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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
//! A [`@container`][container] rule.
//!
use crate::computed_value_flags::ComputedValueFlags;
use crate::dom::TElement;
use crate::logical_geometry::{LogicalSize, WritingMode};
use crate::parser::ParserContext;
use crate::properties::ComputedValues;
use crate::queries::feature::{AllowsRanges, Evaluator, FeatureFlags, QueryFeatureDescription};
use crate::queries::values::Orientation;
use crate::queries::{FeatureType, QueryCondition};
use crate::shared_lock::{
DeepCloneParams, DeepCloneWithLock, Locked, SharedRwLock, SharedRwLockReadGuard, ToCssWithGuard,
};
use crate::str::CssStringWriter;
use crate::stylesheets::CssRules;
use crate::stylist::Stylist;
use crate::values::computed::{CSSPixelLength, ContainerType, Context, Ratio};
use crate::values::specified::ContainerName;
use app_units::Au;
use cssparser::{Parser, SourceLocation};
use euclid::default::Size2D;
#[cfg(feature = "gecko")]
use malloc_size_of::{MallocSizeOfOps, MallocUnconditionalShallowSizeOf};
use servo_arc::Arc;
use std::fmt::{self, Write};
use style_traits::{CssWriter, ParseError, ToCss};
use selectors::kleene_value::KleeneValue;
/// A container rule.
#[derive(Debug, ToShmem)]
pub struct ContainerRule {
/// The container query and name.
pub condition: Arc<ContainerCondition>,
/// The nested rules inside the block.
pub rules: Arc<Locked<CssRules>>,
/// The source position where this rule was found.
pub source_location: SourceLocation,
}
impl ContainerRule {
/// Returns the query condition.
pub fn query_condition(&self) -> &QueryCondition {
&self.condition.condition
}
/// Returns the query name filter.
pub fn container_name(&self) -> &ContainerName {
&self.condition.name
}
/// Measure heap usage.
#[cfg(feature = "gecko")]
pub fn size_of(&self, guard: &SharedRwLockReadGuard, ops: &mut MallocSizeOfOps) -> usize {
// Measurement of other fields may be added later.
self.rules.unconditional_shallow_size_of(ops) +
self.rules.read_with(guard).size_of(guard, ops)
}
}
impl DeepCloneWithLock for ContainerRule {
fn deep_clone_with_lock(
&self,
lock: &SharedRwLock,
guard: &SharedRwLockReadGuard,
params: &DeepCloneParams,
) -> Self {
let rules = self.rules.read_with(guard);
Self {
condition: self.condition.clone(),
rules: Arc::new(lock.wrap(rules.deep_clone_with_lock(lock, guard, params))),
source_location: self.source_location.clone(),
}
}
}
impl ToCssWithGuard for ContainerRule {
fn to_css(&self, guard: &SharedRwLockReadGuard, dest: &mut CssStringWriter) -> fmt::Result {
dest.write_str("@container ")?;
{
let mut writer = CssWriter::new(dest);
if !self.condition.name.is_none() {
self.condition.name.to_css(&mut writer)?;
writer.write_char(' ')?;
}
self.condition.condition.to_css(&mut writer)?;
}
self.rules.read_with(guard).to_css_block(guard, dest)
}
}
/// A container condition and filter, combined.
#[derive(Debug, ToShmem, ToCss)]
pub struct ContainerCondition {
#[css(skip_if = "ContainerName::is_none")]
name: ContainerName,
condition: QueryCondition,
#[css(skip)]
flags: FeatureFlags,
}
/// The result of a successful container query lookup.
pub struct ContainerLookupResult<E> {
/// The relevant container.
pub element: E,
/// The sizing / writing-mode information of the container.
pub info: ContainerInfo,
/// The style of the element.
pub style: Arc<ComputedValues>,
}
fn container_type_axes(ty_: ContainerType, wm: WritingMode) -> FeatureFlags {
match ty_ {
ContainerType::Size => FeatureFlags::all_container_axes(),
ContainerType::InlineSize => {
let physical_axis = if wm.is_vertical() {
FeatureFlags::CONTAINER_REQUIRES_HEIGHT_AXIS
} else {
FeatureFlags::CONTAINER_REQUIRES_WIDTH_AXIS
};
FeatureFlags::CONTAINER_REQUIRES_INLINE_AXIS | physical_axis
},
ContainerType::Normal => FeatureFlags::empty(),
}
}
enum TraversalResult<T> {
InProgress,
StopTraversal,
Done(T),
}
fn traverse_container<E, F, R>(
mut e: E,
originating_element_style: Option<&ComputedValues>,
evaluator: F,
) -> Option<(E, R)>
where
E: TElement,
F: Fn(E, Option<&ComputedValues>) -> TraversalResult<R>,
{
if originating_element_style.is_some() {
match evaluator(e, originating_element_style) {
TraversalResult::InProgress => {},
TraversalResult::StopTraversal => return None,
TraversalResult::Done(result) => return Some((e, result)),
}
}
while let Some(element) = e.traversal_parent() {
match evaluator(element, None) {
TraversalResult::InProgress => {},
TraversalResult::StopTraversal => return None,
TraversalResult::Done(result) => return Some((element, result)),
}
e = element;
}
None
}
impl ContainerCondition {
/// Parse a container condition.
