2144 lines
82 KiB
Rust
2144 lines
82 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
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//! Support for [custom properties for cascading variables][custom].
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//!
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//! [custom]: https://drafts.csswg.org/css-variables/
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use crate::applicable_declarations::CascadePriority;
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use crate::custom_properties_map::CustomPropertiesMap;
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use crate::media_queries::Device;
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use crate::properties::{
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CSSWideKeyword, CustomDeclaration, CustomDeclarationValue, LonghandId, LonghandIdSet,
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PropertyDeclaration,
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};
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use crate::properties_and_values::{
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registry::PropertyRegistrationData,
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syntax::data_type::DependentDataTypes,
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value::{
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AllowComputationallyDependent, ComputedValue as ComputedRegisteredValue,
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SpecifiedValue as SpecifiedRegisteredValue,
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},
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};
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use crate::selector_map::{PrecomputedHashMap, PrecomputedHashSet};
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use crate::stylesheets::UrlExtraData;
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use crate::stylist::Stylist;
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use crate::values::computed::{self, ToComputedValue};
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use crate::values::specified::FontRelativeLength;
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use crate::Atom;
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use cssparser::{
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CowRcStr, Delimiter, Parser, ParserInput, SourcePosition, Token, TokenSerializationType,
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};
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use selectors::parser::SelectorParseErrorKind;
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use servo_arc::Arc;
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use smallvec::SmallVec;
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use std::borrow::Cow;
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use std::collections::hash_map::Entry;
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use std::fmt::{self, Write};
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use std::ops::{Index, IndexMut};
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use std::{cmp, num};
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use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
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/// The environment from which to get `env` function values.
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///
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/// TODO(emilio): If this becomes a bit more complex we should probably move it
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/// to the `media_queries` module, or something.
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#[derive(Debug, MallocSizeOf)]
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pub struct CssEnvironment;
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type EnvironmentEvaluator = fn(device: &Device, url_data: &UrlExtraData) -> VariableValue;
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struct EnvironmentVariable {
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name: Atom,
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evaluator: EnvironmentEvaluator,
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}
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macro_rules! make_variable {
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($name:expr, $evaluator:expr) => {{
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EnvironmentVariable {
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name: $name,
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evaluator: $evaluator,
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}
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}};
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}
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fn get_safearea_inset_top(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::pixels(device.safe_area_insets().top, url_data)
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}
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fn get_safearea_inset_bottom(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::pixels(device.safe_area_insets().bottom, url_data)
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}
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fn get_safearea_inset_left(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::pixels(device.safe_area_insets().left, url_data)
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}
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fn get_safearea_inset_right(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::pixels(device.safe_area_insets().right, url_data)
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}
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#[cfg(feature = "gecko")]
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fn get_content_preferred_color_scheme(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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use crate::queries::values::PrefersColorScheme;
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let prefers_color_scheme = unsafe {
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crate::gecko_bindings::bindings::Gecko_MediaFeatures_PrefersColorScheme(
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device.document(),
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/* use_content = */ true,
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)
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};
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VariableValue::ident(
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match prefers_color_scheme {
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PrefersColorScheme::Light => "light",
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PrefersColorScheme::Dark => "dark",
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},
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url_data,
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)
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}
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#[cfg(feature = "servo")]
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fn get_content_preferred_color_scheme(_device: &Device, url_data: &UrlExtraData) -> VariableValue {
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// TODO: Add an implementation for Servo.
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VariableValue::ident("light", url_data)
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}
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fn get_scrollbar_inline_size(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::pixels(device.scrollbar_inline_size().px(), url_data)
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}
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static ENVIRONMENT_VARIABLES: [EnvironmentVariable; 4] = [
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make_variable!(atom!("safe-area-inset-top"), get_safearea_inset_top),
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make_variable!(atom!("safe-area-inset-bottom"), get_safearea_inset_bottom),
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make_variable!(atom!("safe-area-inset-left"), get_safearea_inset_left),
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make_variable!(atom!("safe-area-inset-right"), get_safearea_inset_right),
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];
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#[cfg(feature = "gecko")]
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macro_rules! lnf_int {
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($id:ident) => {
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unsafe {
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crate::gecko_bindings::bindings::Gecko_GetLookAndFeelInt(
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crate::gecko_bindings::bindings::LookAndFeel_IntID::$id as i32,
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)
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}
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};
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}
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#[cfg(feature = "servo")]
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macro_rules! lnf_int {
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($id:ident) => {
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// TODO: Add an implementation for Servo.
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0
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};
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}
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macro_rules! lnf_int_variable {
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($atom:expr, $id:ident, $ctor:ident) => {{
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fn __eval(_: &Device, url_data: &UrlExtraData) -> VariableValue {
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VariableValue::$ctor(lnf_int!($id), url_data)
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}
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make_variable!($atom, __eval)
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}};
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}
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fn eval_gtk_csd_titlebar_radius(device: &Device, url_data: &UrlExtraData) -> VariableValue {
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let int_pixels = lnf_int!(TitlebarRadius);
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let unzoomed_scale =
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device.device_pixel_ratio_ignoring_full_zoom().get() / device.device_pixel_ratio().get();
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VariableValue::pixels(int_pixels as f32 * unzoomed_scale, url_data)
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}
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static CHROME_ENVIRONMENT_VARIABLES: [EnvironmentVariable; 10] = [
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lnf_int_variable!(
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atom!("-moz-mac-titlebar-height"),
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MacTitlebarHeight,
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int_pixels
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),
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lnf_int_variable!(
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atom!("-moz-gtk-csd-titlebar-button-spacing"),
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TitlebarButtonSpacing,
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int_pixels
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),
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make_variable!(
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atom!("-moz-gtk-csd-titlebar-radius"),
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eval_gtk_csd_titlebar_radius
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),
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lnf_int_variable!(
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atom!("-moz-gtk-csd-tooltip-radius"),
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TooltipRadius,
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int_pixels
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),
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lnf_int_variable!(
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atom!("-moz-gtk-csd-close-button-position"),
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GTKCSDCloseButtonPosition,
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integer
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),
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lnf_int_variable!(
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atom!("-moz-gtk-csd-minimize-button-position"),
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GTKCSDMinimizeButtonPosition,
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integer
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),
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lnf_int_variable!(
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atom!("-moz-gtk-csd-maximize-button-position"),
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GTKCSDMaximizeButtonPosition,
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integer
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),
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lnf_int_variable!(
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atom!("-moz-overlay-scrollbar-fade-duration"),
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ScrollbarFadeDuration,
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int_ms
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),
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make_variable!(
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atom!("-moz-content-preferred-color-scheme"),
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get_content_preferred_color_scheme
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),
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make_variable!(atom!("scrollbar-inline-size"), get_scrollbar_inline_size),
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];
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impl CssEnvironment {
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#[inline]
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fn get(&self, name: &Atom, device: &Device, url_data: &UrlExtraData) -> Option<VariableValue> {
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if let Some(var) = ENVIRONMENT_VARIABLES.iter().find(|var| var.name == *name) {
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return Some((var.evaluator)(device, url_data));
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}
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if !url_data.chrome_rules_enabled() {
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return None;
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}
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let var = CHROME_ENVIRONMENT_VARIABLES
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.iter()
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.find(|var| var.name == *name)?;
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Some((var.evaluator)(device, url_data))
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}
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}
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/// A custom property name is just an `Atom`.
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///
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/// Note that this does not include the `--` prefix
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pub type Name = Atom;
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/// Parse a custom property name.
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///
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/// <https://drafts.csswg.org/css-variables/#typedef-custom-property-name>
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pub fn parse_name(s: &str) -> Result<&str, ()> {
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if s.starts_with("--") && s.len() > 2 {
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Ok(&s[2..])
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} else {
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Err(())
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}
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}
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/// A value for a custom property is just a set of tokens.
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///
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/// We preserve the original CSS for serialization, and also the variable
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/// references to other custom property names.
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#[derive(Clone, Debug, MallocSizeOf, ToShmem)]
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pub struct VariableValue {
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/// The raw CSS string.
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pub css: String,
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/// The url data of the stylesheet where this value came from.
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pub url_data: UrlExtraData,
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first_token_type: TokenSerializationType,
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last_token_type: TokenSerializationType,
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/// var(), env(), or non-custom property (e.g. through `em`) references.
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references: References,
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}
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trivial_to_computed_value!(VariableValue);
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/// Given a potentially registered variable value turn it into a computed custom property value.
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pub fn compute_variable_value(
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value: &Arc<VariableValue>,
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registration: &PropertyRegistrationData,
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computed_context: &computed::Context,
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) -> Option<ComputedRegisteredValue> {
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if registration.syntax.is_universal() {
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return Some(ComputedRegisteredValue::universal(Arc::clone(value)));
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}
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compute_value(
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&value.css,
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&value.url_data,
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registration,
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computed_context,
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).ok()
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}
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// For all purposes, we want values to be considered equal if their css text is equal.
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impl PartialEq for VariableValue {
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fn eq(&self, other: &Self) -> bool {
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self.css == other.css
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}
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}
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impl Eq for VariableValue {}
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impl ToCss for SpecifiedValue {
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fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
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where
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W: Write,
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{
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dest.write_str(&self.css)
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}
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}
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/// A pair of separate CustomPropertiesMaps, split between custom properties
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/// that have the inherit flag set and those with the flag unset.
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#[repr(C)]
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#[derive(Clone, Debug, Default, PartialEq)]
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pub struct ComputedCustomProperties {
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/// Map for custom properties with inherit flag set, including non-registered
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/// ones.
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pub inherited: CustomPropertiesMap,
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/// Map for custom properties with inherit flag unset.
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pub non_inherited: CustomPropertiesMap,
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}
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impl ComputedCustomProperties {
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/// Return whether the inherited and non_inherited maps are none.
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pub fn is_empty(&self) -> bool {
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self.inherited.is_empty() && self.non_inherited.is_empty()
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}
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/// Return the name and value of the property at specified index, if any.
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pub fn property_at(&self, index: usize) -> Option<(&Name, &Option<ComputedRegisteredValue>)> {
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// Just expose the custom property items from custom_properties.inherited, followed
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// by custom property items from custom_properties.non_inherited.
