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/* 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
//! Misc information about a given computed style.
bitflags! {
/// Misc information about a given computed style.
///
/// All flags are currently inherited for text, pseudo elements, and
/// anonymous boxes, see StyleBuilder::for_inheritance and its callsites.
/// If we ever want to add some flags that shouldn't inherit for them,
/// we might want to add a function to handle this.
#[repr(C)]
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub struct ComputedValueFlags: u32 {
/// Whether the style or any of the ancestors has a text-decoration-line
/// property that should get propagated to descendants.
///
/// text-decoration-line is a reset property, but gets propagated in the
/// frame/box tree.
const HAS_TEXT_DECORATION_LINES = 1 << 0;
/// Whether line break inside should be suppressed.
///
/// If this flag is set, the line should not be broken inside,
/// which means inlines act as if nowrap is set, <br> element is
/// suppressed, and blocks are inlinized.
///
/// This bit is propagated to all children of line participants.
/// It is currently used by ruby to make its content unbreakable.
const SHOULD_SUPPRESS_LINEBREAK = 1 << 1;
/// A flag used to mark text that that has text-combine-upright.
///
/// This is used from Gecko's layout engine.
const IS_TEXT_COMBINED = 1 << 2;
/// A flag used to mark styles under a relevant link that is also
/// visited.
const IS_RELEVANT_LINK_VISITED = 1 << 3;
/// A flag used to mark styles which are a pseudo-element or under one.
const IS_IN_PSEUDO_ELEMENT_SUBTREE = 1 << 4;
/// A flag used to mark styles which have contain:style or under one.
const SELF_OR_ANCESTOR_HAS_CONTAIN_STYLE = 1 << 5;
/// Whether this style's `display` property depends on our parent style.
///
/// This is important because it may affect our optimizations to avoid
/// computing the style of pseudo-elements, given whether the
/// pseudo-element is generated depends on the `display` value.
const DISPLAY_DEPENDS_ON_INHERITED_STYLE = 1 << 6;
/// Whether this style's `content` depends on our parent style.
///
/// Important because of the same reason.
const CONTENT_DEPENDS_ON_INHERITED_STYLE = 1 << 7;
/// Whether the child explicitly inherits any reset property.
const INHERITS_RESET_STYLE = 1 << 8;
/// Whether any value on our style is font-metric-dependent on our
/// primary font.
const DEPENDS_ON_SELF_FONT_METRICS = 1 << 9;
/// Whether any value on our style is font-metric-dependent on the
/// primary font of our parent.
const DEPENDS_ON_INHERITED_FONT_METRICS = 1 << 10;
/// Whether the style or any of the ancestors has a multicol style.
///
/// Only used in Servo.
const CAN_BE_FRAGMENTED = 1 << 11;
/// Whether this style is the style of the document element.
const IS_ROOT_ELEMENT_STYLE = 1 << 12;
/// Whether this element is inside an `opacity: 0` subtree.
const IS_IN_OPACITY_ZERO_SUBTREE = 1 << 13;
/// Whether there are author-specified rules for border-* properties
/// (except border-image-*), background-color, or background-image.
///
/// TODO(emilio): Maybe do include border-image, see:
///
const HAS_AUTHOR_SPECIFIED_BORDER_BACKGROUND = 1 << 14;
/// Whether there are author-specified rules for `font-family`.
const HAS_AUTHOR_SPECIFIED_FONT_FAMILY = 1 << 16;
/// Whether there are author-specified rules for `font-synthesis-weight`.
const HAS_AUTHOR_SPECIFIED_FONT_SYNTHESIS_WEIGHT = 1 << 17;
/// Whether there are author-specified rules for `font-synthesis-style`.
const HAS_AUTHOR_SPECIFIED_FONT_SYNTHESIS_STYLE = 1 << 18;
// (There's also font-synthesis-small-caps and font-synthesis-position,
// but we don't currently need to keep track of those.)
/// Whether there are author-specified rules for `letter-spacing`.
const HAS_AUTHOR_SPECIFIED_LETTER_SPACING = 1 << 19;
/// Whether there are author-specified rules for `word-spacing`.
const HAS_AUTHOR_SPECIFIED_WORD_SPACING = 1 << 20;
/// Whether the style depends on viewport units.
const USES_VIEWPORT_UNITS = 1 << 21;
/// Whether the style depends on viewport units on container queries.
///
/// This needs to be a separate flag from `USES_VIEWPORT_UNITS` because
/// it causes us to re-match the style (rather than re-cascascading it,
/// which is enough for other uses of viewport units).
const USES_VIEWPORT_UNITS_ON_CONTAINER_QUERIES = 1 << 22;
/// A flag used to mark styles which have `container-type` of `size` or
/// `inline-size`, or under one.
const SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE = 1 << 23;
/// Whether the style evaluated any relative selector.
const CONSIDERED_RELATIVE_SELECTOR = 1 << 24;
/// Whether the style evaluated the matched element to be an anchor of
/// a relative selector.
const ANCHORS_RELATIVE_SELECTOR = 1 << 25;
/// Whether the style uses container query units, in which case the style depends on the
/// container's size and we can't reuse it across cousins (without double-checking the
/// container at least).
const USES_CONTAINER_UNITS = 1 << 26;
/// Whether there are author-specific rules for text `color`.
const HAS_AUTHOR_SPECIFIED_TEXT_COLOR = 1 << 27;
}
}
impl Default for ComputedValueFlags {
#[inline]
fn default() -> Self {
Self::empty()
}
}
impl ComputedValueFlags {
/// Flags that are unconditionally propagated to descendants.
#[inline]
fn inherited_flags() -> Self {
Self::IS_RELEVANT_LINK_VISITED |
Self::CAN_BE_FRAGMENTED |
Self::IS_IN_PSEUDO_ELEMENT_SUBTREE |
Self::HAS_TEXT_DECORATION_LINES |
Self::IS_IN_OPACITY_ZERO_SUBTREE |
Self::SELF_OR_ANCESTOR_HAS_CONTAIN_STYLE |
Self::SELF_OR_ANCESTOR_HAS_SIZE_CONTAINER_TYPE
}
/// Flags that may be propagated to descendants.
#[inline]
fn maybe_inherited_flags() -> Self {
Self::inherited_flags() | Self::SHOULD_SUPPRESS_LINEBREAK
}
/// Flags that are an input to the cascade.
#[inline]
fn cascade_input_flags() -> Self {
Self::USES_VIEWPORT_UNITS_ON_CONTAINER_QUERIES |
Self::CONSIDERED_RELATIVE_SELECTOR |
Self::ANCHORS_RELATIVE_SELECTOR
}
/// Returns the flags that are always propagated to descendants.
///
/// See StyleAdjuster::set_bits and StyleBuilder.
#[inline]
pub fn inherited(self) -> Self {
self & Self::inherited_flags()
}
/// Flags that are conditionally propagated to descendants, just to handle
/// properly style invalidation.
#[inline]
pub fn maybe_inherited(self) -> Self {
self & Self::maybe_inherited_flags()
}
/// Flags that are an input to the cascade.
#[inline]
pub fn for_cascade_inputs(self) -> Self {
self & Self::cascade_input_flags()
}
}