servo/components/layout/query.rs
Martin Robinson 5c1723c983
rustdoc: Fix many rustdoc errors (#31147)
This fixes many rustdoc errors that occur due to raw URLs in rustdoc
comments as well as unescaped Rust code that should be in backticks.
2024-01-22 13:13:48 +00:00

1262 lines
45 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/. */
//! Utilities for querying the layout, as needed by the layout thread.
use std::cmp::{max, min};
use std::ops::Deref;
use std::sync::{Arc, Mutex};
use app_units::Au;
use euclid::default::{Box2D, Point2D, Rect, Size2D, Vector2D};
use euclid::Size2D as TypedSize2D;
use ipc_channel::ipc::IpcSender;
use msg::constellation_msg::PipelineId;
use script_layout_interface::rpc::{
ContentBoxResponse, ContentBoxesResponse, LayoutRPC, NodeGeometryResponse,
NodeScrollIdResponse, OffsetParentResponse, ResolvedStyleResponse, TextIndexResponse,
};
use script_layout_interface::wrapper_traits::{
LayoutNode, ThreadSafeLayoutElement, ThreadSafeLayoutNode,
};
use script_layout_interface::{LayoutElementType, LayoutNodeType};
use script_traits::{LayoutMsg as ConstellationMsg, UntrustedNodeAddress};
use servo_arc::Arc as ServoArc;
use servo_url::ServoUrl;
use style::computed_values::display::T as Display;
use style::computed_values::position::T as Position;
use style::computed_values::visibility::T as Visibility;
use style::context::{QuirksMode, SharedStyleContext, StyleContext, ThreadLocalStyleContext};
use style::dom::TElement;
use style::logical_geometry::{BlockFlowDirection, InlineBaseDirection, WritingMode};
use style::properties::style_structs::{self, Font};
use style::properties::{
parse_one_declaration_into, ComputedValues, Importance, LonghandId, PropertyDeclarationBlock,
PropertyDeclarationId, PropertyId, SourcePropertyDeclaration,
};
use style::selector_parser::PseudoElement;
use style::shared_lock::SharedRwLock;
use style::stylesheets::{CssRuleType, Origin};
use style_traits::{CSSPixel, ParsingMode, ToCss};
use webrender_api::ExternalScrollId;
use crate::construct::ConstructionResult;
use crate::context::LayoutContext;
use crate::display_list::items::{DisplayList, OpaqueNode, ScrollOffsetMap};
use crate::display_list::IndexableText;
use crate::flow::{Flow, GetBaseFlow};
use crate::fragment::{Fragment, FragmentBorderBoxIterator, FragmentFlags, SpecificFragmentInfo};
use crate::inline::InlineFragmentNodeFlags;
use crate::sequential;
use crate::wrapper::LayoutNodeLayoutData;
/// Mutable data belonging to the LayoutThread.
///
/// This needs to be protected by a mutex so we can do fast RPCs.
pub struct LayoutThreadData {
/// The channel on which messages can be sent to the constellation.
pub constellation_chan: IpcSender<ConstellationMsg>,
/// The root stacking context.
pub display_list: Option<DisplayList>,
pub indexable_text: IndexableText,
/// A queued response for the union of the content boxes of a node.
pub content_box_response: Option<Rect<Au>>,
/// A queued response for the content boxes of a node.
pub content_boxes_response: Vec<Rect<Au>>,
/// A queued response for the client {top, left, width, height} of a node in pixels.
pub client_rect_response: Rect<i32>,
/// A queued response for the scroll id for a given node.
pub scroll_id_response: Option<ExternalScrollId>,
/// A queued response for the scroll {top, left, width, height} of a node in pixels.
pub scrolling_area_response: Rect<i32>,
/// A queued response for the resolved style property of an element.
pub resolved_style_response: String,
/// A queued response for the resolved font style for canvas.
pub resolved_font_style_response: Option<ServoArc<Font>>,
/// A queued response for the offset parent/rect of a node.
pub offset_parent_response: OffsetParentResponse,
/// Scroll offsets of scrolling regions.
pub scroll_offsets: ScrollOffsetMap,
/// Index in a text fragment. We need this do determine the insertion point.
pub text_index_response: TextIndexResponse,
/// A queued response for the list of nodes at a given point.
pub nodes_from_point_response: Vec<UntrustedNodeAddress>,
/// A queued response for the inner text of a given element.
pub element_inner_text_response: String,
/// A queued response for the viewport dimensions for a given browsing context.
