Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-06 14:10:11 +01:00
Code Issues Projects Releases Packages Wiki Activity

layout: Add a new cascading mode that inherits all properties, even

Browse source 
non-inheritable ones.

This works like the `modify_style_for_*` functions and will allow us to
easily migrate from them to real cascading.
This commit is contained in:
Patrick Walton 2016-10-24 18:00:06 -07:00
parent 93e41ba4aa
commit fb2d1e1020
6 changed files with 86 additions and 43 deletions
Download patch file Download diff file Expand all files Collapse all files

61
components/style/properties/properties.mako.rs
View file

@ -1524,6 +1524,17 @@ static CASCADE_PROPERTY: [CascadePropertyFn; ${len(data.longhands)}] = [
% endfor
];
bitflags! {
pub flags CascadeFlags: u8 {
/// Whether the `ComputedValues` structure to be constructed should be considered
/// shareable.
const SHAREABLE = 0x01,
/// Whether to inherit all styles from the parent. If this flag is not present,
/// non-inherited styles are reset to their initial values.
const INHERIT_ALL = 0x02,
}
}
/// Performs the CSS cascade, computing new styles for an element from its parent style and
/// optionally a cached related style. The arguments are:
///
@ -1531,9 +1542,6 @@ static CASCADE_PROPERTY: [CascadePropertyFn; ${len(data.longhands)}] = [
///
/// * `applicable_declarations`: The list of CSS rules that matched.
///
/// * `shareable`: Whether the `ComputedValues` structure to be constructed should be considered
/// shareable.
///
/// * `parent_style`: The parent style, if applicable; if `None`, this is the root node.
///
/// * `cached_style`: If present, cascading is short-circuited for everything but inherited
@ -1541,14 +1549,16 @@ static CASCADE_PROPERTY: [CascadePropertyFn; ${len(data.longhands)}] = [
/// this that it is safe to only provide inherited declarations. If `parent_style` is `None`,
/// this is ignored.
///
/// * `flags`: Various flags.
///
/// Returns the computed values and a boolean indicating whether the result is cacheable.
pub fn cascade(viewport_size: Size2D<Au>,
applicable_declarations: &[ApplicableDeclarationBlock],
shareable: bool,
parent_style: Option<<&ComputedValues>,
cached_style: Option<<&ComputedValues>,
mut cascade_info: Option<<&mut CascadeInfo>,
mut error_reporter: StdBox<ParseErrorReporter + Send>)
mut error_reporter: StdBox<ParseErrorReporter + Send>,
flags: CascadeFlags)
-> (ComputedValues, bool) {
let initial_values = ComputedValues::initial_values();
let (is_root_element, inherited_style) = match parent_style {
@ -1582,7 +1592,7 @@ pub fn cascade(viewport_size: Size2D<Au>,
if let (Some(cached_style), Some(parent_style)) = (cached_style, parent_style) {
let style = cascade_with_cached_declarations(viewport_size,
&applicable_declarations,
shareable,
flags.contains(SHAREABLE),
parent_style,
cached_style,
custom_properties,
@ -1591,24 +1601,35 @@ pub fn cascade(viewport_size: Size2D<Au>,
return (style, false)
}
let starting_style = if !flags.contains(INHERIT_ALL) {
ComputedValues::new(custom_properties,
flags.contains(SHAREABLE),
WritingMode::empty(),
inherited_style.root_font_size(),
% for style_struct in data.active_style_structs():
% if style_struct.inherited:
inherited_style.clone_${style_struct.name_lower}(),
% else:
initial_values.clone_${style_struct.name_lower}(),
% endif
% endfor
)
} else {
ComputedValues::new(custom_properties,
flags.contains(SHAREABLE),
WritingMode::empty(),
inherited_style.root_font_size(),
% for style_struct in data.active_style_structs():
inherited_style.clone_${style_struct.name_lower}(),
% endfor
)
};
let mut context = computed::Context {
is_root_element: is_root_element,
viewport_size: viewport_size,
inherited_style: inherited_style,
style: ComputedValues::new(
custom_properties,
shareable,
WritingMode::empty(),
inherited_style.root_font_size(),
% for style_struct in data.active_style_structs():
% if style_struct.inherited:
inherited_style
% else:
initial_values
% endif
.clone_${style_struct.name_lower}(),
% endfor
),
style: starting_style,
};
// Set computed values, overwriting earlier declarations for the same property.