stylo: Move font-size stuff to values::*::font

This commit is contained in:
Manish Goregaokar 2017-09-18 13:25:59 -07:00 committed by Manish Goregaokar
parent e1a39a2012
commit df9d7cd941
8 changed files with 430 additions and 389 deletions

View file

@ -2161,7 +2161,7 @@ fn static_assert() {
}
pub fn set_font_size(&mut self, v: longhands::font_size::computed_value::T) {
use self::longhands::font_size::KeywordSize;
use values::specified::font::KeywordSize;
self.gecko.mSize = v.size().0;
self.gecko.mScriptUnconstrainedSize = v.size().0;
if let Some(info) = v.info {
@ -2370,7 +2370,8 @@ fn static_assert() {
}
pub fn clone_font_size(&self) -> longhands::font_size::computed_value::T {
use self::longhands::font_size::KeywordSize;
use values::computed::font::KeywordInfo;
use values::specified::font::KeywordSize;
let size = Au(self.gecko.mSize).into();
let kw = match self.gecko.mFontSizeKeyword as u32 {
structs::NS_STYLE_FONT_SIZE_XXSMALL => KeywordSize::XXSmall,
@ -2391,7 +2392,7 @@ fn static_assert() {
};
longhands::font_size::computed_value::T {
size: size,
info: Some(longhands::font_size::computed_value::KeywordInfo {
info: Some(KeywordInfo {
kw: kw,
factor: self.gecko.mFontSizeFactor,
offset: Au(self.gecko.mFontSizeOffset).into()