pub inner_window_dimensions_response: Option<TypedSize2D<f32, CSSPixel>>,
}
pub struct LayoutRPCImpl(pub Arc<Mutex<LayoutThreadData>>);
// https://drafts.csswg.org/cssom-view/#overflow-directions
fn overflow_direction(writing_mode: &WritingMode) -> OverflowDirection {
match (
writing_mode.block_flow_direction(),
writing_mode.inline_base_direction(),
) {
(BlockFlowDirection::TopToBottom, InlineBaseDirection::LeftToRight) |
(BlockFlowDirection::LeftToRight, InlineBaseDirection::LeftToRight) => {
OverflowDirection::RightAndDown
},
(BlockFlowDirection::TopToBottom, InlineBaseDirection::RightToLeft) |
(BlockFlowDirection::RightToLeft, InlineBaseDirection::LeftToRight) => {
OverflowDirection::LeftAndDown
},
(BlockFlowDirection::RightToLeft, InlineBaseDirection::RightToLeft) => {
OverflowDirection::LeftAndUp
},
(BlockFlowDirection::LeftToRight, InlineBaseDirection::RightToLeft) => {
OverflowDirection::RightAndUp
},
}
}
impl LayoutRPC for LayoutRPCImpl {
// The neat thing here is that in order to answer the following two queries we only
// need to compare nodes for equality. Thus we can safely work only with `OpaqueNode`.
fn content_box(&self) -> ContentBoxResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
ContentBoxResponse(rw_data.content_box_response)
}
/// Requests the dimensions of all the content boxes, as in the `getClientRects()` call.
fn content_boxes(&self) -> ContentBoxesResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
ContentBoxesResponse(rw_data.content_boxes_response.clone())
}
fn nodes_from_point_response(&self) -> Vec<UntrustedNodeAddress> {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.nodes_from_point_response.clone()
}
fn node_geometry(&self) -> NodeGeometryResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
NodeGeometryResponse {
client_rect: rw_data.client_rect_response,
}
}
fn scrolling_area(&self) -> NodeGeometryResponse {
NodeGeometryResponse {
client_rect: self.0.lock().unwrap().scrolling_area_response,
}
}
fn node_scroll_id(&self) -> NodeScrollIdResponse {
NodeScrollIdResponse(
self.0
.lock()
.unwrap()
.scroll_id_response
.expect("scroll id is not correctly fetched"),
)
}
/// Retrieves the resolved value for a CSS style property.
fn resolved_style(&self) -> ResolvedStyleResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
ResolvedStyleResponse(rw_data.resolved_style_response.clone())
}
fn resolved_font_style(&self) -> Option<ServoArc<Font>> {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.resolved_font_style_response.clone()
}
fn offset_parent(&self) -> OffsetParentResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.offset_parent_response.clone()
}
fn text_index(&self) -> TextIndexResponse {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.text_index_response.clone()
}
fn element_inner_text(&self) -> String {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.element_inner_text_response.clone()
}
fn inner_window_dimensions(&self) -> Option<TypedSize2D<f32, CSSPixel>> {
let &LayoutRPCImpl(ref rw_data) = self;
let rw_data = rw_data.lock().unwrap();
rw_data.inner_window_dimensions_response.clone()
}
}
struct UnioningFragmentBorderBoxIterator {
node_address: OpaqueNode,
rect: Option<Rect<Au>>,
}
impl UnioningFragmentBorderBoxIterator {
fn new(node_address: OpaqueNode) -> UnioningFragmentBorderBoxIterator {
UnioningFragmentBorderBoxIterator {
node_address: node_address,
rect: None,
}
}
}
impl FragmentBorderBoxIterator for UnioningFragmentBorderBoxIterator {
fn process(&mut self, _: &Fragment, _: i32, border_box: &Rect<Au>) {
self.rect = match self.rect {
Some(rect) => Some(rect.union(border_box)),
None => Some(*border_box),
};
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.contains_node(self.node_address)
}
}
struct CollectingFragmentBorderBoxIterator {
node_address: OpaqueNode,
rects: Vec<Rect<Au>>,
}
impl CollectingFragmentBorderBoxIterator {
fn new(node_address: OpaqueNode) -> CollectingFragmentBorderBoxIterator {
CollectingFragmentBorderBoxIterator {
node_address: node_address,
rects: Vec::new(),
}
}
}
impl FragmentBorderBoxIterator for CollectingFragmentBorderBoxIterator {
fn process(&mut self, _: &Fragment, _: i32, border_box: &Rect<Au>) {
self.rects.push(*border_box);
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.contains_node(self.node_address)
}
}
enum Side {
Left,
Right,
Bottom,
Top,
}
enum MarginPadding {
Margin,
Padding,
}
enum PositionProperty {
Left,
Right,
Top,
Bottom,
Width,
Height,
}
#[derive(Debug)]
enum OverflowDirection {
RightAndDown,
LeftAndDown,
LeftAndUp,
RightAndUp,
}
struct PositionRetrievingFragmentBorderBoxIterator {
node_address: OpaqueNode,
result: Option<Au>,
position: Point2D<Au>,
property: PositionProperty,
}
impl PositionRetrievingFragmentBorderBoxIterator {
fn new(
node_address: OpaqueNode,
property: PositionProperty,
position: Point2D<Au>,
) -> PositionRetrievingFragmentBorderBoxIterator {
PositionRetrievingFragmentBorderBoxIterator {
node_address: node_address,
position: position,
property: property,
result: None,
}
}
}
impl FragmentBorderBoxIterator for PositionRetrievingFragmentBorderBoxIterator {
fn process(&mut self, fragment: &Fragment, _: i32, border_box: &Rect<Au>) {
let border_padding = fragment
.border_padding
.to_physical(fragment.style.writing_mode);
self.result = Some(match self.property {
PositionProperty::Left => self.position.x,
PositionProperty::Top => self.position.y,
PositionProperty::Width => border_box.size.width - border_padding.horizontal(),
PositionProperty::Height => border_box.size.height - border_padding.vertical(),
// TODO: the following 2 calculations are completely wrong.
