Enum style::rule_tree::CascadeLevel

#[repr(u8)]
pub enum CascadeLevel {
    UANormal,
    UserNormal,
    PresHints,
    AuthorNormal {
        shadow_cascade_order: ShadowCascadeOrder,
    },
    SMILOverride,
    Animations,
    AuthorImportant {
        shadow_cascade_order: ShadowCascadeOrder,
    },
    UserImportant,
    UAImportant,
    Transitions,
}

The cascade level these rules are relevant at, as per13.

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.

Variants

UANormal

Normal User-Agent rules.

UserNormal

User normal rules.

PresHints

Presentational hints.

AuthorNormal

Shadow DOM styles from author styles.

Fields

shadow_cascade_order: ShadowCascadeOrder

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

SMILOverride

SVG SMIL animations.

Animations

CSS animations and script-generated animations.

AuthorImportant

Author-supplied important rules.

Fields

shadow_cascade_order: ShadowCascadeOrder

The order in the shadow tree hierarchy, inverted, so that PartialOrd does the right thing.

UserImportant

User important rules.

UAImportant

User-agent important rules.

Transitions

Transitions

Implementations

impl CascadeLevel

pub fn important(&self) -> Self

Convert this level from “unimportant” to “important”.

pub fn unimportant(&self) -> Self

Convert this level from “important” to “non-important”.

pub fn guard<'a>( &self, guards: &'a StylesheetGuards<'a>, ) -> &'a SharedRwLockReadGuard<'a>

Select a lock guard for this level

pub fn same_tree_author_important() -> Self

Returns the cascade level for author important declarations from the same tree as the element.

pub fn same_tree_author_normal() -> Self

Returns the cascade level for author normal declarations from the same tree as the element.

pub fn is_important(&self) -> bool

Returns whether this cascade level represents important rules of some sort.

pub fn importance(&self) -> Importance

Returns the importance relevant for this rule. Pretty similar to is_important.

pub fn origin(&self) -> Origin

Returns the cascade origin of the rule.

pub fn is_animation(&self) -> bool

Returns whether this cascade level represents an animation rules.

Trait Implementations

impl Clone for CascadeLevel

fn clone(&self) -> CascadeLevel

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CascadeLevel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for CascadeLevel

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl MallocSizeOf for CascadeLevel

fn size_of(&self, ops: &mut MallocSizeOfOps) -> usize

Measure the heap usage of all descendant heap-allocated structures, but not the space taken up by the value itself.

impl Ord for CascadeLevel

fn cmp(&self, other: &CascadeLevel) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl PartialEq for CascadeLevel

fn eq(&self, other: &CascadeLevel) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for CascadeLevel

fn partial_cmp(&self, other: &CascadeLevel) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for CascadeLevel

impl Eq for CascadeLevel

impl StructuralPartialEq for CascadeLevel