View file

@ -600,363 +600,23 @@ ${helpers.single_keyword_system("font-variant-caps",
flags="APPLIES_TO_FIRST_LETTER APPLIES_TO_FIRST_LINE APPLIES_TO_PLACEHOLDER"
allow_quirks="True" spec="https://drafts.csswg.org/css-fonts/#propdef-font-size">
use app_units::Au;
use properties::longhands::system_font::SystemFont;
use std::fmt;
use style_traits::ToCss;
use values::FONT_MEDIUM_PX;
use values::computed::NonNegativeLength;
use values::specified::{AllowQuirks, LengthOrPercentage, NoCalcLength};
use values::specified::AllowQuirks;
use values::specified::length::FontBaseSize;
impl ToCss for SpecifiedValue {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
match *self {
SpecifiedValue::Length(ref lop) => lop.to_css(dest),
SpecifiedValue::Keyword(kw, _, _) => kw.to_css(dest),
SpecifiedValue::Smaller => dest.write_str("smaller"),
SpecifiedValue::Larger => dest.write_str("larger"),
SpecifiedValue::System(sys) => sys.to_css(dest),
}
}
}
#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
pub enum SpecifiedValue {
Length(specified::LengthOrPercentage),
/// A keyword value, along with a ratio and absolute offset.
/// The ratio in any specified keyword value
/// will be 1 (with offset 0), but we cascade keywordness even
/// after font-relative (percent and em) values
/// have been applied, which is where the ratio
/// comes in. The offset comes in if we cascaded a calc value,
/// where the font-relative portion (em and percentage) will
/// go into the ratio, and the remaining units all computed together
/// will go into the offset.
/// See bug 1355707.
Keyword(KeywordSize, f32, NonNegativeLength),
Smaller,
Larger,
System(SystemFont)
}
impl From<specified::LengthOrPercentage> for SpecifiedValue {
fn from(other: specified::LengthOrPercentage) -> Self {
SpecifiedValue::Length(other)
}
}
use values::specified::font::{FONT_MEDIUM_PX, KeywordSize};
pub mod computed_value {
use app_units::Au;
use std::fmt;
use style_traits::ToCss;
use values::computed::NonNegativeLength;
#[derive(Copy, Clone, PartialEq, Debug)]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
pub struct T {
pub size: NonNegativeLength,
pub info: Option<KeywordInfo>,
use values::computed::font;
pub type T = font::FontSize;
}
#[derive(Copy, Clone, PartialEq, Debug)]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
pub struct KeywordInfo {
pub kw: super::KeywordSize,
pub factor: f32,
pub offset: NonNegativeLength,
}
impl KeywordInfo {
/// Given a parent keyword info (self), apply an additional factor/offset to it
pub fn compose(self, factor: f32, offset: NonNegativeLength) -> Self {
KeywordInfo {
kw: self.kw,
factor: self.factor * factor,
offset: self.offset.scale_by(factor) + offset,
}
}
}
impl T {
pub fn size(self) -> Au {
self.size.into()
}
}
impl ToCss for T {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
self.size.to_css(dest)
}
}
}
/// CSS font keywords
#[derive(Clone, Copy, Debug, PartialEq)]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
pub enum KeywordSize {
XXSmall = 1, // This is to enable the NonZero optimization
// which simplifies the representation of Option<KeywordSize>
// in bindgen
XSmall,
Small,
Medium,
Large,
XLarge,
XXLarge,
// This is not a real font keyword and will not parse
// HTML font-size 7 corresponds to this value
XXXLarge,
}
pub use self::KeywordSize::*;
impl KeywordSize {
pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
try_match_ident_ignore_ascii_case! { input.expect_ident()?,
"xx-small" => Ok(XXSmall),
"x-small" => Ok(XSmall),
"small" => Ok(Small),
"medium" => Ok(Medium),
"large" => Ok(Large),
"x-large" => Ok(XLarge),
"xx-large" => Ok(XXLarge),
}
}
pub fn html_size(&self) -> u8 {
match *self {
KeywordSize::XXSmall => 0,
KeywordSize::XSmall => 1,
KeywordSize::Small => 2,
KeywordSize::Medium => 3,
KeywordSize::Large => 4,
KeywordSize::XLarge => 5,
KeywordSize::XXLarge => 6,
KeywordSize::XXXLarge => 7,
}
}
}
impl Default for KeywordSize {
fn default() -> Self {
Medium
}
}
impl ToCss for KeywordSize {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