// They should return the difference between the parent's and this
// fragment's border boxes.
PositionProperty::Right => border_box.max_x() + self.position.x,
PositionProperty::Bottom => border_box.max_y() + self.position.y,
});
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.contains_node(self.node_address)
}
}
struct MarginRetrievingFragmentBorderBoxIterator {
node_address: OpaqueNode,
result: Option<Au>,
writing_mode: WritingMode,
margin_padding: MarginPadding,
side: Side,
}
impl MarginRetrievingFragmentBorderBoxIterator {
fn new(
node_address: OpaqueNode,
side: Side,
margin_padding: MarginPadding,
writing_mode: WritingMode,
) -> MarginRetrievingFragmentBorderBoxIterator {
MarginRetrievingFragmentBorderBoxIterator {
node_address: node_address,
side: side,
margin_padding: margin_padding,
result: None,
writing_mode: writing_mode,
}
}
}
impl FragmentBorderBoxIterator for MarginRetrievingFragmentBorderBoxIterator {
fn process(&mut self, fragment: &Fragment, _: i32, _: &Rect<Au>) {
let rect = match self.margin_padding {
MarginPadding::Margin => &fragment.margin,
MarginPadding::Padding => &fragment.border_padding,
};
self.result = Some(match self.side {
Side::Left => rect.left(self.writing_mode),
Side::Right => rect.right(self.writing_mode),
Side::Bottom => rect.bottom(self.writing_mode),
Side::Top => rect.top(self.writing_mode),
});
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.contains_node(self.node_address)
}
}
pub fn process_content_box_request(
requested_node: OpaqueNode,
layout_root: &mut dyn Flow,
) -> Option<Rect<Au>> {
// FIXME(pcwalton): This has not been updated to handle the stacking context relative
// stuff. So the position is wrong in most cases.
let mut iterator = UnioningFragmentBorderBoxIterator::new(requested_node);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
iterator.rect
}
pub fn process_content_boxes_request(
requested_node: OpaqueNode,
layout_root: &mut dyn Flow,
) -> Vec<Rect<Au>> {
// FIXME(pcwalton): This has not been updated to handle the stacking context relative
// stuff. So the position is wrong in most cases.
let mut iterator = CollectingFragmentBorderBoxIterator::new(requested_node);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
iterator.rects
}
struct FragmentClientRectQueryIterator {
node_address: OpaqueNode,
client_rect: Rect<i32>,
}
impl FragmentClientRectQueryIterator {
fn new(node_address: OpaqueNode) -> FragmentClientRectQueryIterator {
FragmentClientRectQueryIterator {
node_address: node_address,
client_rect: Rect::zero(),
}
}
}
struct UnioningFragmentScrollAreaIterator {
node_address: OpaqueNode,
union_rect: Rect<i32>,
origin_rect: Rect<i32>,
level: Option<i32>,
is_child: bool,
overflow_direction: OverflowDirection,
}
impl UnioningFragmentScrollAreaIterator {
fn new(node_address: OpaqueNode) -> UnioningFragmentScrollAreaIterator {
UnioningFragmentScrollAreaIterator {
node_address: node_address,
union_rect: Rect::zero(),
origin_rect: Rect::zero(),
level: None,
is_child: false,
// FIXME(#20867)
overflow_direction: OverflowDirection::RightAndDown,
}
}
}
struct NodeOffsetBoxInfo {
offset: Point2D<Au>,
rectangle: Rect<Au>,
}
struct ParentBorderBoxInfo {
node_address: OpaqueNode,
origin: Point2D<Au>,
}
struct ParentOffsetBorderBoxIterator {
node_address: OpaqueNode,
has_processed_node: bool,
node_offset_box: Option<NodeOffsetBoxInfo>,
parent_nodes: Vec<Option<ParentBorderBoxInfo>>,
}
impl ParentOffsetBorderBoxIterator {
fn new(node_address: OpaqueNode) -> ParentOffsetBorderBoxIterator {
ParentOffsetBorderBoxIterator {
node_address: node_address,
has_processed_node: false,
node_offset_box: None,
parent_nodes: Vec::new(),
}
}
}
impl FragmentBorderBoxIterator for FragmentClientRectQueryIterator {
fn process(&mut self, fragment: &Fragment, _: i32, border_box: &Rect<Au>) {
let style_structs::Border {
border_top_width: top_width,
border_right_width: right_width,
border_bottom_width: bottom_width,
border_left_width: left_width,
..