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self.inherited
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.get_index(index)
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.or_else(|| self.non_inherited.get_index(index - self.inherited.len()))
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}
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/// Insert a custom property in the corresponding inherited/non_inherited
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/// map, depending on whether the inherit flag is set or unset.
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fn insert(
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&mut self,
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registration: &PropertyRegistrationData,
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name: &Name,
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value: ComputedRegisteredValue,
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) {
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self.map_mut(registration).insert(name, value)
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}
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/// Remove a custom property from the corresponding inherited/non_inherited
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/// map, depending on whether the inherit flag is set or unset.
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fn remove(&mut self, registration: &PropertyRegistrationData, name: &Name) {
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self.map_mut(registration).remove(name);
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}
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/// Shrink the capacity of the inherited maps as much as possible.
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fn shrink_to_fit(&mut self) {
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self.inherited.shrink_to_fit();
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self.non_inherited.shrink_to_fit();
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}
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fn map_mut(&mut self, registration: &PropertyRegistrationData) -> &mut CustomPropertiesMap {
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if registration.inherits() {
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&mut self.inherited
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} else {
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&mut self.non_inherited
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}
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}
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/// Returns the relevant custom property value given a registration.
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pub fn get(
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&self,
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registration: &PropertyRegistrationData,
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name: &Name,
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) -> Option<&ComputedRegisteredValue> {
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if registration.inherits() {
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self.inherited.get(name)
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} else {
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self.non_inherited.get(name)
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}
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}
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}
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/// Both specified and computed values are VariableValues, the difference is
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/// whether var() functions are expanded.
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pub type SpecifiedValue = VariableValue;
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/// Both specified and computed values are VariableValues, the difference is
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/// whether var() functions are expanded.
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pub type ComputedValue = VariableValue;
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/// Set of flags to non-custom references this custom property makes.
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#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, MallocSizeOf, ToShmem)]
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struct NonCustomReferences(u8);
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bitflags! {
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impl NonCustomReferences: u8 {
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/// At least one custom property depends on font-relative units.
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const FONT_UNITS = 1 << 0;
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/// At least one custom property depends on root element's font-relative units.
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const ROOT_FONT_UNITS = 1 << 1;
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/// At least one custom property depends on line height units.
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const LH_UNITS = 1 << 2;
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/// At least one custom property depends on root element's line height units.
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const ROOT_LH_UNITS = 1 << 3;
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/// All dependencies not depending on the root element.
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const NON_ROOT_DEPENDENCIES = Self::FONT_UNITS.0 | Self::LH_UNITS.0;
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/// All dependencies depending on the root element.
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const ROOT_DEPENDENCIES = Self::ROOT_FONT_UNITS.0 | Self::ROOT_LH_UNITS.0;
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}
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}
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impl NonCustomReferences {
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fn for_each<F>(&self, mut f: F)
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where
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F: FnMut(SingleNonCustomReference),
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{
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for (_, r) in self.iter_names() {
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let single = match r {
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Self::FONT_UNITS => SingleNonCustomReference::FontUnits,
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Self::ROOT_FONT_UNITS => SingleNonCustomReference::RootFontUnits,
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Self::LH_UNITS => SingleNonCustomReference::LhUnits,
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Self::ROOT_LH_UNITS => SingleNonCustomReference::RootLhUnits,
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_ => unreachable!("Unexpected single bit value"),
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||
};
|
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f(single);
|
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}
|
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}
|
||
|
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fn from_unit(value: &CowRcStr) -> Self {
|
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// For registered properties, any reference to font-relative dimensions
|
||
// make it dependent on font-related properties.
|
||
// TODO(dshin): When we unit algebra gets implemented and handled -
|
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// Is it valid to say that `calc(1em / 2em * 3px)` triggers this?
|
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if value.eq_ignore_ascii_case(FontRelativeLength::LH) {
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return Self::FONT_UNITS | Self::LH_UNITS;
|
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}
|
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if value.eq_ignore_ascii_case(FontRelativeLength::EM) ||
|
||
value.eq_ignore_ascii_case(FontRelativeLength::EX) ||
|
||
value.eq_ignore_ascii_case(FontRelativeLength::CAP) ||
|
||
value.eq_ignore_ascii_case(FontRelativeLength::CH) ||
|
||
value.eq_ignore_ascii_case(FontRelativeLength::IC)
|
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{
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return Self::FONT_UNITS;
|
||
}
|
||
if value.eq_ignore_ascii_case(FontRelativeLength::RLH) {
|
||
return Self::ROOT_FONT_UNITS | Self::ROOT_LH_UNITS;
|
||
}
|
||
if value.eq_ignore_ascii_case(FontRelativeLength::REM) {
|
||
return Self::ROOT_FONT_UNITS;
|
||
}
|
||
Self::empty()
|
||
}
|
||
}
|
||
|
||
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
|
||
enum SingleNonCustomReference {
|
||
FontUnits = 0,
|
||
RootFontUnits,
|
||
LhUnits,
|
||
RootLhUnits,
|
||
}
|
||
|
||
struct NonCustomReferenceMap<T>([Option<T>; 4]);
|
||
|
||
impl<T> Default for NonCustomReferenceMap<T> {
|
||
fn default() -> Self {
|
||
NonCustomReferenceMap(Default::default())
|
||
}
|
||
}
|
||
|
||
impl<T> Index<SingleNonCustomReference> for NonCustomReferenceMap<T> {
|
||
type Output = Option<T>;
|
||
|
||
fn index(&self, reference: SingleNonCustomReference) -> &Self::Output {
|
||
&self.0[reference as usize]
|
||
}
|
||
}
|
||
|
||
impl<T> IndexMut<SingleNonCustomReference> for NonCustomReferenceMap<T> {
|
||
fn index_mut(&mut self, reference: SingleNonCustomReference) -> &mut Self::Output {
|
||
&mut self.0[reference as usize]
|
||
}
|
||
}
|
||
|
||
/// Whether to defer resolving custom properties referencing font relative units.
|
||
#[derive(Clone, Copy, PartialEq, Eq)]
|
||
#[allow(missing_docs)]
|
||
pub enum DeferFontRelativeCustomPropertyResolution {
|
||
Yes,
|
||
No,
|
||
}
|
||
|
||
#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
|
||
struct VariableFallback {
|
||
start: num::NonZeroUsize,
|
||
first_token_type: TokenSerializationType,
|
||
last_token_type: TokenSerializationType,
|
||
}
|
||
|
||
#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToShmem)]
|
||
struct VarOrEnvReference {
|
||
name: Name,
|
||
start: usize,
|
||
end: usize,
|
||
fallback: Option<VariableFallback>,
|
||
prev_token_type: TokenSerializationType,
|
||
next_token_type: TokenSerializationType,
|
||
is_var: bool,
|
||
}
|
||
|
||
/// A struct holding information about the external references to that a custom
|
||
/// property value may have.
|
||
#[derive(Clone, Debug, Default, MallocSizeOf, PartialEq, ToShmem)]
|
||
struct References {
|
||
refs: Vec<VarOrEnvReference>,
|
||
non_custom_references: NonCustomReferences,
|
||
any_env: bool,
|
||
any_var: bool,
|
||
}
|
||
|
||
impl References {
|
||
fn has_references(&self) -> bool {
|
||
!self.refs.is_empty()
|
||
}
|
||
|
||
fn non_custom_references(&self, is_root_element: bool) -> NonCustomReferences {
|
||
let mut mask = NonCustomReferences::NON_ROOT_DEPENDENCIES;
|
||
if is_root_element {
|
||
mask |= NonCustomReferences::ROOT_DEPENDENCIES
|
||
}
|
||
self.non_custom_references & mask
|
||
}
|
||
}
|
||
|
||
impl VariableValue {
|
||
fn empty(url_data: &UrlExtraData) -> Self {
|
||
Self {
|
||
css: String::new(),
|
||
last_token_type: Default::default(),
|
||
first_token_type: Default::default(),
|
||
url_data: url_data.clone(),
|
||
references: Default::default(),
|
||
}
|
||
}
|
||
|
||
/// Create a new custom property without parsing if the CSS is known to be valid and contain no
|
||
/// references.
|
||
pub fn new(
|
||
css: String,
|
||
url_data: &UrlExtraData,
|
||
first_token_type: TokenSerializationType,
|
||
last_token_type: TokenSerializationType,
|
||
) -> Self {
|
||
Self {
|
||
css,
|
||
url_data: url_data.clone(),
|
||
first_token_type,
|
||
last_token_type,
|
||
references: Default::default(),
|
||
}
|
||
}
|
||
|
||
fn push<'i>(
|
||
&mut self,
|
||
css: &str,
|
||
css_first_token_type: TokenSerializationType,
|
||
css_last_token_type: TokenSerializationType,
|
||
) -> Result<(), ()> {
|
||
/// Prevent values from getting terribly big since you can use custom
|
||
/// properties exponentially.
|
||
///
|
||
/// This number (2MB) is somewhat arbitrary, but silly enough that no
|
||
/// reasonable page should hit it. We could limit by number of total
|
||
/// substitutions, but that was very easy to work around in practice
|
||
/// (just choose a larger initial value and boom).
|
||
const MAX_VALUE_LENGTH_IN_BYTES: usize = 2 * 1024 * 1024;
|
||
|
||
if self.css.len() + css.len() > MAX_VALUE_LENGTH_IN_BYTES {
|
||
return Err(());
|
||
}
|
||
|
||
// This happens e.g. between two subsequent var() functions:
|
||
// `var(--a)var(--b)`.
|
||
//
|
||
// In that case, css_*_token_type is nonsensical.
|
||
if css.is_empty() {
|
||
return Ok(());
|
||
}
|
||
|
||
self.first_token_type.set_if_nothing(css_first_token_type);
|
||
// If self.first_token_type was nothing,
|
||
// self.last_token_type is also nothing and this will be false:
|
||
if self
|
||
.last_token_type
|
||
.needs_separator_when_before(css_first_token_type)
|
||
{
|
||
self.css.push_str("/**/")
|
||
}
|
||
self.css.push_str(css);
|
||
self.last_token_type = css_last_token_type;
|
||
Ok(())
|
||
}
|
||
|
||
/// Parse a custom property value.