dest.write_str(match *self {
XXSmall => "xx-small",
XSmall => "x-small",
Small => "small",
Medium => "medium",
Large => "large",
XLarge => "x-large",
XXLarge => "xx-large",
XXXLarge => unreachable!("We should never serialize \
specified values set via
HTML presentation attributes"),
})
}
}
% if product == "servo":
impl ToComputedValue for KeywordSize {
type ComputedValue = NonNegativeLength;
#[inline]
fn to_computed_value(&self, _: &Context) -> NonNegativeLength {
// https://drafts.csswg.org/css-fonts-3/#font-size-prop
use values::FONT_MEDIUM_PX;
match *self {
XXSmall => Au::from_px(FONT_MEDIUM_PX) * 3 / 5,
XSmall => Au::from_px(FONT_MEDIUM_PX) * 3 / 4,
Small => Au::from_px(FONT_MEDIUM_PX) * 8 / 9,
Medium => Au::from_px(FONT_MEDIUM_PX),
Large => Au::from_px(FONT_MEDIUM_PX) * 6 / 5,
XLarge => Au::from_px(FONT_MEDIUM_PX) * 3 / 2,
XXLarge => Au::from_px(FONT_MEDIUM_PX) * 2,
XXXLarge => Au::from_px(FONT_MEDIUM_PX) * 3,
}.into()
}
#[inline]
fn from_computed_value(_: &NonNegativeLength) -> Self {
unreachable!()
}
}
% else:
impl ToComputedValue for KeywordSize {
type ComputedValue = NonNegativeLength;
#[inline]
fn to_computed_value(&self, cx: &Context) -> NonNegativeLength {
use gecko_bindings::structs::nsIAtom;
use values::specified::length::au_to_int_px;
// Data from nsRuleNode.cpp in Gecko
// Mapping from base size and HTML size to pixels
// The first index is (base_size - 9), the second is the
// HTML size. "0" is CSS keyword xx-small, not HTML size 0,
// since HTML size 0 is the same as 1.
//
// xxs xs s m l xl xxl -
// - 0/1 2 3 4 5 6 7
static FONT_SIZE_MAPPING: [[i32; 8]; 8] = [
[9, 9, 9, 9, 11, 14, 18, 27],
[9, 9, 9, 10, 12, 15, 20, 30],
[9, 9, 10, 11, 13, 17, 22, 33],
[9, 9, 10, 12, 14, 18, 24, 36],
[9, 10, 12, 13, 16, 20, 26, 39],
[9, 10, 12, 14, 17, 21, 28, 42],
[9, 10, 13, 15, 18, 23, 30, 45],
[9, 10, 13, 16, 18, 24, 32, 48]
];
static FONT_SIZE_FACTORS: [i32; 8] = [60, 75, 89, 100, 120, 150, 200, 300];
// XXXManishearth handle quirks mode
let ref gecko_font = cx.style().get_font().gecko();
let base_size = unsafe { Atom::with(gecko_font.mLanguage.raw::<nsIAtom>(), |atom| {
cx.font_metrics_provider.get_size(atom, gecko_font.mGenericID).0
}) };
let base_size_px = au_to_int_px(base_size as f32);
let html_size = self.html_size() as usize;
if base_size_px >= 9 && base_size_px <= 16 {
NonNegativeLength::new(FONT_SIZE_MAPPING[(base_size_px - 9) as usize][html_size] as f32)
} else {
Au(FONT_SIZE_FACTORS[html_size] * base_size / 100).into()
}
}
#[inline]
fn from_computed_value(_: &NonNegativeLength) -> Self {
unreachable!()
}
}
% endif
/// This is the ratio applied for font-size: larger
/// and smaller by both Firefox and Chrome
const LARGER_FONT_SIZE_RATIO: f32 = 1.2;
impl SpecifiedValue {
/// https://html.spec.whatwg.org/multipage/#rules-for-parsing-a-legacy-font-size
pub fn from_html_size(size: u8) -> Self {
SpecifiedValue::Keyword(match size {
// If value is less than 1, let it be 1.
0 | 1 => XSmall,
2 => Small,
3 => Medium,
4 => Large,
5 => XLarge,
6 => XXLarge,
// If value is greater than 7, let it be 7.
_ => XXXLarge,
}, 1., Au(0).into())
}
/// Compute it against a given base font size
pub fn to_computed_value_against(
&self,
context: &Context,
base_size: FontBaseSize,
) -> computed_value::T {
use values::specified::length::FontRelativeLength;
let compose_keyword = |factor| {
context.style().get_parent_font()
.clone_font_size().info
.map(|i| i.compose(factor, Au(0).into()))
};
let mut info = None;
let size = match *self {
SpecifiedValue::Length(LengthOrPercentage::Length(
NoCalcLength::FontRelative(value))) => {
if let FontRelativeLength::Em(em) = value {
// If the parent font was keyword-derived, this is too.
// Tack the em unit onto the factor
info = compose_keyword(em);
}
value.to_computed_value(context, base_size).into()
}
SpecifiedValue::Length(LengthOrPercentage::Length(
NoCalcLength::ServoCharacterWidth(value))) => {
value.to_computed_value(base_size.resolve(context)).into()
}
SpecifiedValue::Length(LengthOrPercentage::Length(
NoCalcLength::Absolute(ref l))) => {