} = *fragment.style.get_border();
let (left_width, right_width) = (left_width.to_px(), right_width.to_px());
let (top_width, bottom_width) = (top_width.to_px(), bottom_width.to_px());
self.client_rect.origin.y = top_width;
self.client_rect.origin.x = left_width;
self.client_rect.size.width = border_box.size.width.to_px() - left_width - right_width;
self.client_rect.size.height = border_box.size.height.to_px() - top_width - bottom_width;
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.node == self.node_address
}
}
// https://drafts.csswg.org/cssom-view/#scrolling-area
impl FragmentBorderBoxIterator for UnioningFragmentScrollAreaIterator {
fn process(&mut self, fragment: &Fragment, level: i32, border_box: &Rect<Au>) {
// In cases in which smaller child elements contain less padding than the parent
// the a union of the two elements padding rectangles could result in an unwanted
// increase in size. To work around this, we store the original elements padding
// rectangle as `origin_rect` and the union of all child elements padding and
// margin rectangles as `union_rect`.
let style_structs::Border {
border_top_width: top_border,
border_right_width: right_border,
border_bottom_width: bottom_border,
border_left_width: left_border,
..
} = *fragment.style.get_border();
let (left_border, right_border) = (left_border.to_px(), right_border.to_px());
let (top_border, bottom_border) = (top_border.to_px(), bottom_border.to_px());
let right_padding = border_box.size.width.to_px() - right_border - left_border;
let bottom_padding = border_box.size.height.to_px() - bottom_border - top_border;
let top_padding = top_border as i32;
let left_padding = left_border as i32;
match self.level {
Some(start_level) if level <= start_level => {
self.is_child = false;
},
Some(_) => {
let padding = Rect::new(
Point2D::new(left_padding, top_padding),
Size2D::new(right_padding, bottom_padding),
);
let top_margin = fragment.margin.top(fragment.style.writing_mode).to_px();
let left_margin = fragment.margin.left(fragment.style.writing_mode).to_px();
let bottom_margin = fragment.margin.bottom(fragment.style.writing_mode).to_px();
let right_margin = fragment.margin.right(fragment.style.writing_mode).to_px();
let margin = Rect::new(
Point2D::new(left_margin, top_margin),
Size2D::new(right_margin, bottom_margin),
);
// This is a workaround because euclid does not support unioning empty
// rectangles.
// TODO: The way that this iterator is calculating scroll area is very
// suspect and the code below is a workaround until it can be written
// in a better way.
self.union_rect = Box2D::new(
Point2D::new(
min(
padding.min_x(),
min(margin.min_x(), self.union_rect.min_x()),
),
min(
padding.min_y(),
min(margin.min_y(), self.union_rect.min_y()),
),
),
Point2D::new(
max(
padding.max_x(),
max(margin.max_x(), self.union_rect.max_x()),
),
max(
padding.max_y(),
max(margin.max_y(), self.union_rect.max_y()),
),
),
)
.to_rect();
},
None => {
self.level = Some(level);
self.is_child = true;
self.overflow_direction = overflow_direction(&fragment.style.writing_mode);
self.origin_rect = Rect::new(
Point2D::new(left_padding, top_padding),
Size2D::new(right_padding, bottom_padding),
);
},
};
}
fn should_process(&mut self, fragment: &Fragment) -> bool {
fragment.contains_node(self.node_address) || self.is_child
}
}
// https://drafts.csswg.org/cssom-view/#extensions-to-the-htmlelement-interface
impl FragmentBorderBoxIterator for ParentOffsetBorderBoxIterator {
fn process(&mut self, fragment: &Fragment, level: i32, border_box: &Rect<Au>) {
if self.node_offset_box.is_none() {
// We haven't found the node yet, so we're still looking
// for its parent. Remove all nodes at this level or
// higher, as they can't be parents of this node.
self.parent_nodes.truncate(level as usize);
assert_eq!(
self.parent_nodes.len(),
level as usize,
"Skipped at least one level in the flow tree!"
);
}
if !fragment.is_primary_fragment() {
// This fragment doesn't correspond to anything worth
// taking measurements from.
if self.node_offset_box.is_none() {
// If this is the only fragment in the flow, we need to
// do this to avoid failing the above assertion.
self.parent_nodes.push(None);
}
return;
}
if fragment.node == self.node_address {
// Found the fragment in the flow tree that matches the
// DOM node being looked for.
assert!(
self.node_offset_box.is_none(),
"Node was being treated as inline, but it has an associated fragment!"