|
||
pub fn parse<'i, 't>(
|
||
input: &mut Parser<'i, 't>,
|
||
url_data: &UrlExtraData,
|
||
) -> Result<Self, ParseError<'i>> {
|
||
input.skip_whitespace();
|
||
|
||
let mut references = References::default();
|
||
let mut missing_closing_characters = String::new();
|
||
let start_position = input.position();
|
||
let (first_token_type, last_token_type) = parse_declaration_value(
|
||
input,
|
||
start_position,
|
||
&mut references,
|
||
&mut missing_closing_characters,
|
||
)?;
|
||
let mut css = input.slice_from(start_position).to_owned();
|
||
if !missing_closing_characters.is_empty() {
|
||
// Unescaped backslash at EOF in a quoted string is ignored.
|
||
if css.ends_with("\\") &&
|
||
matches!(missing_closing_characters.as_bytes()[0], b'"' | b'\'')
|
||
{
|
||
css.pop();
|
||
}
|
||
css.push_str(&missing_closing_characters);
|
||
}
|
||
|
||
css.shrink_to_fit();
|
||
references.refs.shrink_to_fit();
|
||
|
||
Ok(Self {
|
||
css,
|
||
url_data: url_data.clone(),
|
||
first_token_type,
|
||
last_token_type,
|
||
references,
|
||
})
|
||
}
|
||
|
||
/// Create VariableValue from an int.
|
||
fn integer(number: i32, url_data: &UrlExtraData) -> Self {
|
||
Self::from_token(
|
||
Token::Number {
|
||
has_sign: false,
|
||
value: number as f32,
|
||
int_value: Some(number),
|
||
},
|
||
url_data,
|
||
)
|
||
}
|
||
|
||
/// Create VariableValue from an int.
|
||
fn ident(ident: &'static str, url_data: &UrlExtraData) -> Self {
|
||
Self::from_token(Token::Ident(ident.into()), url_data)
|
||
}
|
||
|
||
/// Create VariableValue from a float amount of CSS pixels.
|
||
fn pixels(number: f32, url_data: &UrlExtraData) -> Self {
|
||
// FIXME (https://github.com/servo/rust-cssparser/issues/266):
|
||
// No way to get TokenSerializationType::Dimension without creating
|
||
// Token object.
|
||
Self::from_token(
|
||
Token::Dimension {
|
||
has_sign: false,
|
||
value: number,
|
||
int_value: None,
|
||
unit: CowRcStr::from("px"),
|
||
},
|
||
url_data,
|
||
)
|
||
}
|
||
|
||
/// Create VariableValue from an integer amount of milliseconds.
|
||
fn int_ms(number: i32, url_data: &UrlExtraData) -> Self {
|
||
Self::from_token(
|
||
Token::Dimension {
|
||
has_sign: false,
|
||
value: number as f32,
|
||
int_value: Some(number),
|
||
unit: CowRcStr::from("ms"),
|
||
},
|
||
url_data,
|
||
)
|
||
}
|
||
|
||
/// Create VariableValue from an integer amount of CSS pixels.
|
||
fn int_pixels(number: i32, url_data: &UrlExtraData) -> Self {
|
||
Self::from_token(
|
||
Token::Dimension {
|
||
has_sign: false,
|
||
value: number as f32,
|
||
int_value: Some(number),
|
||
unit: CowRcStr::from("px"),
|
||
},
|
||
url_data,
|
||
)
|
||
}
|
||
|
||
fn from_token(token: Token, url_data: &UrlExtraData) -> Self {
|
||
let token_type = token.serialization_type();
|
||
let mut css = token.to_css_string();
|
||
css.shrink_to_fit();
|
||
|
||
VariableValue {
|
||
css,
|
||
url_data: url_data.clone(),
|
||
first_token_type: token_type,
|
||
last_token_type: token_type,
|
||
references: Default::default(),
|
||
}
|
||
}
|
||
|
||
/// Returns the raw CSS text from this VariableValue
|
||
pub fn css_text(&self) -> &str {
|
||
&self.css
|
||
}
|
||
|
||
/// Returns whether this variable value has any reference to the environment or other
|
||
/// variables.
|
||
pub fn has_references(&self) -> bool {
|
||
self.references.has_references()
|
||
}
|
||
}
|
||
|
||
/// <https://drafts.csswg.org/css-syntax-3/#typedef-declaration-value>
|
||
fn parse_declaration_value<'i, 't>(
|
||
input: &mut Parser<'i, 't>,
|
||
input_start: SourcePosition,
|
||
references: &mut References,
|
||
missing_closing_characters: &mut String,
|
||
) -> Result<(TokenSerializationType, TokenSerializationType), ParseError<'i>> {
|
||
input.parse_until_before(Delimiter::Bang | Delimiter::Semicolon, |input| {
|
||
parse_declaration_value_block(input, input_start, references, missing_closing_characters)
|
||
})
|
||
}
|
||
|
||
/// Like parse_declaration_value, but accept `!` and `;` since they are only invalid at the top level.
|
||
fn parse_declaration_value_block<'i, 't>(
|
||
input: &mut Parser<'i, 't>,
|
||
input_start: SourcePosition,
|
||
references: &mut References,
|
||
missing_closing_characters: &mut String,
|
||
) -> Result<(TokenSerializationType, TokenSerializationType), ParseError<'i>> {
|
||
let mut is_first = true;
|
||
let mut first_token_type = TokenSerializationType::Nothing;
|
||
let mut last_token_type = TokenSerializationType::Nothing;
|
||
let mut prev_reference_index: Option<usize> = None;
|
||
loop {
|
||
let token_start = input.position();
|
||
let Ok(token) = input.next_including_whitespace_and_comments() else {
|
||
break;
|
||
};
|
||
|
||
let prev_token_type = last_token_type;
|
||
let serialization_type = token.serialization_type();
|
||
last_token_type = serialization_type;
|
||
if is_first {
|
||
first_token_type = last_token_type;
|
||
is_first = false;
|
||
}
|
||
|
||
macro_rules! nested {
|
||
() => {
|
||
input.parse_nested_block(|input| {
|
||
parse_declaration_value_block(
|
||
input,
|
||
input_start,
|
||
references,
|
||
missing_closing_characters,
|
||
)
|
||
})?
|
||
};
|
||
}
|
||
macro_rules! check_closed {
|
||
($closing:expr) => {
|
||
if !input.slice_from(token_start).ends_with($closing) {
|
||
missing_closing_characters.push_str($closing)
|
||
}
|
||
};
|
||
}
|
||
if let Some(index) = prev_reference_index.take() {
|
||
references.refs[index].next_token_type = serialization_type;
|
||
}
|
||
match *token {
|
||
Token::Comment(_) => {
|
||
let token_slice = input.slice_from(token_start);
|
||
if !token_slice.ends_with("*/") {
|
||
missing_closing_characters.push_str(if token_slice.ends_with('*') {
|
||
"/"
|
||
} else {
|
||
"*/"
|
||
})
|
||
}
|
||
},
|
||
Token::BadUrl(ref u) => {
|
||
let e = StyleParseErrorKind::BadUrlInDeclarationValueBlock(u.clone());
|
||
return Err(input.new_custom_error(e));
|
||
},
|
||
Token::BadString(ref s) => {
|
||
let e = StyleParseErrorKind::BadStringInDeclarationValueBlock(s.clone());
|
||
return Err(input.new_custom_error(e));
|
||
},
|
||
Token::CloseParenthesis => {
|
||
let e = StyleParseErrorKind::UnbalancedCloseParenthesisInDeclarationValueBlock;
|
||
return Err(input.new_custom_error(e));
|
||
},
|
||
Token::CloseSquareBracket => {
|
||
let e = StyleParseErrorKind::UnbalancedCloseSquareBracketInDeclarationValueBlock;
|
||
return Err(input.new_custom_error(e));
|
||
},
|
||
Token::CloseCurlyBracket => {
|
||
let e = StyleParseErrorKind::UnbalancedCloseCurlyBracketInDeclarationValueBlock;
|
||
return Err(input.new_custom_error(e));
|
||
},
|
||
Token::Function(ref name) => {
|
||
let is_var = name.eq_ignore_ascii_case("var");
|
||
if is_var || name.eq_ignore_ascii_case("env") {
|
||
let our_ref_index = references.refs.len();
|
||
let fallback = input.parse_nested_block(|input| {
|
||
// TODO(emilio): For env() this should be <custom-ident> per spec, but no other browser does
|
||
// that, see https://github.com/w3c/csswg-drafts/issues/3262.
|
||
let name = input.expect_ident()?;
|
||
let name = Atom::from(if is_var {
|
||
match parse_name(name.as_ref()) {
|
||
Ok(name) => name,
|
||
Err(()) => {
|
||
let name = name.clone();
|
||
return Err(input.new_custom_error(
|
||
SelectorParseErrorKind::UnexpectedIdent(name),
|
||
));
|
||
},
|
||
}
|
||
} else {
|
||
name.as_ref()
|
||
});
|
||
|
||
// We want the order of the references to match source order. So we need to reserve our slot
|
||
// now, _before_ parsing our fallback. Note that we don't care if parsing fails after all, since
|
||
// if this fails we discard the whole result anyways.
|
||
let start = token_start.byte_index() - input_start.byte_index();
|
||
references.refs.push(VarOrEnvReference {
|
||
name,
|
||
start,
|
||
// To be fixed up after parsing fallback and auto-closing via our_ref_index.
|
||
end: start,
|
||
prev_token_type,
|
||
// To be fixed up (if needed) on the next loop iteration via prev_reference_index.
|
||
next_token_type: TokenSerializationType::Nothing,
|
||
// To be fixed up after parsing fallback.
|
||
fallback: None,
|
||
is_var,
|
||
});
|
||
|
||
let mut fallback = None;
|
||
if input.try_parse(|input| input.expect_comma()).is_ok() {
|
||
input.skip_whitespace();
|
||
let fallback_start = num::NonZeroUsize::new(
|
||
input.position().byte_index() - input_start.byte_index(),
|
||
)
|
||
.unwrap();
|
||
// NOTE(emilio): Intentionally using parse_declaration_value rather than
|
||
// parse_declaration_value_block, since that's what parse_fallback used to do.
