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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
//! Computed values for font properties
use crate::parser::{Parse, ParserContext};
use crate::values::animated::ToAnimatedValue;
use crate::values::computed::{
Angle, Context, Integer, Length, NonNegativeLength, NonNegativeNumber, Number, Percentage,
ToComputedValue, Zoom,
};
use crate::values::generics::font::{
FeatureTagValue, FontSettings, TaggedFontValue, VariationValue,
};
use crate::values::generics::{font as generics, NonNegative};
use crate::values::resolved::{Context as ResolvedContext, ToResolvedValue};
use crate::values::specified::font::{
self as specified, KeywordInfo, MAX_FONT_WEIGHT, MIN_FONT_WEIGHT,
};
use crate::values::specified::length::{FontBaseSize, LineHeightBase, NoCalcLength};
use crate::Atom;
use cssparser::{serialize_identifier, CssStringWriter, Parser};
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocSizeOf, MallocSizeOfOps};
use num_traits::abs;
use num_traits::cast::AsPrimitive;
use std::fmt::{self, Write};
use style_traits::{CssWriter, ParseError, ToCss};
pub use crate::values::computed::Length as MozScriptMinSize;
pub use crate::values::specified::font::MozScriptSizeMultiplier;
pub use crate::values::specified::font::{FontPalette, FontSynthesis};
pub use crate::values::specified::font::{
FontVariantAlternates, FontVariantEastAsian, FontVariantLigatures, FontVariantNumeric, XLang,
XTextScale,
};
pub use crate::values::specified::Integer as SpecifiedInteger;
pub use crate::values::specified::Number as SpecifiedNumber;
/// Generic template for font property type classes that use a fixed-point
/// internal representation with `FRACTION_BITS` for the fractional part.
///
/// Values are constructed from and exposed as floating-point, but stored
/// internally as fixed point, so there will be a quantization effect on
/// fractional values, depending on the number of fractional bits used.
///
/// Using (16-bit) fixed-point types rather than floats for these style
/// attributes reduces the memory footprint of gfxFontEntry and gfxFontStyle; it
/// will also tend to reduce the number of distinct font instances that get
/// created, particularly when styles are animated or set to arbitrary values
/// (e.g. by sliders in the UI), which should reduce pressure on graphics
/// resources and improve cache hit rates.
///
/// cbindgen:derive-lt
/// cbindgen:derive-lte
/// cbindgen:derive-gt
/// cbindgen:derive-gte
#[repr(C)]
#[derive(
Clone,
ComputeSquaredDistance,
Copy,
Debug,
Hash,
MallocSizeOf,
PartialEq,
PartialOrd,
ToResolvedValue,
)]
pub struct FixedPoint<T, const FRACTION_BITS: u16> {
/// The actual representation.
pub value: T,
}
impl<T, const FRACTION_BITS: u16> FixedPoint<T, FRACTION_BITS>
where
T: AsPrimitive<f32>,
f32: AsPrimitive<T>,
u16: AsPrimitive<T>,
{
const SCALE: u16 = 1 << FRACTION_BITS;
const INVERSE_SCALE: f32 = 1.0 / Self::SCALE as f32;
/// Returns a fixed-point bit from a floating-point context.
pub fn from_float(v: f32) -> Self {
Self {
value: (v * Self::SCALE as f32).round().as_(),
}
}
/// Returns the floating-point representation.
pub fn to_float(&self) -> f32 {
self.value.as_() * Self::INVERSE_SCALE
}
}
// We implement this and mul below only for u16 types, because u32 types might need more care about
// overflow. But it's not hard to implement in either case.
impl<const FRACTION_BITS: u16> std::ops::Div for FixedPoint<u16, FRACTION_BITS> {
type Output = Self;
fn div(self, rhs: Self) -> Self {
Self {
value: (((self.value as u32) << (FRACTION_BITS as u32)) / (rhs.value as u32)) as u16,
}
}
}
impl<const FRACTION_BITS: u16> std::ops::Mul for FixedPoint<u16, FRACTION_BITS> {
type Output = Self;
fn mul(self, rhs: Self) -> Self {
Self {
value: (((self.value as u32) * (rhs.value as u32)) >> (FRACTION_BITS as u32)) as u16,
}
}
}
/// font-weight: range 1..1000, fractional values permitted; keywords
/// 'normal', 'bold' aliased to 400, 700 respectively.
///
/// We use an unsigned 10.6 fixed-point value (range 0.0 - 1023.984375)
pub const FONT_WEIGHT_FRACTION_BITS: u16 = 6;
/// This is an alias which is useful mostly as a cbindgen / C++ inference
/// workaround.
pub type FontWeightFixedPoint = FixedPoint<u16, FONT_WEIGHT_FRACTION_BITS>;
/// A value for the font-weight property per:
///
///
/// cbindgen:derive-lt
/// cbindgen:derive-lte
/// cbindgen:derive-gt
/// cbindgen:derive-gte
#[derive(
Clone,
ComputeSquaredDistance,
Copy,
Debug,
Hash,
MallocSizeOf,
PartialEq,
PartialOrd,
ToResolvedValue,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[repr(C)]
pub struct FontWeight(FontWeightFixedPoint);
impl ToAnimatedValue for FontWeight {
type AnimatedValue = Number;
#[inline]
fn to_animated_value(self) -> Self::AnimatedValue {
self.value()
}
#[inline]
fn from_animated_value(animated: Self::AnimatedValue) -> Self {
FontWeight::from_float(animated)
}
}
impl ToCss for FontWeight {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
self.value().to_css(dest)
}
}
impl FontWeight {
/// The `normal` keyword.