);
self.has_processed_node = true;
self.node_offset_box = Some(NodeOffsetBoxInfo {
offset: border_box.origin,
rectangle: *border_box,
});
// offsetParent returns null if the node is fixed.
if fragment.style.get_box().position == Position::Fixed {
self.parent_nodes.clear();
}
} else if let Some(node) = fragment.inline_context.as_ref().and_then(|inline_context| {
inline_context
.nodes
.iter()
.find(|node| node.address == self.node_address)
}) {
// TODO: Handle cases where the `offsetParent` is an inline
// element. This will likely be impossible until
// https://github.com/servo/servo/issues/13982 is fixed.
// Found a fragment in the flow tree whose inline context
// contains the DOM node we're looking for, i.e. the node
// is inline and contains this fragment.
match self.node_offset_box {
Some(NodeOffsetBoxInfo {
ref mut rectangle, ..
}) => {
*rectangle = rectangle.union(border_box);
},
None => {
// https://github.com/servo/servo/issues/13982 will
// cause this assertion to fail sometimes, so it's
// commented out for now.
/*assert!(node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT),
"First fragment of inline node found wasn't its first fragment!");*/
self.node_offset_box = Some(NodeOffsetBoxInfo {
offset: border_box.origin,
rectangle: *border_box,
});
},
}
if node
.flags
.contains(InlineFragmentNodeFlags::LAST_FRAGMENT_OF_ELEMENT)
{
self.has_processed_node = true;
}
} else if self.node_offset_box.is_none() {
let is_body_element = fragment
.flags
.contains(FragmentFlags::IS_BODY_ELEMENT_OF_HTML_ELEMENT_ROOT);
let is_valid_parent = match (
is_body_element,
fragment.style.get_box().position,
&fragment.specific,
) {
// Spec says it's valid if any of these are true:
// 1) Is the body element
// 2) Is static position *and* is a table or table cell
// 3) Is not static position
(true, _, _) |
(false, Position::Static, &SpecificFragmentInfo::Table) |
(false, Position::Static, &SpecificFragmentInfo::TableCell) |
(false, Position::Sticky, _) |
(false, Position::Absolute, _) |
(false, Position::Relative, _) |
(false, Position::Fixed, _) => true,
// Otherwise, it's not a valid parent
(false, Position::Static, _) => false,
};
let parent_info = if is_valid_parent {
let border_width = fragment
.border_width()
.to_physical(fragment.style.writing_mode);
Some(ParentBorderBoxInfo {
node_address: fragment.node,
origin: border_box.origin + Vector2D::new(border_width.left, border_width.top),
})
} else {
None
};
self.parent_nodes.push(parent_info);
}
}
fn should_process(&mut self, _: &Fragment) -> bool {
!self.has_processed_node
}
}
pub fn process_client_rect_query(
requested_node: OpaqueNode,
layout_root: &mut dyn Flow,
) -> Rect<i32> {
let mut iterator = FragmentClientRectQueryIterator::new(requested_node);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
iterator.client_rect
}
pub fn process_node_scroll_id_request<'dom>(
id: PipelineId,
requested_node: impl LayoutNode<'dom>,
) -> ExternalScrollId {
let layout_node = requested_node.to_threadsafe();
layout_node.generate_scroll_id(id)
}
/// <https://drafts.csswg.org/cssom-view/#scrolling-area>
pub fn process_scrolling_area_request(
requested_node: Option<OpaqueNode>,
layout_root: &mut dyn Flow,
) -> Rect<i32> {
let requested_node = match requested_node {
Some(node) => node,
None => {
let rect = layout_root.base().overflow.scroll;
return Rect::new(
Point2D::new(rect.origin.x.to_nearest_px(), rect.origin.y.to_nearest_px()),
Size2D::new(rect.width().ceil_to_px(), rect.height().ceil_to_px()),
);
},
};
let mut iterator = UnioningFragmentScrollAreaIterator::new(requested_node);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
match iterator.overflow_direction {
OverflowDirection::RightAndDown => {
let right = max(
iterator.union_rect.size.width,
iterator.origin_rect.size.width,
);
let bottom = max(
iterator.union_rect.size.height,
iterator.origin_rect.size.height,
);
Rect::new(iterator.origin_rect.origin, Size2D::new(right, bottom))
},
OverflowDirection::LeftAndDown => {
let bottom = max(
iterator.union_rect.size.height,
iterator.origin_rect.size.height,
);
let left = min(iterator.union_rect.origin.x, iterator.origin_rect.origin.x);
Rect::new(
Point2D::new(left, iterator.origin_rect.origin.y),
Size2D::new(iterator.origin_rect.size.width, bottom),
)
},
OverflowDirection::LeftAndUp => {
let top = min(iterator.union_rect.origin.y, iterator.origin_rect.origin.y);
let left = min(iterator.union_rect.origin.x, iterator.origin_rect.origin.x);
Rect::new(Point2D::new(left, top), iterator.origin_rect.size)
},
OverflowDirection::RightAndUp => {
let top = min(iterator.union_rect.origin.y, iterator.origin_rect.origin.y);
let right = max(
iterator.union_rect.size.width,
iterator.origin_rect.size.width,
);
Rect::new(
Point2D::new(iterator.origin_rect.origin.x, top),
Size2D::new(right, iterator.origin_rect.size.height),
)
},
}
}
fn create_font_declaration(
value: &str,
property: &PropertyId,
url_data: &ServoUrl,
quirks_mode: QuirksMode,
) -> Option<PropertyDeclarationBlock> {
let mut declarations = SourcePropertyDeclaration::default();
let result = parse_one_declaration_into(
&mut declarations,
property.clone(),
value,
Origin::Author,
url_data,
None,
ParsingMode::DEFAULT,
quirks_mode,
CssRuleType::Style,
);
let declarations = match result {
Ok(()) => {
let mut block = PropertyDeclarationBlock::new();
block.extend(declarations.drain(), Importance::Normal);
block
},
Err(_) => return None,
};
// TODO: Force to set line-height property to 'normal' font property.