pub fn parse<'a>(
context: &ParserContext,
input: &mut Parser<'a, '_>,
) -> Result<Self, ParseError<'a>> {
let name = input
.try_parse(|input| ContainerName::parse_for_query(context, input))
.ok()
.unwrap_or_else(ContainerName::none);
let condition = QueryCondition::parse(context, input, FeatureType::Container)?;
let flags = condition.cumulative_flags();
Ok(Self {
name,
condition,
flags,
})
}
fn valid_container_info<E>(
&self,
potential_container: E,
originating_element_style: Option<&ComputedValues>,
) -> TraversalResult<ContainerLookupResult<E>>
where
E: TElement,
{
let data;
let style = match originating_element_style {
Some(s) => s,
None => {
data = match potential_container.borrow_data() {
Some(d) => d,
None => return TraversalResult::InProgress,
};
&**data.styles.primary()
},
};
let wm = style.writing_mode;
let box_style = style.get_box();
// Filter by container-type.
let container_type = box_style.clone_container_type();
let available_axes = container_type_axes(container_type, wm);
if !available_axes.contains(self.flags.container_axes()) {
return TraversalResult::InProgress;
}
// Filter by container-name.
let container_name = box_style.clone_container_name();
for filter_name in self.name.0.iter() {
if !container_name.0.contains(filter_name) {
return TraversalResult::InProgress;
}
}
let size = potential_container.query_container_size(&box_style.clone_display());
let style = style.to_arc();
TraversalResult::Done(ContainerLookupResult {
element: potential_container,
info: ContainerInfo { size, wm },
style,
})
}
/// Performs container lookup for a given element.
pub fn find_container<E>(
&self,
e: E,
originating_element_style: Option<&ComputedValues>,
) -> Option<ContainerLookupResult<E>>
where
E: TElement,
{
match traverse_container(
e,
originating_element_style,
|element, originating_element_style| {
self.valid_container_info(element, originating_element_style)
},
) {
Some((_, result)) => Some(result),
None => None,
}
}
/// Tries to match a container query condition for a given element.
pub(crate) fn matches<E>(
&self,
stylist: &Stylist,
element: E,
originating_element_style: Option<&ComputedValues>,
invalidation_flags: &mut ComputedValueFlags,
) -> KleeneValue
where
E: TElement,
{
let result = self.find_container(element, originating_element_style);
let (container, info) = match result {
Some(r) => (Some(r.element), Some((r.info, r.style))),
None => (None, None),
};
// Set up the lookup for the container in question, as the condition may be using container
// query lengths.
let size_query_container_lookup = ContainerSizeQuery::for_option_element(
container, /* known_parent_style = */ None, /* is_pseudo = */ false,
);
Context::for_container_query_evaluation(
stylist.device(),
Some(stylist),
info,
size_query_container_lookup,
|context| {
let matches = self.condition.matches(context);
if context
.style()
.flags()
.contains(ComputedValueFlags::USES_VIEWPORT_UNITS)
{
// TODO(emilio): Might need something similar to improve
// invalidation of font relative container-query lengths.
invalidation_flags
.insert(ComputedValueFlags::USES_VIEWPORT_UNITS_ON_CONTAINER_QUERIES);
}
matches
},
)
}
}
/// Information needed to evaluate an individual container query.
#[derive(Copy, Clone)]
pub struct ContainerInfo {
size: Size2D<Option<Au>>,
wm: WritingMode,
}
impl ContainerInfo {
fn size(&self) -> Option<Size2D<Au>> {
Some(Size2D::new(self.size.width?, self.size.height?))