pub const NORMAL: FontWeight = FontWeight(FontWeightFixedPoint {
value: 400 << FONT_WEIGHT_FRACTION_BITS,
});
/// The `bold` value.
pub const BOLD: FontWeight = FontWeight(FontWeightFixedPoint {
value: 700 << FONT_WEIGHT_FRACTION_BITS,
});
/// The threshold from which we consider a font bold.
pub const BOLD_THRESHOLD: FontWeight = FontWeight(FontWeightFixedPoint {
value: 600 << FONT_WEIGHT_FRACTION_BITS,
});
/// Returns the `normal` keyword value.
pub fn normal() -> Self {
Self::NORMAL
}
/// Weither this weight is bold
pub fn is_bold(&self) -> bool {
*self >= Self::BOLD_THRESHOLD
}
/// Returns the value as a float.
pub fn value(&self) -> f32 {
self.0.to_float()
}
/// Construct a valid weight from a float value.
pub fn from_float(v: f32) -> Self {
Self(FixedPoint::from_float(
v.max(MIN_FONT_WEIGHT).min(MAX_FONT_WEIGHT),
))
}
/// Return the bolder weight.
///
/// See the table in:
pub fn bolder(self) -> Self {
let value = self.value();
if value < 350. {
return Self::NORMAL;
}
if value < 550. {
return Self::BOLD;
}
Self::from_float(value.max(900.))
}
/// Return the lighter weight.
///
/// See the table in:
pub fn lighter(self) -> Self {
let value = self.value();
if value < 550. {
return Self::from_float(value.min(100.));
}
if value < 750. {
return Self::NORMAL;
}
Self::BOLD
}
}
#[derive(
Animate,
Clone,
ComputeSquaredDistance,
Copy,
Debug,
MallocSizeOf,
PartialEq,
ToAnimatedZero,
ToCss,
ToResolvedValue,
)]
#[cfg_attr(feature = "servo", derive(Serialize, Deserialize))]
/// The computed value of font-size
pub struct FontSize {
/// The computed size, that we use to compute ems etc. This accounts for
/// e.g., text-zoom.
pub computed_size: NonNegativeLength,
/// The actual used size. This is the computed font size, potentially
/// constrained by other factors like minimum font-size settings and so on.
#[css(skip)]
pub used_size: NonNegativeLength,
/// If derived from a keyword, the keyword and additional transformations applied to it
#[css(skip)]
pub keyword_info: KeywordInfo,
}
impl FontSize {
/// The actual computed font size.
#[inline]
pub fn computed_size(&self) -> Length {
self.computed_size.0
}
/// The actual used font size.
#[inline]
pub fn used_size(&self) -> Length {
self.used_size.0
}
/// Apply zoom to the font-size. This is usually done by ToComputedValue.
#[inline]
pub fn zoom(&self, zoom: Zoom) -> Self {
Self {
computed_size: NonNegative(Length::new(zoom.zoom(self.computed_size.0.px()))),
used_size: NonNegative(Length::new(zoom.zoom(self.used_size.0.px()))),
keyword_info: self.keyword_info,
}
}
#[inline]
/// Get default value of font size.
pub fn medium() -> Self {
Self {
computed_size: NonNegative(Length::new(specified::FONT_MEDIUM_PX)),
used_size: NonNegative(Length::new(specified::FONT_MEDIUM_PX)),
keyword_info: KeywordInfo::medium(),
}
}
}
impl ToAnimatedValue for FontSize {
type AnimatedValue = Length;
#[inline]
fn to_animated_value(self) -> Self::AnimatedValue {
self.computed_size.0
}
#[inline]
fn from_animated_value(animated: Self::AnimatedValue) -> Self {
FontSize {
computed_size: NonNegative(animated.clamp_to_non_negative()),
used_size: NonNegative(animated.clamp_to_non_negative()),
keyword_info: KeywordInfo::none(),
}
}
}
#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToResolvedValue)]
#[cfg_attr(feature = "servo", derive(Hash, MallocSizeOf, Serialize, Deserialize))]
/// Specifies a prioritized list of font family names or generic family names.
#[repr(C)]
pub struct FontFamily {
/// The actual list of family names.
pub families: FontFamilyList,
/// Whether this font-family came from a specified system-font.
pub is_system_font: bool,
/// Whether this is the initial font-family that might react to language
/// changes.
pub is_initial: bool,
}
macro_rules! static_font_family {
($ident:ident, $family:expr) => {
lazy_static! {
static ref $ident: FontFamily = FontFamily {
families: FontFamilyList {
list: crate::ArcSlice::from_iter_leaked(std::iter::once($family)),
},
is_system_font: false,
is_initial: false,
};
}
};
}
impl FontFamily {
#[inline]
/// Get default font family as `serif` which is a generic font-family
pub fn serif() -> Self {
Self::generic(GenericFontFamily::Serif).clone()
}
/// Returns the font family for `-moz-bullet-font`.
