1 | // font-kit/src/properties.rs |
2 | // |
3 | // Copyright © 2018 The Pathfinder Project Developers. |
4 | // |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
8 | // option. This file may not be copied, modified, or distributed |
9 | // except according to those terms. |
10 | |
11 | //! Properties that specify which font in a family to use: e.g. style, weight, and stretchiness. |
12 | //! |
13 | //! Much of the documentation in this modules comes from the CSS 3 Fonts specification: |
14 | //! https://drafts.csswg.org/css-fonts-3/ |
15 | |
16 | use std::fmt::{self, Debug, Display, Formatter}; |
17 | |
18 | /// Properties that specify which font in a family to use: e.g. style, weight, and stretchiness. |
19 | /// |
20 | /// This object supports a method chaining style for idiomatic initialization; e.g. |
21 | /// |
22 | /// # use font_kit::properties::{Properties, Style}; |
23 | /// println!("{:?}", Properties::new().style(Style::Italic)); |
24 | #[derive (Clone, Copy, Debug, Default, PartialEq)] |
25 | pub struct Properties { |
26 | /// The font style, as defined in CSS. |
27 | pub style: Style, |
28 | /// The font weight, as defined in CSS. |
29 | pub weight: Weight, |
30 | /// The font stretchiness, as defined in CSS. |
31 | pub stretch: Stretch, |
32 | } |
33 | |
34 | impl Properties { |
35 | /// Initializes a property set to its default values: normal style, normal weight, and normal |
36 | /// stretchiness. |
37 | #[inline ] |
38 | pub fn new() -> Properties { |
39 | Properties::default() |
40 | } |
41 | |
42 | /// Sets the value of the style property and returns this property set for method chaining. |
43 | #[inline ] |
44 | pub fn style(&mut self, style: Style) -> &mut Properties { |
45 | self.style = style; |
46 | self |
47 | } |
48 | |
49 | /// Sets the value of the weight property and returns this property set for method chaining. |
50 | #[inline ] |
51 | pub fn weight(&mut self, weight: Weight) -> &mut Properties { |
52 | self.weight = weight; |
53 | self |
54 | } |
55 | |
56 | /// Sets the value of the stretch property and returns this property set for method chaining. |
57 | #[inline ] |
58 | pub fn stretch(&mut self, stretch: Stretch) -> &mut Properties { |
59 | self.stretch = stretch; |
60 | self |
61 | } |
62 | } |
63 | |
64 | /// Allows italic or oblique faces to be selected. |
65 | #[derive (Clone, Copy, PartialEq, Debug)] |
66 | pub enum Style { |
67 | /// A face that is neither italic not obliqued. |
68 | Normal, |
69 | /// A form that is generally cursive in nature. |
70 | Italic, |
71 | /// A typically-sloped version of the regular face. |
72 | Oblique, |
73 | } |
74 | |
75 | impl Default for Style { |
76 | fn default() -> Style { |
77 | Style::Normal |
78 | } |
79 | } |
80 | |
81 | impl Display for Style { |
82 | fn fmt(&self, f: &mut Formatter) -> fmt::Result { |
83 | Debug::fmt(self, f) |
84 | } |
85 | } |
86 | |
87 | /// The degree of blackness or stroke thickness of a font. This value ranges from 100.0 to 900.0, |
88 | /// with 400.0 as normal. |
89 | #[derive (Clone, Copy, Debug, PartialEq, PartialOrd)] |
90 | pub struct Weight(pub f32); |
91 | |
92 | impl Default for Weight { |
93 | #[inline ] |
94 | fn default() -> Weight { |
95 | Weight::NORMAL |
96 | } |
97 | } |
98 | |
99 | impl Weight { |
100 | /// Thin weight (100), the thinnest value. |
101 | pub const THIN: Weight = Weight(100.0); |
102 | /// Extra light weight (200). |
103 | pub const EXTRA_LIGHT: Weight = Weight(200.0); |
104 | /// Light weight (300). |
105 | pub const LIGHT: Weight = Weight(300.0); |
106 | /// Normal (400). |
107 | pub const NORMAL: Weight = Weight(400.0); |
108 | /// Medium weight (500, higher than normal). |
109 | pub const MEDIUM: Weight = Weight(500.0); |
110 | /// Semibold weight (600). |
111 | pub const SEMIBOLD: Weight = Weight(600.0); |
112 | /// Bold weight (700). |
113 | pub const BOLD: Weight = Weight(700.0); |
114 | /// Extra-bold weight (800). |
115 | pub const EXTRA_BOLD: Weight = Weight(800.0); |
116 | /// Black weight (900), the thickest value. |
117 | pub const BLACK: Weight = Weight(900.0); |
118 | } |
119 | |
120 | /// The width of a font as an approximate fraction of the normal width. |
121 | /// |
122 | /// Widths range from 0.5 to 2.0 inclusive, with 1.0 as the normal width. |
123 | #[derive (Clone, Copy, Debug, PartialEq, PartialOrd)] |
124 | pub struct Stretch(pub f32); |
125 | |
126 | impl Default for Stretch { |
127 | #[inline ] |
128 | fn default() -> Stretch { |
129 | Stretch::NORMAL |
130 | } |
131 | } |
132 | |
133 | impl Stretch { |
134 | /// Ultra-condensed width (50%), the narrowest possible. |
135 | pub const ULTRA_CONDENSED: Stretch = Stretch(0.5); |
136 | /// Extra-condensed width (62.5%). |
137 | pub const EXTRA_CONDENSED: Stretch = Stretch(0.625); |
138 | /// Condensed width (75%). |
139 | pub const CONDENSED: Stretch = Stretch(0.75); |
140 | /// Semi-condensed width (87.5%). |
141 | pub const SEMI_CONDENSED: Stretch = Stretch(0.875); |
142 | /// Normal width (100%). |
143 | pub const NORMAL: Stretch = Stretch(1.0); |
144 | /// Semi-expanded width (112.5%). |
145 | pub const SEMI_EXPANDED: Stretch = Stretch(1.125); |
146 | /// Expanded width (125%). |
147 | pub const EXPANDED: Stretch = Stretch(1.25); |
148 | /// Extra-expanded width (150%). |
149 | pub const EXTRA_EXPANDED: Stretch = Stretch(1.5); |
150 | /// Ultra-expanded width (200%), the widest possible. |
151 | pub const ULTRA_EXPANDED: Stretch = Stretch(2.0); |
152 | |
153 | // Mapping from `usWidthClass` values to CSS `font-stretch` values. |
154 | pub(crate) const MAPPING: [f32; 9] = [ |
155 | Stretch::ULTRA_CONDENSED.0, |
156 | Stretch::EXTRA_CONDENSED.0, |
157 | Stretch::CONDENSED.0, |
158 | Stretch::SEMI_CONDENSED.0, |
159 | Stretch::NORMAL.0, |
160 | Stretch::SEMI_EXPANDED.0, |
161 | Stretch::EXPANDED.0, |
162 | Stretch::EXTRA_EXPANDED.0, |
163 | Stretch::ULTRA_EXPANDED.0, |
164 | ]; |
165 | } |
166 | |