Some(declarations)
}
fn resolve_for_declarations<'dom, E>(
context: &SharedStyleContext,
parent_style: Option<&ComputedValues>,
declarations: PropertyDeclarationBlock,
shared_lock: &SharedRwLock,
) -> ServoArc<ComputedValues>
where
E: LayoutNode<'dom>,
{
let parent_style = match parent_style {
Some(parent) => &*parent,
None => context.stylist.device().default_computed_values(),
};
context
.stylist
.compute_for_declarations::<E::ConcreteElement>(
&context.guards,
&*parent_style,
ServoArc::new(shared_lock.wrap(declarations)),
)
}
pub fn process_resolved_font_style_request<'dom, E>(
context: &LayoutContext,
node: E,
value: &str,
property: &PropertyId,
url_data: ServoUrl,
shared_lock: &SharedRwLock,
) -> Option<ServoArc<Font>>
where
E: LayoutNode<'dom>,
{
use style::stylist::RuleInclusion;
use style::traversal::resolve_style;
// 1. Parse the given font property value
let quirks_mode = context.style_context.quirks_mode();
let declarations = create_font_declaration(value, property, &url_data, quirks_mode)?;
// TODO: Reject 'inherit' and 'initial' values for the font property.
// 2. Get resolved styles for the parent element
let element = node.as_element().unwrap();
let parent_style = if node.is_connected() {
if element.has_data() {
node.to_threadsafe().as_element().unwrap().resolved_style()
} else {
let mut tlc = ThreadLocalStyleContext::new();
let mut context = StyleContext {
shared: &context.style_context,
thread_local: &mut tlc,
};
let styles = resolve_style(&mut context, element, RuleInclusion::All, None, None);
styles.primary().clone()
}
} else {
let default_declarations =
create_font_declaration("10px sans-serif", property, &url_data, quirks_mode).unwrap();
resolve_for_declarations::<E>(
&context.style_context,
None,
default_declarations,
shared_lock,
)
};
// 3. Resolve the parsed value with resolved styles of the parent element
let computed_values = resolve_for_declarations::<E>(
&context.style_context,
Some(&*parent_style),
declarations,
shared_lock,
);
Some(computed_values.clone_font())
}
/// Return the resolved value of property for a given (pseudo)element.
/// <https://drafts.csswg.org/cssom/#resolved-value>
pub fn process_resolved_style_request<'dom>(
context: &LayoutContext,
node: impl LayoutNode<'dom>,
pseudo: &Option<PseudoElement>,
property: &PropertyId,
layout_root: &mut dyn Flow,
) -> String {
use style::stylist::RuleInclusion;
use style::traversal::resolve_style;
let element = node.as_element().unwrap();
// We call process_resolved_style_request after performing a whole-document
// traversal, so in the common case, the element is styled.
if element.has_data() {
return process_resolved_style_request_internal(node, pseudo, property, layout_root);
}
// In a display: none subtree. No pseudo-element exists.
if pseudo.is_some() {
return String::new();
}
let mut tlc = ThreadLocalStyleContext::new();
let mut context = StyleContext {
shared: &context.style_context,
thread_local: &mut tlc,
};
let styles = resolve_style(
&mut context,
element,
RuleInclusion::All,
pseudo.as_ref(),
None,
);
let style = styles.primary();
let longhand_id = match *property {
PropertyId::LonghandAlias(id, _) | PropertyId::Longhand(id) => id,
// Firefox returns blank strings for the computed value of shorthands,
// so this should be web-compatible.