pub(crate) fn moz_bullet() -> &'static Self {
static_font_family!(
MOZ_BULLET,
SingleFontFamily::FamilyName(FamilyName {
name: atom!("-moz-bullet-font"),
syntax: FontFamilyNameSyntax::Identifiers,
})
);
&*MOZ_BULLET
}
/// Returns a font family for a single system font.
pub fn for_system_font(name: &str) -> Self {
Self {
families: FontFamilyList {
list: crate::ArcSlice::from_iter(std::iter::once(SingleFontFamily::FamilyName(
FamilyName {
name: Atom::from(name),
syntax: FontFamilyNameSyntax::Identifiers,
},
))),
},
is_system_font: true,
is_initial: false,
}
}
/// Returns a generic font family.
pub fn generic(generic: GenericFontFamily) -> &'static Self {
macro_rules! generic_font_family {
($ident:ident, $family:ident) => {
static_font_family!(
$ident,
SingleFontFamily::Generic(GenericFontFamily::$family)
)
};
}
generic_font_family!(SERIF, Serif);
generic_font_family!(SANS_SERIF, SansSerif);
generic_font_family!(MONOSPACE, Monospace);
generic_font_family!(CURSIVE, Cursive);
generic_font_family!(FANTASY, Fantasy);
generic_font_family!(MOZ_EMOJI, MozEmoji);
generic_font_family!(SYSTEM_UI, SystemUi);
let family = match generic {
GenericFontFamily::None => {
debug_assert!(false, "Bogus caller!");
&*SERIF
},
GenericFontFamily::Serif => &*SERIF,
GenericFontFamily::SansSerif => &*SANS_SERIF,
GenericFontFamily::Monospace => &*MONOSPACE,
GenericFontFamily::Cursive => &*CURSIVE,
GenericFontFamily::Fantasy => &*FANTASY,
GenericFontFamily::MozEmoji => &*MOZ_EMOJI,
GenericFontFamily::SystemUi => &*SYSTEM_UI,
};
debug_assert_eq!(
*family.families.iter().next().unwrap(),
SingleFontFamily::Generic(generic)
);
family
}
}
#[cfg(feature = "gecko")]
impl MallocSizeOf for FontFamily {
fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize {
use malloc_size_of::MallocUnconditionalSizeOf;
// SharedFontList objects are generally measured from the pointer stored
// in the specified value. So only count this if the SharedFontList is
// unshared.
let shared_font_list = &self.families.list;
if shared_font_list.is_unique() {
shared_font_list.unconditional_size_of(ops)
} else {
0
}
}
}
impl ToCss for FontFamily {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
let mut iter = self.families.iter();
match iter.next() {
Some(f) => f.to_css(dest)?,
None => return Ok(()),
}
for family in iter {
dest.write_str(", ")?;
family.to_css(dest)?;
}
Ok(())
}
}
/// The name of a font family of choice.
#[derive(
Clone, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[repr(C)]
pub struct FamilyName {
/// Name of the font family.
pub name: Atom,
/// Syntax of the font family.
pub syntax: FontFamilyNameSyntax,
}
impl FamilyName {
fn is_known_icon_font_family(&self) -> bool {
use crate::gecko_bindings::bindings;
unsafe { bindings::Gecko_IsKnownIconFontFamily(self.name.as_ptr()) }
}
}
impl ToCss for FamilyName {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
match self.syntax {
FontFamilyNameSyntax::Quoted => {
dest.write_char('"')?;
write!(CssStringWriter::new(dest), "{}", self.name)?;
dest.write_char('"')
},
FontFamilyNameSyntax::Identifiers => {
let mut first = true;
for ident in self.name.to_string().split(' ') {
if first {
first = false;
} else {
dest.write_char(' ')?;
}
debug_assert!(
!ident.is_empty(),
"Family name with leading, \
trailing, or consecutive white spaces should \
have been marked quoted by the parser"
);
serialize_identifier(ident, dest)?;
}
Ok(())
},
}
}
}
#[derive(
Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
/// Font family names must either be given quoted as strings,
/// or unquoted as a sequence of one or more identifiers.
#[repr(u8)]
pub enum FontFamilyNameSyntax {
/// The family name was specified in a quoted form, e.g. "Font Name"
/// or 'Font Name'.
Quoted,
/// The family name was specified in an unquoted form as a sequence of
/// identifiers.
Identifiers,
}
/// A set of faces that vary in weight, width or slope.
/// cbindgen:derive-mut-casts=true
#[derive(
Clone, Debug, Eq, MallocSizeOf, PartialEq, ToCss, ToComputedValue, ToResolvedValue, ToShmem,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize, Hash))]
#[repr(u8)]
pub enum SingleFontFamily {
/// The name of a font family of choice.
FamilyName(FamilyName),
/// Generic family name.
Generic(GenericFontFamily),
}
fn system_ui_enabled(_: &ParserContext) -> bool {
static_prefs::pref!("layout.css.system-ui.enabled")
}
/// A generic font-family name.
///
/// The order here is important, if you change it make sure that
/// `gfxPlatformFontList.h`s ranged array and `gfxFontFamilyList`'s
/// sSingleGenerics are updated as well.
///
/// NOTE(emilio): Should be u8, but it's a u32 because of ABI issues between GCC
#[derive(
Clone,
Copy,
Debug,
Eq,
Hash,
MallocSizeOf,
PartialEq,
Parse,
ToCss,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
#[repr(u32)]
#[allow(missing_docs)]
pub enum GenericFontFamily {
/// No generic family specified, only for internal usage.
