servo/components/layout_2020/fragments.rs
Martin Robinson 89855afa4d layout_2020: Tag fragments with their pseudo content type
This will allow us to answer queries and properly handle animations in
the future for fragments generated for pseudo content.
2020-06-06 17:25:08 +02:00

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/* 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 crate::cell::ArcRefCell;
use crate::dom_traversal::{NodeAndStyleInfo, NodeExt, WhichPseudoElement};
use crate::geom::flow_relative::{Rect, Sides};
use crate::geom::{PhysicalPoint, PhysicalRect};
#[cfg(debug_assertions)]
use crate::layout_debug;
use gfx::font::FontMetrics as GfxFontMetrics;
use gfx::text::glyph::GlyphStore;
use gfx_traits::print_tree::PrintTree;
use gfx_traits::{combine_id_with_fragment_type, FragmentType};
#[cfg(not(debug_assertions))]
use serde::ser::{Serialize, Serializer};
use servo_arc::Arc as ServoArc;
use std::sync::Arc;
use style::computed_values::overflow_x::T as ComputedOverflow;
use style::computed_values::position::T as ComputedPosition;
use style::dom::OpaqueNode;
use style::logical_geometry::WritingMode;
use style::properties::ComputedValues;
use style::values::computed::Length;
use style::values::specified::text::TextDecorationLine;
use style::Zero;
use webrender_api::{FontInstanceKey, ImageKey};
#[derive(Clone, Copy, Debug, Eq, PartialEq, Serialize)]
pub(crate) enum Tag {
Node(OpaqueNode),
BeforePseudo(OpaqueNode),
AfterPseudo(OpaqueNode),
}
impl Tag {
pub(crate) fn node(&self) -> OpaqueNode {
match self {
Self::Node(node) | Self::AfterPseudo(node) | Self::BeforePseudo(node) => *node,
}
}
pub(crate) fn to_display_list_fragment_id(&self) -> u64 {
let (node, content_type) = match self {
Self::Node(node) => (node, FragmentType::FragmentBody),
Self::AfterPseudo(node) => (node, FragmentType::BeforePseudoContent),
Self::BeforePseudo(node) => (node, FragmentType::AfterPseudoContent),
};
combine_id_with_fragment_type(node.id() as usize, content_type) as u64
}
pub(crate) fn from_node_and_style_info<'dom, Node>(info: &NodeAndStyleInfo<Node>) -> Self
where
Node: NodeExt<'dom>,
{
let opaque_node = info.node.as_opaque();
match info.pseudo_element_type {
None => Self::Node(opaque_node),
Some(WhichPseudoElement::Before) => Self::BeforePseudo(opaque_node),
Some(WhichPseudoElement::After) => Self::AfterPseudo(opaque_node),
}
}
}
#[derive(Serialize)]
pub(crate) enum Fragment {
Box(BoxFragment),
Anonymous(AnonymousFragment),
AbsoluteOrFixedPositioned(AbsoluteOrFixedPositionedFragment),
Text(TextFragment),
Image(ImageFragment),
}
#[derive(Serialize)]
pub(crate) struct AbsoluteOrFixedPositionedFragment {
pub position: ComputedPosition,
pub hoisted_fragment: ArcRefCell<Option<ArcRefCell<Fragment>>>,
}
#[derive(Serialize)]
pub(crate) struct BoxFragment {
pub tag: Tag,
pub debug_id: DebugId,
#[serde(skip_serializing)]
pub style: ServoArc<ComputedValues>,
pub children: Vec<ArcRefCell<Fragment>>,
/// From the containing blocks start corner…?
/// This might be broken when the containing block is in a different writing mode:
/// https://drafts.csswg.org/css-writing-modes/#orthogonal-flows
pub content_rect: Rect<Length>,
pub padding: Sides<Length>,
pub border: Sides<Length>,
pub margin: Sides<Length>,
pub block_margins_collapsed_with_children: CollapsedBlockMargins,
/// The scrollable overflow of this box fragment.
pub scrollable_overflow_from_children: PhysicalRect<Length>,
}
#[derive(Serialize)]
pub(crate) struct CollapsedBlockMargins {
pub collapsed_through: bool,
pub start: CollapsedMargin,
pub end: CollapsedMargin,
}
#[derive(Clone, Copy, Serialize)]
pub(crate) struct CollapsedMargin {
max_positive: Length,
min_negative: Length,
}
/// Can contain child fragments with relative coordinates, but does not contribute to painting itself.
