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servo/components/layout/display_list/builder.rs
Martin Robinson 9a6973d629
style: Remove dependency on servo_url (#31358) 
In order for stylo to be a separate crate, it needs to depend on less
things from Servo. This change makes it so that stylo no longer depends
on servo_url.
2024-02-16 11:56:35 +00:00

3108 lines
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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
//! Builds display lists from flows and fragments.
//!
//! Other browser engines sometimes call this "painting", but it is more accurately called display
//! list building, as the actual painting does not happen here—only deciding *what* we're going to
//! paint.
use std::default::Default;
use std::sync::Arc;
use std::{f32, mem};
use app_units::{Au, AU_PER_PX};
use bitflags::bitflags;
use canvas_traits::canvas::{CanvasMsg, FromLayoutMsg};
use embedder_traits::Cursor;
use euclid::default::{Point2D, Rect, SideOffsets2D as UntypedSideOffsets2D, Size2D};
use euclid::{rect, SideOffsets2D};
use fnv::FnvHashMap;
use gfx::text::glyph::ByteIndex;
use gfx::text::TextRun;
use gfx_traits::{combine_id_with_fragment_type, FragmentType, StackingContextId};
use ipc_channel::ipc;
use log::{debug, warn};
use msg::constellation_msg::{BrowsingContextId, PipelineId};
use net_traits::image_cache::UsePlaceholder;
use range::Range;
use servo_config::opts;
use servo_geometry::{self, MaxRect};
use style::color::AbsoluteColor;
use style::computed_values::border_style::T as BorderStyle;
use style::computed_values::overflow_x::T as StyleOverflow;
use style::computed_values::pointer_events::T as PointerEvents;
use style::computed_values::position::T as StylePosition;
use style::computed_values::visibility::T as Visibility;
use style::logical_geometry::{LogicalMargin, LogicalPoint, LogicalRect};
use style::properties::{style_structs, ComputedValues};
use style::servo::restyle_damage::ServoRestyleDamage;
use style::values::computed::effects::SimpleShadow;
use style::values::computed::image::Image;
use style::values::computed::{ClipRectOrAuto, Gradient};
use style::values::generics::background::BackgroundSize;
use style::values::generics::image::PaintWorklet;
use style::values::specified::ui::CursorKind;
use style_traits::{CSSPixel, ToCss};
use webrender_api::units::{LayoutRect, LayoutTransform, LayoutVector2D};
use webrender_api::{
self, BorderDetails, BorderRadius, BorderSide, BoxShadowClipMode, ColorF, ColorU,
ExternalScrollId, FilterOp, GlyphInstance, ImageRendering, LineStyle, NinePatchBorder,
NinePatchBorderSource, NormalBorder, PropertyBinding, ScrollSensitivity, StickyOffsetBounds,
};
use crate::block::BlockFlow;
use crate::context::LayoutContext;
use crate::display_list::background::{self, get_cyclic};
use crate::display_list::items::{
self, BaseDisplayItem, ClipScrollNode, ClipScrollNodeIndex, ClipScrollNodeType, ClipType,
ClippingAndScrolling, ClippingRegion, CommonDisplayItem, DisplayItem, DisplayItemMetadata,
DisplayList, DisplayListSection, IframeDisplayItem, OpaqueNode, PopAllTextShadowsDisplayItem,
PushTextShadowDisplayItem, StackingContext, StackingContextType, StickyFrameData,
TextOrientation, WebRenderImageInfo,
};
use crate::display_list::{border, gradient, FilterToLayout, ToLayout};
use crate::flow::{BaseFlow, Flow, FlowFlags};
use crate::flow_ref::FlowRef;
use crate::fragment::{
CanvasFragmentSource, CoordinateSystem, Fragment, ScannedTextFragmentInfo, SpecificFragmentInfo,
};
use crate::inline::InlineFragmentNodeFlags;
use crate::model::MaybeAuto;
use crate::table_cell::CollapsedBordersForCell;
static THREAD_TINT_COLORS: [ColorF; 8] = [
ColorF {
r: 6.0 / 255.0,
g: 153.0 / 255.0,
b: 198.0 / 255.0,
a: 0.7,
},
ColorF {
r: 255.0 / 255.0,
g: 212.0 / 255.0,
b: 83.0 / 255.0,
a: 0.7,
},
ColorF {
r: 116.0 / 255.0,
g: 29.0 / 255.0,
b: 109.0 / 255.0,
a: 0.7,
},
ColorF {
r: 204.0 / 255.0,
g: 158.0 / 255.0,
b: 199.0 / 255.0,
a: 0.7,
},
ColorF {
r: 242.0 / 255.0,
g: 46.0 / 255.0,
b: 121.0 / 255.0,
a: 0.7,
},
ColorF {
r: 116.0 / 255.0,
g: 203.0 / 255.0,
b: 196.0 / 255.0,
a: 0.7,
},
ColorF {
r: 255.0 / 255.0,
g: 249.0 / 255.0,
b: 201.0 / 255.0,
a: 0.7,
},
ColorF {
r: 137.0 / 255.0,
g: 196.0 / 255.0,
b: 78.0 / 255.0,
a: 0.7,
},
];
// An internal WebRender limit.
