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

Detect body elements during layout

Browse source 
During layout it is often useful, for various specification reasons, to
know if an element is the `<body>` element of an `<html>` element root. There
are a couple places where a brittle heuristic is used to detect `<body>`
elements. This information is going to be even more important to
properly handle `<html>` elements that inherit their overflow property from
their `<body>` children.

Implementing this properly requires updating the DOM wrapper interface.
This check does reach up to the parent of thread-safe nodes, but this is
essentially the same kind of operation that `parent_style()` does, so is
ostensibly safe.

This change should not change any behavior and is just a preparation
step for properly handle `<body>` overflow.
This commit is contained in:
Martin Robinson 2023-04-30 20:21:58 +02:00
parent 77a184a0e7
commit 72302e2dae
26 changed files with 487 additions and 277 deletions
Download patch file Download diff file Expand all files Collapse all files

15
components/layout/flow.rs
View file

@ -967,13 +967,23 @@ impl fmt::Debug for BaseFlow {
"".to_owned()
};
let flags_string = if !self.flags.is_empty() {
format!("\nflags={:?}", self.flags)
} else {
"".to_owned()
};
write!(
f,
"\nsc={:?}\
\npos={:?}{}{}\
\nfloatspec-in={:?}\
\nfloatspec-out={:?}\
\noverflow={:?}{}{}{}",
\noverflow={:?}\
{child_count_string}\
{absolute_descendants_string}\
{damage_string}\
{flags_string}",
self.stacking_context_id,
self.position,
if self.flags.contains(FlowFlags::FLOATS_LEFT) {
@ -989,9 +999,6 @@ impl fmt::Debug for BaseFlow {
self.speculated_float_placement_in,
self.speculated_float_placement_out,
self.overflow,
child_count_string,
absolute_descendants_string,
damage_string
)
}
}

35
components/layout/fragment.rs
View file

@ -677,18 +677,27 @@ impl Fragment {
let mut restyle_damage = node.restyle_damage();
restyle_damage.remove(ServoRestyleDamage::RECONSTRUCT_FLOW);
let mut flags = FragmentFlags::empty();
let is_body = node
.as_element()
.map(|element| element.is_body_element_of_html_element_root())
.unwrap_or(false);
if is_body {
flags |= FragmentFlags::IS_BODY_ELEMENT_OF_HTML_ELEMENT_ROOT;
}
Fragment {
node: node.opaque(),
style: style,
style,
selected_style: node.selected_style(),
restyle_damage: restyle_damage,
restyle_damage,
border_box: LogicalRect::zero(writing_mode),
border_padding: LogicalMargin::zero(writing_mode),
margin: LogicalMargin::zero(writing_mode),
specific: specific,
specific,
inline_context: None,
pseudo: node.get_pseudo_element_type(),
flags: FragmentFlags::empty(),
flags,
debug_id: DebugId::new(),
stacking_context_id: StackingContextId::root(),
established_reference_frame: None,
@ -3277,16 +3286,24 @@ impl fmt::Debug for Fragment {
"".to_owned()
};
let flags_string = if !self.flags.is_empty() {
format!("\nflags={:?}", self.flags)
} else {
"".to_owned()
};
write!(
f,
"\n{}({}) [{:?}]\nborder_box={:?}{}{}{}",
"\n{}({}) [{:?}]\
\nborder_box={:?}\
{border_padding_string}\
{margin_string}\
{damage_string}\
{flags_string}",
self.specific.get_type(),
self.debug_id,
self.specific,
self.border_box,
border_padding_string,
margin_string,
damage_string
)
}
}
@ -3430,6 +3447,8 @@ bitflags! {
const IS_BLOCK_FLEX_ITEM = 0b0000_0010;
/// Whether this fragment represents the generated text from a text-overflow clip.
const IS_ELLIPSIS = 0b0000_0100;
/// Whether this fragment is for the body element child of a html element root element.
const IS_BODY_ELEMENT_OF_HTML_ELEMENT_ROOT = 0b0000_1000;
}
}

10
components/layout/query.rs
View file

@ -9,7 +9,7 @@ use crate::context::LayoutContext;
use crate::display_list::items::{DisplayList, OpaqueNode, ScrollOffsetMap};
use crate::display_list::IndexableText;
use crate::flow::{Flow, GetBaseFlow};
use crate::fragment::{Fragment, FragmentBorderBoxIterator, SpecificFragmentInfo};
use crate::fragment::{Fragment, FragmentBorderBoxIterator, FragmentFlags, SpecificFragmentInfo};
use crate::inline::InlineFragmentNodeFlags;
use crate::opaque_node::OpaqueNodeMethods;
use crate::sequential;
@ -666,11 +666,9 @@ impl FragmentBorderBoxIterator for ParentOffsetBorderBoxIterator {
self.has_processed_node = true;
}
} else if self.node_offset_box.is_none() {
// TODO(gw): Is there a less fragile way of checking whether this
// fragment is the body element, rather than just checking that
// it's at level 1 (below the root node)?
let is_body_element = level == 1;
let is_body_element = fragment
.flags
.contains(FragmentFlags::IS_BODY_ELEMENT_OF_HTML_ELEMENT_ROOT);
let is_valid_parent = match (
is_body_element,
fragment.style.get_box().position,