|
||
let (first, last) = parse_declaration_value(
|
||
input,
|
||
input_start,
|
||
references,
|
||
missing_closing_characters,
|
||
)?;
|
||
fallback = Some(VariableFallback {
|
||
start: fallback_start,
|
||
first_token_type: first,
|
||
last_token_type: last,
|
||
});
|
||
} else {
|
||
let state = input.state();
|
||
// We still need to consume the rest of the potentially-unclosed
|
||
// tokens, but make sure to not consume tokens that would otherwise be
|
||
// invalid, by calling reset().
|
||
parse_declaration_value_block(
|
||
input,
|
||
input_start,
|
||
references,
|
||
missing_closing_characters,
|
||
)?;
|
||
input.reset(&state);
|
||
}
|
||
Ok(fallback)
|
||
})?;
|
||
check_closed!(")");
|
||
prev_reference_index = Some(our_ref_index);
|
||
let reference = &mut references.refs[our_ref_index];
|
||
reference.end = input.position().byte_index() - input_start.byte_index() +
|
||
missing_closing_characters.len();
|
||
reference.fallback = fallback;
|
||
if is_var {
|
||
references.any_var = true;
|
||
} else {
|
||
references.any_env = true;
|
||
}
|
||
} else {
|
||
nested!();
|
||
check_closed!(")");
|
||
}
|
||
},
|
||
Token::ParenthesisBlock => {
|
||
nested!();
|
||
check_closed!(")");
|
||
},
|
||
Token::CurlyBracketBlock => {
|
||
nested!();
|
||
check_closed!("}");
|
||
},
|
||
Token::SquareBracketBlock => {
|
||
nested!();
|
||
check_closed!("]");
|
||
},
|
||
Token::QuotedString(_) => {
|
||
let token_slice = input.slice_from(token_start);
|
||
let quote = &token_slice[..1];
|
||
debug_assert!(matches!(quote, "\"" | "'"));
|
||
if !(token_slice.ends_with(quote) && token_slice.len() > 1) {
|
||
missing_closing_characters.push_str(quote)
|
||
}
|
||
},
|
||
Token::Ident(ref value) |
|
||
Token::AtKeyword(ref value) |
|
||
Token::Hash(ref value) |
|
||
Token::IDHash(ref value) |
|
||
Token::UnquotedUrl(ref value) |
|
||
Token::Dimension {
|
||
unit: ref value, ..
|
||
} => {
|
||
references
|
||
.non_custom_references
|
||
.insert(NonCustomReferences::from_unit(value));
|
||
let is_unquoted_url = matches!(token, Token::UnquotedUrl(_));
|
||
if value.ends_with("<EFBFBD>") && input.slice_from(token_start).ends_with("\\") {
|
||
// Unescaped backslash at EOF in these contexts is interpreted as U+FFFD
|
||
// Check the value in case the final backslash was itself escaped.
|
||
// Serialize as escaped U+FFFD, which is also interpreted as U+FFFD.
|
||
// (Unescaped U+FFFD would also work, but removing the backslash is annoying.)
|
||
missing_closing_characters.push_str("<EFBFBD>")
|
||
}
|
||
if is_unquoted_url {
|
||
check_closed!(")");
|
||
}
|
||
},
|
||
_ => {},
|
||
};
|
||
}
|
||
Ok((first_token_type, last_token_type))
|
||
}
|
||
|
||
/// A struct that takes care of encapsulating the cascade process for custom properties.
|
||
pub struct CustomPropertiesBuilder<'a, 'b: 'a> {
|
||
seen: PrecomputedHashSet<&'a Name>,
|
||
may_have_cycles: bool,
|
||
has_color_scheme: bool,
|
||
custom_properties: ComputedCustomProperties,
|
||
reverted: PrecomputedHashMap<&'a Name, (CascadePriority, bool)>,
|
||
stylist: &'a Stylist,
|
||
computed_context: &'a mut computed::Context<'b>,
|
||
references_from_non_custom_properties: NonCustomReferenceMap<Vec<Name>>,
|
||
}
|
||
|
||
fn find_non_custom_references(
|
||
registration: &PropertyRegistrationData,
|
||
value: &VariableValue,
|
||
may_have_color_scheme: bool,
|
||
is_root_element: bool,
|
||
include_universal: bool,
|
||
) -> Option<NonCustomReferences> {
|
||
let dependent_types = registration.syntax.dependent_types();
|
||
let may_reference_length = dependent_types.intersects(DependentDataTypes::LENGTH) ||
|
||
(include_universal && registration.syntax.is_universal());
|
||
if may_reference_length {
|
||
let value_dependencies = value.references.non_custom_references(is_root_element);
|
||
if !value_dependencies.is_empty() {
|
||
return Some(value_dependencies);
|
||
}
|
||
}
|
||
if dependent_types.intersects(DependentDataTypes::COLOR) && may_have_color_scheme {
|
||
// NOTE(emilio): We might want to add a NonCustomReferences::COLOR_SCHEME or something but
|
||
// it's not really needed for correctness, so for now we use an Option for that to signal
|
||
// that there might be a dependencies.
|
||
return Some(NonCustomReferences::empty());
|
||
}
|
||
None
|
||
}
|
||
|
||
impl<'a, 'b: 'a> CustomPropertiesBuilder<'a, 'b> {
|
||
/// Create a new builder, inheriting from a given custom properties map.
|
||
///
|
||
/// We expose this publicly mostly for @keyframe blocks.
|
||
pub fn new_with_properties(
|
||
stylist: &'a Stylist,
|
||
custom_properties: ComputedCustomProperties,
|
||
computed_context: &'a mut computed::Context<'b>,
|
||
) -> Self {
|
||
Self {
|
||
seen: PrecomputedHashSet::default(),
|
||
reverted: Default::default(),
|
||
may_have_cycles: false,
|
||
has_color_scheme: false,
|
||
custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
references_from_non_custom_properties: NonCustomReferenceMap::default(),
|
||
}
|
||
}
|
||
|
||
/// Create a new builder, inheriting from the right style given context.
|
||
pub fn new(stylist: &'a Stylist, context: &'a mut computed::Context<'b>) -> Self {
|
||
let is_root_element = context.is_root_element();
|
||
|
||
let inherited = context.inherited_custom_properties();
|
||
let initial_values = stylist.get_custom_property_initial_values();
|
||
let properties = ComputedCustomProperties {
|
||
inherited: if is_root_element {
|
||
debug_assert!(inherited.is_empty());
|
||
initial_values.inherited.clone()
|
||
} else {
|
||
inherited.inherited.clone()
|
||
},
|
||
non_inherited: initial_values.non_inherited.clone(),
|
||
};
|
||
|
||
// Reuse flags from computing registered custom properties initial values, such as
|
||
// whether they depend on viewport units.
|
||
context
|
||
.style()
|
||
.add_flags(stylist.get_custom_property_initial_values_flags());
|
||
Self::new_with_properties(stylist, properties, context)
|
||
}
|
||
|
||
/// Cascade a given custom property declaration.
|
||
pub fn cascade(&mut self, declaration: &'a CustomDeclaration, priority: CascadePriority) {
|
||
let CustomDeclaration {
|
||
ref name,
|
||
ref value,
|
||
} = *declaration;
|
||
|
||
if let Some(&(reverted_priority, is_origin_revert)) = self.reverted.get(&name) {
|
||
if !reverted_priority.allows_when_reverted(&priority, is_origin_revert) {
|
||
return;
|
||
}
|
||
}
|
||
|
||
let was_already_present = !self.seen.insert(name);
|
||
if was_already_present {
|
||
return;
|
||
}
|
||
|
||
if !self.value_may_affect_style(name, value) {
|
||
return;
|
||
}
|
||
|
||
let map = &mut self.custom_properties;
|
||
let registration = self.stylist.get_custom_property_registration(&name);
|
||
match value {
|
||
CustomDeclarationValue::Unparsed(unparsed_value) => {
|
||
// At this point of the cascade we're not guaranteed to have seen the color-scheme
|
||
// declaration, so need to assume the worst. We could track all system color
|
||
// keyword tokens + the light-dark() function, but that seems non-trivial /
|
||
// probably overkill.
|
||
let may_have_color_scheme = true;
|
||
// Non-custom dependency is really relevant for registered custom properties
|
||
// that require computed value of such dependencies.
|
||
let has_dependency = unparsed_value.references.any_var ||
|
||
find_non_custom_references(
|
||
registration,
|
||
unparsed_value,
|
||
may_have_color_scheme,
|
||
self.computed_context.is_root_element(),
|
||
/* include_unregistered = */ false,
|
||
)
|
||
.is_some();
|
||
// If the variable value has no references to other properties, perform
|
||
// substitution here instead of forcing a full traversal in `substitute_all`
|
||
// afterwards.
|
||
if !has_dependency {
|
||
return substitute_references_if_needed_and_apply(
|
||
name,
|
||
unparsed_value,
|
||
map,
|
||
self.stylist,
|
||
self.computed_context,
|
||
);
|
||
}
|
||
self.may_have_cycles = true;
|
||
let value = ComputedRegisteredValue::universal(Arc::clone(unparsed_value));
|
||
map.insert(registration, name, value);
|
||
},
|
||
CustomDeclarationValue::Parsed(parsed_value) => {
|
||
let value = parsed_value.to_computed_value(&self.computed_context);
|
||
map.insert(registration, name, value);
|
||
},
|
||
CustomDeclarationValue::CSSWideKeyword(keyword) => match keyword {
|
||
CSSWideKeyword::RevertLayer | CSSWideKeyword::Revert => {
|
||
let origin_revert = matches!(keyword, CSSWideKeyword::Revert);
|
||
self.seen.remove(name);
|
||
self.reverted.insert(name, (priority, origin_revert));
|
||
},
|
||
CSSWideKeyword::Initial => {
|
||
// For non-inherited custom properties, 'initial' was handled in value_may_affect_style.