context.maybe_zoom_text(l.to_computed_value(context).into())
}
SpecifiedValue::Length(LengthOrPercentage::Length(ref l)) => {
l.to_computed_value(context).into()
}
SpecifiedValue::Length(LengthOrPercentage::Percentage(pc)) => {
// If the parent font was keyword-derived, this is too.
// Tack the % onto the factor
info = compose_keyword(pc.0);
base_size.resolve(context).scale_by(pc.0).into()
}
SpecifiedValue::Length(LengthOrPercentage::Calc(ref calc)) => {
let parent = context.style().get_parent_font().clone_font_size();
// if we contain em/% units and the parent was keyword derived, this is too
// Extract the ratio/offset and compose it
if (calc.em.is_some() || calc.percentage.is_some()) && parent.info.is_some() {
let ratio = calc.em.unwrap_or(0.) + calc.percentage.map_or(0., |pc| pc.0);
// Compute it, but shave off the font-relative part (em, %)
// This will mean that other font-relative units like ex and ch will be computed against
// the old font even when the font changes. There's no particular "right answer" for what
// to do here -- Gecko recascades as if the font had changed, we instead track the changes
// and reapply, which means that we carry over old computed ex/ch values whilst Gecko
// recomputes new ones. This is enough of an edge case to not really matter.
let abs = calc.to_computed_value_zoomed(context, FontBaseSize::Custom(Au(0).into()))
.length_component().into();
info = parent.info.map(|i| i.compose(ratio, abs));
}
let calc = calc.to_computed_value_zoomed(context, base_size);
calc.to_used_value(Some(base_size.resolve(context))).unwrap().into()
}
SpecifiedValue::Keyword(key, fraction, offset) => {
// As a specified keyword, this is keyword derived
info = Some(computed_value::KeywordInfo {
kw: key,
factor: fraction,
offset: offset,
});
let key_len = key.to_computed_value(context).scale_by(fraction) + offset;
context.maybe_zoom_text(key_len).into()
}
SpecifiedValue::Smaller => {
info = compose_keyword(1. / LARGER_FONT_SIZE_RATIO);
FontRelativeLength::Em(1. / LARGER_FONT_SIZE_RATIO)
.to_computed_value(context, base_size).into()
}
SpecifiedValue::Larger => {
info = compose_keyword(LARGER_FONT_SIZE_RATIO);
FontRelativeLength::Em(LARGER_FONT_SIZE_RATIO)
.to_computed_value(context, base_size).into()
}
SpecifiedValue::System(_) => {
<%self:nongecko_unreachable>
context.cached_system_font.as_ref().unwrap().font_size.size
</%self:nongecko_unreachable>
}
};
computed_value::T { size, info }
}
}
pub use values::specified::font::FontSize as SpecifiedValue;
#[inline]
#[allow(missing_docs)]
pub fn get_initial_value() -> computed_value::T {
computed_value::T {
size: Au::from_px(FONT_MEDIUM_PX).into(),
info: Some(computed_value::KeywordInfo {
info: Some(::values::computed::font::KeywordInfo {
kw: KeywordSize::Medium,
factor: 1.,
offset: Au(0).into(),
@ -966,26 +626,10 @@ ${helpers.single_keyword_system("font-variant-caps",
#[inline]
pub fn get_initial_specified_value() -> SpecifiedValue {
SpecifiedValue::Keyword(Medium, 1., Au(0).into())
SpecifiedValue::Keyword(KeywordSize::Medium, 1., Au(0).into())
}
impl ToComputedValue for SpecifiedValue {
type ComputedValue = computed_value::T;
#[inline]
fn to_computed_value(&self, context: &Context) -> computed_value::T {
self.to_computed_value_against(context, FontBaseSize::InheritedStyle)
}
#[inline]
fn from_computed_value(computed: &computed_value::T) -> Self {
SpecifiedValue::Length(LengthOrPercentage::Length(
ToComputedValue::from_computed_value(&computed.size.0)
))
}
}
/// <length> | <percentage> | <absolute-size> | <relative-size>
pub fn parse<'i, 't>(context: &ParserContext, input: &mut Parser<'i, 't>)
-> Result<SpecifiedValue, ParseError<'i>> {
@ -1012,19 +656,6 @@ ${helpers.single_keyword_system("font-variant-caps",
}
}
impl SpecifiedValue {
pub fn system_font(f: SystemFont) -> Self {
SpecifiedValue::System(f)
}
pub fn get_system(&self) -> Option<SystemFont> {
if let SpecifiedValue::System(s) = *self {
Some(s)
} else {
None
}
}
}
#[allow(unused_mut)]
pub fn cascade_specified_font_size(context: &mut Context,
specified_value: &SpecifiedValue,

