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6b2bbdd02d
Clearance was implemented as a Length, where zero meant no clearance. However, having a clearance of 0px should be different than having no clearance, since the former can still prevent margin collapse. This patch keeps the existing behavior, so it won't be possible to get a clearance of Some(Length::zero()), but it prepares the terrain for a follow-up to fix calculate_clearance to return the proper thing.
286 lines
11 KiB
Rust
286 lines
11 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
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use super::{BaseFragment, BaseFragmentInfo, CollapsedBlockMargins, Fragment};
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use crate::cell::ArcRefCell;
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use crate::geom::flow_relative::{Rect, Sides};
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use crate::geom::{PhysicalPoint, PhysicalRect, PhysicalSides, PhysicalSize};
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use gfx_traits::print_tree::PrintTree;
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use servo_arc::Arc as ServoArc;
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use style::computed_values::overflow_x::T as ComputedOverflow;
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use style::computed_values::position::T as ComputedPosition;
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use style::properties::ComputedValues;
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use style::values::computed::{CSSPixelLength, Length, LengthPercentage, LengthPercentageOrAuto};
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use style::Zero;
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#[derive(Serialize)]
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pub(crate) struct BoxFragment {
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pub base: BaseFragment,
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#[serde(skip_serializing)]
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pub style: ServoArc<ComputedValues>,
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pub children: Vec<ArcRefCell<Fragment>>,
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/// From the containing block’s start corner…?
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/// This might be broken when the containing block is in a different writing mode:
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/// https://drafts.csswg.org/css-writing-modes/#orthogonal-flows
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pub content_rect: Rect<Length>,
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pub padding: Sides<Length>,
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pub border: Sides<Length>,
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pub margin: Sides<Length>,
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/// When the `clear` property is not set to `none`, it may introduce clearance.
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/// Clearance is some extra spacing that is added above the top margin,
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/// so that the element doesn't overlap earlier floats in the same BFC.
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/// The presence of clearance prevents the top margin from collapsing with
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/// earlier margins or with the bottom margin of the parent block.
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/// https://drafts.csswg.org/css2/#clearance
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pub clearance: Option<Length>,
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pub block_margins_collapsed_with_children: CollapsedBlockMargins,
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/// The scrollable overflow of this box fragment.
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pub scrollable_overflow_from_children: PhysicalRect<Length>,
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/// Whether or not this box was overconstrained in the given dimension.
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overconstrained: PhysicalSize<bool>,
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}
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impl BoxFragment {
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pub fn new(
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base_fragment_info: BaseFragmentInfo,
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style: ServoArc<ComputedValues>,
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children: Vec<Fragment>,
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content_rect: Rect<Length>,
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padding: Sides<Length>,
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border: Sides<Length>,
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margin: Sides<Length>,
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clearance: Option<Length>,
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block_margins_collapsed_with_children: CollapsedBlockMargins,
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) -> BoxFragment {
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let position = style.get_box().position;
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let insets = style.get_position();
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let width_overconstrained = position == ComputedPosition::Relative &&
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!insets.left.is_auto() &&
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!insets.right.is_auto();
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let height_overconstrained = position == ComputedPosition::Relative &&
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!insets.left.is_auto() &&
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!insets.bottom.is_auto();
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Self::new_with_overconstrained(
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base_fragment_info,
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style,
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children,
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content_rect,
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padding,
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border,
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margin,
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clearance,
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block_margins_collapsed_with_children,
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PhysicalSize::new(width_overconstrained, height_overconstrained),
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)
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}
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pub fn new_with_overconstrained(
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base_fragment_info: BaseFragmentInfo,
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style: ServoArc<ComputedValues>,
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children: Vec<Fragment>,
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content_rect: Rect<Length>,
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padding: Sides<Length>,
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border: Sides<Length>,
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margin: Sides<Length>,
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clearance: Option<Length>,
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block_margins_collapsed_with_children: CollapsedBlockMargins,
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overconstrained: PhysicalSize<bool>,
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) -> BoxFragment {
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// FIXME(mrobinson, bug 25564): We should be using the containing block
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// here to properly convert scrollable overflow to physical geometry.