///
/// NOTE(emilio): Gecko code relies on this variant being zero.
#[css(skip)]
None = 0,
Serif,
SansSerif,
#[parse(aliases = "-moz-fixed")]
Monospace,
Cursive,
Fantasy,
#[parse(condition = "system_ui_enabled")]
SystemUi,
/// An internal value for emoji font selection.
#[css(skip)]
#[cfg(feature = "gecko")]
MozEmoji,
}
impl GenericFontFamily {
/// When we disallow websites to override fonts, we ignore some generic
/// families that the website might specify, since they're not configured by
pub(crate) fn valid_for_user_font_prioritization(self) -> bool {
match self {
Self::None | Self::Fantasy | Self::Cursive | Self::SystemUi | Self::MozEmoji => false,
Self::Serif | Self::SansSerif | Self::Monospace => true,
}
}
}
impl Parse for SingleFontFamily {
/// Parse a font-family value.
fn parse<'i, 't>(
context: &ParserContext,
input: &mut Parser<'i, 't>,
) -> Result<Self, ParseError<'i>> {
if let Ok(value) = input.try_parse(|i| i.expect_string_cloned()) {
return Ok(SingleFontFamily::FamilyName(FamilyName {
name: Atom::from(&*value),
syntax: FontFamilyNameSyntax::Quoted,
}));
}
if let Ok(generic) = input.try_parse(|i| GenericFontFamily::parse(context, i)) {
return Ok(SingleFontFamily::Generic(generic));
}
let first_ident = input.expect_ident_cloned()?;
let reserved = match_ignore_ascii_case! { &first_ident,
// "Font family names that happen to be the same as a keyword value
// (`inherit`, `serif`, `sans-serif`, `monospace`, `fantasy`, and `cursive`)
// must be quoted to prevent confusion with the keywords with the same names.
// The keywords ‘initial’ and ‘default’ are reserved for future use
// and must also be quoted when used as font names.
// UAs must not consider these keywords as matching the <family-name> type."
"inherit" | "initial" | "unset" | "revert" | "default" => true,
_ => false,
};
let mut value = first_ident.as_ref().to_owned();
let mut serialize_quoted = value.contains(' ');
// These keywords are not allowed by themselves.
// The only way this value can be valid with with another keyword.
if reserved {
let ident = input.expect_ident()?;
serialize_quoted = serialize_quoted || ident.contains(' ');
value.push(' ');
value.push_str(&ident);
}
while let Ok(ident) = input.try_parse(|i| i.expect_ident_cloned()) {
serialize_quoted = serialize_quoted || ident.contains(' ');
value.push(' ');
value.push_str(&ident);
}
let syntax = if serialize_quoted {
// For font family names which contains special white spaces, e.g.
// `font-family: \ a\ \ b\ \ c\ ;`, it is tricky to serialize them
// as identifiers correctly. Just mark them quoted so we don't need
// to worry about them in serialization code.
FontFamilyNameSyntax::Quoted
} else {
FontFamilyNameSyntax::Identifiers
};
Ok(SingleFontFamily::FamilyName(FamilyName {
name: Atom::from(value),
syntax,
}))
}
}
#[cfg(feature = "servo")]
impl SingleFontFamily {
/// Get the corresponding font-family with Atom
pub fn from_atom(input: Atom) -> SingleFontFamily {
match input {
atom!("serif") => return SingleFontFamily::Generic(GenericFontFamily::Serif),
atom!("sans-serif") => return SingleFontFamily::Generic(GenericFontFamily::SansSerif),
atom!("cursive") => return SingleFontFamily::Generic(GenericFontFamily::Cursive),
atom!("fantasy") => return SingleFontFamily::Generic(GenericFontFamily::Fantasy),
atom!("monospace") => return SingleFontFamily::Generic(GenericFontFamily::Monospace),
_ => {},
}
match_ignore_ascii_case! { &input,
"serif" => return SingleFontFamily::Generic(GenericFontFamily::Serif),
"sans-serif" => return SingleFontFamily::Generic(GenericFontFamily::SansSerif),
"cursive" => return SingleFontFamily::Generic(GenericFontFamily::Cursive),
"fantasy" => return SingleFontFamily::Generic(GenericFontFamily::Fantasy),
"monospace" => return SingleFontFamily::Generic(GenericFontFamily::Monospace),
_ => {}
}
// We don't know if it's quoted or not. So we set it to
// quoted by default.
SingleFontFamily::FamilyName(FamilyName {
name: input,
syntax: FontFamilyNameSyntax::Quoted,
})
}
}
/// A list of font families.
#[derive(Clone, Debug, ToComputedValue, ToResolvedValue, ToShmem, PartialEq, Eq)]
#[repr(C)]
pub struct FontFamilyList {
/// The actual list of font families specified.
pub list: crate::ArcSlice<SingleFontFamily>,
}
impl FontFamilyList {
/// Return iterator of SingleFontFamily
pub fn iter(&self) -> impl Iterator<Item = &SingleFontFamily> {
self.list.iter()
}
/// If there's a generic font family on the list which is suitable for user
/// font prioritization, then move it ahead of the other families in the list,
/// except for any families known to be ligature-based icon fonts, where using a
/// generic instead of the site's specified font may cause substantial breakage.
