live on the x / y scale; the
71                // build creates that scale from them only if no layer did
72                // (so a `geom_vline(0)` added first can't force a
73                // continuous scale onto a discrete axis).
74                | Aesthetic::Xintercept
75                | Aesthetic::Yintercept
76                // Interactive aesthetics carry their value straight through
77                // to the mark's attributes — no visual mapping, no legend.
78                | Aesthetic::Tooltip
79                | Aesthetic::DataAttr(_)
80                | Aesthetic::Class
81                | Aesthetic::GroupWrap(_)
82                // Per-row fontface (#228) is parsed straight into
83                // `FontFace` — no visual mapping, no legend.
84                | Aesthetic::Fontface
85                // Boxplot stat="identity" hinges/outliers (B3-5) live on
86                // the y scale (via `column_aesthetic`/`Y_FAMILY`/the
87                // build's stat_aes training list), not a scale of their
88                // own.
89                | Aesthetic::Lower
90                | Aesthetic::Middle
91                | Aesthetic::Upper
92                | Aesthetic::Outliers
93                // Edge-list node names (flow charts) — no scale.
94                | Aesthetic::From
95                | Aesthetic::To
96                | Aesthetic::Subgroup
97                | Aesthetic::Sets
98        ) {
99            return;
100        }
101        // A position scale created from extent columns alone (`xmin`/`xmax`
102        // with no `x`, e.g. a Gantt bar) detects its type from them, so a
103        // date range still gets a date scale.
104        let fallback: &[&str] = match aes {
105            Aesthetic::X => &["xmin", "xmax", "xend"],
106            Aesthetic::Y => &["ymin", "ymax", "yend"],
107            _ => &[],
108        };
109        let values = data
110            .column(aes.col_name())
111            .or_else(|| fallback.iter().find_map(|c| data.column(c)));
112
113        let is_discrete = match values {
114            Some(vals) => vals
115                .iter()
116                .any(|v| matches!(v, Value::Str(_) | Value::Bool(_))),
117            None => false,
118        };
119
120        let is_datetime = match values {
121            Some(vals) => vals.iter().any(|v| v.is_datetime()),
122            None => false,
123        };
124
125        match aes {
126            Aesthetic::Color | Aesthetic::Fill => {
127                if is_discrete {
128                    let scale = ScaleColorDiscrete::new(aes.clone());
129                    self.scales.push(Box::new(scale));
130                } else {
131                    let scale = ScaleColorContinuous::new(aes.clone());
132                    self.scales.push(Box::new(scale));
133                }
134            }
135            Aesthetic::Shape => {
136                let scale = ScaleShapeDiscrete::new();
137                self.scales.push(Box::new(scale));
138            }
139            Aesthetic::Linetype => {
140                let scale = ScaleLinetypeDiscrete::new();
141                self.scales.push(Box::new(scale));
142            }
143            Aesthetic::Size => {
144                let scale = ScaleSizeContinuous::new();
145                self.scales.push(Box::new(scale));
146            }
147            Aesthetic::Linewidth => {
148                let scale = ScaleLinewidthContinuous::new();
149                self.scales.push(Box::new(scale));
150            }
151            Aesthetic::Alpha => {
152                let scale = ScaleAlphaContinuous::new();
153                self.scales.push(Box::new(scale));
154            }
155            _ => {
156                if is_discrete {
157                    let scale = ScaleDiscrete::new().for_aesthetic(aes.clone());
158                    self.scales.push(Box::new(scale));
159                } else if is_datetime {
160                    let scale = ScaleDateTime::new().for_aesthetic(aes.clone());
161                    self.scales.push(Box::new(scale));
162                } else {
163                    let scale = ScaleContinuous::new().for_aesthetic(aes.clone());
164                    self.scales.push(Box::new(scale));
165                }
166            }
167        }
168    }
169
170    /// Train all scales on data from one layer.
171    pub fn train_layer(&mut self, data: &DataFrame) {
172        for scale in &mut self.scales {
173            let col_name = scale.aesthetic().col_name().to_string();
174            if let Some(values) = data.column(&col_name) {
175                scale.train(values);
176            }
177        }
178    }
179
180    /// Map a single value through the appropriate scale.
181    pub fn map_value(&self, aes: &Aesthetic, value: &Value) -> f64 {
182        self.get(aes).map(|s| s.map(value)).unwrap_or(0.0)
183    }
184
185    /// Map a value to an RGB color through the appropriate color/fill scale.
186    pub fn map_color(&self, aes: &Aesthetic, value: &Value) -> Option<(u8, u8, u8)> {
187        self.get(aes).and_then(|s| s.map_to_color(value))
188    }
189
190    /// The `aes` scale's configured na-pattern, if any (`ScaleFillBinned::
191    /// na_pattern`, #206) — a geom checks this for a row/key it would
192    /// otherwise draw with the scale's flat na colour, before falling
193    /// back to [`map_color`](Self::map_color)'s plain result.
194    pub fn na_fill_pattern(&self, aes: &Aesthetic) -> Option<crate::render::backend::FillPattern> {
195        self.get(aes).and_then(|s| s.na_fill_pattern())
196    }
197
198    /// Map a value to a point shape through the shape scale.
199    pub fn map_shape(&self, value: &Value) -> Option<PointShape> {
200        self.get(&Aesthetic::Shape)
201            .and_then(|s| s.map_to_shape(value))
202    }
203
204    /// Map a value to a linetype through the linetype scale.
205    pub fn map_linetype(&self, value: &Value) -> Option<Linetype> {
206        self.get(&Aesthetic::Linetype)
207            .and_then(|s| s.map_to_linetype(value))
208    }
209
210    /// Map a value to a point size through the size scale.
211    pub fn map_size(&self, value: &Value) -> Option<f64> {
212        self.get(&Aesthetic::Size)
213            .and_then(|s| s.map_to_size(value))
214    }
215
216    /// Map a value to an alpha (opacity) through the alpha scale.
217    pub fn map_alpha(&self, value: &Value) -> Option<f64> {
218        self.get(&Aesthetic::Alpha)
219            .and_then(|s| s.map_to_alpha(value))
220    }
221
222    /// Map a value to a stroke width through the linewidth scale.
223    pub fn map_linewidth(&self, value: &Value) -> Option<f64> {
224        self.get(&Aesthetic::Linewidth)
225            .and_then(|s| s.map_to_size(value))
226    }
227
228    /// Override the domain limits for a scale (used by coord_cartesian zoom).
229    pub fn set_limits(&mut self, aes: &Aesthetic, min: f64, max: f64) {
230        if let Some(scale) = self.get_mut(aes) {
231            scale.set_limits(min, max);
232        }
233    }
234
235    /// Get the secondary axis for an aesthetic, if one exists.
236    pub fn sec_axis(&self, aes: &Aesthetic) -> Option<&crate::scale::sec_axis::SecAxis> {
237        self.get(aes).and_then(|s| s.sec_axis())
238    }
239
240    /// Get all scales.
241    pub fn iter(&self) -> impl Iterator<Item = &dyn Scale> {
242        self.scales.iter().map(|s| s.as_ref())
243    }
244}
245
246impl Clone for ScaleSet {
247    fn clone(&self) -> Self {
248        ScaleSet {
249            scales: self.scales.iter().map(|s| s.clone_box()).collect(),
250        }
251    }
252}
253
254impl Default for ScaleSet {
255    fn default() -> Self {
256        Self::new()
257    }
258}
ggplot_rs/scale/scale_set.rs

ggplot_rs/scale/
scale_set.rs
