diff options
Diffstat (limited to 'components/style/selector_matching.rs')
| -rw-r--r-- | components/style/selector_matching.rs | 985 |
1 files changed, 14 insertions, 971 deletions
diff --git a/components/style/selector_matching.rs b/components/style/selector_matching.rs index bf780ac6f0a..3bd03be1eae 100644 --- a/components/style/selector_matching.rs +++ b/components/style/selector_matching.rs @@ -2,258 +2,25 @@ * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ -use std::ascii::AsciiExt; -use std::cmp::Ordering; -use std::collections::HashMap; -use std::sync::Arc; - use url::Url; -use util::bloom::BloomFilter; +use selectors::bloom::BloomFilter; +use selectors::matching::{SelectorMap, Rule}; +use selectors::matching::DeclarationBlock as GenericDeclarationBlock; +use selectors::parser::PseudoElement; +use selectors::smallvec::VecLike; +use selectors::tree::{TNode, TElement}; use util::resource_files::read_resource_file; -use util::smallvec::VecLike; -use util::sort; -use string_cache::Atom; use legacy::PresentationalHintSynthesis; use media_queries::Device; -use node::{TElement, TElementAttributes, TNode}; +use node::TElementAttributes; use properties::{PropertyDeclaration, PropertyDeclarationBlock}; -use selectors::{CaseSensitivity, Combinator, CompoundSelector, LocalName}; -use selectors::{PseudoElement, SimpleSelector, Selector}; use stylesheets::{Stylesheet, iter_stylesheet_media_rules, iter_stylesheet_style_rules, Origin}; -/// The definition of whitespace per CSS Selectors Level 3 § 4. -pub static SELECTOR_WHITESPACE: &'static [char] = &[' ', '\t', '\n', '\r', '\x0C']; - -/// Map node attributes to Rules whose last simple selector starts with them. -/// -/// e.g., -/// "p > img" would go into the set of Rules corresponding to the -/// element "img" -/// "a .foo .bar.baz" would go into the set of Rules corresponding to -/// the class "bar" -/// -/// Because we match Rules right-to-left (i.e., moving up the tree -/// from a node), we need to compare the last simple selector in the -/// Rule with the node. -/// -/// So, if a node has ID "id1" and classes "foo" and "bar", then all -/// the rules it matches will have their last simple selector starting -/// either with "#id1" or with ".foo" or with ".bar". -/// -/// Hence, the union of the rules keyed on each of node's classes, ID, -/// element name, etc. will contain the Rules that actually match that -/// node. -struct SelectorMap { - // TODO: Tune the initial capacity of the HashMap - id_hash: HashMap<Atom, Vec<Rule>>, - class_hash: HashMap<Atom, Vec<Rule>>, - local_name_hash: HashMap<Atom, Vec<Rule>>, - /// Same as local_name_hash, but keys are lower-cased. - /// For HTML elements in HTML documents. - lower_local_name_hash: HashMap<Atom, Vec<Rule>>, - // For Rules that don't have ID, class, or element selectors. - universal_rules: Vec<Rule>, - /// Whether this hash is empty. - empty: bool, -} - -impl SelectorMap { - fn new() -> SelectorMap { - SelectorMap { - id_hash: HashMap::new(), - class_hash: HashMap::new(), - local_name_hash: HashMap::new(), - lower_local_name_hash: HashMap::new(), - universal_rules: vec!(), - empty: true, - } - } - - /// Append to `rule_list` all Rules in `self` that match node. - /// - /// Extract matching rules as per node's ID, classes, tag name, etc.. - /// Sort the Rules at the end to maintain cascading order. - fn get_all_matching_rules<'a,E,N,V>(&self, - node: &N, - parent_bf: &Option<Box<BloomFilter>>, - matching_rules_list: &mut V, - shareable: &mut bool) - where E: TElement<'a> + TElementAttributes, - N: TNode<'a,E>, - V: VecLike<DeclarationBlock> { - if self.empty { - return - } - - // At the end, we're going to sort the rules that we added, so remember where we began. - let init_len = matching_rules_list.vec_len(); - let element = node.as_element(); - match element.get_id() { - Some(id) => { - SelectorMap::get_matching_rules_from_hash(node, - parent_bf, - &self.id_hash, - &id, - matching_rules_list, - shareable) - } - None => {} - } - - element.each_class(|class| { - SelectorMap::get_matching_rules_from_hash(node, - parent_bf, - &self.class_hash, - class, - matching_rules_list, - shareable); - }); +pub type DeclarationBlock = GenericDeclarationBlock<Vec<PropertyDeclaration>>; - let local_name_hash = if node.is_html_element_in_html_document() { - &self.lower_local_name_hash - } else { - &self.local_name_hash - }; - SelectorMap::get_matching_rules_from_hash(node, - parent_bf, - local_name_hash, - element.get_local_name(), - matching_rules_list, - shareable); - - SelectorMap::get_matching_rules(node, - parent_bf, - &self.universal_rules, - matching_rules_list, - shareable); - - // Sort only the rules we just added. - sort::quicksort_by(matching_rules_list.vec_slice_from_mut(init_len), compare); - - fn compare(a: &DeclarationBlock, b: &DeclarationBlock) -> Ordering { - (a.specificity, a.source_order).cmp(&(b.specificity, b.source_order)) - } - } - - fn get_matching_rules_from_hash<'a,E,N,V>(node: &N, - parent_bf: &Option<Box<BloomFilter>>, - hash: &HashMap<Atom, Vec<Rule>>, - key: &Atom, - matching_rules: &mut V, - shareable: &mut bool) - where E: TElement<'a> + TElementAttributes, - N: TNode<'a,E>, - V: VecLike<DeclarationBlock> { - match hash.get(key) { - Some(rules) => { - SelectorMap::get_matching_rules(node, - parent_bf, - rules, - matching_rules, - shareable) - } - None => {} - } - } - - /// Adds rules in `rules` that match `node` to the `matching_rules` list. - fn get_matching_rules<'a,E,N,V>(node: &N, - parent_bf: &Option<Box<BloomFilter>>, - rules: &[Rule], - matching_rules: &mut V, - shareable: &mut bool) - where E: TElement<'a> + TElementAttributes, - N: TNode<'a,E>, - V: VecLike<DeclarationBlock> { - for rule in rules.iter() { - if matches_compound_selector(&*rule.selector, node, parent_bf, shareable) { - matching_rules.vec_push(rule.declarations.clone()); - } - } - } - - /// Insert rule into the correct hash. - /// Order in which to try: id_hash, class_hash, local_name_hash, universal_rules. - fn insert(&mut self, rule: Rule) { - self.empty = false; - - match SelectorMap::get_id_name(&rule) { - Some(id_name) => { - find_push(&mut self.id_hash, id_name, rule); - return; - } - None => {} - } - match SelectorMap::get_class_name(&rule) { - Some(class_name) => { - find_push(&mut self.class_hash, class_name, rule); - return; - } - None => {} - } - - match SelectorMap::get_local_name(&rule) { - Some(LocalName { name, lower_name }) => { - find_push(&mut self.local_name_hash, name, rule.clone()); - find_push(&mut self.lower_local_name_hash, lower_name, rule); - return; - } - None => {} - } - - self.universal_rules.push(rule); - } - - /// Retrieve the first ID name in Rule, or None otherwise. - fn get_id_name(rule: &Rule) -> Option<Atom> { - let simple_selector_sequence = &rule.selector.simple_selectors; - for ss in simple_selector_sequence.iter() { - match *ss { - // TODO(pradeep): Implement case-sensitivity based on the document type and quirks - // mode. - SimpleSelector::ID(ref id) => return Some(id.clone()), - _ => {} - } - } - return None - } - - /// Retrieve the FIRST class name in Rule, or None otherwise. - fn get_class_name(rule: &Rule) -> Option<Atom> { - let simple_selector_sequence = &rule.selector.simple_selectors; - for ss in simple_selector_sequence.iter() { - match *ss { - // TODO(pradeep): Implement case-sensitivity based on the document type and quirks - // mode. - SimpleSelector::Class(ref class) => return Some(class.clone()), - _ => {} - } - } - return None - } - - /// Retrieve the name if it is a type selector, or None otherwise. - fn get_local_name(rule: &Rule) -> Option<LocalName> { - let simple_selector_sequence = &rule.selector.simple_selectors; - for ss in simple_selector_sequence.iter() { - match *ss { - SimpleSelector::LocalName(ref name) => { - return Some(name.clone()) - } - _ => {} - } - } - return None - } -} - -// The bloom filter for descendant CSS selectors will have a <1% false -// positive rate until it has this many selectors in it, then it