Struct CascadeLevel 

pub struct CascadeLevel(/* private fields */);

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

We store them as a bitfield with:

• Shadow cascade order (4 bits). See ShadowCascadeOrder for details.
• Importance bit. Whether the declaration was !important or not.
• The CascadeOrigin of the declaration as per 1.

Presentational hints for SVG and HTML are in the “author-level zero-specificity” level, that is, right after user rules, and before author rules.

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.

Implementations

impl CascadeLevel

pub const ORIGIN_BITS: Self

The three bits that represent the CascadeOrigin.

pub const IMPORTANT: Self

Whether the declarations are !important or not.

pub const CASCADE_ORDER_BITS: Self

The three bits for cascade order absolute value. If you change this, please change CASCADE_ORDER_SHIFT accordingly.

pub const CASCADE_ORDER_SIGN: Self

The bit for the sign.

impl CascadeLevel

pub const fn empty() -> Self

Get a flags value with all bits unset.

pub const fn all() -> Self

Get a flags value with all known bits set.

pub const fn bits(&self) -> u8

Get the underlying bits value.

The returned value is exactly the bits set in this flags value.

pub const fn from_bits(bits: u8) -> Option<Self>

Convert from a bits value.

This method will return None if any unknown bits are set.

pub const fn from_bits_truncate(bits: u8) -> Self

Convert from a bits value, unsetting any unknown bits.

pub const fn from_bits_retain(bits: u8) -> Self

Convert from a bits value exactly.

pub fn from_name(name: &str) -> Option<Self>

Get a flags value with the bits of a flag with the given name set.

This method will return None if name is empty or doesn’t correspond to any named flag.

pub const fn is_empty(&self) -> bool

Whether all bits in this flags value are unset.

pub const fn is_all(&self) -> bool

Whether all known bits in this flags value are set.

pub const fn intersects(&self, other: Self) -> bool

Whether any set bits in a source flags value are also set in a target flags value.

pub const fn contains(&self, other: Self) -> bool

Whether all set bits in a source flags value are also set in a target flags value.

pub fn insert(&mut self, other: Self)

The bitwise or (|) of the bits in two flags values.

pub fn remove(&mut self, other: Self)

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. remove won’t truncate other, but the ! operator will.

pub fn toggle(&mut self, other: Self)

The bitwise exclusive-or (^) of the bits in two flags values.

pub fn set(&mut self, other: Self, value: bool)

Call insert when value is true or remove when value is false.

pub const fn intersection(self, other: Self) -> Self

The bitwise and (&) of the bits in two flags values.

pub const fn union(self, other: Self) -> Self

The bitwise or (|) of the bits in two flags values.

pub const fn difference(self, other: Self) -> Self

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

pub const fn symmetric_difference(self, other: Self) -> Self

The bitwise exclusive-or (^) of the bits in two flags values.

pub const fn complement(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

impl CascadeLevel

pub const fn iter(&self) -> Iter<CascadeLevel>

Yield a set of contained flags values.

Each yielded flags value will correspond to a defined named flag. Any unknown bits will be yielded together as a final flags value.

pub const fn iter_names(&self) -> IterNames<CascadeLevel>

Yield a set of contained named flags values.

This method is like iter, except only yields bits in contained named flags. Any unknown bits, or bits not corresponding to a contained flag will not be yielded.

impl CascadeLevel

pub const CASCADE_ORDER_SHIFT: usize = 4

The shift that we apply to the cascade order.

pub const SAME_TREE_AUTHOR_NORMAL: Self

The author level at the same tree. Here for convenience to avoid duplicating it from C++.

pub fn new(origin: CascadeOrigin) -> Self

Returns a cascade level with a given origin.

pub fn origin(self) -> CascadeOrigin

Returns the cascade origin.

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 is_animation(&self) -> bool

Returns whether this cascade level represents an animation rules.

pub fn is_tree(self) -> bool

Returns whether this cascade level is tree.

pub fn author_normal(shadow_cascade_order: ShadowCascadeOrder) -> Self

Returns an author normal cascade level with the given shadow cascade order.

Trait Implementations

impl Binary for CascadeLevel

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

Formats the value using the given formatter.

impl BitAnd for CascadeLevel

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

The bitwise and (&) of the bits in two flags values.

type Output = CascadeLevel

The resulting type after applying the & operator.

impl BitAndAssign for CascadeLevel

fn bitand_assign(&mut self, other: Self)

The bitwise and (&) of the bits in two flags values.

impl BitOr for CascadeLevel

fn bitor(self, other: CascadeLevel) -> Self

The bitwise or (|) of the bits in two flags values.

type Output = CascadeLevel

The resulting type after applying the | operator.

impl BitOrAssign for CascadeLevel

fn bitor_assign(&mut self, other: Self)

The bitwise or (|) of the bits in two flags values.

impl BitXor for CascadeLevel

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

The bitwise exclusive-or (^) of the bits in two flags values.

type Output = CascadeLevel

The resulting type after applying the ^ operator.