/// If no suitable generic is found in the list, insert the default generic ahead
/// of all the listed families except for known ligature-based icon fonts.
pub(crate) fn prioritize_first_generic_or_prepend(&mut self, generic: GenericFontFamily) {
let mut index_of_first_generic = None;
let mut target_index = None;
for (i, f) in self.iter().enumerate() {
match &*f {
SingleFontFamily::Generic(f) => {
if index_of_first_generic.is_none() && f.valid_for_user_font_prioritization() {
// If we haven't found a target position, there's nothing to do;
// this entry is already ahead of everything except any whitelisted
// icon fonts.
if target_index.is_none() {
return;
}
index_of_first_generic = Some(i);
break;
}
// A non-prioritized generic (e.g. cursive, fantasy) becomes the target
// position for prioritization, just like arbitrary named families.
if target_index.is_none() {
target_index = Some(i);
}
},
SingleFontFamily::FamilyName(fam) => {
// Target position for the first generic is in front of the first
// non-whitelisted icon font family we find.
if target_index.is_none() && !fam.is_known_icon_font_family() {
target_index = Some(i);
}
},
}
}
let mut new_list = self.list.iter().cloned().collect::<Vec<_>>();
let first_generic = match index_of_first_generic {
Some(i) => new_list.remove(i),
None => SingleFontFamily::Generic(generic),
};
if let Some(i) = target_index {
new_list.insert(i, first_generic);
} else {
new_list.push(first_generic);
}
self.list = crate::ArcSlice::from_iter(new_list.into_iter());
}
/// Returns whether we need to prioritize user fonts.
pub(crate) fn needs_user_font_prioritization(&self) -> bool {
self.iter().next().map_or(true, |f| match f {
SingleFontFamily::Generic(f) => !f.valid_for_user_font_prioritization(),
_ => true,
})
}
/// Return the generic ID if it is a single generic font
pub fn single_generic(&self) -> Option<GenericFontFamily> {
let mut iter = self.iter();
if let Some(SingleFontFamily::Generic(f)) = iter.next() {
if iter.next().is_none() {
return Some(*f);
}
}
None
}
}
/// Preserve the readability of text when font fallback occurs.
pub type FontSizeAdjust = generics::GenericFontSizeAdjust<NonNegativeNumber>;
impl FontSizeAdjust {
#[inline]
/// Default value of font-size-adjust
pub fn none() -> Self {
FontSizeAdjust::None
}
}
impl ToComputedValue for specified::FontSizeAdjust {
type ComputedValue = FontSizeAdjust;
fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
use crate::font_metrics::FontMetricsOrientation;
let font_metrics = |vertical| {
let orient = if vertical {
FontMetricsOrientation::MatchContextPreferVertical
} else {
FontMetricsOrientation::Horizontal
};
let metrics = context.query_font_metrics(FontBaseSize::CurrentStyle, orient, false);
let font_size = context.style().get_font().clone_font_size().used_size.0;
(metrics, font_size)
};
// Macro to resolve a from-font value using the given metric field. If not present,
// returns the fallback value, or if that is negative, resolves using ascent instead
// of the missing field (this is the fallback for cap-height).
macro_rules! resolve {
($basis:ident, $value:expr, $vertical:expr, $field:ident, $fallback:expr) => {{
match $value {
specified::FontSizeAdjustFactor::Number(f) => {
FontSizeAdjust::$basis(f.to_computed_value(context))
},
specified::FontSizeAdjustFactor::FromFont => {
let (metrics, font_size) = font_metrics($vertical);
let ratio = if let Some(metric) = metrics.$field {
metric / font_size
} else if $fallback >= 0.0 {
$fallback
} else {
metrics.ascent / font_size
};
if ratio.is_nan() {
FontSizeAdjust::$basis(NonNegative(abs($fallback)))
} else {
FontSizeAdjust::$basis(NonNegative(ratio))
}
},
}
}};
}
match *self {
Self::None => FontSizeAdjust::None,
Self::ExHeight(val) => resolve!(ExHeight, val, false, x_height, 0.5),
Self::CapHeight(val) => {
resolve!(CapHeight, val, false, cap_height, -1.0 /* fall back to ascent */)
},
Self::ChWidth(val) => resolve!(ChWidth, val, false, zero_advance_measure, 0.5),
Self::IcWidth(val) => resolve!(IcWidth, val, false, ic_width, 1.0),
Self::IcHeight(val) => resolve!(IcHeight, val, true, ic_width, 1.0),
}
}
fn from_computed_value(computed: &Self::ComputedValue) -> Self {
macro_rules! case {
($basis:ident, $val:expr) => {
Self::$basis(specified::FontSizeAdjustFactor::Number(
ToComputedValue::from_computed_value($val),
))
};
}
match *computed {
FontSizeAdjust::None => Self::None,
FontSizeAdjust::ExHeight(ref val) => case!(ExHeight, val),
FontSizeAdjust::CapHeight(ref val) => case!(CapHeight, val),
FontSizeAdjust::ChWidth(ref val) => case!(ChWidth, val),
FontSizeAdjust::IcWidth(ref val) => case!(IcWidth, val),
FontSizeAdjust::IcHeight(ref val) => case!(IcHeight, val),
}
}
}
/// Use FontSettings as computed type of FontFeatureSettings.
