1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */

//! Generic types for font stuff.

use crate::parser::{Parse, ParserContext};
use crate::values::animated::ToAnimatedZero;
use crate::One;
use byteorder::{BigEndian, ReadBytesExt};
use cssparser::Parser;
use std::fmt::{self, Write};
use std::io::Cursor;
use style_traits::{CssWriter, ParseError};
use style_traits::{StyleParseErrorKind, ToCss};

/// A trait for values that are labelled with a FontTag (for feature and
/// variation settings).
pub trait TaggedFontValue {
    /// The value's tag.
    fn tag(&self) -> FontTag;
}

/// https://drafts.csswg.org/css-fonts-4/#feature-tag-value
#[derive(
    Clone,
    Debug,
    Eq,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToComputedValue,
    ToResolvedValue,
    ToShmem,
)]
pub struct FeatureTagValue<Integer> {
    /// A four-character tag, packed into a u32 (one byte per character).
    pub tag: FontTag,
    /// The actual value.
    pub value: Integer,
}

impl<T> TaggedFontValue for FeatureTagValue<T> {
    fn tag(&self) -> FontTag {
        self.tag
    }
}

impl<Integer> ToCss for FeatureTagValue<Integer>
where
    Integer: One + ToCss + PartialEq,
{
    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
    where
        W: Write,
    {
        self.tag.to_css(dest)?;
        // Don't serialize the default value.
        if !self.value.is_one() {
            dest.write_char(' ')?;
            self.value.to_css(dest)?;
        }

        Ok(())
    }
}

/// Variation setting for a single feature, see:
///
/// https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Debug,
    Eq,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToComputedValue,
    ToCss,
    ToResolvedValue,
    ToShmem,
)]
pub struct VariationValue<Number> {
    /// A four-character tag, packed into a u32 (one byte per character).
    #[animation(constant)]
    pub tag: FontTag,
    /// The actual value.
    pub value: Number,
}

impl<T> TaggedFontValue for VariationValue<T> {
    fn tag(&self) -> FontTag {
        self.tag
    }
}

/// A value both for font-variation-settings and font-feature-settings.
#[derive(
    Clone, Debug, Eq, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToAnimatedValue, ToCss, ToResolvedValue, ToShmem,
)]
#[css(comma)]
pub struct FontSettings<T>(#[css(if_empty = "normal", iterable)] pub Box<[T]>);

impl<T> FontSettings<T> {
    /// Default value of font settings as `normal`.
    #[inline]
    pub fn normal() -> Self {
        FontSettings(vec![].into_boxed_slice())
    }
}

impl<T: Parse> Parse for FontSettings<T> {
    /// https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-feature-settings
    /// https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
    fn parse<'i, 't>(
        context: &ParserContext,
        input: &mut Parser<'i, 't>,
    ) -> Result<Self, ParseError<'i>> {
        if input
            .try_parse(|i| i.expect_ident_matching("normal"))
            .is_ok()
        {
            return Ok(Self::normal());
        }

        Ok(FontSettings(
            input
                .parse_comma_separated(|i| T::parse(context, i))?
                .into_boxed_slice(),
        ))
    }
}

/// A font four-character tag, represented as a u32 for convenience.
///
/// See:
///   https://drafts.csswg.org/css-fonts-4/#font-variation-settings-def
///   https://drafts.csswg.org/css-fonts-4/#descdef-font-face-font-feature-settings
///
#[derive(
    Clone,
    Copy,
    Debug,
    Eq,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToComputedValue,
    ToResolvedValue,
    ToShmem,
)]
pub struct FontTag(pub u32);

impl ToCss for FontTag {
    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
    where
        W: Write,
    {
        use byteorder::ByteOrder;
        use std::str;

        let mut raw = [0u8; 4];
        BigEndian::write_u32(&mut raw, self.0);
        str::from_utf8(&raw).unwrap_or_default().to_css(dest)
    }
}

impl Parse for FontTag {
    fn parse<'i, 't>(
        _context: &ParserContext,
        input: &mut Parser<'i, 't>,
    ) -> Result<Self, ParseError<'i>> {
        let location = input.current_source_location();
        let tag = input.expect_string()?;

        // allowed strings of length 4 containing chars: <U+20, U+7E>
        if tag.len() != 4 || tag.as_bytes().iter().any(|c| *c < b' ' || *c > b'~') {
            return Err(location.new_custom_error(StyleParseErrorKind::UnspecifiedError));
        }

        let mut raw = Cursor::new(tag.as_bytes());
        Ok(FontTag(raw.read_u32::<BigEndian>().unwrap()))
    }
}

/// A generic value for the `font-style` property.
///
/// https://drafts.csswg.org/css-fonts-4/#font-style-prop
#[allow(missing_docs)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    Hash,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToAnimatedZero,
    ToResolvedValue,
    ToShmem,
)]
pub enum FontStyle<Angle> {
    #[animation(error)]
    Normal,
    #[animation(error)]
    Italic,
    #[value_info(starts_with_keyword)]
    Oblique(Angle),
}

/// A generic value for the `font-size-adjust` property.
///
/// https://drafts.csswg.org/css-fonts-5/#font-size-adjust-prop
#[allow(missing_docs)]
#[repr(u8)]
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    Hash,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToAnimatedZero,
    ToComputedValue,
    ToResolvedValue,
    ToShmem,
)]
pub enum GenericFontSizeAdjust<Factor> {
    #[animation(error)]
    None,
    #[value_info(starts_with_keyword)]
    ExHeight(Factor),
    #[value_info(starts_with_keyword)]
    CapHeight(Factor),
    #[value_info(starts_with_keyword)]
    ChWidth(Factor),
    #[value_info(starts_with_keyword)]
    IcWidth(Factor),
    #[value_info(starts_with_keyword)]
    IcHeight(Factor),
}

impl<Factor: ToCss> ToCss for GenericFontSizeAdjust<Factor> {
    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
    where
        W: Write,
    {
        let (prefix, value) = match self {
            Self::None => return dest.write_str("none"),
            Self::ExHeight(v) => ("", v),
            Self::CapHeight(v) => ("cap-height ", v),
            Self::ChWidth(v) => ("ch-width ", v),
            Self::IcWidth(v) => ("ic-width ", v),
            Self::IcHeight(v) => ("ic-height ", v),
        };

        dest.write_str(prefix)?;
        value.to_css(dest)
    }
}

/// A generic value for the `line-height` property.
#[derive(
    Animate,
    Clone,
    ComputeSquaredDistance,
    Copy,
    Debug,
    MallocSizeOf,
    PartialEq,
    SpecifiedValueInfo,
    ToAnimatedValue,
    ToCss,
    ToShmem,
    Parse,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[repr(C, u8)]
pub enum GenericLineHeight<N, L> {
    /// `normal`
    Normal,
    /// `-moz-block-height`
    #[cfg(feature = "gecko")]
    #[parse(condition = "ParserContext::in_ua_sheet")]
    MozBlockHeight,
    /// `<number>`
    Number(N),
    /// `<length-percentage>`
    Length(L),
}

pub use self::GenericLineHeight as LineHeight;

impl<N, L> ToAnimatedZero for LineHeight<N, L> {
    #[inline]
    fn to_animated_zero(&self) -> Result<Self, ()> {
        Err(())
    }
}

impl<N, L> LineHeight<N, L> {
    /// Returns `normal`.
    #[inline]
    pub fn normal() -> Self {
        LineHeight::Normal
    }
}