#[derive(Serialize)]
pub(crate) struct AnonymousFragment {
pub debug_id: DebugId,
pub rect: Rect<Length>,
pub children: Vec<ArcRefCell<Fragment>>,
pub mode: WritingMode,
/// The scrollable overflow of this anonymous fragment's children.
pub scrollable_overflow: PhysicalRect<Length>,
}
#[derive(Clone, Copy, Serialize)]
pub(crate) struct FontMetrics {
pub ascent: Length,
pub line_gap: Length,
pub underline_offset: Length,
pub underline_size: Length,
pub strikeout_offset: Length,
pub strikeout_size: Length,
}
impl From<&GfxFontMetrics> for FontMetrics {
fn from(metrics: &GfxFontMetrics) -> FontMetrics {
FontMetrics {
ascent: metrics.ascent.into(),
line_gap: metrics.line_gap.into(),
underline_offset: metrics.underline_offset.into(),
underline_size: metrics.underline_size.into(),
strikeout_offset: metrics.strikeout_offset.into(),
strikeout_size: metrics.strikeout_size.into(),
}
}
}
#[derive(Serialize)]
pub(crate) struct TextFragment {
pub debug_id: DebugId,
pub tag: Tag,
#[serde(skip_serializing)]
pub parent_style: ServoArc<ComputedValues>,
pub rect: Rect<Length>,
pub font_metrics: FontMetrics,
#[serde(skip_serializing)]
pub font_key: FontInstanceKey,
pub glyphs: Vec<Arc<GlyphStore>>,
/// A flag that represents the _used_ value of the text-decoration property.
pub text_decoration_line: TextDecorationLine,
}
#[derive(Serialize)]
pub(crate) struct ImageFragment {
pub debug_id: DebugId,
#[serde(skip_serializing)]
pub style: ServoArc<ComputedValues>,
pub rect: Rect<Length>,
#[serde(skip_serializing)]
pub image_key: ImageKey,
}
impl Fragment {
pub fn offset_inline(&mut self, offset: &Length) {
let position = match self {
Fragment::Box(f) => &mut f.content_rect.start_corner,
Fragment::AbsoluteOrFixedPositioned(_) => return,
Fragment::Anonymous(f) => &mut f.rect.start_corner,
Fragment::Text(f) => &mut f.rect.start_corner,
Fragment::Image(f) => &mut f.rect.start_corner,
};
position.inline += *offset;
}
pub fn tag(&self) -> Option<Tag> {
match self {
Fragment::Box(fragment) => Some(fragment.tag),
Fragment::Text(fragment) => Some(fragment.tag),
Fragment::AbsoluteOrFixedPositioned(_) |
Fragment::Anonymous(_) |
Fragment::Image(_) => None,
}
}
pub fn print(&self, tree: &mut PrintTree) {
match self {
Fragment::Box(fragment) => fragment.print(tree),
Fragment::AbsoluteOrFixedPositioned(fragment) => fragment.print(tree),
Fragment::Anonymous(fragment) => fragment.print(tree),
Fragment::Text(fragment) => fragment.print(tree),
Fragment::Image(fragment) => fragment.print(tree),
}
}
pub fn scrollable_overflow(
&self,
containing_block: &PhysicalRect<Length>,
) -> PhysicalRect<Length> {
match self {
Fragment::Box(fragment) => fragment.scrollable_overflow_for_parent(&containing_block),
Fragment::AbsoluteOrFixedPositioned(_) => PhysicalRect::zero(),