will -// rapidly increase. -pub static RECOMMENDED_SELECTOR_BLOOM_FILTER_SIZE: uint = 4096; pub struct Stylist { // List of stylesheets (including all media rules) @@ -448,8 +215,8 @@ impl Stylist { // Step 3: Normal style attributes. style_attribute.map(|sa| { shareable = false; - applicable_declarations.vec_push(DeclarationBlock::from_declarations(sa.normal - .clone())) + applicable_declarations.vec_push( + GenericDeclarationBlock::from_declarations(sa.normal.clone())) }); // Step 4: Author-supplied `!important` rules. @@ -461,8 +228,8 @@ impl Stylist { // Step 5: `!important` style attributes. style_attribute.map(|sa| { shareable = false; - applicable_declarations.vec_push(DeclarationBlock::from_declarations(sa.important - .clone())) + applicable_declarations.vec_push( + GenericDeclarationBlock::from_declarations(sa.important.clone())) }); // Step 6: User and UA `!important` rules. @@ -480,8 +247,8 @@ impl Stylist { } struct PerOriginSelectorMap { - normal: SelectorMap, - important: SelectorMap, + normal: SelectorMap<Vec<PropertyDeclaration>>, + important: SelectorMap<Vec<PropertyDeclaration>>, } impl PerOriginSelectorMap { @@ -510,727 +277,3 @@ impl PerPseudoElementSelectorMap { } } } - -#[derive(Clone)] -struct Rule { - // This is an Arc because Rule will essentially be cloned for every node - // that it matches. Selector contains an owned vector (through - // CompoundSelector) and we want to avoid the allocation. - selector: Arc<CompoundSelector>, - declarations: DeclarationBlock, -} - -/// A property declaration together with its precedence among rules of equal specificity so that -/// we can sort them. -#[derive(Clone, Debug)] -pub struct DeclarationBlock { - pub declarations: Arc<Vec<PropertyDeclaration>>, - source_order: uint, - specificity: u32, -} - -impl DeclarationBlock { - #[inline] - pub fn from_declarations(declarations: Arc<Vec<PropertyDeclaration>>) -> DeclarationBlock { - DeclarationBlock { - declarations: declarations, - source_order: 0, - specificity: 0, - } - } - - /// A convenience function to create a declaration block from a single declaration. This is - /// primarily used in `synthesize_rules_for_legacy_attributes`. - #[inline] - pub fn from_declaration(rule: PropertyDeclaration) -> DeclarationBlock { - DeclarationBlock::from_declarations(Arc::new(vec![rule])) - } -} - -pub fn matches<'a,E,N>(selector_list: &Vec<Selector>, - element: &N, - parent_bf: &Option<Box<BloomFilter>>) - -> bool - where E: TElement<'a>, N: TNode<'a,E> { - selector_list.iter().any(|selector| { - selector.pseudo_element.is_none() && - matches_compound_selector(&*selector.compound_selectors, element, parent_bf, &mut false) - }) -} - -/// Determines whether the given element matches the given single or compound selector. -/// -/// NB: If you add support for any new kinds of selectors to this routine, be sure to set -/// `shareable` to false unless you are willing to update the style sharing logic. Otherwise things -/// will almost certainly break as nodes will start mistakenly sharing styles. (See the code in -/// `main/css/matching.rs`.) -fn matches_compound_selector<'a,E,N>(selector: &CompoundSelector, - element: &N, - parent_bf: &Option<Box<BloomFilter>>, - shareable: &mut bool) - -> bool - where E: TElement<'a>, N: TNode<'a,E> { - match matches_compound_selector_internal(selector, element, parent_bf, shareable) { - SelectorMatchingResult::Matched => true, - _ => false - } -} - -/// A result of selector matching, includes 3 failure types, -/// -/// NotMatchedAndRestartFromClosestLaterSibling -/// NotMatchedAndRestartFromClosestDescendant -/// NotMatchedGlobally -/// -/// When NotMatchedGlobally appears, stop selector matching completely since -/// the succeeding selectors never matches. -/// It is raised when -/// Child combinator cannot find the candidate element. -/// Descendant combinator cannot find the candidate element. -/// -/// When NotMatchedAndRestartFromClosestDescendant appears, the selector -/// matching does backtracking and