View file

@ -0,0 +1,61 @@
/* 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 http://mozilla.org/MPL/2.0/. */
//! Computed values for font properties
use app_units::Au;
use std::fmt;
use style_traits::ToCss;
use values::computed::NonNegativeLength;
use values::specified::font as specified;
#[derive(Copy, Clone, PartialEq, Debug)]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
/// The computed value of font-size
pub struct FontSize {
/// The size.
pub size: NonNegativeLength,
/// If derived from a keyword, the keyword and additional transformations applied to it
pub info: Option<KeywordInfo>,
}
#[derive(Copy, Clone, PartialEq, Debug)]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
/// Additional information for keyword-derived font sizes.
pub struct KeywordInfo {
/// The keyword used
pub kw: specified::KeywordSize,
/// A factor to be multiplied by the computed size of the keyword
pub factor: f32,
/// An additional Au offset to add to the kw*factor in the case of calcs
pub offset: NonNegativeLength,
}
impl KeywordInfo {
/// Given a parent keyword info (self), apply an additional factor/offset to it
pub fn compose(self, factor: f32, offset: NonNegativeLength) -> Self {
KeywordInfo {
kw: self.kw,
factor: self.factor * factor,
offset: self.offset.scale_by(factor) + offset,
}
}
}
impl FontSize {
/// The actual computed font size.
pub fn size(self) -> Au {
self.size.into()
}
}
impl ToCss for FontSize {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
self.size.to_css(dest)
}
}

View file

@ -67,6 +67,7 @@ pub mod box_;
pub mod color;
pub mod effects;
pub mod flex;
pub mod font;
pub mod image;
#[cfg(feature = "gecko")]
pub mod gecko;

View file

@ -29,9 +29,6 @@ pub type CSSFloat = f32;
/// A CSS integer value.
pub type CSSInteger = i32;
/// The default font size.
pub const FONT_MEDIUM_PX: i32 = 16;
define_keyword_type!(None_, "none");
define_keyword_type!(Auto, "auto");
define_keyword_type!(Normal, "normal");