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let containing_block = PhysicalRect::zero();
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let scrollable_overflow_from_children =
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children.iter().fold(PhysicalRect::zero(), |acc, child| {
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acc.union(&child.scrollable_overflow(&containing_block))
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});
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BoxFragment {
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base: base_fragment_info.into(),
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style,
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children: children
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.into_iter()
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.map(|fragment| ArcRefCell::new(fragment))
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.collect(),
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content_rect,
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padding,
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border,
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margin,
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clearance,
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block_margins_collapsed_with_children,
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scrollable_overflow_from_children,
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overconstrained,
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}
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}
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pub fn scrollable_overflow(
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&self,
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containing_block: &PhysicalRect<Length>,
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) -> PhysicalRect<Length> {
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let physical_padding_rect = self
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.padding_rect()
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.to_physical(self.style.writing_mode, containing_block);
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let content_origin = self
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.content_rect
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.start_corner
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.to_physical(self.style.writing_mode);
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physical_padding_rect.union(
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&self
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.scrollable_overflow_from_children
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.translate(content_origin.to_vector()),
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)
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}
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pub fn padding_rect(&self) -> Rect<Length> {
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self.content_rect.inflate(&self.padding)
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}
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pub fn border_rect(&self) -> Rect<Length> {
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self.padding_rect().inflate(&self.border)
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}
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pub fn print(&self, tree: &mut PrintTree) {
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tree.new_level(format!(
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"Box\
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\nbase={:?}\
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\ncontent={:?}\
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\npadding rect={:?}\
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\nborder rect={:?}\
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\nclearance={:?}\
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\nscrollable_overflow={:?}\
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\noverflow={:?} / {:?}",
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self.base,
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self.content_rect,
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self.padding_rect(),
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self.border_rect(),
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self.clearance,
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self.scrollable_overflow(&PhysicalRect::zero()),
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self.style.get_box().overflow_x,
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self.style.get_box().overflow_y,
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));
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for child in &self.children {
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child.borrow().print(tree);
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}
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tree.end_level();
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}
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pub fn scrollable_overflow_for_parent(
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&self,
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containing_block: &PhysicalRect<Length>,
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) -> PhysicalRect<Length> {
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let mut overflow = self
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.border_rect()
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.to_physical(self.style.writing_mode, containing_block);
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if self.style.get_box().overflow_y != ComputedOverflow::Visible &&
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self.style.get_box().overflow_x != ComputedOverflow::Visible
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{
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return overflow;
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}
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// https://www.w3.org/TR/css-overflow-3/#scrollable
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// Only include the scrollable overflow of a child box if it has overflow: visible.
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let scrollable_overflow = self.scrollable_overflow(&containing_block);
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let bottom_right = PhysicalPoint::new(
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overflow.max_x().max(scrollable_overflow.max_x()),
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overflow.max_y().max(scrollable_overflow.max_y()),
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);
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if self.style.get_box().overflow_y == ComputedOverflow::Visible {
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overflow.origin.y = overflow.origin.y.min(scrollable_overflow.origin.y);
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overflow.size.height = bottom_right.y - overflow.origin.y;
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}
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if self.style.get_box().overflow_x == ComputedOverflow::Visible {
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overflow.origin.x = overflow.origin.x.min(scrollable_overflow.origin.x);
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overflow.size.width = bottom_right.x - overflow.origin.x;
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}
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overflow
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}
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pub(crate) fn calculate_resolved_insets_if_positioned(
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&self,
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containing_block: &PhysicalRect<CSSPixelLength>,
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) -> PhysicalSides<CSSPixelLength> {
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let position = self.style.get_box().position;
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debug_assert_ne!(
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position,
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ComputedPosition::Static,
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"Should not call this method on statically positioned box."
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);
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let (cb_width, cb_height) = (containing_block.width(), containing_block.height());
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let content_rect = self
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.content_rect
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.to_physical(self.style.writing_mode, &containing_block);
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// "A resolved value special case property like top defined in another
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// specification If the property applies to a positioned element and the
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// resolved value of the display property is not none or contents, and
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// the property is not over-constrained, then the resolved value is the
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// used value. Otherwise the resolved value is the computed value."
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// https://drafts.csswg.org/cssom/#resolved-values
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let insets = self.style.get_position();
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if position == ComputedPosition::Relative {
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let get_resolved_axis =
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|start: &LengthPercentageOrAuto,
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end: &LengthPercentageOrAuto,
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container_length: CSSPixelLength| {
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let start = start.map(|v| v.percentage_relative_to(container_length));
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let end = end.map(|v| v.percentage_relative_to(container_length));
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match (start.non_auto(), end.non_auto()) {
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(None, None) => (Length::zero(), Length::zero()),
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(None, Some(end)) => (-end, end),
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(Some(start), None) => (start, -start),
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// This is the overconstrained case, for which the resolved insets will
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// simply be the computed insets.
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(Some(start), Some(end)) => (start, end),
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}
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};
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let (left, right) = get_resolved_axis(&insets.left, &insets.right, cb_width);
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let (top, bottom) = get_resolved_axis(&insets.top, &insets.bottom, cb_height);
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return PhysicalSides::new(top, right, bottom, left);
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}
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debug_assert!(
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position == ComputedPosition::Fixed || position == ComputedPosition::Absolute,
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"Got unknown position."
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);
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let resolve = |value: &LengthPercentageOrAuto, container_length| {
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value
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.auto_is(LengthPercentage::zero)
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.percentage_relative_to(container_length)
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};
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let (top, bottom) = if self.overconstrained.height {
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(
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resolve(&insets.top, cb_height),
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resolve(&insets.bottom, cb_height),
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)
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} else {
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(content_rect.origin.y, cb_height - content_rect.max_y())
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};
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let (left, right) = if self.overconstrained.width {
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(
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resolve(&insets.left, cb_width),
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resolve(&insets.right, cb_width),
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)
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} else {
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(content_rect.origin.x, cb_width - content_rect.max_x())
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};
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PhysicalSides::new(top, right, bottom, left)
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}
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}
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