plotters/style/
size.rs

1use crate::coord::CoordTranslate;
2use crate::drawing::DrawingArea;
3use plotters_backend::DrawingBackend;
4
5/// The trait indicates that the type has a dimensional data.
6/// This is the abstraction for the relative sizing model.
7/// A relative sizing value is able to be converted into a concrete size
8/// when coupling with a type with `HasDimension` type.
9pub trait HasDimension {
10    /// Get the dimensional data for this object
11    fn dim(&self) -> (u32, u32);
12}
13
14impl<D: DrawingBackend, C: CoordTranslate> HasDimension for DrawingArea<D, C> {
15    fn dim(&self) -> (u32, u32) {
16        self.dim_in_pixel()
17    }
18}
19
20impl HasDimension for (u32, u32) {
21    fn dim(&self) -> (u32, u32) {
22        *self
23    }
24}
25
26/// The trait that describes a size, it may be a relative size which the
27/// size is determined by the parent size, e.g., 10% of the parent width
28pub trait SizeDesc {
29    /// Convert the size into the number of pixels
30    ///
31    /// - `parent`: The reference to the parent container of this size
32    /// - **returns**: The number of pixels
33    fn in_pixels<T: HasDimension>(&self, parent: &T) -> i32;
34}
35
36impl SizeDesc for i32 {
37    fn in_pixels<D: HasDimension>(&self, _parent: &D) -> i32 {
38        *self
39    }
40}
41
42impl SizeDesc for u32 {
43    fn in_pixels<D: HasDimension>(&self, _parent: &D) -> i32 {
44        *self as i32
45    }
46}
47
48impl SizeDesc for f32 {
49    fn in_pixels<D: HasDimension>(&self, _parent: &D) -> i32 {
50        *self as i32
51    }
52}
53
54impl SizeDesc for f64 {
55    fn in_pixels<D: HasDimension>(&self, _parent: &D) -> i32 {
56        *self as i32
57    }
58}
59
60/// Describes a relative size, might be
61///     1. portion of height
62///     2. portion of width
63///     3. portion of the minimal of height and weight
64pub enum RelativeSize {
65    /// Percentage height
66    Height(f64),
67    /// Percentage width
68    Width(f64),
69    /// Percentage of either height or width, which is smaller
70    Smaller(f64),
71}
72
73impl RelativeSize {
74    /// Set the lower bound of the relative size.
75    ///
76    /// - `min_sz`: The minimal size the relative size can be in pixels
77    /// - **returns**: The relative size with the bound
78    pub fn min(self, min_sz: i32) -> RelativeSizeWithBound {
79        RelativeSizeWithBound {
80            size: self,
81            min: Some(min_sz),
82            max: None,
83        }
84    }
85
86    /// Set the upper bound of the relative size
87    ///
88    /// - `max_size`: The maximum size in pixels for this relative size
89    /// - **returns** The relative size with the upper bound
90    pub fn max(self, max_sz: i32) -> RelativeSizeWithBound {
91        RelativeSizeWithBound {
92            size: self,
93            max: Some(max_sz),
94            min: None,
95        }
96    }
97}
98
99impl SizeDesc for RelativeSize {
100    fn in_pixels<D: HasDimension>(&self, parent: &D) -> i32 {
101        let (w, h) = parent.dim();
102        match self {
103            RelativeSize::Width(p) => *p * f64::from(w),
104            RelativeSize::Height(p) => *p * f64::from(h),
105            RelativeSize::Smaller(p) => *p * f64::from(w.min(h)),
106        }
107        .round() as i32
108    }
109}
110
111/// Allows a value turns into a relative size
112pub trait AsRelative: Into<f64> {
113    /// Make the value a relative size of percentage of width
114    fn percent_width(self) -> RelativeSize {
115        RelativeSize::Width(self.into() / 100.0)
116    }
117    /// Make the value a relative size of percentage of height
118    fn percent_height(self) -> RelativeSize {
119        RelativeSize::Height(self.into() / 100.0)
120    }
121    /// Make the value a relative size of percentage of minimal of height and width
122    fn percent(self) -> RelativeSize {
123        RelativeSize::Smaller(self.into() / 100.0)
124    }
125}
126
127impl<T: Into<f64>> AsRelative for T {}
128
129/// The struct describes a relative size with upper bound and lower bound
130pub struct RelativeSizeWithBound {
131    size: RelativeSize,
132    min: Option<i32>,
133    max: Option<i32>,
134}
135
136impl RelativeSizeWithBound {
137    /// Set the lower bound of the bounded relative size
138    ///
139    /// - `min_sz`: The lower bound of this size description
140    /// - **returns**: The newly created size description with the bound
141    pub fn min(mut self, min_sz: i32) -> RelativeSizeWithBound {
142        self.min = Some(min_sz);
143        self
144    }
145
146    /// Set the upper bound of the bounded relative size
147    ///
148    /// - `min_sz`: The upper bound of this size description
149    /// - **returns**: The newly created size description with the bound
150    pub fn max(mut self, max_sz: i32) -> RelativeSizeWithBound {
151        self.max = Some(max_sz);
152        self
153    }
154}
155
156impl SizeDesc for RelativeSizeWithBound {
157    fn in_pixels<D: HasDimension>(&self, parent: &D) -> i32 {
158        let size = self.size.in_pixels(parent);
159        let size_lower_capped = self.min.map_or(size, |x| x.max(size));
160        self.max.map_or(size_lower_capped, |x| x.min(size))
161    }
162}
163
164#[cfg(test)]
165mod test {
166    use super::*;
167    #[test]
168    fn test_relative_size() {
169        let size = (10).percent_height();
170        assert_eq!(size.in_pixels(&(100, 200)), 20);
171
172        let size = (10).percent_width();
173        assert_eq!(size.in_pixels(&(100, 200)), 10);
174
175        let size = (-10).percent_width();
176        assert_eq!(size.in_pixels(&(100, 200)), -10);
177
178        let size = (10).percent_width().min(30);
179        assert_eq!(size.in_pixels(&(100, 200)), 30);
180        assert_eq!(size.in_pixels(&(400, 200)), 40);
181
182        let size = (10).percent();
183        assert_eq!(size.in_pixels(&(100, 200)), 10);
184        assert_eq!(size.in_pixels(&(400, 200)), 20);
185    }
186}