PropertyId::ShorthandAlias(..) | PropertyId::Shorthand(_) => return String::new(),
PropertyId::Custom(ref name) => {
return style.computed_value_to_string(PropertyDeclarationId::Custom(name));
},
};
// No need to care about used values here, since we're on a display: none
// subtree, use the resolved value.
style.computed_value_to_string(PropertyDeclarationId::Longhand(longhand_id))
}
/// The primary resolution logic, which assumes that the element is styled.
fn process_resolved_style_request_internal<'dom>(
requested_node: impl LayoutNode<'dom>,
pseudo: &Option<PseudoElement>,
property: &PropertyId,
layout_root: &mut dyn Flow,
) -> String {
let layout_el = requested_node.to_threadsafe().as_element().unwrap();
let layout_el = match *pseudo {
Some(PseudoElement::Before) => layout_el.get_before_pseudo(),
Some(PseudoElement::After) => layout_el.get_after_pseudo(),
Some(PseudoElement::DetailsSummary) |
Some(PseudoElement::DetailsContent) |
Some(PseudoElement::Selection) => None,
// FIXME(emilio): What about the other pseudos? Probably they shouldn't
// just return the element's style!
_ => Some(layout_el),
};
let layout_el = match layout_el {
None => {
// The pseudo doesn't exist, return nothing. Chrome seems to query
// the element itself in this case, Firefox uses the resolved value.
// https://www.w3.org/Bugs/Public/show_bug.cgi?id=29006
return String::new();
},
Some(layout_el) => layout_el,
};
let style = &*layout_el.resolved_style();
let longhand_id = match *property {
PropertyId::LonghandAlias(id, _) | PropertyId::Longhand(id) => id,
// Firefox returns blank strings for the computed value of shorthands,
// so this should be web-compatible.
PropertyId::ShorthandAlias(..) | PropertyId::Shorthand(_) => return String::new(),
PropertyId::Custom(ref name) => {
return style.computed_value_to_string(PropertyDeclarationId::Custom(name));
},
};
let positioned = match style.get_box().position {
Position::Relative | Position::Sticky | Position::Fixed | Position::Absolute => true,
_ => false,
};
//TODO: determine whether requested property applies to the element.
// eg. width does not apply to non-replaced inline elements.
// Existing browsers disagree about when left/top/right/bottom apply
// (Chrome seems to think they never apply and always returns resolved values).
// There are probably other quirks.
let applies = true;
fn used_value_for_position_property<'dom, N>(
layout_el: <N::ConcreteThreadSafeLayoutNode as ThreadSafeLayoutNode<'dom>>::ConcreteThreadSafeLayoutElement,
layout_root: &mut dyn Flow,
requested_node: N,
longhand_id: LonghandId,
) -> String
where
N: LayoutNode<'dom>,
{
let maybe_data = layout_el.borrow_layout_data();
let position = maybe_data.map_or(Point2D::zero(), |data| {
match (*data).flow_construction_result {
ConstructionResult::Flow(ref flow_ref, _) => flow_ref
.deref()
.base()
.stacking_relative_position
.to_point(),
// TODO(dzbarsky) search parents until we find node with a flow ref.
// https://github.com/servo/servo/issues/8307
_ => Point2D::zero(),
}
});
let property = match longhand_id {
LonghandId::Bottom => PositionProperty::Bottom,
LonghandId::Top => PositionProperty::Top,
LonghandId::Left => PositionProperty::Left,
LonghandId::Right => PositionProperty::Right,
LonghandId::Width => PositionProperty::Width,
LonghandId::Height => PositionProperty::Height,
_ => unreachable!(),
};
let mut iterator = PositionRetrievingFragmentBorderBoxIterator::new(
requested_node.opaque(),
property,
position,
);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
iterator
.result
.map(|r| r.to_css_string())
.unwrap_or(String::new())
}
// TODO: we will return neither the computed nor used value for margin and padding.
match longhand_id {
LonghandId::MarginBottom |
LonghandId::MarginTop |
LonghandId::MarginLeft |
LonghandId::MarginRight |
LonghandId::PaddingBottom |
LonghandId::PaddingTop |
LonghandId::PaddingLeft |
LonghandId::PaddingRight
if applies && style.get_box().display != Display::None =>
{
let (margin_padding, side) = match longhand_id {
LonghandId::MarginBottom => (MarginPadding::Margin, Side::Bottom),
LonghandId::MarginTop => (MarginPadding::Margin, Side::Top),
LonghandId::MarginLeft => (MarginPadding::Margin, Side::Left),
LonghandId::MarginRight => (MarginPadding::Margin, Side::Right),
LonghandId::PaddingBottom => (MarginPadding::Padding, Side::Bottom),
LonghandId::PaddingTop => (MarginPadding::Padding, Side::Top),
LonghandId::PaddingLeft => (MarginPadding::Padding, Side::Left),
LonghandId::PaddingRight => (MarginPadding::Padding, Side::Right),
_ => unreachable!(),
};
let mut iterator = MarginRetrievingFragmentBorderBoxIterator::new(
requested_node.opaque(),
side,
margin_padding,
style.writing_mode,
);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
