Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-03 04:30:10 +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

58
components/layout_thread_2020/dom_wrapper.rs
View file

@ -428,6 +428,40 @@ impl<'le> fmt::Debug for ServoLayoutElement<'le> {
}
}
impl<'dom> ServoLayoutElement<'dom> {
/// Returns true if this element is the body child of an html element root element.
fn is_body_element_of_html_element_root(&self) -> bool {
if self.element.local_name() != &local_name!("body") {
return false;
}
self.parent_element()
.map(|element| {
element.is_root() && element.element.local_name() == &local_name!("html")
})
.unwrap_or(false)
}
/// Returns the parent element of this element, if it has one.
fn parent_element(&self) -> Option<Self> {
self.element
.upcast()
.composed_parent_node_ref()
.and_then(as_element)
}
// Returns true is this is the root element.
fn is_root(&self) -> bool {
match self.as_node().parent_node() {
None => false,
Some(node) => match node.script_type_id() {
NodeTypeId::Document(_) => true,
_ => false,
},
}
}
}
impl<'le> TElement for ServoLayoutElement<'le> {
type ConcreteNode = ServoLayoutNode<'le>;
type TraversalChildrenIterator = DomChildren<Self::ConcreteNode>;
@ -679,11 +713,7 @@ impl<'le> TElement for ServoLayoutElement<'le> {
}
fn is_html_document_body_element(&self) -> bool {
// This is only used for the "tables inherit from body" quirk, which we
// don't implement.
//
// FIXME(emilio): We should be able to give the right answer though!
false
self.is_body_element_of_html_element_root()
}
fn synthesize_presentational_hints_for_legacy_attributes<V>(
@ -839,13 +869,7 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
}
fn is_root(&self) -> bool {
match self.as_node().parent_node() {
None => false,
Some(node) => match node.script_type_id() {
NodeTypeId::Document(_) => true,
_ => false,
},
}
ServoLayoutElement::is_root(self)
}
fn is_empty(&self) -> bool {
@ -981,11 +1005,7 @@ impl<'le> ::selectors::Element for ServoLayoutElement<'le> {
}
fn is_html_element_in_html_document(&self) -> bool {
if !self.element.is_html_element() {
return false;
}
self.as_node().owner_doc().is_html_document()
self.element.is_html_element() && self.as_node().owner_doc().is_html_document()
}
}
@ -1361,6 +1381,10 @@ impl<'le> ThreadSafeLayoutElement<'le> for ServoThreadSafeLayoutElement<'le> {
fn is_shadow_host(&self) -> bool {
self.element.shadow_root().is_some()
}
fn is_body_element_of_html_element_root(&self) -> bool {
self.element.is_body_element_of_html_element_root()
}
}
/// This implementation of `::selectors::Element` is used for implementing lazy