impl BitXorAssign for CascadeLevel

fn bitxor_assign(&mut self, other: Self)

The bitwise exclusive-or (^) of the bits in two flags values.

impl Clone for CascadeLevel

fn clone(&self) -> CascadeLevel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for CascadeLevel

impl Debug for CascadeLevel

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CascadeLevel

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for CascadeLevel

impl Extend<CascadeLevel> for CascadeLevel

fn extend<T: IntoIterator<Item = Self>>(&mut self, iterator: T)

The bitwise or (|) of the bits in each flags value.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.

impl Flags for CascadeLevel

const FLAGS: &'static [Flag<CascadeLevel>]

The set of defined flags.

type Bits = u8

The underlying bits type.

fn bits(&self) -> u8

Get the underlying bits value.

fn from_bits_retain(bits: u8) -> CascadeLevel

Convert from a bits value exactly.

fn empty() -> Self

Get a flags value with all bits unset.

fn all() -> Self

Get a flags value with all known bits set.

fn from_bits(bits: Self::Bits) -> Option<Self>

Convert from a bits value.

fn from_bits_truncate(bits: Self::Bits) -> Self

Convert from a bits value, unsetting any unknown bits.

fn from_name(name: &str) -> Option<Self>

Get a flags value with the bits of a flag with the given name set.

fn iter(&self) -> Iter<Self>

Yield a set of contained flags values.

fn iter_names(&self) -> IterNames<Self>

Yield a set of contained named flags values.

fn is_empty(&self) -> bool

Whether all bits in this flags value are unset.

fn is_all(&self) -> bool

Whether all known bits in this flags value are set.

fn intersects(&self, other: Self) -> bool

where Self: Sized,

Whether any set bits in a source flags value are also set in a target flags value.

fn contains(&self, other: Self) -> bool

where Self: Sized,

Whether all set bits in a source flags value are also set in a target flags value.

fn insert(&mut self, other: Self)

where Self: Sized,

The bitwise or (|) of the bits in two flags values.

fn remove(&mut self, other: Self)

where Self: Sized,

The intersection of a source flags value with the complement of a target flags value (&!).

fn toggle(&mut self, other: Self)

where Self: Sized,

The bitwise exclusive-or (^) of the bits in two flags values.

fn set(&mut self, other: Self, value: bool)

where Self: Sized,

Call Flags::insert when value is true or Flags::remove when value is false.

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

The bitwise and (&) of the bits in two flags values.

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

The bitwise or (|) of the bits in two flags values.

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

The intersection of a source flags value with the complement of a target flags value (&!).

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

The bitwise exclusive-or (^) of the bits in two flags values.

fn complement(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

impl FromIterator<CascadeLevel> for CascadeLevel

fn from_iter<T: IntoIterator<Item = Self>>(iterator: T) -> Self

The bitwise or (|) of the bits in each flags value.

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 IntoIterator for CascadeLevel

type Item = CascadeLevel

The type of the elements being iterated over.

type IntoIter = Iter<CascadeLevel>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl LowerHex for CascadeLevel

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

Formats the value using the given formatter.

impl MallocSizeOf for CascadeLevel

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

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

impl Not for CascadeLevel

fn not(self) -> Self

The bitwise negation (!) of the bits in a flags value, truncating the result.

type Output = CascadeLevel

The resulting type after applying the ! operator.

impl Octal for CascadeLevel

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

Formats the value using the given formatter.

impl Ord for CascadeLevel

fn cmp(&self, other: &Self) -> 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,

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: &Self) -> 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 Serialize for CascadeLevel

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for CascadeLevel

impl Sub for CascadeLevel

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

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

type Output = CascadeLevel

The resulting type after applying the - operator.

impl SubAssign for CascadeLevel

fn sub_assign(&mut self, other: Self)

The intersection of a source flags value with the complement of a target flags value (&!).

This method is not equivalent to self & !other when other has unknown bits set. difference won’t truncate other, but the ! operator will.

impl ToAnimatedValue for CascadeLevel

where u8: ToAnimatedValue<AnimatedValue = u8>,

type AnimatedValue = CascadeLevel

The type of the animated value.

fn from_animated_value(from: Self::AnimatedValue) -> Self

Converts back an animated value into a computed value.

fn to_animated_value(self, context: &Context<'_>) -> Self::AnimatedValue

Converts this value to an animated value.

impl ToResolvedValue for CascadeLevel

where u8: ToResolvedValue<ResolvedValue = u8>,

type ResolvedValue = CascadeLevel

The resolved value type we’re going to be converted to.

fn from_resolved_value(from: Self::ResolvedValue) -> Self

Convert a resolved value to resolved value form.

fn to_resolved_value(self, context: &Context<'_>) -> Self::ResolvedValue

Convert a resolved value to a resolved value.

impl ToShmem for CascadeLevel

fn to_shmem(&self, builder: &mut SharedMemoryBuilder) -> Result<Self>

Clones this value into a form suitable for writing into a SharedMemoryBuilder.

impl UpperHex for CascadeLevel

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

Formats the value using the given formatter.