}
}
fn eval_width(context: &Context) -> Option<CSSPixelLength> {
let info = context.container_info.as_ref()?;
Some(CSSPixelLength::new(info.size.width?.to_f32_px()))
}
fn eval_height(context: &Context) -> Option<CSSPixelLength> {
let info = context.container_info.as_ref()?;
Some(CSSPixelLength::new(info.size.height?.to_f32_px()))
}
fn eval_inline_size(context: &Context) -> Option<CSSPixelLength> {
let info = context.container_info.as_ref()?;
Some(CSSPixelLength::new(
LogicalSize::from_physical(info.wm, info.size)
.inline?
.to_f32_px(),
))
}
fn eval_block_size(context: &Context) -> Option<CSSPixelLength> {
let info = context.container_info.as_ref()?;
Some(CSSPixelLength::new(
LogicalSize::from_physical(info.wm, info.size)
.block?
.to_f32_px(),
))
}
fn eval_aspect_ratio(context: &Context) -> Option<Ratio> {
let info = context.container_info.as_ref()?;
Some(Ratio::new(
info.size.width?.0 as f32,
info.size.height?.0 as f32,
))
}
fn eval_orientation(context: &Context, value: Option<Orientation>) -> KleeneValue {
let size = match context.container_info.as_ref().and_then(|info| info.size()) {
Some(size) => size,
None => return KleeneValue::Unknown,
};
KleeneValue::from(Orientation::eval(size, value))
}
///
/// TODO: Support style queries, perhaps.
pub static CONTAINER_FEATURES: [QueryFeatureDescription; 6] = [
feature!(
atom!("width"),
AllowsRanges::Yes,
Evaluator::OptionalLength(eval_width),
FeatureFlags::CONTAINER_REQUIRES_WIDTH_AXIS,
),
feature!(
atom!("height"),
AllowsRanges::Yes,
Evaluator::OptionalLength(eval_height),
FeatureFlags::CONTAINER_REQUIRES_HEIGHT_AXIS,
),
feature!(
atom!("inline-size"),
AllowsRanges::Yes,
Evaluator::OptionalLength(eval_inline_size),
FeatureFlags::CONTAINER_REQUIRES_INLINE_AXIS,
),
feature!(
atom!("block-size"),
AllowsRanges::Yes,
Evaluator::OptionalLength(eval_block_size),
FeatureFlags::CONTAINER_REQUIRES_BLOCK_AXIS,
),
feature!(
atom!("aspect-ratio"),
AllowsRanges::Yes,
Evaluator::OptionalNumberRatio(eval_aspect_ratio),
// XXX from_bits_truncate is const, but the pipe operator isn't, so this
// works around it.
FeatureFlags::from_bits_truncate(
FeatureFlags::CONTAINER_REQUIRES_BLOCK_AXIS.bits() |
FeatureFlags::CONTAINER_REQUIRES_INLINE_AXIS.bits()
),
),
feature!(
atom!("orientation"),
AllowsRanges::No,
keyword_evaluator!(eval_orientation, Orientation),
FeatureFlags::from_bits_truncate(
FeatureFlags::CONTAINER_REQUIRES_BLOCK_AXIS.bits() |
FeatureFlags::CONTAINER_REQUIRES_INLINE_AXIS.bits()
),
),
];
/// Result of a container size query, signifying the hypothetical containment boundary in terms of physical axes.
/// Defined by up to two size containers. Queries on logical axes are resolved with respect to the querying
/// element's writing mode.
#[derive(Copy, Clone, Default)]
pub struct ContainerSizeQueryResult {
width: Option<Au>,
height: Option<Au>,
}
impl ContainerSizeQueryResult {
fn get_viewport_size(context: &Context) -> Size2D<Au> {
use crate::values::specified::ViewportVariant;
context.viewport_size_for_viewport_unit_resolution(ViewportVariant::Small)
}
fn get_logical_viewport_size(context: &Context) -> LogicalSize<Au> {
LogicalSize::from_physical(
context.builder.writing_mode,
Self::get_viewport_size(context),
)
}
/// Get the inline-size of the query container.
pub fn get_container_inline_size(&self, context: &Context) -> Au {
if context.builder.writing_mode.is_horizontal() {
if let Some(w) = self.width {
return w;
}
} else {
if let Some(h) = self.height {
return h;
}
}
Self::get_logical_viewport_size(context).inline
}
/// Get the block-size of the query container.
pub fn get_container_block_size(&self, context: &Context) -> Au {
if context.builder.writing_mode.is_horizontal() {
self.get_container_height(context)
} else {
self.get_container_width(context)
}
}
/// Get the width of the query container.
pub fn get_container_width(&self, context: &Context) -> Au {
if let Some(w) = self.width {
return w;
}
Self::get_viewport_size(context).width
}
/// Get the height of the query container.
pub fn get_container_height(&self, context: &Context) -> Au {
if let Some(h) = self.height {
return h;
}
Self::get_viewport_size(context).height
}
// Merge the result of a subsequent lookup, preferring the initial result.
fn merge(self, new_result: Self) -> Self {
let mut result = self;
if let Some(width) = new_result.width {
result.width.get_or_insert(width);
}
if let Some(height) = new_result.height {
result.height.get_or_insert(height);
}
result
}
fn is_complete(&self) -> bool {
self.width.is_some() && self.height.is_some()
}
}
/// Unevaluated lazy container size query.
pub enum ContainerSizeQuery<'a> {
/// Query prior to evaluation.