|
||
debug_assert!(registration.inherits(), "Should've been handled earlier");
|
||
remove_and_insert_initial_value(name, registration, map);
|
||
},
|
||
CSSWideKeyword::Inherit => {
|
||
// For inherited custom properties, 'inherit' was handled in value_may_affect_style.
|
||
debug_assert!(!registration.inherits(), "Should've been handled earlier");
|
||
if let Some(inherited_value) = self
|
||
.computed_context
|
||
.inherited_custom_properties()
|
||
.non_inherited
|
||
.get(name)
|
||
{
|
||
map.insert(registration, name, inherited_value.clone());
|
||
}
|
||
},
|
||
// handled in value_may_affect_style
|
||
CSSWideKeyword::Unset => unreachable!(),
|
||
},
|
||
}
|
||
}
|
||
|
||
/// Fast check to avoid calling maybe_note_non_custom_dependency in ~all cases.
|
||
#[inline]
|
||
pub fn might_have_non_custom_dependency(id: LonghandId, decl: &PropertyDeclaration) -> bool {
|
||
if id == LonghandId::ColorScheme {
|
||
return true;
|
||
}
|
||
if matches!(id, LonghandId::LineHeight | LonghandId::FontSize) {
|
||
return matches!(decl, PropertyDeclaration::WithVariables(..));
|
||
}
|
||
false
|
||
}
|
||
|
||
/// Note a non-custom property with variable reference that may in turn depend on that property.
|
||
/// e.g. `font-size` depending on a custom property that may be a registered property using `em`.
|
||
pub fn maybe_note_non_custom_dependency(&mut self, id: LonghandId, decl: &PropertyDeclaration) {
|
||
debug_assert!(Self::might_have_non_custom_dependency(id, decl));
|
||
if id == LonghandId::ColorScheme {
|
||
// If we might change the color-scheme, we need to defer computation of colors.
|
||
self.has_color_scheme = true;
|
||
return;
|
||
}
|
||
|
||
let refs = match decl {
|
||
PropertyDeclaration::WithVariables(ref v) => &v.value.variable_value.references,
|
||
_ => return,
|
||
};
|
||
|
||
if !refs.any_var {
|
||
return;
|
||
}
|
||
|
||
// With unit algebra in `calc()`, references aren't limited to `font-size`.
|
||
// For example, `--foo: 100ex; font-weight: calc(var(--foo) / 1ex);`,
|
||
// or `--foo: 1em; zoom: calc(var(--foo) * 30px / 2em);`
|
||
let references = match id {
|
||
LonghandId::FontSize => {
|
||
if self.computed_context.is_root_element() {
|
||
NonCustomReferences::ROOT_FONT_UNITS
|
||
} else {
|
||
NonCustomReferences::FONT_UNITS
|
||
}
|
||
},
|
||
LonghandId::LineHeight => {
|
||
if self.computed_context.is_root_element() {
|
||
NonCustomReferences::ROOT_LH_UNITS | NonCustomReferences::ROOT_FONT_UNITS
|
||
} else {
|
||
NonCustomReferences::LH_UNITS | NonCustomReferences::FONT_UNITS
|
||
}
|
||
},
|
||
_ => return,
|
||
};
|
||
|
||
let variables: Vec<Atom> = refs
|
||
.refs
|
||
.iter()
|
||
.filter_map(|reference| {
|
||
if !reference.is_var {
|
||
return None;
|
||
}
|
||
let registration = self
|
||
.stylist
|
||
.get_custom_property_registration(&reference.name);
|
||
if !registration
|
||
.syntax
|
||
.dependent_types()
|
||
.intersects(DependentDataTypes::LENGTH)
|
||
{
|
||
return None;
|
||
}
|
||
Some(reference.name.clone())
|
||
})
|
||
.collect();
|
||
references.for_each(|idx| {
|
||
let entry = &mut self.references_from_non_custom_properties[idx];
|
||
let was_none = entry.is_none();
|
||
let v = entry.get_or_insert_with(|| variables.clone());
|
||
if was_none {
|
||
return;
|
||
}
|
||
v.extend(variables.iter().cloned());
|
||
});
|
||
}
|
||
|
||
fn value_may_affect_style(&self, name: &Name, value: &CustomDeclarationValue) -> bool {
|
||
let registration = self.stylist.get_custom_property_registration(&name);
|
||
match *value {
|
||
CustomDeclarationValue::CSSWideKeyword(CSSWideKeyword::Inherit) => {
|
||
// For inherited custom properties, explicit 'inherit' means we
|
||
// can just use any existing value in the inherited
|
||
// CustomPropertiesMap.
|
||
if registration.inherits() {
|
||
return false;
|
||
}
|
||
},
|
||
CustomDeclarationValue::CSSWideKeyword(CSSWideKeyword::Initial) => {
|
||
// For non-inherited custom properties, explicit 'initial' means
|
||
// we can just use any initial value in the registration.
|
||
if !registration.inherits() {
|
||
return false;
|
||
}
|
||
},
|
||
CustomDeclarationValue::CSSWideKeyword(CSSWideKeyword::Unset) => {
|
||
// Explicit 'unset' means we can either just use any existing
|
||
// value in the inherited CustomPropertiesMap or the initial
|
||
// value in the registration.
|
||
return false;
|
||
},
|
||
_ => {},
|
||
}
|
||
|
||
let existing_value = self.custom_properties.get(registration, &name);
|
||
let existing_value = match existing_value {
|
||
None => {
|
||
if matches!(value, CustomDeclarationValue::CSSWideKeyword(CSSWideKeyword::Initial)) {
|
||
debug_assert!(registration.inherits(), "Should've been handled earlier");
|
||
// The initial value of a custom property without a
|
||
// guaranteed-invalid initial value is the same as it
|
||
// not existing in the map.
|
||
if registration.initial_value.is_none() {
|
||
return false;
|
||
}
|
||
}
|
||
return true;
|
||
},
|
||
Some(v) => v,
|
||
};
|
||
let computed_value = match value {
|
||
CustomDeclarationValue::Unparsed(value) => {
|
||
// Don't bother overwriting an existing value with the same
|
||
// specified value.
|
||
if let Some(existing_value) = existing_value.as_universal() {
|
||
return existing_value != value;
|
||
}
|
||
if !registration.syntax.is_universal() {
|
||
compute_value(
|
||
&value.css,
|
||
&value.url_data,
|
||
registration,
|
||
self.computed_context,
|
||
).ok()
|
||
} else {
|
||
None
|
||
}
|
||
},
|
||
CustomDeclarationValue::Parsed(value) => {
|
||
Some(value.to_computed_value(&self.computed_context))
|
||
},
|
||
CustomDeclarationValue::CSSWideKeyword(kw) => {
|
||
match kw {
|
||
CSSWideKeyword::Inherit => {
|
||
debug_assert!(!registration.inherits(), "Should've been handled earlier");
|
||
// existing_value is the registered initial value.
|
||
// Don't bother adding it to self.custom_properties.non_inherited
|
||
// if the key is also absent from self.inherited.non_inherited.
|
||
if self
|
||
.computed_context
|
||
.inherited_custom_properties()
|
||
.non_inherited
|
||
.get(name)
|
||
.is_none()
|
||
{
|
||
return false;
|
||
}
|
||
},
|
||
CSSWideKeyword::Initial => {
|
||
debug_assert!(registration.inherits(), "Should've been handled earlier");
|
||
// Don't bother overwriting an existing value with the initial value specified in
|
||
// the registration.
|
||
if let Some(initial_value) = self
|
||
.stylist
|
||
.get_custom_property_initial_values()
|
||
.get(registration, name)
|
||
{
|
||
return existing_value != initial_value;
|
||
}
|
||
},
|
||
CSSWideKeyword::Unset => {
|
||
debug_assert!(false, "Should've been handled earlier");
|
||
},
|
||
CSSWideKeyword::Revert | CSSWideKeyword::RevertLayer => {},
|
||
}
|
||
None
|
||
}
|
||
};
|
||
|
||
if let Some(value) = computed_value {
|
||
return existing_value.v != value.v;
|
||
}
|
||
|
||
true
|
||
}
|
||
|
||
/// Computes the map of applicable custom properties, as well as
|
||
/// longhand properties that are now considered invalid-at-compute time.
|
||
/// The result is saved into the computed context.
|
||
///
|
||
/// If there was any specified property or non-inherited custom property
|
||
/// with an initial value, we've created a new map and now we
|
||
/// need to remove any potential cycles (And marking non-custom
|
||
/// properties), and wrap it in an arc.
|
||
///
|
||
/// Some registered custom properties may require font-related properties
|
||
/// be resolved to resolve. If these properties are not resolved at this time,
|
||
/// `defer` should be set to `Yes`, which will leave such custom properties,
|
||
/// and other properties referencing them, untouched. These properties are
|
||
/// returned separately, to be resolved by `build_deferred` to fully resolve
|
||
/// all custom properties after all necessary non-custom properties are resolved.
|
||
pub fn build(
|
||
mut self,
|
||
defer: DeferFontRelativeCustomPropertyResolution,
|
||
) -> Option<CustomPropertiesMap> {
|
||
let mut deferred_custom_properties = None;
|
||
if self.may_have_cycles {
|
||
if defer == DeferFontRelativeCustomPropertyResolution::Yes {
|
||
deferred_custom_properties = Some(CustomPropertiesMap::default());
|
||
}
|
||
let mut invalid_non_custom_properties = LonghandIdSet::default();
|
||
substitute_all(
|
||
&mut self.custom_properties,
|
||
deferred_custom_properties.as_mut(),
|
||
&mut invalid_non_custom_properties,
|
||
self.has_color_scheme,
|
||
&self.seen,
|
||
&self.references_from_non_custom_properties,
|
||
self.stylist,
|
||
self.computed_context,
|
||
);
|
||
self.computed_context.builder.invalid_non_custom_properties =
|
||
invalid_non_custom_properties;
|
||
}
|
||
|
||
self.custom_properties.shrink_to_fit();
|
||
|
||
// Some pages apply a lot of redundant custom properties, see e.g.
|
||
// bug 1758974 comment 5. Try to detect the case where the values
|
||
// haven't really changed, and save some memory by reusing the inherited
|
||
// map in that case.