Fragment::Anonymous(fragment) => fragment.scrollable_overflow.clone(),
Fragment::Text(fragment) => fragment
.rect
.to_physical(fragment.parent_style.writing_mode, &containing_block),
Fragment::Image(fragment) => fragment
.rect
.to_physical(fragment.style.writing_mode, &containing_block),
}
}
pub(crate) fn find<T>(
&self,
containing_block: &PhysicalRect<Length>,
process_func: &mut impl FnMut(&Fragment, &PhysicalRect<Length>) -> Option<T>,
) -> Option<T> {
if let Some(result) = process_func(self, containing_block) {
return Some(result);
}
match self {
Fragment::Box(fragment) => {
let new_containing_block = fragment
.content_rect
.to_physical(fragment.style.writing_mode, containing_block)
.translate(containing_block.origin.to_vector());
fragment
.children
.iter()
.find_map(|child| child.borrow().find(&new_containing_block, process_func))
},
Fragment::Anonymous(fragment) => {
let new_containing_block = fragment
.rect
.to_physical(fragment.mode, containing_block)
.translate(containing_block.origin.to_vector());
fragment
.children
.iter()
.find_map(|child| child.borrow().find(&new_containing_block, process_func))
},
_ => None,
}
}
}
impl AbsoluteOrFixedPositionedFragment {
pub fn print(&self, tree: &mut PrintTree) {
tree.add_item(format!("AbsoluteOrFixedPositionedFragment"));
}
}
impl AnonymousFragment {
pub fn no_op(mode: WritingMode) -> Self {
Self {
debug_id: DebugId::new(),
children: vec![],
rect: Rect::zero(),
mode,
scrollable_overflow: PhysicalRect::zero(),
}
}
pub fn new(rect: Rect<Length>, children: Vec<Fragment>, mode: WritingMode) -> Self {
// FIXME(mrobinson, bug 25564): We should be using the containing block
// here to properly convert scrollable overflow to physical geometry.
let containing_block = PhysicalRect::zero();
let content_origin = rect.start_corner.to_physical(mode);
let scrollable_overflow = children.iter().fold(PhysicalRect::zero(), |acc, child| {
acc.union(
&child
.scrollable_overflow(&containing_block)
.translate(content_origin.to_vector()),
)
});
AnonymousFragment {
debug_id: DebugId::new(),
rect,
children: children
.into_iter()
.map(|fragment| ArcRefCell::new(fragment))
.collect(),
mode,
scrollable_overflow,
}
}
pub fn print(&self, tree: &mut PrintTree) {
tree.new_level(format!(
"Anonymous\
\nrect={:?}\
\nscrollable_overflow={:?}",
self.rect, self.scrollable_overflow
));
for child in &self.children {
child.borrow().print(tree);
}
tree.end_level();
}
}
impl BoxFragment {
pub fn new(
tag: Tag,
style: ServoArc<ComputedValues>,
children: Vec<Fragment>,
content_rect: Rect<Length>,
padding: Sides<Length>,
border: Sides<Length>,
margin: Sides<Length>,
block_margins_collapsed_with_children: CollapsedBlockMargins,
) -> BoxFragment {
// FIXME(mrobinson, bug 25564): We should be using the containing block
// here to properly convert scrollable overflow to physical geometry.