iterator
.result
.map(|r| r.to_css_string())
.unwrap_or(String::new())
},
LonghandId::Bottom | LonghandId::Top | LonghandId::Right | LonghandId::Left
if applies && positioned && style.get_box().display != Display::None =>
{
used_value_for_position_property(layout_el, layout_root, requested_node, longhand_id)
},
LonghandId::Width | LonghandId::Height
if applies && style.get_box().display != Display::None =>
{
used_value_for_position_property(layout_el, layout_root, requested_node, longhand_id)
},
// FIXME: implement used value computation for line-height
_ => style.computed_value_to_string(PropertyDeclarationId::Longhand(longhand_id)),
}
}
pub fn process_offset_parent_query(
requested_node: OpaqueNode,
layout_root: &mut dyn Flow,
) -> OffsetParentResponse {
let mut iterator = ParentOffsetBorderBoxIterator::new(requested_node);
sequential::iterate_through_flow_tree_fragment_border_boxes(layout_root, &mut iterator);
let node_offset_box = iterator.node_offset_box;
let parent_info = iterator
.parent_nodes
.into_iter()
.rev()
.filter_map(|info| info)
.next();
match (node_offset_box, parent_info) {
(Some(node_offset_box), Some(parent_info)) => {
let origin = node_offset_box.offset - parent_info.origin.to_vector();
let size = node_offset_box.rectangle.size;
OffsetParentResponse {
node_address: Some(parent_info.node_address.into()),
rect: Rect::new(origin, size),
}
},
_ => OffsetParentResponse::empty(),
}
}
enum InnerTextItem {
Text(String),
RequiredLineBreakCount(u32),
}
// https://html.spec.whatwg.org/multipage/#the-innertext-idl-attribute
pub fn process_element_inner_text_query<'dom>(
node: impl LayoutNode<'dom>,
indexable_text: &IndexableText,
) -> String {
// Step 1.
let mut results = Vec::new();
// Step 2.
inner_text_collection_steps(node, indexable_text, &mut results);
let mut max_req_line_break_count = 0;
let mut inner_text = Vec::new();
for item in results {
match item {
InnerTextItem::Text(s) => {
if max_req_line_break_count > 0 {
// Step 5.
for _ in 0..max_req_line_break_count {
inner_text.push("\u{000A}".to_owned());
}
max_req_line_break_count = 0;
}
// Step 3.
if !s.is_empty() {
inner_text.push(s.to_owned());
}
},
InnerTextItem::RequiredLineBreakCount(count) => {
// Step 4.
if inner_text.len() == 0 {
// Remove required line break count at the start.
continue;
}
// Store the count if it's the max of this run,
// but it may be ignored if no text item is found afterwards,
// which means that these are consecutive line breaks at the end.
if count > max_req_line_break_count {
max_req_line_break_count = count;
}
},
}
}
inner_text.into_iter().collect()
}
// https://html.spec.whatwg.org/multipage/#inner-text-collection-steps
#[allow(unsafe_code)]
fn inner_text_collection_steps<'dom>(
node: impl LayoutNode<'dom>,
indexable_text: &IndexableText,
results: &mut Vec<InnerTextItem>,
) {
let mut items = Vec::new();
for child in node.traverse_preorder() {
let node = match child.type_id() {
LayoutNodeType::Text => child.parent_node().unwrap(),
_ => child,
};
let element_data = match node.get_style_and_opaque_layout_data() {
Some(data) => &data.style_data.element_data,
None => continue,
};
let style = match element_data.borrow().styles.get_primary() {
None => continue,
Some(style) => style.clone(),
};
// Step 2.
if style.get_inherited_box().visibility != Visibility::Visible {
continue;
}
// Step 3.
let display = style.get_box().display;
if !child.is_connected() || display == Display::None {
continue;
}
match child.type_id() {
LayoutNodeType::Text => {
// Step 4.
if let Some(text_content) = indexable_text.get(child.opaque()) {
for content in text_content {
items.push(InnerTextItem::Text(content.text_run.text.to_string()));
}
}
},
LayoutNodeType::Element(LayoutElementType::HTMLBRElement) => {
// Step 5.
items.push(InnerTextItem::Text(String::from(
"\u{000A}", /* line feed */
)));
},
LayoutNodeType::Element(LayoutElementType::HTMLParagraphElement) => {
// Step 8.
items.insert(0, InnerTextItem::RequiredLineBreakCount(2));
items.push(InnerTextItem::RequiredLineBreakCount(2));
},
_ => {},
}
match display {
Display::TableCell if !is_last_table_cell() => {
// Step 6.
items.push(InnerTextItem::Text(String::from("\u{0009}" /* tab */)));
},
Display::TableRow if !is_last_table_row() => {
// Step 7.
items.push(InnerTextItem::Text(String::from(
"\u{000A}", /* line feed */
)));
},
Display::Block | Display::Flex | Display::TableCaption | Display::Table => {
// Step 9.
items.insert(0, InnerTextItem::RequiredLineBreakCount(1));
items.push(InnerTextItem::RequiredLineBreakCount(1));
},
_ => {},
}
}
results.append(&mut items);
}
fn is_last_table_cell() -> bool {
// FIXME(ferjm) Implement this.
false
}
fn is_last_table_row() -> bool {
// FIXME(ferjm) Implement this.
false
}