|
||
let initial_values = self.stylist.get_custom_property_initial_values();
|
||
self.computed_context.builder.custom_properties = ComputedCustomProperties {
|
||
inherited: if self
|
||
.computed_context
|
||
.inherited_custom_properties()
|
||
.inherited ==
|
||
self.custom_properties.inherited
|
||
{
|
||
self.computed_context
|
||
.inherited_custom_properties()
|
||
.inherited
|
||
.clone()
|
||
} else {
|
||
self.custom_properties.inherited
|
||
},
|
||
non_inherited: if initial_values.non_inherited == self.custom_properties.non_inherited {
|
||
initial_values.non_inherited.clone()
|
||
} else {
|
||
self.custom_properties.non_inherited
|
||
},
|
||
};
|
||
|
||
deferred_custom_properties
|
||
}
|
||
|
||
/// Fully resolve all deferred custom properties, assuming that the incoming context
|
||
/// has necessary properties resolved.
|
||
pub fn build_deferred(
|
||
deferred: CustomPropertiesMap,
|
||
stylist: &Stylist,
|
||
computed_context: &mut computed::Context,
|
||
) {
|
||
if deferred.is_empty() {
|
||
return;
|
||
}
|
||
let mut custom_properties = std::mem::take(&mut computed_context.builder.custom_properties);
|
||
// Since `CustomPropertiesMap` preserves insertion order, we shouldn't have to worry about
|
||
// resolving in a wrong order.
|
||
for (k, v) in deferred.iter() {
|
||
let Some(v) = v else { continue };
|
||
let Some(v) = v.as_universal() else {
|
||
unreachable!("Computing should have been deferred!")
|
||
};
|
||
substitute_references_if_needed_and_apply(
|
||
k,
|
||
v,
|
||
&mut custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
);
|
||
}
|
||
computed_context.builder.custom_properties = custom_properties;
|
||
}
|
||
}
|
||
|
||
/// Resolve all custom properties to either substituted, invalid, or unset
|
||
/// (meaning we should use the inherited value).
|
||
///
|
||
/// It does cycle dependencies removal at the same time as substitution.
|
||
fn substitute_all(
|
||
custom_properties_map: &mut ComputedCustomProperties,
|
||
mut deferred_properties_map: Option<&mut CustomPropertiesMap>,
|
||
invalid_non_custom_properties: &mut LonghandIdSet,
|
||
has_color_scheme: bool,
|
||
seen: &PrecomputedHashSet<&Name>,
|
||
references_from_non_custom_properties: &NonCustomReferenceMap<Vec<Name>>,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
) {
|
||
// The cycle dependencies removal in this function is a variant
|
||
// of Tarjan's algorithm. It is mostly based on the pseudo-code
|
||
// listed in
|
||
// https://en.wikipedia.org/w/index.php?
|
||
// title=Tarjan%27s_strongly_connected_components_algorithm&oldid=801728495
|
||
|
||
#[derive(Clone, Eq, PartialEq, Debug)]
|
||
enum VarType {
|
||
Custom(Name),
|
||
NonCustom(SingleNonCustomReference),
|
||
}
|
||
|
||
/// Struct recording necessary information for each variable.
|
||
#[derive(Debug)]
|
||
struct VarInfo {
|
||
/// The name of the variable. It will be taken to save addref
|
||
/// when the corresponding variable is popped from the stack.
|
||
/// This also serves as a mark for whether the variable is
|
||
/// currently in the stack below.
|
||
var: Option<VarType>,
|
||
/// If the variable is in a dependency cycle, lowlink represents
|
||
/// a smaller index which corresponds to a variable in the same
|
||
/// strong connected component, which is known to be accessible
|
||
/// from this variable. It is not necessarily the root, though.
|
||
lowlink: usize,
|
||
}
|
||
/// Context struct for traversing the variable graph, so that we can
|
||
/// avoid referencing all the fields multiple times.
|
||
struct Context<'a, 'b: 'a> {
|
||
/// Number of variables visited. This is used as the order index
|
||
/// when we visit a new unresolved variable.
|
||
count: usize,
|
||
/// The map from custom property name to its order index.
|
||
index_map: PrecomputedHashMap<Name, usize>,
|
||
/// Mapping from a non-custom dependency to its order index.
|
||
non_custom_index_map: NonCustomReferenceMap<usize>,
|
||
/// Information of each variable indexed by the order index.
|
||
var_info: SmallVec<[VarInfo; 5]>,
|
||
/// The stack of order index of visited variables. It contains
|
||
/// all unfinished strong connected components.
|
||
stack: SmallVec<[usize; 5]>,
|
||
/// References to non-custom properties in this strongly connected component.
|
||
non_custom_references: NonCustomReferences,
|
||
/// Whether the builder has seen a non-custom color-scheme reference.
|
||
has_color_scheme: bool,
|
||
/// Whether this strongly connected component contains any custom properties involving
|
||
/// value computation.
|
||
contains_computed_custom_property: bool,
|
||
map: &'a mut ComputedCustomProperties,
|
||
/// The stylist is used to get registered properties, and to resolve the environment to
|
||
/// substitute `env()` variables.
|
||
stylist: &'a Stylist,
|
||
/// The computed context is used to get inherited custom
|
||
/// properties and compute registered custom properties.
|
||
computed_context: &'a computed::Context<'b>,
|
||
/// Longhand IDs that became invalid due to dependency cycle(s).
|
||
invalid_non_custom_properties: &'a mut LonghandIdSet,
|
||
/// Properties that cannot yet be substituted. Note we store both inherited and
|
||
/// non-inherited properties in the same map, since we need to make sure we iterate through
|
||
/// them in the right order.
|
||
deferred_properties: Option<&'a mut CustomPropertiesMap>,
|
||
}
|
||
|
||
/// This function combines the traversal for cycle removal and value
|
||
/// substitution. It returns either a signal None if this variable
|
||
/// has been fully resolved (to either having no reference or being
|
||
/// marked invalid), or the order index for the given name.
|
||
///
|
||
/// When it returns, the variable corresponds to the name would be
|
||
/// in one of the following states:
|
||
/// * It is still in context.stack, which means it is part of an
|
||
/// potentially incomplete dependency circle.
|
||
/// * It has been removed from the map. It can be either that the
|
||
/// substitution failed, or it is inside a dependency circle.
|
||
/// When this function removes a variable from the map because
|
||
/// of dependency circle, it would put all variables in the same
|
||
/// strong connected component to the set together.
|
||
/// * It doesn't have any reference, because either this variable
|
||
/// doesn't have reference at all in specified value, or it has
|
||
/// been completely resolved.
|
||
/// * There is no such variable at all.
|
||
fn traverse<'a, 'b>(
|
||
var: VarType,
|
||
non_custom_references: &NonCustomReferenceMap<Vec<Name>>,
|
||
context: &mut Context<'a, 'b>,
|
||
) -> Option<usize> {
|
||
// Some shortcut checks.
|
||
let value = match var {
|
||
VarType::Custom(ref name) => {
|
||
let registration = context.stylist.get_custom_property_registration(name);
|
||
let value = context.map.get(registration, name)?.as_universal()?;
|
||
let is_root = context.computed_context.is_root_element();
|
||
// We need to keep track of potential non-custom-references even on unregistered
|
||
// properties for cycle-detection purposes.
|
||
let non_custom_refs = find_non_custom_references(
|
||
registration,
|
||
value,
|
||
context.has_color_scheme,
|
||
is_root,
|
||
/* include_unregistered = */ true,
|
||
);
|
||
context.non_custom_references |= non_custom_refs.unwrap_or_default();
|
||
let has_dependency = value.references.any_var || non_custom_refs.is_some();
|
||
// Nothing to resolve.
|
||
if !has_dependency {
|
||
debug_assert!(!value.references.any_env, "Should've been handled earlier");
|
||
if !registration.syntax.is_universal() {
|
||
// We might still need to compute the value if this is not an universal
|
||
// registration if we thought this had a dependency before but turned out
|
||
// not to be (due to has_color_scheme, for example). Note that if this was
|
||
// already computed we would've bailed out in the as_universal() check.
|
||
debug_assert!(
|
||
registration
|
||
.syntax
|
||
.dependent_types()
|
||
.intersects(DependentDataTypes::COLOR),
|
||
"How did an unresolved value get here otherwise?",
|
||
);
|
||
let value = value.clone();
|
||
substitute_references_if_needed_and_apply(
|
||
name,
|
||
&value,
|
||
&mut context.map,
|
||
context.stylist,
|
||
context.computed_context,
|
||
);
|
||
}
|
||
return None;
|
||
}
|
||
|
||
// Has this variable been visited?
|
||
match context.index_map.entry(name.clone()) {
|
||
Entry::Occupied(entry) => {
|
||
return Some(*entry.get());
|
||
},
|
||
Entry::Vacant(entry) => {
|
||
entry.insert(context.count);
|
||
},
|
||
}
|
||
context.contains_computed_custom_property |= !registration.syntax.is_universal();
|
||
|
||
// Hold a strong reference to the value so that we don't
|
||
// need to keep reference to context.map.
|
||
Some(value.clone())
|
||
},
|
||
VarType::NonCustom(ref non_custom) => {
|
||
let entry = &mut context.non_custom_index_map[*non_custom];
|
||
if let Some(v) = entry {
|
||
return Some(*v);
|
||
}
|
||
*entry = Some(context.count);
|
||
None
|
||
},
|
||
};
|
||
|
||
// Add new entry to the information table.
|
||
let index = context.count;
|
||
context.count += 1;
|
||
debug_assert_eq!(index, context.var_info.len());
|
||
context.var_info.push(VarInfo {
|
||
var: Some(var.clone()),
|
||
lowlink: index,
|
||
});
|
||
context.stack.push(index);
|
||
|
||
let mut self_ref = false;
|
||
let mut lowlink = index;
|
||
let visit_link =
|
||
|var: VarType, context: &mut Context, lowlink: &mut usize, self_ref: &mut bool| {
|
||
let next_index = match traverse(var, non_custom_references, context) {
|
||
Some(index) => index,
|
||
// There is nothing to do if the next variable has been
|
||
// fully resolved at this point.
