layout: Implement ordered lists, CSS counters, and quotes per CSS 2.1

§ 12.3-12.5.

Only simple alphabetic and numeric counter styles are supported. (This
is most of them though.)

Although this PR adds a sequential pass to layout, I verified that on
pages that contain a reasonable number of ordered lists (Reddit
`/r/rust`), the time spent in generated content resolution is dwarfed by
the time spent in the parallelizable parts of layout. So I don't expect
this to negatively affect our parallelism expect perhaps in pathological
cases.
This commit is contained in:
Patrick Walton 2015-03-05 12:37:37 -08:00
parent 2df4dd9e09
commit f9cdd05d58
39 changed files with 1704 additions and 537 deletions

View file

@ -2,8 +2,7 @@
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use flow::{self, Flow};
use flow::{IS_ABSOLUTELY_POSITIONED};
use flow::{self, AFFECTS_COUNTERS, Flow, HAS_COUNTER_AFFECTING_CHILDREN, IS_ABSOLUTELY_POSITIONED};
use std::fmt;
use std::sync::Arc;
@ -32,8 +31,12 @@ bitflags! {
#[doc = "top-down."]
const REFLOW = 0x08,
#[doc = "Re-resolve generated content. \
Propagates up the flow tree because the computation is inorder."]
const RESOLVE_GENERATED_CONTENT = 0x10,
#[doc = "The entire flow needs to be reconstructed."]
const RECONSTRUCT_FLOW = 0x10
const RECONSTRUCT_FLOW = 0x20
}
}
@ -50,9 +53,9 @@ impl RestyleDamage {
/// we should add to the *parent* of this flow.
pub fn damage_for_parent(self, child_is_absolutely_positioned: bool) -> RestyleDamage {
if child_is_absolutely_positioned {
self & (REPAINT | REFLOW_OUT_OF_FLOW)
self & (REPAINT | REFLOW_OUT_OF_FLOW | RESOLVE_GENERATED_CONTENT)
} else {
self & (REPAINT | REFLOW | REFLOW_OUT_OF_FLOW)
self & (REPAINT | REFLOW | REFLOW_OUT_OF_FLOW | RESOLVE_GENERATED_CONTENT)
}
}
@ -91,10 +94,11 @@ impl fmt::Debug for RestyleDamage {
let mut first_elem = true;
let to_iter =
[ (REPAINT, "Repaint")
, (BUBBLE_ISIZES, "BubbleISizes")
[ (REPAINT, "Repaint")
, (BUBBLE_ISIZES, "BubbleISizes")
, (REFLOW_OUT_OF_FLOW, "ReflowOutOfFlow")
, (REFLOW, "Reflow")
, (REFLOW, "Reflow")
, (RESOLVE_GENERATED_CONTENT, "ResolveGeneratedContent")
, (RECONSTRUCT_FLOW, "ReconstructFlow")
];
@ -126,10 +130,18 @@ macro_rules! add_if_not_equal(
})
);
/// Returns a bitmask that represents a flow that needs to be rebuilt and reflowed.
///
/// Use this instead of `RestyleDamage::all()` because `RestyleDamage::all()` will result in
/// unnecessary sequential resolution of generated content.
pub fn rebuild_and_reflow() -> RestyleDamage {
REPAINT | BUBBLE_ISIZES | REFLOW_OUT_OF_FLOW | REFLOW | RECONSTRUCT_FLOW
}
pub fn compute_damage(old: &Option<Arc<ComputedValues>>, new: &ComputedValues) -> RestyleDamage {
let old: &ComputedValues =
match old.as_ref() {
None => return RestyleDamage::all(),
None => return rebuild_and_reflow(),
Some(cv) => &**cv,
};
@ -186,6 +198,9 @@ impl<'a> LayoutDamageComputation for &'a mut (Flow + 'a) {
let mut special_damage = SpecialRestyleDamage::empty();
let is_absolutely_positioned = flow::base(self).flags.contains(IS_ABSOLUTELY_POSITIONED);
// In addition to damage, we use this phase to compute whether nodes affect CSS counters.
let mut has_counter_affecting_children = false;
{
let self_base = flow::mut_base(self);
for kid in self_base.children.iter_mut() {
@ -199,21 +214,32 @@ impl<'a> LayoutDamageComputation for &'a mut (Flow + 'a) {
self_base.restyle_damage
.insert(flow::base(kid).restyle_damage.damage_for_parent(
child_is_absolutely_positioned));
has_counter_affecting_children = has_counter_affecting_children ||
flow::base(kid).flags.intersects(AFFECTS_COUNTERS |
HAS_COUNTER_AFFECTING_CHILDREN);
}
}
let self_base = flow::base(self);
let self_base = flow::mut_base(self);
if self_base.flags.float_kind() != float::T::none &&
self_base.restyle_damage.intersects(REFLOW) {
special_damage.insert(REFLOW_ENTIRE_DOCUMENT);
}
if has_counter_affecting_children {
self_base.flags.insert(HAS_COUNTER_AFFECTING_CHILDREN)
} else {
self_base.flags.remove(HAS_COUNTER_AFFECTING_CHILDREN)
}
special_damage
}
fn reflow_entire_document(self) {
let self_base = flow::mut_base(self);
self_base.restyle_damage.insert(RestyleDamage::all());
self_base.restyle_damage.insert(rebuild_and_reflow());
self_base.restyle_damage.remove(RECONSTRUCT_FLOW);
for kid in self_base.children.iter_mut() {
kid.reflow_entire_document();