pub type FontFeatureSettings = FontSettings<FeatureTagValue<Integer>>;
/// The computed value for font-variation-settings.
pub type FontVariationSettings = FontSettings<VariationValue<Number>>;
// The computed value of font-{feature,variation}-settings discards values
// with duplicate tags, keeping only the last occurrence of each tag.
fn dedup_font_settings<T>(settings_list: &mut Vec<T>)
where
T: TaggedFontValue,
{
if settings_list.len() > 1 {
settings_list.sort_by_key(|k| k.tag().0);
// dedup() keeps the first of any duplicates, but we want the last,
// so we implement it manually here.
let mut prev_tag = settings_list.last().unwrap().tag();
for i in (0..settings_list.len() - 1).rev() {
let cur_tag = settings_list[i].tag();
if cur_tag == prev_tag {
settings_list.remove(i);
}
prev_tag = cur_tag;
}
}
}
impl<T> ToComputedValue for FontSettings<T>
where
T: ToComputedValue,
<T as ToComputedValue>::ComputedValue: TaggedFontValue,
{
type ComputedValue = FontSettings<T::ComputedValue>;
fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
let mut v = self
.0
.iter()
.map(|item| item.to_computed_value(context))
.collect::<Vec<_>>();
dedup_font_settings(&mut v);
FontSettings(v.into_boxed_slice())
}
fn from_computed_value(computed: &Self::ComputedValue) -> Self {
Self(
computed
.0
.iter()
.map(T::from_computed_value)
.collect::<Vec<_>>()
.into_boxed_slice(),
)
}
}
/// font-language-override can only have a single 1-4 ASCII character
/// OpenType "language system" tag, so we should be able to compute
/// it and store it as a 32-bit integer
#[derive(
Clone,
Copy,
Debug,
Eq,
MallocSizeOf,
PartialEq,
SpecifiedValueInfo,
ToComputedValue,
ToResolvedValue,
ToShmem,
)]
#[repr(C)]
#[value_info(other_values = "normal")]
pub struct FontLanguageOverride(pub u32);
impl FontLanguageOverride {
#[inline]
/// Get computed default value of `font-language-override` with 0
pub fn normal() -> FontLanguageOverride {
FontLanguageOverride(0)
}
/// Returns this value as a `&str`, backed by `storage`.
#[inline]
pub(crate) fn to_str(self, storage: &mut [u8; 4]) -> &str {
*storage = u32::to_be_bytes(self.0);
// Safe because we ensure it's ASCII during parsing
let slice = if cfg!(debug_assertions) {
std::str::from_utf8(&storage[..]).unwrap()
} else {
unsafe { std::str::from_utf8_unchecked(&storage[..]) }
};
slice.trim_end()
}
/// Unsafe because `Self::to_str` requires the value to represent a UTF-8
/// string.
#[inline]
pub unsafe fn from_u32(value: u32) -> Self {
Self(value)
}
}
impl ToCss for FontLanguageOverride {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
if self.0 == 0 {
return dest.write_str("normal");
}
self.to_str(&mut [0; 4]).to_css(dest)
}
}
// FIXME(emilio): Make Gecko use the cbindgen'd fontLanguageOverride, then
// remove this.
#[cfg(feature = "gecko")]
impl From<u32> for FontLanguageOverride {
fn from(v: u32) -> Self {
unsafe { Self::from_u32(v) }
}
}
#[cfg(feature = "gecko")]
impl From<FontLanguageOverride> for u32 {
fn from(v: FontLanguageOverride) -> u32 {
v.0
}
}
impl ToComputedValue for specified::MozScriptMinSize {
type ComputedValue = MozScriptMinSize;
fn to_computed_value(&self, cx: &Context) -> MozScriptMinSize {
// this value is used in the computation of font-size, so
// we use the parent size
let base_size = FontBaseSize::InheritedStyle;
let line_height_base = LineHeightBase::InheritedStyle;
match self.0 {
NoCalcLength::FontRelative(value) => {
value.to_computed_value(cx, base_size, line_height_base)
},
NoCalcLength::ServoCharacterWidth(value) => {
value.to_computed_value(base_size.resolve(cx).computed_size())
},
ref l => l.to_computed_value(cx),
}
}
fn from_computed_value(other: &MozScriptMinSize) -> Self {
specified::MozScriptMinSize(ToComputedValue::from_computed_value(other))
}
}
/// The computed value of the math-depth property.
pub type MathDepth = i8;
#[cfg(feature = "gecko")]
impl ToComputedValue for specified::MathDepth {
type ComputedValue = MathDepth;
fn to_computed_value(&self, cx: &Context) -> i8 {
use crate::properties::longhands::math_style::SpecifiedValue as MathStyleValue;
use std::{cmp, i8};
let int = match *self {
specified::MathDepth::AutoAdd => {
let parent = cx.builder.get_parent_font().clone_math_depth() as i32;
let style = cx.builder.get_parent_font().clone_math_style();
if style == MathStyleValue::Compact {
parent.saturating_add(1)
} else {
parent
}
},
specified::MathDepth::Add(rel) => {
let parent = cx.builder.get_parent_font().clone_math_depth();
(parent as i32).saturating_add(rel.to_computed_value(cx))
},
specified::MathDepth::Absolute(abs) => abs.to_computed_value(cx),
};
cmp::min(int, i8::MAX as i32) as i8
}
fn from_computed_value(other: &i8) -> Self {
let computed_value = *other as i32;
specified::MathDepth::Absolute(SpecifiedInteger::from_computed_value(&computed_value))
}
}
/// - Use a signed 8.8 fixed-point value (representable range -128.0..128)
///
/// Values of <angle> below -90 or above 90 not permitted, so we use out of
/// range values to represent normal | oblique
pub const FONT_STYLE_FRACTION_BITS: u16 = 8;
/// This is an alias which is useful mostly as a cbindgen / C++ inference
/// workaround.
pub type FontStyleFixedPoint = FixedPoint<i16, FONT_STYLE_FRACTION_BITS>;
/// The computed value of `font-style`.