restarts from the closest Descendant -/// combinator. -/// It is raised when -/// NextSibling combinator cannot find the candidate element. -/// LaterSibling combinator cannot find the candidate element. -/// Child combinator doesn't match on the found element. -/// -/// When NotMatchedAndRestartFromClosestLaterSibling appears, the selector -/// matching does backtracking and restarts from the closest LaterSibling -/// combinator. -/// It is raised when -/// NextSibling combinator doesn't match on the found element. -/// -/// For example, when the selector "d1 d2 a" is provided and we cannot *find* -/// an appropriate ancestor node for "d1", this selector matching raises -/// NotMatchedGlobally since even if "d2" is moved to more upper node, the -/// candidates for "d1" becomes less than before and d1 . -/// -/// The next example is siblings. When the selector "b1 + b2 ~ d1 a" is -/// provided and we cannot *find* an appropriate brother node for b1, -/// the selector matching raises NotMatchedAndRestartFromClosestDescendant. -/// The selectors ("b1 + b2 ~") doesn't match and matching restart from "d1". -/// -/// The additional example is child and sibling. When the selector -/// "b1 + c1 > b2 ~ d1 a" is provided and the selector "b1" doesn't match on -/// the element, this "b1" raises NotMatchedAndRestartFromClosestLaterSibling. -/// However since the selector "c1" raises -/// NotMatchedAndRestartFromClosestDescendant. So the selector -/// "b1 + c1 > b2 ~ " doesn't match and restart matching from "d1". -#[derive(PartialEq, Eq, Copy)] -enum SelectorMatchingResult { - Matched, - NotMatchedAndRestartFromClosestLaterSibling, - NotMatchedAndRestartFromClosestDescendant, - NotMatchedGlobally, -} - -/// Quickly figures out whether or not the compound selector is worth doing more -/// work on. If the simple selectors don't match, or there's a child selector -/// that does not appear in the bloom parent bloom filter, we can exit early. -fn can_fast_reject<'a,E,N>(mut selector: &CompoundSelector, - element: &N, - parent_bf: &Option<Box<BloomFilter>>, - shareable: &mut bool) - -> Option<SelectorMatchingResult> - where E: TElement<'a>, N: TNode<'a,E> { - if !selector.simple_selectors.iter().all(|simple_selector| { - matches_simple_selector(simple_selector, element, shareable) }) { - return Some(SelectorMatchingResult::NotMatchedAndRestartFromClosestLaterSibling); - } - - let bf: &BloomFilter = match *parent_bf { - None => return None, - Some(ref bf) => &**bf, - }; - - // See if the bloom filter can exclude any of the descendant selectors, and - // reject if we can. - loop { - match selector.next { - None => break, - Some((ref cs, Combinator::Descendant)) => selector = &**cs, - Some((ref cs, _)) => { - selector = &**cs; - continue; - } - }; - - for ss in selector.simple_selectors.iter() { - match *ss { - SimpleSelector::LocalName(LocalName { ref name, ref lower_name }) => { - if !bf.might_contain(name) - && !bf.might_contain(lower_name) { - return Some(SelectorMatchingResult::NotMatchedGlobally); - } - }, - SimpleSelector::Namespace(ref namespace) => { - if !bf.might_contain(namespace) { - return Some(SelectorMatchingResult::NotMatchedGlobally); - } - }, - SimpleSelector::ID(ref id) => { - if !bf.might_contain(id) { - return Some(SelectorMatchingResult::NotMatchedGlobally); - } - }, - SimpleSelector::Class(ref class) => { - if !bf.might_contain(class) { - return Some(SelectorMatchingResult::NotMatchedGlobally); - } - }, - _ => {}, - } - } - - } - - // Can't fast reject. - return None; -} - -fn matches_compound_selector_internal<'a,E,N>(selector: &CompoundSelector, - element: &N, - parent_bf: &Option<Box<BloomFilter>>, - shareable: &mut bool) - -> SelectorMatchingResult - where E: TElement<'a>, N: TNode<'a,E> { - match can_fast_reject(selector, element, parent_bf, shareable) { - None => {}, - Some(result) => return result, - }; - - match selector.next { - None => SelectorMatchingResult::Matched, - Some((ref next_selector, combinator)) => { - let (siblings, candidate_not_found) = match combinator { - Combinator::Child => (false, SelectorMatchingResult::NotMatchedGlobally), - Combinator::Descendant => (false, SelectorMatchingResult::NotMatchedGlobally), - Combinator::NextSibling => (true, SelectorMatchingResult::NotMatchedAndRestartFromClosestDescendant), - Combinator::LaterSibling => (true, SelectorMatchingResult::NotMatchedAndRestartFromClosestDescendant), - }; - let mut node = (*element).clone(); - loop { - let next_node = if siblings { - node.prev_sibling() - } else { - node.parent_node() - }; - match next_node { - None => return candidate_not_found, - Some(next_node) => node = next_node, - } - if node.is_element() { - let result = matches_compound_selector_internal(&**next_selector, - &node, - parent_bf, - shareable); - match (result, combinator) { - // Return the status immediately. - (SelectorMatchingResult::Matched, _) => return result, - (SelectorMatchingResult::NotMatchedGlobally, _) => return result, - - // Upgrade the failure status to - // NotMatchedAndRestartFromClosestDescendant. - (_, Combinator::Child) => return SelectorMatchingResult::NotMatchedAndRestartFromClosestDescendant, - - // Return the status directly. - (_, Combinator::NextSibling) => return result, - - // If the failure status is NotMatchedAndRestartFromClosestDescendant - // and combinator is Combinator::LaterSibling, give up this Combinator::LaterSibling matching - // and restart from the closest descendant combinator. - (SelectorMatchingResult::NotMatchedAndRestartFromClosestDescendant, Combinator::LaterSibling) => return result, - - // The Combinator::Descendant combinator and the status is - // NotMatchedAndRestartFromClosestLaterSibling or - // NotMatchedAndRestartFromClosestDescendant, - // or the Combinator::LaterSibling combinator and the status is - // NotMatchedAndRestartFromClosestDescendant - // can continue to matching on the next candidate element. - _ => {}, - } - } - } - } - } -} - -bitflags! { - flags CommonStyleAffectingAttributes: u8 { - const HIDDEN_ATTRIBUTE = 0x01, - const NO_WRAP_ATTRIBUTE = 0x02, - const ALIGN_LEFT_ATTRIBUTE = 0x04, - const ALIGN_CENTER_ATTRIBUTE = 0x08, - const ALIGN_RIGHT_ATTRIBUTE = 0x10, - } -} - -pub struct CommonStyleAffectingAttributeInfo { - pub atom: Atom, - pub mode: CommonStyleAffectingAttributeMode, -} - -#[derive(Copy)] -pub enum CommonStyleAffectingAttributeMode { - IsPresent(CommonStyleAffectingAttributes), - IsEqual(&'static str, CommonStyleAffectingAttributes), -} - -// NB: This must match the order in `layout::css::matching::CommonStyleAffectingAttributes`. -#[inline] -pub fn common_style_affecting_attributes() -> [CommonStyleAffectingAttributeInfo; 5] { - [ - CommonStyleAffectingAttributeInfo { - atom: atom!("hidden"), - mode: CommonStyleAffectingAttributeMode::IsPresent(HIDDEN_ATTRIBUTE), - }, - CommonStyleAffectingAttributeInfo { - atom: atom!("nowrap"), - mode: CommonStyleAffectingAttributeMode::IsPresent(NO_WRAP_ATTRIBUTE), - }, - CommonStyleAffectingAttributeInfo { - atom: atom!("align"), - mode: CommonStyleAffectingAttributeMode::IsEqual("left", ALIGN_LEFT_ATTRIBUTE), - }, - CommonStyleAffectingAttributeInfo { - atom: atom!("align"), - mode: CommonStyleAffectingAttributeMode::IsEqual("center", ALIGN_CENTER_ATTRIBUTE), - }, - CommonStyleAffectingAttributeInfo { - atom: atom!("align"), - mode: CommonStyleAffectingAttributeMode::IsEqual("right", ALIGN_RIGHT_ATTRIBUTE), - } - ] -} - -/// Attributes that, if present, disable style sharing. All legacy HTML attributes must be in -/// either this list or `common_style_affecting_attributes`. See the comment in -/// `synthesize_presentational_hints_for_legacy_attributes`. -pub fn rare_style_affecting_attributes() -> [Atom; 3] { - [ atom!("bgcolor"), atom!("border"), atom!