//
// See: https://github.com/servo/servo/issues/17230#issuecomment-564307277
const MAX_GLYPHS_PER_TEXT_RUN: usize = 2000;
pub struct InlineNodeBorderInfo {
is_first_fragment_of_element: bool,
is_last_fragment_of_element: bool,
}
#[derive(Debug)]
struct StackingContextInfo {
children: Vec<StackingContext>,
clip_scroll_nodes: Vec<ClipScrollNodeIndex>,
real_stacking_context_id: StackingContextId,
}
impl StackingContextInfo {
fn new(real_stacking_context_id: StackingContextId) -> StackingContextInfo {
StackingContextInfo {
children: Vec::new(),
clip_scroll_nodes: Vec::new(),
real_stacking_context_id,
}
}
fn take_children(&mut self) -> Vec<StackingContext> {
mem::take(&mut self.children)
}
}
pub struct StackingContextCollectionState {
/// The PipelineId of this stacking context collection.
pub pipeline_id: PipelineId,
/// The root of the StackingContext tree.
pub root_stacking_context: StackingContext,
/// StackingContext and ClipScrollNode children for each StackingContext.
stacking_context_info: FnvHashMap<StackingContextId, StackingContextInfo>,
pub clip_scroll_nodes: Vec<ClipScrollNode>,
/// The current stacking context id, used to keep track of state when building.
/// recursively building and processing the display list.
pub current_stacking_context_id: StackingContextId,
/// The current reference frame ClipScrollNodeIndex.
pub current_real_stacking_context_id: StackingContextId,
/// The next stacking context id that we will assign to a stacking context.
pub next_stacking_context_id: StackingContextId,
/// The current reference frame id. This is used to assign items to the parent
/// reference frame when we encounter a fixed position stacking context.
pub current_parent_reference_frame_id: ClipScrollNodeIndex,
/// The current clip and scroll info, used to keep track of state when
/// recursively building and processing the display list.
pub current_clipping_and_scrolling: ClippingAndScrolling,
/// The clip and scroll info of the first ancestor which defines a containing block.
/// This is necessary because absolutely positioned items should be clipped
/// by their containing block's scroll root.
pub containing_block_clipping_and_scrolling: ClippingAndScrolling,
/// A stack of clips used to cull display list entries that are outside the
/// rendered region.
pub clip_stack: Vec<Rect<Au>>,
/// A stack of clips used to cull display list entries that are outside the
/// rendered region, but only collected at containing block boundaries.
pub containing_block_clip_stack: Vec<Rect<Au>>,
/// The flow parent's content box, used to calculate sticky constraints.
parent_stacking_relative_content_box: Rect<Au>,
}
impl StackingContextCollectionState {
pub fn new(pipeline_id: PipelineId) -> StackingContextCollectionState {
let root_clip_indices =
ClippingAndScrolling::simple(ClipScrollNodeIndex::root_scroll_node());
let mut stacking_context_info = FnvHashMap::default();
stacking_context_info.insert(
StackingContextId::root(),
StackingContextInfo::new(StackingContextId::root()),
);
// We add two empty nodes to represent the WebRender root reference frame and
// root scroll nodes. WebRender adds these automatically and we add them here
// so that the ids in the array match up with the ones we assign during display
// list building. We ignore these two nodes during conversion to WebRender
// display lists.