///
/// - Define out of range values min value (-128.0) as meaning 'normal'
/// - Define max value (127.99609375) as 'italic'
/// - Other values represent 'oblique <angle>'
/// - Note that 'oblique 0deg' is distinct from 'normal' (should it be?)
///
/// cbindgen:derive-lt
/// cbindgen:derive-lte
/// cbindgen:derive-gt
/// cbindgen:derive-gte
#[derive(
Clone,
ComputeSquaredDistance,
Copy,
Debug,
Hash,
MallocSizeOf,
PartialEq,
PartialOrd,
ToResolvedValue,
)]
#[repr(C)]
pub struct FontStyle(FontStyleFixedPoint);
impl FontStyle {
/// The normal keyword.
pub const NORMAL: FontStyle = FontStyle(FontStyleFixedPoint {
value: 100 << FONT_STYLE_FRACTION_BITS,
});
/// The italic keyword.
pub const ITALIC: FontStyle = FontStyle(FontStyleFixedPoint {
value: 101 << FONT_STYLE_FRACTION_BITS,
});
/// The default angle for `font-style: oblique`.
pub const DEFAULT_OBLIQUE_DEGREES: i16 = 14;
/// The `oblique` keyword with the default degrees.
pub const OBLIQUE: FontStyle = FontStyle(FontStyleFixedPoint {
value: Self::DEFAULT_OBLIQUE_DEGREES << FONT_STYLE_FRACTION_BITS,
});
/// The `normal` value.
#[inline]
pub fn normal() -> Self {
Self::NORMAL
}
/// Returns the oblique angle for this style.
pub fn oblique(degrees: f32) -> Self {
Self(FixedPoint::from_float(
degrees
.max(specified::FONT_STYLE_OBLIQUE_MIN_ANGLE_DEGREES)
.min(specified::FONT_STYLE_OBLIQUE_MAX_ANGLE_DEGREES),
))
}
/// Returns the oblique angle for this style.
pub fn oblique_degrees(&self) -> f32 {
debug_assert_ne!(*self, Self::NORMAL);
debug_assert_ne!(*self, Self::ITALIC);
self.0.to_float()
}
}
impl ToCss for FontStyle {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
if *self == Self::NORMAL {
return dest.write_str("normal");
}
if *self == Self::ITALIC {
return dest.write_str("italic");
}
if *self == Self::OBLIQUE {
return dest.write_str("oblique");
}
dest.write_str("oblique ")?;
let angle = Angle::from_degrees(self.oblique_degrees());
angle.to_css(dest)?;
Ok(())
}
}
impl ToAnimatedValue for FontStyle {
type AnimatedValue = generics::FontStyle<Angle>;
#[inline]
fn to_animated_value(self) -> Self::AnimatedValue {
if self == Self::NORMAL {
// This allows us to animate between normal and oblique values. Per spec,
// Animation type: by computed value type; 'normal' animates as 'oblique 0deg'
return generics::FontStyle::Oblique(Angle::from_degrees(0.0));
}
if self == Self::ITALIC {
return generics::FontStyle::Italic;
}
generics::FontStyle::Oblique(Angle::from_degrees(self.oblique_degrees()))
}
#[inline]
fn from_animated_value(animated: Self::AnimatedValue) -> Self {
match animated {
generics::FontStyle::Normal => Self::NORMAL,
generics::FontStyle::Italic => Self::ITALIC,
generics::FontStyle::Oblique(ref angle) => {
if angle.degrees() == 0.0 {
// Reverse the conversion done in to_animated_value()
Self::NORMAL
} else {
Self::oblique(angle.degrees())
}
},
}
}
}
/// font-stretch is a percentage relative to normal.
///
/// We use an unsigned 10.6 fixed-point value (range 0.0 - 1023.984375)
///
/// We arbitrarily limit here to 1000%. (If that becomes a problem, we could
/// reduce the number of fractional bits and increase the limit.)
pub const FONT_STRETCH_FRACTION_BITS: u16 = 6;
/// This is an alias which is useful mostly as a cbindgen / C++ inference
/// workaround.
pub type FontStretchFixedPoint = FixedPoint<u16, FONT_STRETCH_FRACTION_BITS>;
/// A value for the font-stretch property per:
///
///
/// cbindgen:derive-lt
/// cbindgen:derive-lte
/// cbindgen:derive-gt
/// cbindgen:derive-gte
#[derive(
Clone, ComputeSquaredDistance, Copy, Debug, MallocSizeOf, PartialEq, PartialOrd, ToResolvedValue,
)]
#[repr(C)]
pub struct FontStretch(pub FontStretchFixedPoint);
impl FontStretch {
/// The fraction bits, as an easy-to-access-constant.
