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e167526618
The specification dictates quite quite idiosyncratic return values when querying insets of positioned elements via getComputedStyle(). These depend on whether or not the elements size was overconstrained. This change adds a better implementation of that in preparation for returning proper values for position: sticky.
633 lines
22 KiB
Rust
633 lines
22 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 crate::cell::ArcRefCell;
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use crate::fragment_tree::{BaseFragment, BaseFragmentInfo, ContainingBlockManager, Tag};
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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 crate::positioned::HoistedSharedFragment;
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use crate::style_ext::ComputedValuesExt;
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use gfx::font::FontMetrics as GfxFontMetrics;
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use gfx::text::glyph::GlyphStore;
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use gfx_traits::print_tree::PrintTree;
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use msg::constellation_msg::{BrowsingContextId, PipelineId};
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use servo_arc::Arc as ServoArc;
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use std::sync::Arc;
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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::logical_geometry::WritingMode;
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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::values::specified::text::TextDecorationLine;
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use style::Zero;
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use webrender_api::{FontInstanceKey, ImageKey};
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#[derive(Serialize)]
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pub(crate) enum Fragment {
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Box(BoxFragment),
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Anonymous(AnonymousFragment),
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/// Absolute and fixed position fragments are hoisted up so that they
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/// are children of the BoxFragment that establishes their containing
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/// blocks, so that they can be laid out properly. When this happens
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/// an `AbsoluteOrFixedPositioned` fragment is left at the original tree
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/// position. This allows these hoisted fragments to be painted with
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/// regard to their original tree order during stacking context tree /
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/// display list construction.
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AbsoluteOrFixedPositioned(ArcRefCell<HoistedSharedFragment>),
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Text(TextFragment),
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Image(ImageFragment),
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IFrame(IFrameFragment),
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}
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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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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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#[derive(Serialize)]
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pub(crate) struct CollapsedBlockMargins {
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pub collapsed_through: bool,
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pub start: CollapsedMargin,
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pub end: CollapsedMargin,
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}
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#[derive(Clone, Copy, Serialize)]
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pub(crate) struct CollapsedMargin {
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max_positive: Length,
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min_negative: Length,
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}
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/// Can contain child fragments with relative coordinates, but does not contribute to painting itself.
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#[derive(Serialize)]
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pub(crate) struct AnonymousFragment {
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pub base: BaseFragment,
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pub rect: Rect<Length>,
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pub children: Vec<ArcRefCell<Fragment>>,
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pub mode: WritingMode,
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/// The scrollable overflow of this anonymous fragment's children.
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pub scrollable_overflow: PhysicalRect<Length>,
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}
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#[derive(Clone, Copy, Serialize)]
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pub(crate) struct FontMetrics {
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pub ascent: Length,
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pub line_gap: Length,
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pub underline_offset: Length,
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pub underline_size: Length,
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pub strikeout_offset: Length,
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pub strikeout_size: Length,
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}
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impl From<&GfxFontMetrics> for FontMetrics {
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fn from(metrics: &GfxFontMetrics) -> FontMetrics {
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FontMetrics {
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ascent: metrics.ascent.into(),
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line_gap: metrics.line_gap.into(),
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underline_offset: metrics.underline_offset.into(),
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underline_size: metrics.underline_size.into(),
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strikeout_offset: metrics.strikeout_offset.into(),
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strikeout_size: metrics.strikeout_size.into(),
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}
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}
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}
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#[derive(Serialize)]
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pub(crate) struct TextFragment {
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pub base: BaseFragment,
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#[serde(skip_serializing)]
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pub parent_style: ServoArc<ComputedValues>,
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pub rect: Rect<Length>,
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pub font_metrics: FontMetrics,
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#[serde(skip_serializing)]
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pub font_key: FontInstanceKey,
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pub glyphs: Vec<Arc<GlyphStore>>,
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/// A flag that represents the _used_ value of the text-decoration property.
