servo/components/layout_2020/fragment_tree/positioning_fragment.rs
Martin Robinson d941d2fd67
layout: Convert the FragmentTree to physical geometry (#33030)
This converts all geometry in the FragmentTree into physical geometry,
doing conversions ahead of time instead of when traversing the fragment
tree. This is necessary to properly implement BiDi in Servo as we need
to know what side borders are on in mixed RTL and LTR contexts.

In addition, fragments are laid out in a particular context and only
that context knows its writing mode. There were issues where were using
one writing mode to lay out and another to convert to phyisical
coordinates. This isn't an issue now since we only use the default
writing mode, but starts to be an issue with BiDi text.

Closes #25564.

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
2024-08-14 12:22:06 +00:00

81 lines
2.6 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 https://mozilla.org/MPL/2.0/. */
use app_units::Au;
use base::print_tree::PrintTree;
use serde::Serialize;
use servo_arc::Arc as ServoArc;
use style::properties::ComputedValues;
use super::{BaseFragment, BaseFragmentInfo, Fragment};
use crate::cell::ArcRefCell;
use crate::geom::PhysicalRect;
/// Can contain child fragments with relative coordinates, but does not contribute to painting
/// itself. [`PositioningFragment`]s may be completely anonymous, or just non-painting Fragments
/// generated by boxes.
#[derive(Serialize)]
pub(crate) struct PositioningFragment {
pub base: BaseFragment,
pub rect: PhysicalRect<Au>,
pub children: Vec<ArcRefCell<Fragment>>,
/// The scrollable overflow of this anonymous fragment's children.
pub scrollable_overflow: PhysicalRect<Au>,
/// If this fragment was created with a style, the style of the fragment.
#[serde(skip_serializing)]
pub style: Option<ServoArc<ComputedValues>>,
}
impl PositioningFragment {
pub fn new_anonymous(rect: PhysicalRect<Au>, children: Vec<Fragment>) -> Self {
Self::new_with_base_fragment(BaseFragment::anonymous(), None, rect, children)
}
pub fn new_empty(
base_fragment_info: BaseFragmentInfo,
rect: PhysicalRect<Au>,
style: ServoArc<ComputedValues>,
) -> Self {
Self::new_with_base_fragment(base_fragment_info.into(), Some(style), rect, Vec::new())
}
fn new_with_base_fragment(
base: BaseFragment,
style: Option<ServoArc<ComputedValues>>,
rect: PhysicalRect<Au>,
children: Vec<Fragment>,
) -> Self {
let content_origin = rect.origin;
let scrollable_overflow = children.iter().fold(PhysicalRect::zero(), |acc, child| {
acc.union(
&child
.scrollable_overflow()
.translate(content_origin.to_vector()),
)
});
PositioningFragment {
base,
style,
rect,
children: children.into_iter().map(ArcRefCell::new).collect(),
scrollable_overflow,
}
}
pub fn print(&self, tree: &mut PrintTree) {
tree.new_level(format!(
"PositioningFragment\
\nbase={:?}\
\nrect={:?}\
\nscrollable_overflow={:?}",
self.base, self.rect, self.scrollable_overflow
));
for child in &self.children {
child.borrow().print(tree);
}
tree.end_level();
}
}