diff options
Diffstat (limited to 'servo/components/style/stylesheets/container_rule.rs')
| -rw-r--r-- | servo/components/style/stylesheets/container_rule.rs | 632 |
1 files changed, 632 insertions, 0 deletions
diff --git a/servo/components/style/stylesheets/container_rule.rs b/servo/components/style/stylesheets/container_rule.rs new file mode 100644 index 0000000000..f9d488b9b4 --- /dev/null +++ b/servo/components/style/stylesheets/container_rule.rs @@ -0,0 +1,632 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ + +//! A [`@container`][container] rule. +//! +//! [container]: https://drafts.csswg.org/css-contain-3/#container-rule + +use crate::computed_value_flags::ComputedValueFlags; +use crate::dom::TElement; +use crate::logical_geometry::{LogicalSize, WritingMode}; +use crate::media_queries::Device; +use crate::parser::ParserContext; +use crate::properties::ComputedValues; +use crate::queries::condition::KleeneValue; +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::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}; + +/// 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, + device: &Device, + 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, None); + Context::for_container_query_evaluation( + device, + 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)) +} + +/// https://drafts.csswg.org/css-contain-3/#container-features +/// +/// 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, originating_element_style: Option<&'a ComputedValues>) -> Self + where + E: TElement + 'a, + { + let parent; + let data; + let style = match originating_element_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()) + }, + }; + let should_traverse = match style { + Some(style) => style + .flags + .contains(ComputedValueFlags::SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE), + None => true, // `display: none`, still want to show a correct computed value, so give it a try. + }; + if should_traverse { + return Self::NotEvaluated(Box::new(move || { + Self::lookup(element, originating_element_style) + })); + } + Self::none() + } + + /// Create a new instance, but with optional element. + pub fn for_option_element<E>( + element: Option<E>, + originating_element_style: Option<&'a ComputedValues>, + ) -> Self + where + E: TElement + 'a, + { + if let Some(e) = element { + Self::for_element(e, originating_element_style) + } 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, + } + } +} |