View file

@ -0,0 +1,355 @@
/* 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 http://mozilla.org/MPL/2.0/. */
//! Specified values for font properties
#[cfg(feature = "gecko")]
use Atom;
use app_units::Au;
use cssparser::Parser;
use properties::longhands::system_font::SystemFont;
use std::fmt;
use style_traits::{ToCss, ParseError};
use values::computed::{font as computed, Context, NonNegativeLength, ToComputedValue};
use values::specified::{LengthOrPercentage, NoCalcLength};
use values::specified::length::FontBaseSize;
#[derive(Clone, Debug, PartialEq)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
/// A specified font-size value
pub enum FontSize {
/// A length; e.g. 10px.
Length(LengthOrPercentage),
/// A keyword value, along with a ratio and absolute offset.
/// The ratio in any specified keyword value
/// will be 1 (with offset 0), but we cascade keywordness even
/// after font-relative (percent and em) values
/// have been applied, which is where the ratio
/// comes in. The offset comes in if we cascaded a calc value,
/// where the font-relative portion (em and percentage) will
/// go into the ratio, and the remaining units all computed together
/// will go into the offset.
/// See bug 1355707.
Keyword(KeywordSize, f32, NonNegativeLength),
/// font-size: smaller
Smaller,
/// font-size: larger
Larger,
/// Derived from a specified system font.
System(SystemFont)
}
impl ToCss for FontSize {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
match *self {
FontSize::Length(ref lop) => lop.to_css(dest),
FontSize::Keyword(kw, _, _) => kw.to_css(dest),
FontSize::Smaller => dest.write_str("smaller"),
FontSize::Larger => dest.write_str("larger"),
FontSize::System(sys) => sys.to_css(dest),
}
}
}
impl From<LengthOrPercentage> for FontSize {
fn from(other: LengthOrPercentage) -> Self {
FontSize::Length(other)
}
}
/// CSS font keywords
#[derive(Clone, Copy, Debug, PartialEq)]
#[derive(ToAnimatedValue, Animate, ToAnimatedZero, ComputeSquaredDistance)]
#[cfg_attr(feature = "servo", derive(HeapSizeOf))]
#[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
#[allow(missing_docs)]
pub enum KeywordSize {
XXSmall = 1, // This is to enable the NonZero optimization
// which simplifies the representation of Option<KeywordSize>
// in bindgen
XSmall,
Small,
Medium,
Large,
XLarge,
XXLarge,
// This is not a real font keyword and will not parse
// HTML font-size 7 corresponds to this value
XXXLarge,
}
impl KeywordSize {
/// Parse a keyword size
pub fn parse<'i, 't>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i>> {
try_match_ident_ignore_ascii_case! { input.expect_ident()?,
"xx-small" => Ok(KeywordSize::XXSmall),
"x-small" => Ok(KeywordSize::XSmall),
"small" => Ok(KeywordSize::Small),
"medium" => Ok(KeywordSize::Medium),
"large" => Ok(KeywordSize::Large),
"x-large" => Ok(KeywordSize::XLarge),
"xx-large" => Ok(KeywordSize::XXLarge),
}
}
/// Convert to an HTML <font size> value
pub fn html_size(&self) -> u8 {
match *self {
KeywordSize::XXSmall => 0,
KeywordSize::XSmall => 1,
KeywordSize::Small => 2,
KeywordSize::Medium => 3,
KeywordSize::Large => 4,
KeywordSize::XLarge => 5,
KeywordSize::XXLarge => 6,
KeywordSize::XXXLarge => 7,
}
}
}
impl Default for KeywordSize {
fn default() -> Self {
KeywordSize::Medium
}
}
impl ToCss for KeywordSize {
fn to_css<W>(&self, dest: &mut W) -> fmt::Result where W: fmt::Write {
dest.write_str(match *self {
KeywordSize::XXSmall => "xx-small",
KeywordSize::XSmall => "x-small",
KeywordSize::Small => "small",
KeywordSize::Medium => "medium",
KeywordSize::Large => "large",
KeywordSize::XLarge => "x-large",
KeywordSize::XXLarge => "xx-large",
KeywordSize::XXXLarge => unreachable!("We should never serialize \
specified values set via
HTML presentation attributes"),
})
}
}
/// This is the ratio applied for font-size: larger
/// and smaller by both Firefox and Chrome
const LARGER_FONT_SIZE_RATIO: f32 = 1.2;
/// The default font size.