NotEvaluated(Box<dyn Fn() -> ContainerSizeQueryResult + 'a>),
/// Cached evaluated result.
Evaluated(ContainerSizeQueryResult),
}
impl<'a> ContainerSizeQuery<'a> {
fn evaluate_potential_size_container<E>(
e: E,
originating_element_style: Option<&ComputedValues>,
) -> TraversalResult<ContainerSizeQueryResult>
where
E: TElement,
{
let data;
let style = match originating_element_style {
Some(s) => s,
None => {
data = match e.borrow_data() {
Some(d) => d,
None => return TraversalResult::InProgress,
};
&**data.styles.primary()
},
};
if !style
.flags
.contains(ComputedValueFlags::SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE)
{
// We know we won't find a size container.
return TraversalResult::StopTraversal;
}
let wm = style.writing_mode;
let box_style = style.get_box();
let container_type = box_style.clone_container_type();
let size = e.query_container_size(&box_style.clone_display());
match container_type {
ContainerType::Size => TraversalResult::Done(ContainerSizeQueryResult {
width: size.width,
height: size.height,
}),
ContainerType::InlineSize => {
if wm.is_horizontal() {
TraversalResult::Done(ContainerSizeQueryResult {
width: size.width,
height: None,
})
} else {
TraversalResult::Done(ContainerSizeQueryResult {
width: None,
height: size.height,
})
}
},
ContainerType::Normal => TraversalResult::InProgress,
}
}
/// Find the query container size for a given element. Meant to be used as a callback for new().
fn lookup<E>(
element: E,
originating_element_style: Option<&ComputedValues>,
) -> ContainerSizeQueryResult
where
E: TElement + 'a,
{
match traverse_container(
element,
originating_element_style,
|e, originating_element_style| {
Self::evaluate_potential_size_container(e, originating_element_style)
},
) {
Some((container, result)) => {
if result.is_complete() {
result
} else {
// Traverse up from the found size container to see if we can get a complete containment.
result.merge(Self::lookup(container, None))
}
},
None => ContainerSizeQueryResult::default(),
}
}
/// Create a new instance of the container size query for given element, with a deferred lookup callback.
pub fn for_element<E>(
element: E,
known_parent_style: Option<&'a ComputedValues>,
is_pseudo: bool,
) -> Self
where
E: TElement + 'a,
{
let parent;
let data;
let parent_style = match known_parent_style {
Some(s) => Some(s),
None => {
// No need to bother if we're the top element.
parent = match element.traversal_parent() {
Some(parent) => parent,
None => return Self::none(),
};
data = parent.borrow_data();
data.as_ref().map(|data| &**data.styles.primary())
},
};
// If there's no style, such as being `display: none` or so, we still want to show a
// correct computed value, so give it a try.
let should_traverse = parent_style.map_or(true, |s| {
s.flags
.contains(ComputedValueFlags::SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE)
});
if !should_traverse {
return Self::none();
}
return Self::NotEvaluated(Box::new(move || {
Self::lookup(element, if is_pseudo { known_parent_style } else { None })
}));
}
/// Create a new instance, but with optional element.
pub fn for_option_element<E>(
element: Option<E>,
known_parent_style: Option<&'a ComputedValues>,
is_pseudo: bool,
) -> Self
where
E: TElement + 'a,
{
if let Some(e) = element {
Self::for_element(e, known_parent_style, is_pseudo)
} else {
Self::none()
}
}
/// Create a query that evaluates to empty, for cases where container size query is not required.
pub fn none() -> Self {
ContainerSizeQuery::Evaluated(ContainerSizeQueryResult::default())
}
/// Get the result of the container size query, doing the lookup if called for the first time.
pub fn get(&mut self) -> ContainerSizeQueryResult {
match self {
Self::NotEvaluated(lookup) => {
*self = Self::Evaluated((lookup)());
match self {
Self::Evaluated(info) => *info,
_ => unreachable!("Just evaluated but not set?"),
}
},
Self::Evaluated(info) => *info,
}
}
}