let containing_block = PhysicalRect::zero();
let scrollable_overflow_from_children =
children.iter().fold(PhysicalRect::zero(), |acc, child| {
acc.union(&child.scrollable_overflow(&containing_block))
});
BoxFragment {
tag,
debug_id: DebugId::new(),
style,
children: children
.into_iter()
.map(|fragment| ArcRefCell::new(fragment))
.collect(),
content_rect,
padding,
border,
margin,
block_margins_collapsed_with_children,
scrollable_overflow_from_children,
}
}
pub fn scrollable_overflow(
&self,
containing_block: &PhysicalRect<Length>,
) -> PhysicalRect<Length> {
let physical_padding_rect = self
.padding_rect()
.to_physical(self.style.writing_mode, containing_block);
let content_origin = self
.content_rect
.start_corner
.to_physical(self.style.writing_mode);
physical_padding_rect.union(
&self
.scrollable_overflow_from_children
.translate(content_origin.to_vector()),
)
}
pub fn padding_rect(&self) -> Rect<Length> {
self.content_rect.inflate(&self.padding)
}
pub fn border_rect(&self) -> Rect<Length> {
self.padding_rect().inflate(&self.border)
}
pub fn print(&self, tree: &mut PrintTree) {
tree.new_level(format!(
"Box\
\ncontent={:?}\
\npadding rect={:?}\
\nborder rect={:?}\
\nscrollable_overflow={:?}\
\noverflow={:?} / {:?}\
\nstyle={:p}",
self.content_rect,
self.padding_rect(),
self.border_rect(),
self.scrollable_overflow(&PhysicalRect::zero()),
self.style.get_box().overflow_x,
self.style.get_box().overflow_y,
self.style,
));
for child in &self.children {
child.borrow().print(tree);
}
tree.end_level();
}
pub fn scrollable_overflow_for_parent(
&self,
containing_block: &PhysicalRect<Length>,
) -> PhysicalRect<Length> {
let mut overflow = self
.border_rect()
.to_physical(self.style.writing_mode, containing_block);
if self.style.get_box().overflow_y != ComputedOverflow::Visible &&
self.style.get_box().overflow_x != ComputedOverflow::Visible
{
return overflow;
}
// https://www.w3.org/TR/css-overflow-3/#scrollable
// Only include the scrollable overflow of a child box if it has overflow: visible.
let scrollable_overflow = self.scrollable_overflow(&containing_block);
let bottom_right = PhysicalPoint::new(
overflow.max_x().max(scrollable_overflow.max_x()),
overflow.max_y().max(scrollable_overflow.max_y()),
);
if self.style.get_box().overflow_y == ComputedOverflow::Visible {
overflow.origin.y = overflow.origin.y.min(scrollable_overflow.origin.y);
overflow.size.height = bottom_right.y - overflow.origin.y;
}
if self.style.get_box().overflow_x == ComputedOverflow::Visible {
overflow.origin.x = overflow.origin.x.min(scrollable_overflow.origin.x);
overflow.size.width = bottom_right.x - overflow.origin.x;
}
overflow
}
}
impl TextFragment {
pub fn print(&self, tree: &mut PrintTree) {
tree.add_item(format!(
"Text num_glyphs={}",
self.glyphs
.iter()
.map(|glyph_store| glyph_store.len().0)
.sum::<isize>()
));
}
}
impl ImageFragment {
pub fn print(&self, tree: &mut PrintTree) {
tree.add_item(format!(
"Image\
\nrect={:?}",
self.rect
));
}
}
impl CollapsedBlockMargins {
pub fn from_margin(margin: &Sides<Length>) -> Self {
Self {
collapsed_through: false,
start: CollapsedMargin::new(margin.block_start),
end: CollapsedMargin::new(margin.block_end),
}
}
pub fn zero() -> Self {
Self {
collapsed_through: false,
start: CollapsedMargin::zero(),
end: CollapsedMargin::zero(),
}
}
}
impl CollapsedMargin {
pub fn zero() -> Self {
Self {
max_positive: Length::zero(),
min_negative: Length::zero(),
}
}
pub fn new(margin: Length) -> Self {
Self {
max_positive: margin.max(Length::zero()),
min_negative: margin.min(Length::zero()),
}
}
pub fn adjoin(&self, other: &Self) -> Self {
Self {
max_positive: self.max_positive.max(other.max_positive),
min_negative: self.min_negative.min(other.min_negative),
}
}
pub fn adjoin_assign(&mut self, other: &Self) {
*self = self.adjoin(other);
}
pub fn solve(&self) -> Length {
self.max_positive + self.min_negative
}
}
#[cfg(not(debug_assertions))]
#[derive(Clone)]
pub struct DebugId;
#[cfg(debug_assertions)]
#[derive(Clone, Serialize)]
#[serde(transparent)]
pub struct DebugId(u16);
#[cfg(not(debug_assertions))]
impl DebugId {
pub fn new() -> DebugId {
DebugId
}
}
#[cfg(debug_assertions)]
impl DebugId {
pub fn new() -> DebugId {
DebugId(layout_debug::generate_unique_debug_id())
}
}
#[cfg(not(debug_assertions))]
impl Serialize for DebugId {
fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
serializer.serialize_str(&format!("{:p}", &self))
}
}