pub const FONT_MEDIUM_PX: i32 = 16;
#[cfg(feature = "servo")]
impl ToComputedValue for KeywordSize {
type ComputedValue = NonNegativeLength;
#[inline]
fn to_computed_value(&self, _: &Context) -> NonNegativeLength {
// https://drafts.csswg.org/css-fonts-3/#font-size-prop
match *self {
KeywordSize::XXSmall => Au::from_px(FONT_MEDIUM_PX) * 3 / 5,
KeywordSize::XSmall => Au::from_px(FONT_MEDIUM_PX) * 3 / 4,
KeywordSize::Small => Au::from_px(FONT_MEDIUM_PX) * 8 / 9,
KeywordSize::Medium => Au::from_px(FONT_MEDIUM_PX),
KeywordSize::Large => Au::from_px(FONT_MEDIUM_PX) * 6 / 5,
KeywordSize::XLarge => Au::from_px(FONT_MEDIUM_PX) * 3 / 2,
KeywordSize::XXLarge => Au::from_px(FONT_MEDIUM_PX) * 2,
KeywordSize::XXXLarge => Au::from_px(FONT_MEDIUM_PX) * 3,
}.into()
}
#[inline]
fn from_computed_value(_: &NonNegativeLength) -> Self {
unreachable!()
}
}
#[cfg(feature = "gecko")]
impl ToComputedValue for KeywordSize {
type ComputedValue = NonNegativeLength;
#[inline]
fn to_computed_value(&self, cx: &Context) -> NonNegativeLength {
use gecko_bindings::structs::nsIAtom;
use values::specified::length::au_to_int_px;
// Data from nsRuleNode.cpp in Gecko
// Mapping from base size and HTML size to pixels
// The first index is (base_size - 9), the second is the
// HTML size. "0" is CSS keyword xx-small, not HTML size 0,
// since HTML size 0 is the same as 1.
//
// xxs xs s m l xl xxl -
// - 0/1 2 3 4 5 6 7
static FONT_SIZE_MAPPING: [[i32; 8]; 8] = [
[9, 9, 9, 9, 11, 14, 18, 27],
[9, 9, 9, 10, 12, 15, 20, 30],
[9, 9, 10, 11, 13, 17, 22, 33],
[9, 9, 10, 12, 14, 18, 24, 36],
[9, 10, 12, 13, 16, 20, 26, 39],
[9, 10, 12, 14, 17, 21, 28, 42],
[9, 10, 13, 15, 18, 23, 30, 45],
[9, 10, 13, 16, 18, 24, 32, 48]
];
static FONT_SIZE_FACTORS: [i32; 8] = [60, 75, 89, 100, 120, 150, 200, 300];
// XXXManishearth handle quirks mode (bug 1401322)
let ref gecko_font = cx.style().get_font().gecko();
let base_size = unsafe { Atom::with(gecko_font.mLanguage.raw::<nsIAtom>(), |atom| {
cx.font_metrics_provider.get_size(atom, gecko_font.mGenericID).0
}) };
let base_size_px = au_to_int_px(base_size as f32);
let html_size = self.html_size() as usize;
if base_size_px >= 9 && base_size_px <= 16 {
Au::from_px(FONT_SIZE_MAPPING[(base_size_px - 9) as usize][html_size]).into()
} else {
Au(FONT_SIZE_FACTORS[html_size] * base_size / 100).into()
}
}
#[inline]
fn from_computed_value(_: &NonNegativeLength) -> Self {
unreachable!()
}
}
impl FontSize {
/// https://html.spec.whatwg.org/multipage/#rules-for-parsing-a-legacy-font-size
pub fn from_html_size(size: u8) -> Self {
FontSize::Keyword(match size {
// If value is less than 1, let it be 1.
0 | 1 => KeywordSize::XSmall,
2 => KeywordSize::Small,
3 => KeywordSize::Medium,
4 => KeywordSize::Large,
5 => KeywordSize::XLarge,
6 => KeywordSize::XXLarge,
// If value is greater than 7, let it be 7.
_ => KeywordSize::XXXLarge,
}, 1., Au(0).into())
}
/// Compute it against a given base font size
pub fn to_computed_value_against(
&self,
context: &Context,
base_size: FontBaseSize,
) -> computed::FontSize {
use values::specified::length::FontRelativeLength;
let compose_keyword = |factor| {
context.style().get_parent_font()
.clone_font_size().info
.map(|i| i.compose(factor, Au(0).into()))
};
let mut info = None;
let size = match *self {
FontSize::Length(LengthOrPercentage::Length(
NoCalcLength::FontRelative(value))) => {
if let FontRelativeLength::Em(em) = value {
// If the parent font was keyword-derived, this is too.
// Tack the em unit onto the factor
info = compose_keyword(em);
}
value.to_computed_value(context, base_size).into()
}
FontSize::Length(LengthOrPercentage::Length(
NoCalcLength::ServoCharacterWidth(value))) => {
value.to_computed_value(base_size.resolve(context)).into()
}
FontSize::Length(LengthOrPercentage::Length(
NoCalcLength::Absolute(ref l))) => {
context.maybe_zoom_text(l.to_computed_value(context).into())
}
FontSize::Length(LengthOrPercentage::Length(ref l)) => {
