servo/components/style/properties/computed_value_flags.rs

60 lines
2.5 KiB
Rust

/* 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 http://mozilla.org/MPL/2.0/. */
//! 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.
pub flags ComputedValueFlags: u8 {
/// 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 are in a display: none subtree, or
/// under one.
const IS_IN_DISPLAY_NONE_SUBTREE = 1 << 5,
/// Whether this style inherits the `display` property.
///
/// 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 INHERITS_DISPLAY = 1 << 6,
/// Whether this style inherits the `content` property.
///
/// Important because of the same reason.
const INHERITS_CONTENT = 1 << 7,
}
}