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-rw-r--r--servo/components/style/values/generics/font.rs271
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diff --git a/servo/components/style/values/generics/font.rs b/servo/components/style/values/generics/font.rs
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+/* 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::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,
+ 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,
+ 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, 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,
+ 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://www.w3.org/TR/css-fonts-4/#font-size-adjust-prop
+/// https://github.com/w3c/csswg-drafts/issues/6160
+/// https://github.com/w3c/csswg-drafts/issues/6288
+#[allow(missing_docs)]
+#[repr(u8)]
+#[derive(
+ Animate,
+ Clone,
+ ComputeSquaredDistance,
+ Copy,
+ Debug,
+ Hash,
+ MallocSizeOf,
+ PartialEq,
+ SpecifiedValueInfo,
+ ToAnimatedValue,
+ ToAnimatedZero,
+ ToComputedValue,
+ ToResolvedValue,
+ ToShmem,
+)]
+pub enum GenericFontSizeAdjust<Number> {
+ #[animation(error)]
+ None,
+ // 'ex-height' is the implied basis, so the keyword can be omitted
+ ExHeight(Number),
+ #[value_info(starts_with_keyword)]
+ CapHeight(Number),
+ #[value_info(starts_with_keyword)]
+ ChWidth(Number),
+ #[value_info(starts_with_keyword)]
+ IcWidth(Number),
+ #[value_info(starts_with_keyword)]
+ IcHeight(Number),
+}
+
+impl<Number: ToCss> ToCss for GenericFontSizeAdjust<Number> {
+ 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)
+ }
+}
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