("colspan") ] -} - -/// Determines whether the given element matches the given single selector. -/// -/// NB: If you add support for any new kinds of selectors to this routine, be sure to set -/// `shareable` to false unless you are willing to update the style sharing logic. Otherwise things -/// will almost certainly break as nodes will start mistakenly sharing styles. (See the code in -/// `main/css/matching.rs`.) -#[inline] -pub fn matches_simple_selector<'a,E,N>(selector: &SimpleSelector, - element: &N, - shareable: &mut bool) - -> bool - where E: TElement<'a>, N: TNode<'a,E> { - match *selector { - SimpleSelector::LocalName(LocalName { ref name, ref lower_name }) => { - let name = if element.is_html_element_in_html_document() { lower_name } else { name }; - let element = element.as_element(); - element.get_local_name() == name - } - - SimpleSelector::Namespace(ref namespace) => { - let element = element.as_element(); - element.get_namespace() == namespace - } - // TODO: case-sensitivity depends on the document type and quirks mode - SimpleSelector::ID(ref id) => { - *shareable = false; - let element = element.as_element(); - element.get_id().map_or(false, |attr| { - attr == *id - }) - } - SimpleSelector::Class(ref class) => { - let element = element.as_element(); - element.has_class(class) - } - - SimpleSelector::AttrExists(ref attr) => { - // NB(pcwalton): If you update this, remember to update the corresponding list in - // `can_share_style_with()` as well. - if common_style_affecting_attributes().iter().all(|common_attr_info| { - !(common_attr_info.atom == attr.name && match common_attr_info.mode { - CommonStyleAffectingAttributeMode::IsPresent(_) => true, - CommonStyleAffectingAttributeMode::IsEqual(..) => false, - }) - }) { - *shareable = false; - } - element.match_attr(attr, |_| true) - } - SimpleSelector::AttrEqual(ref attr, ref value, case_sensitivity) => { - if *value != "DIR" && - common_style_affecting_attributes().iter().all(|common_attr_info| { - !(common_attr_info.atom == attr.name && match common_attr_info.mode { - CommonStyleAffectingAttributeMode::IsEqual(target_value, _) => *value == target_value, - CommonStyleAffectingAttributeMode::IsPresent(_) => false, - }) - }) { - // FIXME(pcwalton): Remove once we start actually supporting RTL text. This is in - // here because the UA style otherwise disables all style sharing completely. - *shareable = false - } - element.match_attr(attr, |attr_value| { - match case_sensitivity { - CaseSensitivity::CaseSensitive => attr_value == *value, - CaseSensitivity::CaseInsensitive => attr_value.eq_ignore_ascii_case(value), - } - }) - } - SimpleSelector::AttrIncludes(ref attr, ref value) => { - *shareable = false; - element.match_attr(attr, |attr_value| { - attr_value.split(SELECTOR_WHITESPACE).any(|v| v == *value) - }) - } - SimpleSelector::AttrDashMatch(ref attr, ref value, ref dashing_value) => { - *shareable = false; - element.match_attr(attr, |attr_value| { - attr_value == *value || - attr_value.starts_with(dashing_value) - }) - } - SimpleSelector::AttrPrefixMatch(ref attr, ref value) => { - *shareable = false; - element.match_attr(attr, |attr_value| { - attr_value.starts_with(value) - }) - } - SimpleSelector::AttrSubstringMatch(ref attr, ref value) => { - *shareable = false; - element.match_attr(attr, |attr_value| { - attr_value.contains(value) - }) - } - SimpleSelector::AttrSuffixMatch(ref attr, ref value) => { - *shareable = false; - element.match_attr(attr, |attr_value| { - attr_value.ends_with(value) - }) - } - - SimpleSelector::AnyLink => { - *shareable = false; - let element = element.as_element(); - element.get_link().is_some() - } - SimpleSelector::Link => { - let elem = element.as_element(); - match elem.get_link() { - Some(url) => !url_is_visited(url), - None => false, - } - } - SimpleSelector::Visited => { - // NB(pcwalton): When we actually start supporting visited links, remember to update - // `can_share_style_with`. - let elem = element.as_element(); - match elem.get_link() { - Some(url) => url_is_visited(url), - None => false, - } - } - - SimpleSelector::Hover => { - *shareable = false; - let elem = element.as_element(); - elem.get_hover_state() - }, - // http://www.whatwg.org/html/#selector-disabled - SimpleSelector::Disabled => { - *shareable = false; - let elem = element.as_element(); - elem.get_disabled_state() - }, - // http://www.whatwg.org/html/#selector-enabled - SimpleSelector::Enabled => { - *shareable = false; - let elem = element.as_element(); - elem.get_enabled_state() - }, - // https://html.spec.whatwg.org/multipage/scripting.html#selector-checked - SimpleSelector::Checked => { - *shareable = false; - let elem = element.as_element(); - elem.get_checked_state() - } - // https://html.spec.whatwg.org/multipage/scripting.html#selector-indeterminate - SimpleSelector::Indeterminate => { - *shareable = false; - let elem = element.as_element(); - elem.get_indeterminate_state() - } - SimpleSelector::FirstChild => { - *shareable = false; - matches_first_child(element) - } - SimpleSelector::LastChild => { - *shareable = false; - matches_last_child(element) - } - SimpleSelector::OnlyChild => { - *shareable = false; - matches_first_child(element) && matches_last_child(element) - } - - SimpleSelector::Root => { - *shareable = false; - matches_root(element) - } - - SimpleSelector::NthChild(a, b) => { - *shareable = false; - matches_generic_nth_child(element, a, b, false, false) - } - SimpleSelector::NthLastChild(a, b) => { - *shareable = false; - matches_generic_nth_child(element, a, b, false, true) - } - SimpleSelector::NthOfType(a, b) => { - *shareable = false; - matches_generic_nth_child(element, a, b, true, false) - } - SimpleSelector::NthLastOfType(a, b) => { - *shareable = false; - matches_generic_nth_child(element, a, b, true, true) - } - - SimpleSelector::FirstOfType => { - *shareable = false; - matches_generic_nth_child(element, 0, 1, true, false) - } - SimpleSelector::LastOfType => { - *shareable = false; - matches_generic_nth_child(element, 0, 1, true, true) - } - SimpleSelector::OnlyOfType => { - *shareable = false; - matches_generic_nth_child(element, 0, 1, true, false) && - matches_generic_nth_child(element, 0, 1, true, true) - } - - SimpleSelector::ServoNonzeroBorder => { - *shareable = false; - let elem = element.as_element(); - elem.has_nonzero_border() - } - - SimpleSelector::Negation(ref negated) => { - *shareable = false; - !negated.iter().all(|s| matches_simple_selector(s, element, shareable)) - }, - } -} - -#[inline] -fn url_is_visited(_url: &str) -> bool { - // FIXME: implement this. - // This function will probably need to take a "session" - // or something containing browsing history as an additional parameter. - // NB(pcwalton): When you implement this, remember to update `can_share_style_with`! - false -} - -#[inline] -fn matches_generic_nth_child<'a,E,N>(element: &N, - a: i32, - b: i32, - is_of_type: bool, - is_from_end: bool) - -> bool - where E: TElement<'a>, N: TNode<'a,E> { - let mut node = element.clone(); - // fail if we can't find a parent or if the node is the root element - // of the document (Cf. Selectors Level 3) - match node.parent_node() { - Some(parent) => if parent.is_document() { - return false; - }, - None => return false - }; - - let mut index = 1; - loop { - if is_from_end { - match node.next_sibling() { - None => break, - Some(next_sibling) => node = next_sibling - } - } else { - match node.prev_sibling() { - None => break, - Some(prev_sibling) => node = prev_sibling - } - } - - if node.is_element() { - if is_of_type { - let element = element.as_element(); - let node = node.as_element(); - if element.get_local_name() == node.get_local_name() && - element.get_namespace() == node.get_namespace() { - index += 1; - } - } else { - index += 1; - } - } - } - - if a == 0 { - b == index - } else { - (index - b) / a >= 0 && - (index - b) % a == 0 - } -} - -#[inline] -fn matches_root<'a,E,N>(element: &N) -> bool where E: TElement<'a>, N: TNode<'a,E> { - match element.parent_node() { - Some(parent) => parent.is_document(), - None => false - } -} - -#[inline] -fn matches_first_child<'a,E,N>(element: &N) -> bool where E: TElement<'a>, N: TNode<'a,E> { - let mut node = element.clone(); - loop { - match node.prev_sibling() { - Some(prev_sibling) => { - node = prev_sibling; - if node.is_element() { - return false - } - }, - None => match node.parent_node() { - // Selectors level 3 says :first-child does not match the - // root of the document; Warning, level 4 says, for the time - // being, the contrary... - Some(parent) => return !parent.is_document(), - None => return false - } - } - } -} - -#[inline] -fn matches_last_child<'a,E,N>(element: &N) -> bool where E: TElement<'a>, N: TNode<'a,E> { - let mut node = element.clone(); - loop { - match node.next_sibling() { - Some(next_sibling) => { - node = next_sibling; - if node.is_element() { - return false - } - }, - None => match node.parent_node() { - // Selectors level 3 says :last-child does not match the - // root of the document; Warning, level 4 says, for the time - // being, the contrary... - Some(parent) => return !parent.is_document(), - None => return false - } - } - } -} - -fn find_push(map: &mut HashMap<Atom, Vec<Rule>>, key: Atom, value: Rule) { - match map.get_mut(&key) { - Some(vec) => { - vec.push(value); - return - } - None => {} - } - map.insert(key, vec![value]); -} - -#[cfg(test)] -mod tests { - use std::cmp::Ordering; - use std::sync::Arc; - use super::{DeclarationBlock, Rule, SelectorMap}; - use selectors::LocalName; - use string_cache::Atom; - use cssparser::Parser; - use parser::ParserContext; - use url::Url; - - /// Helper method to get some Rules from selector strings. - /// Each sublist of the result contains the Rules for one StyleRule. - fn get_mock_rules(css_selectors: &[&str]) -> Vec<Vec<Rule>> { - use selectors::parse_selector_list; - use stylesheets::Origin; - - css_selectors.iter().enumerate().map(|(i, selectors)| { - let url = Url::parse("about:blank").unwrap(); - let context = ParserContext::new(Origin::Author, &url); - parse_selector_list(&context, &mut Parser::new(*selectors)) - .unwrap().into_iter().map(|s| { - Rule { - selector: s.compound_selectors.clone(), - declarations: DeclarationBlock { - specificity: s.specificity, - declarations: Arc::new(vec!()), - source_order: i, - } - } - }).collect() - }).collect() - } - - #[test] - fn test_rule_ordering_same_specificity(){ - let rules_list = get_mock_rules(&["a.intro", "img.sidebar"]); - let a = &rules_list[0][0].declarations; - let b = &rules_list[1][0].declarations; - assert!((a.specificity, a.source_order).cmp(&(b.specificity, b.source_order)) == Ordering::Less, - "The rule that comes later should win."); - } - - #[test] - fn test_get_id_name(){ - let rules_list = get_mock_rules(&[".intro", "#top"]); - assert_eq!(SelectorMap::get_id_name(&rules_list[0][0]), None); - assert_eq!(SelectorMap::get_id_name(&rules_list[1][0]), Some(atom!("top"))); - } - - #[test] - fn test_get_class_name(){ - let rules_list = get_mock_rules(&[".intro.foo", "#top"]); - assert_eq!(SelectorMap::get_class_name(&rules_list[0][0]), Some(Atom::from_slice("intro"))); - assert_eq!(SelectorMap::get_class_name(&rules_list[1][0]), None); - } - - #[test] - fn test_get_local_name(){ - let rules_list = get_mock_rules(&["img.foo", "#top", "IMG", "ImG"]); - let check = |&:i: uint, names: Option<(&str, &str)>| { - assert!(SelectorMap::get_local_name(&rules_list[i][0]) - == names.map(|(name, lower_name)| LocalName { - name: Atom::from_slice(name), - lower_name: Atom::from_slice(lower_name) })) - }; - check(0, Some(("img", "img"))); - check(1, None); - check(2, Some(("IMG", "img"))); - check(3, Some(("ImG", "img"))); - } - - #[test] - fn test_insert(){ - let rules_list = get_mock_rules(&[".intro.foo", "#top"]); - let mut selector_map = SelectorMap::new(); - selector_map.insert(rules_list[1][0].clone()); - assert_eq!(1, selector_map.id_hash.get(&atom!("top")).unwrap()[0].declarations.source_order); - selector_map.insert(rules_list[0][0].clone()); - assert_eq!(0, selector_map.class_hash.get(&Atom::from_slice("intro")).unwrap()[0].declarations.source_order); - assert!(selector_map.class_hash.get(&Atom::from_slice("foo")).is_none()); - } -} |