Mirrors/servo
1
0
Fork 0
mirror of https://github.com/servo/servo.git synced 2025-08-05 13:40:08 +01:00
Code Issues Projects Releases Packages Wiki Activity

layout: Propagate overflow values from <body> to root element (#31618)

Browse source 
The specification gives instructions for how these values should be
propagated. The other big changs here is that they aren't applied to the
`<body>`.

 Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This commit is contained in:
Martin Robinson 2024-03-13 10:17:09 +01:00 • committed by GitHub
parent 03d64d0675
commit 716f4a006d
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
17 changed files with 82 additions and 27 deletions
Download patch file Download diff file Expand all files Collapse all files

48
components/layout_2020/flow/root.rs
View file

@ -3,14 +3,17 @@
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use atomic_refcell::AtomicRef;
use script_layout_interface::wrapper_traits::LayoutNode;
use script_layout_interface::wrapper_traits::{
LayoutNode, ThreadSafeLayoutElement, ThreadSafeLayoutNode,
};
use script_layout_interface::{LayoutElementType, LayoutNodeType};
use serde::Serialize;
use servo_arc::Arc;
use style::dom::OpaqueNode;
use style::properties::ComputedValues;
use style::values::computed::Length;
use style::values::computed::{Length, Overflow};
use style_traits::CSSPixel;
use webrender_api::ScrollSensitivity;
use crate::cell::ArcRefCell;
use crate::context::LayoutContext;
@ -36,6 +39,9 @@ pub struct BoxTree {
/// <https://drafts.csswg.org/css-backgrounds/#special-backgrounds>
canvas_background: CanvasBackground,
/// Whether or not the root element should be sensitive to scrolling input events.
sensitive_to_scroll_input: bool,
}
impl BoxTree {
@ -48,6 +54,35 @@ impl BoxTree {
// Zero box for `:root { display: none }`, one for the root element otherwise.
assert!(boxes.len() <= 1);
// From https://drafts.csswg.org/css-overflow/#propdef-overflow:
// > UAs must apply the overflow-* values set on the root element to the viewport when the
// > root element’s display value is not none. However, when the root element is an [HTML]
// > html element (including XML syntax for HTML) whose overflow value is visible (in both
// > axes), and that element has as a child a body element whose display value is also not
// > none, user agents must instead apply the overflow-* values of the first such child
// > element to the viewport. The element from which the value is propagated must then have a
// > used overflow value of visible.
//
// TODO: This should handle when different overflow is set multiple axes, which requires the
// compositor scroll tree to allow setting a value per axis.
let root_style = root_element.style(context);
let mut root_overflow = root_style.get_box().overflow_y;
if root_overflow == Overflow::Visible && !root_style.get_box().display.is_none() {
for child in iter_child_nodes(root_element) {
if !child.to_threadsafe().as_element().map_or(false, |element| {
element.is_body_element_of_html_element_root()
}) {
continue;
}
let style = child.style(context);
if !style.get_box().display.is_none() {
root_overflow = style.get_box().overflow_y;
break;
}
}
}
let contents = BlockContainer::BlockLevelBoxes(boxes);
let contains_floats = contents.contains_floats();
Self {
@ -56,6 +91,7 @@ impl BoxTree {
contains_floats,
},
canvas_background: CanvasBackground::for_root_element(context, root_element),
sensitive_to_scroll_input: root_overflow != Overflow::Hidden,
}
}
@ -252,6 +288,7 @@ fn construct_for_root_element<'dom>(
propagated_text_decoration_line,
))
};
let root_box = ArcRefCell::new(root_box);
root_element
.element_box_slot()
@ -330,11 +367,18 @@ impl BoxTree {
acc.union(&child_overflow)
});
let root_scroll_sensitivity = if self.sensitive_to_scroll_input {
ScrollSensitivity::ScriptAndInputEvents
} else {
ScrollSensitivity::Script
};
FragmentTree {
root_fragments,
scrollable_overflow,
initial_containing_block: physical_containing_block,
canvas_background: self.canvas_background.clone(),
root_scroll_sensitivity,
}
}
}