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pub text_decoration_line: TextDecorationLine,
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}
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#[derive(Serialize)]
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pub(crate) struct ImageFragment {
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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 rect: Rect<Length>,
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#[serde(skip_serializing)]
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pub image_key: ImageKey,
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}
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#[derive(Serialize)]
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pub(crate) struct IFrameFragment {
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pub base: BaseFragment,
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pub pipeline_id: PipelineId,
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pub browsing_context_id: BrowsingContextId,
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pub rect: Rect<Length>,
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#[serde(skip_serializing)]
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pub style: ServoArc<ComputedValues>,
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}
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impl Fragment {
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pub fn offset_inline(&mut self, offset: &Length) {
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let position = match self {
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Fragment::Box(f) => &mut f.content_rect.start_corner,
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Fragment::AbsoluteOrFixedPositioned(_) => return,
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Fragment::Anonymous(f) => &mut f.rect.start_corner,
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Fragment::Text(f) => &mut f.rect.start_corner,
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Fragment::Image(f) => &mut f.rect.start_corner,
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Fragment::IFrame(f) => &mut f.rect.start_corner,
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};
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position.inline += *offset;
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}
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pub fn base(&self) -> Option<&BaseFragment> {
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Some(match self {
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Fragment::Box(fragment) => &fragment.base,
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Fragment::Text(fragment) => &fragment.base,
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Fragment::AbsoluteOrFixedPositioned(_) => return None,
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Fragment::Anonymous(fragment) => &fragment.base,
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Fragment::Image(fragment) => &fragment.base,
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Fragment::IFrame(fragment) => &fragment.base,
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})
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}
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pub fn tag(&self) -> Option<Tag> {
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self.base().and_then(|base| base.tag)
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}
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pub fn print(&self, tree: &mut PrintTree) {
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match self {
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Fragment::Box(fragment) => fragment.print(tree),
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Fragment::AbsoluteOrFixedPositioned(_) => {
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tree.add_item("AbsoluteOrFixedPositioned".to_string());
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},
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Fragment::Anonymous(fragment) => fragment.print(tree),
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Fragment::Text(fragment) => fragment.print(tree),
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Fragment::Image(fragment) => fragment.print(tree),
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Fragment::IFrame(fragment) => fragment.print(tree),
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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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match self {
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Fragment::Box(fragment) => fragment.scrollable_overflow_for_parent(&containing_block),
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Fragment::AbsoluteOrFixedPositioned(_) => PhysicalRect::zero(),
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Fragment::Anonymous(fragment) => fragment.scrollable_overflow.clone(),
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Fragment::Text(fragment) => fragment
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.rect
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.to_physical(fragment.parent_style.writing_mode, &containing_block),
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Fragment::Image(fragment) => fragment
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.rect
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.to_physical(fragment.style.writing_mode, &containing_block),
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Fragment::IFrame(fragment) => fragment
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.rect
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.to_physical(fragment.style.writing_mode, &containing_block),
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}
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}
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pub(crate) fn find<T>(
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&self,
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manager: &ContainingBlockManager<PhysicalRect<Length>>,
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level: usize,
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process_func: &mut impl FnMut(&Fragment, usize, &PhysicalRect<Length>) -> Option<T>,
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) -> Option<T> {
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let containing_block = manager.get_containing_block_for_fragment(self);
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if let Some(result) = process_func(self, level, containing_block) {
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return Some(result);
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}
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match self {
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Fragment::Box(fragment) => {
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let content_rect = fragment
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.content_rect
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.to_physical(fragment.style.writing_mode, containing_block)
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.translate(containing_block.origin.to_vector());
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let padding_rect = fragment
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.padding_rect()
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.to_physical(fragment.style.writing_mode, containing_block)
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.translate(containing_block.origin.to_vector());
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let new_manager = if fragment
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.style
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.establishes_containing_block_for_all_descendants()
