Source code
Revision control
Copy as Markdown
Other Tools
/* 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
//! Write colors into CSS strings.
use super::{
parsing::{NumberOrAngleComponent, NumberOrPercentageComponent},
AbsoluteColor, ColorFlags, ColorSpace,
};
use crate::values::normalize;
use cssparser::color::{clamp_unit_f32, serialize_color_alpha, OPAQUE};
use std::fmt::{self, Write};
use style_traits::{CssWriter, ToCss};
/// A [`ModernComponent`] can serialize to `none`, `nan`, `infinity` and
/// floating point values.
struct ModernComponent<'a>(&'a Option<f32>);
impl<'a> ToCss for ModernComponent<'a> {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: fmt::Write,
{
if let Some(value) = self.0 {
if value.is_finite() {
value.to_css(dest)
} else if value.is_nan() {
dest.write_str("calc(NaN)")
} else {
debug_assert!(value.is_infinite());
if value.is_sign_negative() {
dest.write_str("calc(-infinity)")
} else {
dest.write_str("calc(infinity)")
}
}
} else {
dest.write_str("none")
}
}
}
impl ToCss for NumberOrPercentageComponent {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
use crate::values::computed::Percentage;
match self {
Self::Number(number) => number.to_css(dest)?,
Self::Percentage(percentage) => Percentage(*percentage).to_css(dest)?,
}
Ok(())
}
}
impl ToCss for NumberOrAngleComponent {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
use crate::values::computed::Angle;
match self {
Self::Number(number) => number.to_css(dest)?,
Self::Angle(degrees) => Angle::from_degrees(*degrees).to_css(dest)?,
}
Ok(())
}
}
impl ToCss for AbsoluteColor {
fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
match self.color_space {
ColorSpace::Srgb if self.flags.contains(ColorFlags::IS_LEGACY_SRGB) => {
// The "none" keyword is not supported in the rgb/rgba legacy syntax.
let has_alpha = self.alpha != OPAQUE;
dest.write_str(if has_alpha { "rgba(" } else { "rgb(" })?;
clamp_unit_f32(self.components.0).to_css(dest)?;
dest.write_str(", ")?;
clamp_unit_f32(self.components.1).to_css(dest)?;
dest.write_str(", ")?;
clamp_unit_f32(self.components.2).to_css(dest)?;
// Legacy syntax does not allow none components.
serialize_color_alpha(dest, Some(self.alpha), true)?;
dest.write_char(')')
},
ColorSpace::Hsl | ColorSpace::Hwb => {
if self.flags.contains(ColorFlags::IS_LEGACY_SRGB) {
self.into_srgb_legacy().to_css(dest)
} else {
self.to_color_space(ColorSpace::Srgb).to_css(dest)
}
},
ColorSpace::Oklab | ColorSpace::Lab | ColorSpace::Oklch | ColorSpace::Lch => {
if let ColorSpace::Oklab | ColorSpace::Oklch = self.color_space {
dest.write_str("ok")?;
}
if let ColorSpace::Oklab | ColorSpace::Lab = self.color_space {
dest.write_str("lab(")?;
} else {
dest.write_str("lch(")?;
}
ModernComponent(&self.c0()).to_css(dest)?;
dest.write_char(' ')?;
ModernComponent(&self.c1()).to_css(dest)?;
dest.write_char(' ')?;
ModernComponent(&self.c2()).to_css(dest)?;
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
_ => {
#[cfg(debug_assertions)]
match self.color_space {
ColorSpace::Srgb => {
debug_assert!(
!self.flags.contains(ColorFlags::IS_LEGACY_SRGB),
"legacy srgb is not a color function"
);
},
ColorSpace::SrgbLinear |
ColorSpace::DisplayP3 |
ColorSpace::A98Rgb |
ColorSpace::ProphotoRgb |
ColorSpace::Rec2020 |
ColorSpace::XyzD50 |
ColorSpace::XyzD65 => {
// These color spaces are allowed.
},
_ => {
unreachable!("other color spaces do not support color() syntax")
},
};
dest.write_str("color(")?;
self.color_space.to_css(dest)?;
dest.write_char(' ')?;
ModernComponent(&self.c0()).to_css(dest)?;
dest.write_char(' ')?;
ModernComponent(&self.c1()).to_css(dest)?;
dest.write_char(' ')?;
ModernComponent(&self.c2()).to_css(dest)?;
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
}
}
}
impl AbsoluteColor {
/// Write a string to `dest` that represents a color as an author would
/// enter it.
/// NOTE: The format of the output is NOT according to any specification,
/// but makes assumptions about the best ways that authors would want to
/// enter color values in style sheets, devtools, etc.
pub fn write_author_preferred_value<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
where
W: Write,
{
macro_rules! precision {
($v:expr) => {{
($v * 100.0).round() / 100.0
}};
}
macro_rules! number {
($c:expr) => {{
if let Some(v) = $c.map(normalize) {
precision!(v).to_css(dest)?;
} else {
write!(dest, "none")?;
}
}};
}
macro_rules! percentage {
($c:expr) => {{
if let Some(v) = $c.map(normalize) {
precision!(v).to_css(dest)?;
dest.write_char('%')?;
} else {
write!(dest, "none")?;
}
}};
}
macro_rules! unit_percentage {
($c:expr) => {{
if let Some(v) = $c.map(normalize) {
precision!(v * 100.0).to_css(dest)?;
dest.write_char('%')?;
} else {
write!(dest, "none")?;
}
}};
}
macro_rules! angle {
($c:expr) => {{
if let Some(v) = $c.map(normalize) {
precision!(v).to_css(dest)?;
dest.write_str("deg")?;
} else {
write!(dest, "none")?;
}
}};
}
match self.color_space {
ColorSpace::Srgb => {
write!(dest, "rgb(")?;
unit_percentage!(self.c0());
dest.write_char(' ')?;
unit_percentage!(self.c1());
dest.write_char(' ')?;
unit_percentage!(self.c2());
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
ColorSpace::Hsl | ColorSpace::Hwb => {
dest.write_str(if self.color_space == ColorSpace::Hsl {
"hsl("
} else {
"hwb("
})?;
angle!(self.c0());
dest.write_char(' ')?;
percentage!(self.c1());
dest.write_char(' ')?;
percentage!(self.c2());
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
ColorSpace::Lab | ColorSpace::Oklab => {
if self.color_space == ColorSpace::Oklab {
dest.write_str("ok")?;
}
dest.write_str("lab(")?;
if self.color_space == ColorSpace::Lab {
percentage!(self.c0())
} else {
unit_percentage!(self.c0())
}
dest.write_char(' ')?;
number!(self.c1());
dest.write_char(' ')?;
number!(self.c2());
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
ColorSpace::Lch | ColorSpace::Oklch => {
if self.color_space == ColorSpace::Oklch {
dest.write_str("ok")?;
}
dest.write_str("lch(")?;
number!(self.c0());
dest.write_char(' ')?;
number!(self.c1());
dest.write_char(' ')?;
angle!(self.c2());
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
ColorSpace::SrgbLinear |
ColorSpace::DisplayP3 |
ColorSpace::A98Rgb |
ColorSpace::ProphotoRgb |
ColorSpace::Rec2020 |
ColorSpace::XyzD50 |
ColorSpace::XyzD65 => {
dest.write_str("color(")?;
self.color_space.to_css(dest)?;
dest.write_char(' ')?;
number!(self.c0());
dest.write_char(' ')?;
number!(self.c1());
dest.write_char(' ')?;
number!(self.c2());
serialize_color_alpha(dest, self.alpha(), false)?;
dest.write_char(')')
},
}
}
}