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Diffstat (limited to 'components/style/rule_tree/level.rs')
| -rw-r--r-- | components/style/rule_tree/level.rs | 249 |
1 files changed, 0 insertions, 249 deletions
diff --git a/components/style/rule_tree/level.rs b/components/style/rule_tree/level.rs deleted file mode 100644 index b8cbe55ed9c..00000000000 --- a/components/style/rule_tree/level.rs +++ /dev/null @@ -1,249 +0,0 @@ -/* 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/. */ - -#![forbid(unsafe_code)] - -use crate::properties::Importance; -use crate::shared_lock::{SharedRwLockReadGuard, StylesheetGuards}; -use crate::stylesheets::Origin; - -/// The cascade level these rules are relevant at, as per[1][2][3]. -/// -/// Presentational hints for SVG and HTML are in the "author-level -/// zero-specificity" level, that is, right after user rules, and before author -/// rules. -/// -/// The order of variants declared here is significant, and must be in -/// _ascending_ order of precedence. -/// -/// See also [4] for the Shadow DOM bits. We rely on the invariant that rules -/// from outside the tree the element is in can't affect the element. -/// -/// The opposite is not true (i.e., :host and ::slotted) from an "inner" shadow -/// tree may affect an element connected to the document or an "outer" shadow -/// tree. -/// -/// [1]: https://drafts.csswg.org/css-cascade/#cascade-origin -/// [2]: https://drafts.csswg.org/css-cascade/#preshint -/// [3]: https://html.spec.whatwg.org/multipage/#presentational-hints -/// [4]: https://drafts.csswg.org/css-scoping/#shadow-cascading -#[repr(u8)] -#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd)] -pub enum CascadeLevel { - /// Normal User-Agent rules. - UANormal, - /// User normal rules. - UserNormal, - /// Presentational hints. - PresHints, - /// Shadow DOM styles from author styles. - AuthorNormal { - /// The order in the shadow tree hierarchy. This number is relative to - /// the tree of the element, and thus the only invariants that need to - /// be preserved is: - /// - /// * Zero is the same tree as the element that matched the rule. This - /// is important so that we can optimize style attribute insertions. - /// - /// * The levels are ordered in accordance with - /// https://drafts.csswg.org/css-scoping/#shadow-cascading - shadow_cascade_order: ShadowCascadeOrder, - }, - /// SVG SMIL animations. - SMILOverride, - /// CSS animations and script-generated animations. - Animations, - /// Author-supplied important rules. - AuthorImportant { - /// The order in the shadow tree hierarchy, inverted, so that PartialOrd - /// does the right thing. - shadow_cascade_order: ShadowCascadeOrder, - }, - /// User important rules. - UserImportant, - /// User-agent important rules. - UAImportant, - /// Transitions - Transitions, -} - -impl CascadeLevel { - /// Convert this level from "unimportant" to "important". - pub fn important(&self) -> Self { - match *self { - Self::UANormal => Self::UAImportant, - Self::UserNormal => Self::UserImportant, - Self::AuthorNormal { - shadow_cascade_order, - } => Self::AuthorImportant { - shadow_cascade_order: -shadow_cascade_order, - }, - Self::PresHints | - Self::SMILOverride | - Self::Animations | - Self::AuthorImportant { .. } | - Self::UserImportant | - Self::UAImportant | - Self::Transitions => *self, - } - } - - /// Convert this level from "important" to "non-important". - pub fn unimportant(&self) -> Self { - match *self { - Self::UAImportant => Self::UANormal, - Self::UserImportant => Self::UserNormal, - Self::AuthorImportant { - shadow_cascade_order, - } => Self::AuthorNormal { - shadow_cascade_order: -shadow_cascade_order, - }, - Self::PresHints | - Self::SMILOverride | - Self::Animations | - Self::AuthorNormal { .. } | - Self::UserNormal | - Self::UANormal | - Self::Transitions => *self, - } - } - - /// Select a lock guard for this level - pub fn guard<'a>(&self, guards: &'a StylesheetGuards<'a>) -> &'a SharedRwLockReadGuard<'a> { - match *self { - Self::UANormal | Self::UserNormal | Self::UserImportant | Self::UAImportant => { - guards.ua_or_user - }, - _ => guards.author, - } - } - - /// Returns the cascade level for author important declarations from the - /// same tree as the element. - #[inline] - pub fn same_tree_author_important() -> Self { - Self::AuthorImportant { - shadow_cascade_order: ShadowCascadeOrder::for_same_tree(), - } - } - - /// Returns the cascade level for author normal declarations from the same - /// tree as the element. - #[inline] - pub fn same_tree_author_normal() -> Self { - Self::AuthorNormal { - shadow_cascade_order: ShadowCascadeOrder::for_same_tree(), - } - } - - /// Returns whether this cascade level represents important rules of some - /// sort. - #[inline] - pub fn is_important(&self) -> bool { - match *self { - Self::AuthorImportant { .. } | Self::UserImportant | Self::UAImportant => true, - _ => false, - } - } - - /// Returns the importance relevant for this rule. Pretty similar to - /// `is_important`. - #[inline] - pub fn importance(&self) -> Importance { - if self.is_important() { - Importance::Important - } else { - Importance::Normal - } - } - - /// Returns the cascade origin of the rule. - #[inline] - pub fn origin(&self) -> Origin { - match *self { - Self::UAImportant | Self::UANormal => Origin::UserAgent, - Self::UserImportant | Self::UserNormal => Origin::User, - Self::PresHints | - Self::AuthorNormal { .. } | - Self::AuthorImportant { .. } | - Self::SMILOverride | - Self::Animations | - Self::Transitions => Origin::Author, - } - } - - /// Returns whether this cascade level represents an animation rules. - #[inline] - pub fn is_animation(&self) -> bool { - match *self { - Self::SMILOverride | Self::Animations | Self::Transitions => true, - _ => false, - } - } -} - -/// A counter to track how many shadow root rules deep we are. This is used to -/// handle: -/// -/// https://drafts.csswg.org/css-scoping/#shadow-cascading -/// -/// See the static functions for the meaning of different values. -#[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, Ord, PartialEq, PartialOrd)] -pub struct ShadowCascadeOrder(i8); - -impl ShadowCascadeOrder { - /// We keep a maximum of 3 bits of order as a limit so that we can pack - /// CascadeLevel in one byte by using half of it for the order, if that ends - /// up being necessary. - const MAX: i8 = 0b111; - const MIN: i8 = -Self::MAX; - - /// A level for the outermost shadow tree (the shadow tree we own, and the - /// ones from the slots we're slotted in). - #[inline] - pub fn for_outermost_shadow_tree() -> Self { - Self(-1) - } - - /// A level for the element's tree. - #[inline] - fn for_same_tree() -> Self { - Self(0) - } - - /// A level for the innermost containing tree (the one closest to the - /// element). - #[inline] - pub fn for_innermost_containing_tree() -> Self { - Self(1) - } - - /// Decrement the level, moving inwards. We should only move inwards if - /// we're traversing slots. - #[inline] - pub fn dec(&mut self) { - debug_assert!(self.0 < 0); - if self.0 != Self::MIN { - self.0 -= 1; - } - } - - /// The level, moving inwards. We should only move inwards if we're - /// traversing slots. - #[inline] - pub fn inc(&mut self) { - debug_assert_ne!(self.0, -1); - if self.0 != Self::MAX { - self.0 += 1; - } - } -} - -impl std::ops::Neg for ShadowCascadeOrder { - type Output = Self; - #[inline] - fn neg(self) -> Self { - Self(self.0.neg()) - } -} |