|
||
None => {
|
||
return;
|
||
},
|
||
};
|
||
let next_info = &context.var_info[next_index];
|
||
if next_index > index {
|
||
// The next variable has a larger index than us, so it
|
||
// must be inserted in the recursive call above. We want
|
||
// to get its lowlink.
|
||
*lowlink = cmp::min(*lowlink, next_info.lowlink);
|
||
} else if next_index == index {
|
||
*self_ref = true;
|
||
} else if next_info.var.is_some() {
|
||
// The next variable has a smaller order index and it is
|
||
// in the stack, so we are at the same component.
|
||
*lowlink = cmp::min(*lowlink, next_index);
|
||
}
|
||
};
|
||
if let Some(ref v) = value.as_ref() {
|
||
debug_assert!(
|
||
matches!(var, VarType::Custom(_)),
|
||
"Non-custom property has references?"
|
||
);
|
||
|
||
// Visit other custom properties...
|
||
// FIXME: Maybe avoid visiting the same var twice if not needed?
|
||
for next in &v.references.refs {
|
||
if !next.is_var {
|
||
continue;
|
||
}
|
||
visit_link(
|
||
VarType::Custom(next.name.clone()),
|
||
context,
|
||
&mut lowlink,
|
||
&mut self_ref,
|
||
);
|
||
}
|
||
|
||
// ... Then non-custom properties.
|
||
v.references.non_custom_references.for_each(|r| {
|
||
visit_link(VarType::NonCustom(r), context, &mut lowlink, &mut self_ref);
|
||
});
|
||
} else if let VarType::NonCustom(non_custom) = var {
|
||
let entry = &non_custom_references[non_custom];
|
||
if let Some(deps) = entry.as_ref() {
|
||
for d in deps {
|
||
// Visit any reference from this non-custom property to custom properties.
|
||
visit_link(
|
||
VarType::Custom(d.clone()),
|
||
context,
|
||
&mut lowlink,
|
||
&mut self_ref,
|
||
);
|
||
}
|
||
}
|
||
}
|
||
|
||
context.var_info[index].lowlink = lowlink;
|
||
if lowlink != index {
|
||
// This variable is in a loop, but it is not the root of
|
||
// this strong connected component. We simply return for
|
||
// now, and the root would remove it from the map.
|
||
//
|
||
// This cannot be removed from the map here, because
|
||
// otherwise the shortcut check at the beginning of this
|
||
// function would return the wrong value.
|
||
return Some(index);
|
||
}
|
||
|
||
// This is the root of a strong-connected component.
|
||
let mut in_loop = self_ref;
|
||
let name;
|
||
|
||
let handle_variable_in_loop = |name: &Name, context: &mut Context<'a, 'b>| {
|
||
if context.contains_computed_custom_property {
|
||
// These non-custom properties can't become invalid-at-compute-time from
|
||
// cyclic dependencies purely consisting of non-registered properties.
|
||
if context
|
||
.non_custom_references
|
||
.intersects(NonCustomReferences::FONT_UNITS | NonCustomReferences::ROOT_FONT_UNITS)
|
||
{
|
||
context
|
||
.invalid_non_custom_properties
|
||
.insert(LonghandId::FontSize);
|
||
}
|
||
if context
|
||
.non_custom_references
|
||
.intersects(NonCustomReferences::LH_UNITS | NonCustomReferences::ROOT_LH_UNITS)
|
||
{
|
||
context
|
||
.invalid_non_custom_properties
|
||
.insert(LonghandId::LineHeight);
|
||
}
|
||
}
|
||
// This variable is in loop. Resolve to invalid.
|
||
handle_invalid_at_computed_value_time(name, context.map, context.computed_context);
|
||
};
|
||
loop {
|
||
let var_index = context
|
||
.stack
|
||
.pop()
|
||
.expect("The current variable should still be in stack");
|
||
let var_info = &mut context.var_info[var_index];
|
||
// We should never visit the variable again, so it's safe
|
||
// to take the name away, so that we don't do additional
|
||
// reference count.
|
||
let var_name = var_info
|
||
.var
|
||
.take()
|
||
.expect("Variable should not be poped from stack twice");
|
||
if var_index == index {
|
||
name = match var_name {
|
||
VarType::Custom(name) => name,
|
||
// At the root of this component, and it's a non-custom
|
||
// reference - we have nothing to substitute, so
|
||
// it's effectively resolved.
|
||
VarType::NonCustom(..) => return None,
|
||
};
|
||
break;
|
||
}
|
||
if let VarType::Custom(name) = var_name {
|
||
// Anything here is in a loop which can traverse to the
|
||
// variable we are handling, so it's invalid at
|
||
// computed-value time.
|
||
handle_variable_in_loop(&name, context);
|
||
}
|
||
in_loop = true;
|
||
}
|
||
// We've gotten to the root of this strongly connected component, so clear
|
||
// whether or not it involved non-custom references.
|
||
// It's fine to track it like this, because non-custom properties currently
|
||
// being tracked can only participate in any loop only once.
|
||
if in_loop {
|
||
handle_variable_in_loop(&name, context);
|
||
context.non_custom_references = NonCustomReferences::default();
|
||
return None;
|
||
}
|
||
|
||
if let Some(ref v) = value {
|
||
let registration = context.stylist.get_custom_property_registration(&name);
|
||
|
||
let mut defer = false;
|
||
if let Some(ref mut deferred) = context.deferred_properties {
|
||
// We need to defer this property if it has a non-custom property dependency, or
|
||
// any variable that it references is already deferred.
|
||
defer = find_non_custom_references(
|
||
registration,
|
||
v,
|
||
context.has_color_scheme,
|
||
context.computed_context.is_root_element(),
|
||
/* include_unregistered = */ false,
|
||
)
|
||
.is_some() ||
|
||
v.references.refs.iter().any(|reference| {
|
||
reference.is_var && deferred.get(&reference.name).is_some()
|
||
});
|
||
|
||
if defer {
|
||
let value = ComputedRegisteredValue::universal(Arc::clone(v));
|
||
deferred.insert(&name, value);
|
||
context.map.remove(registration, &name);
|
||
}
|
||
}
|
||
|
||
// If there are no var references we should already be computed and substituted by now.
|
||
if !defer && v.references.any_var {
|
||
substitute_references_if_needed_and_apply(
|
||
&name,
|
||
v,
|
||
&mut context.map,
|
||
context.stylist,
|
||
context.computed_context,
|
||
);
|
||
}
|
||
}
|
||
context.non_custom_references = NonCustomReferences::default();
|
||
|
||
// All resolved, so return the signal value.
|
||
None
|
||
}
|
||
|
||
// Note that `seen` doesn't contain names inherited from our parent, but
|
||
// those can't have variable references (since we inherit the computed
|
||
// variables) so we don't want to spend cycles traversing them anyway.
|
||
for name in seen {
|
||
let mut context = Context {
|
||
count: 0,
|
||
index_map: PrecomputedHashMap::default(),
|
||
non_custom_index_map: NonCustomReferenceMap::default(),
|
||
stack: SmallVec::new(),
|
||
var_info: SmallVec::new(),
|
||
map: custom_properties_map,
|
||
non_custom_references: NonCustomReferences::default(),
|
||
has_color_scheme,
|
||
stylist,
|
||
computed_context,
|
||
invalid_non_custom_properties,
|
||
deferred_properties: deferred_properties_map.as_deref_mut(),
|
||
contains_computed_custom_property: false,
|
||
};
|
||
traverse(
|
||
VarType::Custom((*name).clone()),
|
||
references_from_non_custom_properties,
|
||
&mut context,
|
||
);
|
||
}
|
||
}
|
||
|
||
// See https://drafts.csswg.org/css-variables-2/#invalid-at-computed-value-time
|
||
fn handle_invalid_at_computed_value_time(
|
||
name: &Name,
|
||
custom_properties: &mut ComputedCustomProperties,
|
||
computed_context: &computed::Context,
|
||
) {
|
||
let stylist = computed_context.style().stylist.unwrap();
|
||
let registration = stylist.get_custom_property_registration(&name);
|
||
if !registration.syntax.is_universal() {
|
||
// For the root element, inherited maps are empty. We should just
|
||
// use the initial value if any, rather than removing the name.
|
||
if registration.inherits() && !computed_context.is_root_element() {
|
||
let inherited = computed_context.inherited_custom_properties();
|
||
if let Some(value) = inherited.get(registration, name) {
|
||
custom_properties.insert(registration, name, value.clone());
|
||
return;
|
||
}
|
||
} else if let Some(ref initial_value) = registration.initial_value {
|
||
if let Ok(initial_value) = compute_value(
|
||
&initial_value.css,
|
||
&initial_value.url_data,
|
||
registration,
|
||
computed_context,
|
||
) {
|
||
custom_properties.insert(registration, name, initial_value);
|
||
return;
|
||
}
|
||
}
|
||
}
|
||
custom_properties.remove(registration, name);
|
||
}
|
||
|
||
/// Replace `var()` and `env()` functions in a pre-existing variable value.
|
||
fn substitute_references_if_needed_and_apply(
|
||
name: &Name,
|
||
value: &Arc<VariableValue>,
|
||
custom_properties: &mut ComputedCustomProperties,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
) {
|
||
let registration = stylist.get_custom_property_registration(&name);
|
||
if !value.has_references() && registration.syntax.is_universal() {
|
||
// Trivial path: no references and no need to compute the value, just apply it directly.
|
||
let computed_value = ComputedRegisteredValue::universal(Arc::clone(value));
|
||
custom_properties.insert(registration, name, computed_value);
|
||
return;
|
||
}
|
||
|
||
let inherited = computed_context.inherited_custom_properties();
|
||
let url_data = &value.url_data;
|
||
let substitution = match substitute_internal(
|
||
value,
|
||
custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
) {
|
||
Ok(v) => v,
|
||
Err(..) => {
|
||
handle_invalid_at_computed_value_time(name, custom_properties, computed_context);
|
||
return;
|
||
},
|
||
};
|
||
|
||
// If variable fallback results in a wide keyword, deal with it now.