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{
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manager.new_for_absolute_and_fixed_descendants(&content_rect, &padding_rect)
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} else if fragment
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.style
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.establishes_containing_block_for_absolute_descendants()
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{
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manager.new_for_absolute_descendants(&content_rect, &padding_rect)
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} else {
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manager.new_for_non_absolute_descendants(&content_rect)
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};
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fragment
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.children
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.iter()
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.find_map(|child| child.borrow().find(&new_manager, level + 1, process_func))
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},
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Fragment::Anonymous(fragment) => {
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let content_rect = fragment
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.rect
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.to_physical(fragment.mode, containing_block)
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.translate(containing_block.origin.to_vector());
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let new_manager = manager.new_for_non_absolute_descendants(&content_rect);
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fragment
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.children
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.iter()
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.find_map(|child| child.borrow().find(&new_manager, level + 1, process_func))
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},
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_ => None,
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}
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}
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}
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impl AnonymousFragment {
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pub fn no_op(mode: WritingMode) -> Self {
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Self {
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base: BaseFragment::anonymous(),
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children: vec![],
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rect: Rect::zero(),
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mode,
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scrollable_overflow: PhysicalRect::zero(),
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}
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}
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pub fn new(rect: Rect<Length>, children: Vec<Fragment>, mode: WritingMode) -> Self {
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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 content_origin = rect.start_corner.to_physical(mode);
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let scrollable_overflow = children.iter().fold(PhysicalRect::zero(), |acc, child| {
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acc.union(
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&child
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.scrollable_overflow(&containing_block)
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.translate(content_origin.to_vector()),
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)
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});
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AnonymousFragment {
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base: BaseFragment::anonymous(),
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rect,
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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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mode,
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scrollable_overflow,
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}
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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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"Anonymous\
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\nrect={:?}\
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\nscrollable_overflow={:?}",
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self.rect, self.scrollable_overflow
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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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}
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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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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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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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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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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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\nscrollable_overflow={:?}\
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\noverflow={:?} / {:?}\
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\noverconstrained={:?}
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\nstyle={:p}",
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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.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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self.overconstrained,
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self.style,
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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));
|
||
match (start.non_auto(), end.non_auto()) {
|
||
(None, None) => (Length::zero(), Length::zero()),
|
||
(None, Some(end)) => (-end, end),
|
||
(Some(start), None) => (start, -start),
|
||
// This is the overconstrained case, for which the resolved insets will
|
||
// simply be the computed insets.
|
||
(Some(start), Some(end)) => (start, end),
|
||
}
|
||
};
|
||
let (left, right) = get_resolved_axis(&insets.left, &insets.right, cb_width);
|
||
let (top, bottom) = get_resolved_axis(&insets.top, &insets.bottom, cb_height);
|
||
return PhysicalSides::new(top, right, bottom, left);
|
||
}
|
||
|
||
debug_assert!(
|
||
position == ComputedPosition::Fixed || position == ComputedPosition::Absolute,
|
||
"Got unknown position."
|
||
);
|
||
|
||
let resolve = |value: &LengthPercentageOrAuto, container_length| {
|
||
value
|
||
.auto_is(LengthPercentage::zero)
|
||
.percentage_relative_to(container_length)
|
||
};
|
||
|
||
let (top, bottom) = if self.overconstrained.height {
|
||
(
|
||
resolve(&insets.top, cb_height),
|
||
resolve(&insets.bottom, cb_height),
|
||
)
|
||
} else {
|
||
(content_rect.origin.y, cb_height - content_rect.max_y())
|
||
};
|
||
let (left, right) = if self.overconstrained.width {
|
||
(
|
||
resolve(&insets.left, cb_width),
|
||
resolve(&insets.right, cb_width),
|
||
)
|
||
} else {
|
||
(content_rect.origin.x, cb_width - content_rect.max_x())
|
||
};
|
||
|
||
PhysicalSides::new(top, right, bottom, left)
|
||
}
|
||
}
|
||
|
||
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 IFrameFragment {
|
||
pub fn print(&self, tree: &mut PrintTree) {
|
||
tree.add_item(format!(
|
||
"IFrame\
|
||
\npipeline={:?} rect={:?}",
|
||
self.pipeline_id, 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
|
||
}
|
||
}
|