l.to_computed_value(context).into()
}
FontSize::Length(LengthOrPercentage::Percentage(pc)) => {
// If the parent font was keyword-derived, this is too.
// Tack the % onto the factor
info = compose_keyword(pc.0);
base_size.resolve(context).scale_by(pc.0).into()
}
FontSize::Length(LengthOrPercentage::Calc(ref calc)) => {
let parent = context.style().get_parent_font().clone_font_size();
// if we contain em/% units and the parent was keyword derived, this is too
// Extract the ratio/offset and compose it
if (calc.em.is_some() || calc.percentage.is_some()) && parent.info.is_some() {
let ratio = calc.em.unwrap_or(0.) + calc.percentage.map_or(0., |pc| pc.0);
// Compute it, but shave off the font-relative part (em, %)
// This will mean that other font-relative units like ex and ch will be computed against
// the old font even when the font changes. There's no particular "right answer" for what
// to do here -- Gecko recascades as if the font had changed, we instead track the changes
// and reapply, which means that we carry over old computed ex/ch values whilst Gecko
// recomputes new ones. This is enough of an edge case to not really matter.
let abs = calc.to_computed_value_zoomed(context, FontBaseSize::Custom(Au(0).into()))
.length_component().into();
info = parent.info.map(|i| i.compose(ratio, abs));
}
let calc = calc.to_computed_value_zoomed(context, base_size);
calc.to_used_value(Some(base_size.resolve(context))).unwrap().into()
}
FontSize::Keyword(key, fraction, offset) => {
// As a specified keyword, this is keyword derived
info = Some(computed::KeywordInfo {
kw: key,
factor: fraction,
offset: offset,
});
context.maybe_zoom_text(key.to_computed_value(context).scale_by(fraction) + offset)
}
FontSize::Smaller => {
info = compose_keyword(1. / LARGER_FONT_SIZE_RATIO);
FontRelativeLength::Em(1. / LARGER_FONT_SIZE_RATIO)
.to_computed_value(context, base_size).into()
}
FontSize::Larger => {
info = compose_keyword(LARGER_FONT_SIZE_RATIO);
FontRelativeLength::Em(LARGER_FONT_SIZE_RATIO)
.to_computed_value(context, base_size).into()
}
FontSize::System(_) => {
#[cfg(feature = "servo")] {
unreachable!()
}
#[cfg(feature = "gecko")] {
context.cached_system_font.as_ref().unwrap().font_size.size
}
}
};
computed::FontSize { size, info }
}
}
impl ToComputedValue for FontSize {
type ComputedValue = computed::FontSize;
#[inline]
fn to_computed_value(&self, context: &Context) -> computed::FontSize {
self.to_computed_value_against(context, FontBaseSize::InheritedStyle)
}
#[inline]
fn from_computed_value(computed: &computed::FontSize) -> Self {
FontSize::Length(LengthOrPercentage::Length(
ToComputedValue::from_computed_value(&computed.size.0)
))
}
}
impl FontSize {
/// Construct a system font value.
pub fn system_font(f: SystemFont) -> Self {
FontSize::System(f)
}
/// Obtain the system font, if any
pub fn get_system(&self) -> Option<SystemFont> {
if let FontSize::System(s) = *self {
Some(s)
} else {
None
}
}
}

View file

@ -18,7 +18,7 @@ use style_traits::{ToCss, ParseError, StyleParseError};
use style_traits::values::specified::AllowedNumericType;
use stylesheets::CssRuleType;
use super::{AllowQuirks, Number, ToComputedValue, Percentage};
use values::{Auto, CSSFloat, Either, FONT_MEDIUM_PX, None_, Normal};
use values::{Auto, CSSFloat, Either, None_, Normal};
use values::{ExtremumLength, serialize_dimension};
use values::computed::{self, CSSPixelLength, Context};
use values::generics::NonNegative;
@ -571,12 +571,6 @@ impl NoCalcLength {
}
}
#[inline]
/// Returns a `medium` length.
pub fn medium() -> NoCalcLength {
NoCalcLength::Absolute(AbsoluteLength::Px(FONT_MEDIUM_PX as f32))
}
/// Get an absolute length from a px value.
#[inline]
pub fn from_px(px_value: CSSFloat) -> NoCalcLength {

View file

@ -65,6 +65,7 @@ pub mod calc;
pub mod color;
pub mod effects;
pub mod flex;
pub mod font;
#[cfg(feature = "gecko")]
pub mod gecko;
pub mod grid;