|
||
{
|
||
let css = &substitution.css;
|
||
let css_wide_kw = {
|
||
let mut input = ParserInput::new(&css);
|
||
let mut input = Parser::new(&mut input);
|
||
input.try_parse(CSSWideKeyword::parse)
|
||
};
|
||
|
||
if let Ok(kw) = css_wide_kw {
|
||
// TODO: It's unclear what this should do for revert / revert-layer, see
|
||
// https://github.com/w3c/csswg-drafts/issues/9131. For now treating as unset
|
||
// seems fine?
|
||
match (
|
||
kw,
|
||
registration.inherits(),
|
||
computed_context.is_root_element(),
|
||
) {
|
||
(CSSWideKeyword::Initial, _, _) |
|
||
(CSSWideKeyword::Revert, false, _) |
|
||
(CSSWideKeyword::RevertLayer, false, _) |
|
||
(CSSWideKeyword::Unset, false, _) |
|
||
(CSSWideKeyword::Revert, true, true) |
|
||
(CSSWideKeyword::RevertLayer, true, true) |
|
||
(CSSWideKeyword::Unset, true, true) |
|
||
(CSSWideKeyword::Inherit, _, true) => {
|
||
remove_and_insert_initial_value(name, registration, custom_properties);
|
||
},
|
||
(CSSWideKeyword::Revert, true, false) |
|
||
(CSSWideKeyword::RevertLayer, true, false) |
|
||
(CSSWideKeyword::Inherit, _, false) |
|
||
(CSSWideKeyword::Unset, true, false) => {
|
||
match inherited.get(registration, name) {
|
||
Some(value) => {
|
||
custom_properties.insert(registration, name, value.clone());
|
||
},
|
||
None => {
|
||
custom_properties.remove(registration, name);
|
||
},
|
||
};
|
||
},
|
||
}
|
||
return;
|
||
}
|
||
}
|
||
|
||
let value = match substitution.into_value(url_data, registration, computed_context) {
|
||
Ok(v) => v,
|
||
Err(()) => {
|
||
handle_invalid_at_computed_value_time(name, custom_properties, computed_context);
|
||
return;
|
||
}
|
||
};
|
||
|
||
custom_properties.insert(registration, name, value);
|
||
}
|
||
|
||
#[derive(Default)]
|
||
struct Substitution<'a> {
|
||
css: Cow<'a, str>,
|
||
first_token_type: TokenSerializationType,
|
||
last_token_type: TokenSerializationType,
|
||
}
|
||
|
||
impl<'a> Substitution<'a> {
|
||
fn from_value(v: VariableValue) -> Self {
|
||
Substitution {
|
||
css: v.css.into(),
|
||
first_token_type: v.first_token_type,
|
||
last_token_type: v.last_token_type,
|
||
}
|
||
}
|
||
|
||
fn into_value(
|
||
self,
|
||
url_data: &UrlExtraData,
|
||
registration: &PropertyRegistrationData,
|
||
computed_context: &computed::Context,
|
||
) -> Result<ComputedRegisteredValue, ()> {
|
||
if registration.syntax.is_universal() {
|
||
return Ok(ComputedRegisteredValue::universal(Arc::new(VariableValue {
|
||
css: self.css.into_owned(),
|
||
first_token_type: self.first_token_type,
|
||
last_token_type: self.last_token_type,
|
||
url_data: url_data.clone(),
|
||
references: Default::default(),
|
||
})))
|
||
}
|
||
compute_value(&self.css, url_data, registration, computed_context)
|
||
}
|
||
|
||
fn new(
|
||
css: &'a str,
|
||
first_token_type: TokenSerializationType,
|
||
last_token_type: TokenSerializationType,
|
||
) -> Self {
|
||
Self {
|
||
css: Cow::Borrowed(css),
|
||
first_token_type,
|
||
last_token_type,
|
||
}
|
||
}
|
||
}
|
||
|
||
fn compute_value(
|
||
css: &str,
|
||
url_data: &UrlExtraData,
|
||
registration: &PropertyRegistrationData,
|
||
computed_context: &computed::Context,
|
||
) -> Result<ComputedRegisteredValue, ()> {
|
||
debug_assert!(!registration.syntax.is_universal());
|
||
|
||
let mut input = ParserInput::new(&css);
|
||
let mut input = Parser::new(&mut input);
|
||
|
||
SpecifiedRegisteredValue::compute(
|
||
&mut input,
|
||
registration,
|
||
url_data,
|
||
computed_context,
|
||
AllowComputationallyDependent::Yes,
|
||
)
|
||
}
|
||
|
||
/// Removes the named registered custom property and inserts its uncomputed initial value.
|
||
fn remove_and_insert_initial_value(
|
||
name: &Name,
|
||
registration: &PropertyRegistrationData,
|
||
custom_properties: &mut ComputedCustomProperties,
|
||
) {
|
||
custom_properties.remove(registration, name);
|
||
if let Some(ref initial_value) = registration.initial_value {
|
||
let value = ComputedRegisteredValue::universal(Arc::clone(initial_value));
|
||
custom_properties.insert(registration, name, value);
|
||
}
|
||
}
|
||
|
||
fn do_substitute_chunk<'a>(
|
||
css: &'a str,
|
||
start: usize,
|
||
end: usize,
|
||
first_token_type: TokenSerializationType,
|
||
last_token_type: TokenSerializationType,
|
||
url_data: &UrlExtraData,
|
||
custom_properties: &'a ComputedCustomProperties,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
references: &mut std::iter::Peekable<std::slice::Iter<VarOrEnvReference>>,
|
||
) -> Result<Substitution<'a>, ()> {
|
||
if start == end {
|
||
// Empty string. Easy.
|
||
return Ok(Substitution::default());
|
||
}
|
||
// Easy case: no references involved.
|
||
if references
|
||
.peek()
|
||
.map_or(true, |reference| reference.end > end)
|
||
{
|
||
let result = &css[start..end];
|
||
return Ok(Substitution::new(result, first_token_type, last_token_type));
|
||
}
|
||
|
||
let mut substituted = ComputedValue::empty(url_data);
|
||
let mut next_token_type = first_token_type;
|
||
let mut cur_pos = start;
|
||
while let Some(reference) = references.next_if(|reference| reference.end <= end) {
|
||
if reference.start != cur_pos {
|
||
substituted.push(
|
||
&css[cur_pos..reference.start],
|
||
next_token_type,
|
||
reference.prev_token_type,
|
||
)?;
|
||
}
|
||
|
||
let substitution = substitute_one_reference(
|
||
css,
|
||
url_data,
|
||
custom_properties,
|
||
reference,
|
||
stylist,
|
||
computed_context,
|
||
references,
|
||
)?;
|
||
|
||
// Optimize the property: var(--...) case to avoid allocating at all.
|
||
if reference.start == start && reference.end == end {
|
||
return Ok(substitution);
|
||
}
|
||
|
||
substituted.push(
|
||
&substitution.css,
|
||
substitution.first_token_type,
|
||
substitution.last_token_type,
|
||
)?;
|
||
next_token_type = reference.next_token_type;
|
||
cur_pos = reference.end;
|
||
}
|
||
// Push the rest of the value if needed.
|
||
if cur_pos != end {
|
||
substituted.push(&css[cur_pos..end], next_token_type, last_token_type)?;
|
||
}
|
||
Ok(Substitution::from_value(substituted))
|
||
}
|
||
|
||
fn substitute_one_reference<'a>(
|
||
css: &'a str,
|
||
url_data: &UrlExtraData,
|
||
custom_properties: &'a ComputedCustomProperties,
|
||
reference: &VarOrEnvReference,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
references: &mut std::iter::Peekable<std::slice::Iter<VarOrEnvReference>>,
|
||
) -> Result<Substitution<'a>, ()> {
|
||
if reference.is_var {
|
||
let registration = stylist.get_custom_property_registration(&reference.name);
|
||
if let Some(v) = custom_properties.get(registration, &reference.name) {
|
||
// Skip references that are inside the outer variable (in fallback for example).
|
||
while references
|
||
.next_if(|next_ref| next_ref.end <= reference.end)
|
||
.is_some()
|
||
{}
|
||
return Ok(Substitution::from_value(v.to_variable_value()))
|
||
}
|
||
} else {
|
||
let device = stylist.device();
|
||
if let Some(v) = device.environment().get(&reference.name, device, url_data) {
|
||
while references
|
||
.next_if(|next_ref| next_ref.end <= reference.end)
|
||
.is_some()
|
||
{}
|
||
return Ok(Substitution::from_value(v));
|
||
}
|
||
}
|
||
|
||
let Some(ref fallback) = reference.fallback else {
|
||
return Err(());
|
||
};
|
||
|
||
do_substitute_chunk(
|
||
css,
|
||
fallback.start.get(),
|
||
reference.end - 1, // Skip the closing parenthesis of the reference value.
|
||
fallback.first_token_type,
|
||
fallback.last_token_type,
|
||
url_data,
|
||
custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
references,
|
||
)
|
||
}
|
||
|
||
/// Replace `var()` and `env()` functions. Return `Err(..)` for invalid at computed time.
|
||
fn substitute_internal<'a>(
|
||
variable_value: &'a VariableValue,
|
||
custom_properties: &'a ComputedCustomProperties,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
) -> Result<Substitution<'a>, ()> {
|
||
let mut refs = variable_value.references.refs.iter().peekable();
|
||
do_substitute_chunk(
|
||
&variable_value.css,
|
||
/* start = */ 0,
|
||
/* end = */ variable_value.css.len(),
|
||
variable_value.first_token_type,
|
||
variable_value.last_token_type,
|
||
&variable_value.url_data,
|
||
custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
&mut refs,
|
||
)
|
||
}
|
||
|
||
/// Replace var() and env() functions, returning the resulting CSS string.
|
||
pub fn substitute<'a>(
|
||
variable_value: &'a VariableValue,
|
||
custom_properties: &'a ComputedCustomProperties,
|
||
stylist: &Stylist,
|
||
computed_context: &computed::Context,
|
||
) -> Result<Cow<'a, str>, ()> {
|
||
debug_assert!(variable_value.has_references());
|
||
let v = substitute_internal(
|
||
variable_value,
|
||
custom_properties,
|
||
stylist,
|
||
computed_context,
|
||
)?;
|
||
Ok(v.css)
|
||
}
|