pub const FRACTION_BITS: u16 = FONT_STRETCH_FRACTION_BITS;
/// 0.5 in our floating point representation.
pub const HALF: u16 = 1 << (Self::FRACTION_BITS - 1);
/// The `ultra-condensed` keyword.
pub const ULTRA_CONDENSED: FontStretch = FontStretch(FontStretchFixedPoint {
value: 50 << Self::FRACTION_BITS,
});
/// The `extra-condensed` keyword.
pub const EXTRA_CONDENSED: FontStretch = FontStretch(FontStretchFixedPoint {
value: (62 << Self::FRACTION_BITS) + Self::HALF,
});
/// The `condensed` keyword.
pub const CONDENSED: FontStretch = FontStretch(FontStretchFixedPoint {
value: 75 << Self::FRACTION_BITS,
});
/// The `semi-condensed` keyword.
pub const SEMI_CONDENSED: FontStretch = FontStretch(FontStretchFixedPoint {
value: (87 << Self::FRACTION_BITS) + Self::HALF,
});
/// The `normal` keyword.
pub const NORMAL: FontStretch = FontStretch(FontStretchFixedPoint {
value: 100 << Self::FRACTION_BITS,
});
/// The `semi-expanded` keyword.
pub const SEMI_EXPANDED: FontStretch = FontStretch(FontStretchFixedPoint {
value: (112 << Self::FRACTION_BITS) + Self::HALF,
});
/// The `expanded` keyword.
pub const EXPANDED: FontStretch = FontStretch(FontStretchFixedPoint {
value: 125 << Self::FRACTION_BITS,
});
/// The `extra-expanded` keyword.
pub const EXTRA_EXPANDED: FontStretch = FontStretch(FontStretchFixedPoint {
value: 150 << Self::FRACTION_BITS,
});
/// The `ultra-expanded` keyword.
pub const ULTRA_EXPANDED: FontStretch = FontStretch(FontStretchFixedPoint {
value: 200 << Self::FRACTION_BITS,
});
/// 100%
pub fn hundred() -> Self {
Self::NORMAL
}
/// Converts to a computed percentage.
#[inline]
pub fn to_percentage(&self) -> Percentage {
Percentage(self.0.to_float() / 100.0)
}
/// Converts from a computed percentage value.
pub fn from_percentage(p: f32) -> Self {
Self(FixedPoint::from_float((p * 100.).max(0.0).min(1000.0)))
}
/// Returns a relevant stretch value from a keyword.
pub fn from_keyword(kw: specified::FontStretchKeyword) -> Self {
use specified::FontStretchKeyword::*;
match kw {
UltraCondensed => Self::ULTRA_CONDENSED,
ExtraCondensed => Self::EXTRA_CONDENSED,
Condensed => Self::CONDENSED,
SemiCondensed => Self::SEMI_CONDENSED,
Normal => Self::NORMAL,
SemiExpanded => Self::SEMI_EXPANDED,
Expanded => Self::EXPANDED,
ExtraExpanded => Self::EXTRA_EXPANDED,
UltraExpanded => Self::ULTRA_EXPANDED,
}
}
/// Returns the stretch keyword if we map to one of the relevant values.
pub fn as_keyword(&self) -> Option<specified::FontStretchKeyword> {
use specified::FontStretchKeyword::*;
// TODO: Can we use match here?
if *self == Self::ULTRA_CONDENSED {
return Some(UltraCondensed);
}
if *self == Self::EXTRA_CONDENSED {
return Some(ExtraCondensed);
}
if *self == Self::CONDENSED {
return Some(Condensed);
}
if *self == Self::SEMI_CONDENSED {
return Some(SemiCondensed);
}
if *self == Self::NORMAL {
return Some(Normal);
}
if *self == Self::SEMI_EXPANDED {
return Some(SemiExpanded);
}
if *self == Self::EXPANDED {
return Some(Expanded);
}
if *self == Self::EXTRA_EXPANDED {
return Some(ExtraExpanded);
}
if *self == Self::ULTRA_EXPANDED {
return Some(UltraExpanded);
}
None
}
}
impl ToCss for FontStretch {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
self.to_percentage().to_css(dest)
}
}
impl ToAnimatedValue for FontStretch {
type AnimatedValue = Percentage;
#[inline]
fn to_animated_value(self) -> Self::AnimatedValue {
self.to_percentage()
}
#[inline]
fn from_animated_value(animated: Self::AnimatedValue) -> Self {
Self::from_percentage(animated.0)
}
}
/// A computed value for the `line-height` property.
pub type LineHeight = generics::GenericLineHeight<NonNegativeNumber, NonNegativeLength>;
impl ToResolvedValue for LineHeight {
type ResolvedValue = Self;
fn to_resolved_value(self, context: &ResolvedContext) -> Self::ResolvedValue {
// Resolve <number> to an absolute <length> based on font size.
if matches!(self, Self::Normal | Self::MozBlockHeight) {
return self;
}
let wm = context.style.writing_mode;
Self::Length(context.device.calc_line_height(
context.style.get_font(),
wm,
Some(context.element_info.element),
).to_resolved_value(context))
}
#[inline]
fn from_resolved_value(value: Self::ResolvedValue) -> Self {
value
}
}