let clip_scroll_nodes = vec![ClipScrollNode::placeholder(), ClipScrollNode::placeholder()];
StackingContextCollectionState {
pipeline_id,
root_stacking_context: StackingContext::root(),
stacking_context_info,
clip_scroll_nodes,
current_stacking_context_id: StackingContextId::root(),
current_real_stacking_context_id: StackingContextId::root(),
next_stacking_context_id: StackingContextId::root().next(),
current_parent_reference_frame_id: ClipScrollNodeIndex::root_reference_frame(),
current_clipping_and_scrolling: root_clip_indices,
containing_block_clipping_and_scrolling: root_clip_indices,
clip_stack: Vec::new(),
containing_block_clip_stack: Vec::new(),
parent_stacking_relative_content_box: Rect::zero(),
}
}
fn allocate_stacking_context_info(
&mut self,
stacking_context_type: StackingContextType,
) -> StackingContextId {
let next_stacking_context_id = self.next_stacking_context_id.next();
let allocated_id =
mem::replace(&mut self.next_stacking_context_id, next_stacking_context_id);
let real_stacking_context_id = match stacking_context_type {
StackingContextType::Real => allocated_id,
_ => self.current_real_stacking_context_id,
};
self.stacking_context_info.insert(
allocated_id,
StackingContextInfo::new(real_stacking_context_id),
);
allocated_id
}
fn add_stacking_context(
&mut self,
parent_id: StackingContextId,
stacking_context: StackingContext,
) {
self.stacking_context_info
.get_mut(&parent_id)
.unwrap()
.children
.push(stacking_context);
}
fn add_clip_scroll_node(&mut self, clip_scroll_node: ClipScrollNode) -> ClipScrollNodeIndex {
let is_placeholder = clip_scroll_node.is_placeholder();
self.clip_scroll_nodes.push(clip_scroll_node);
let index = ClipScrollNodeIndex::new(self.clip_scroll_nodes.len() - 1);
// If this node is a placeholder node (currently just reference frames), then don't add
// it to the stacking context list. Placeholder nodes are created automatically by
// WebRender and we don't want to explicitly create them in the display list. The node
// is just there to take up a spot in the global list of ClipScrollNodes.
if !is_placeholder {
// We want the scroll root to be defined before any possible item that could use it,
// so we make sure that it is added to the beginning of the parent "real" (non-pseudo)
// stacking context. This ensures that item reordering will not result in an item using
// the scroll root before it is defined.
self.stacking_context_info
.get_mut(&self.current_real_stacking_context_id)
.unwrap()
.clip_scroll_nodes
.push(index);
}
index
}
}
pub struct DisplayListBuildState<'a> {
/// A LayoutContext reference important for creating WebRender images.
pub layout_context: &'a LayoutContext<'a>,
/// The root of the StackingContext tree.
pub root_stacking_context: StackingContext,
/// StackingContext and ClipScrollNode children for each StackingContext.
stacking_context_info: FnvHashMap<StackingContextId, StackingContextInfo>,
/// A vector of ClipScrollNodes which will be given ids during WebRender DL conversion.
pub clip_scroll_nodes: Vec<ClipScrollNode>,
/// The items in this display list.
pub items: FnvHashMap<StackingContextId, Vec<DisplayItem>>,
/// Whether or not we are processing an element that establishes scrolling overflow. Used
/// to determine what ClipScrollNode to place backgrounds and borders into.
pub processing_scrolling_overflow_element: bool,
/// The current stacking context id, used to keep track of state when building.
/// recursively building and processing the display list.
pub current_stacking_context_id: StackingContextId,
/// The current clip and scroll info, used to keep track of state when
/// recursively building and processing the display list.
pub current_clipping_and_scrolling: ClippingAndScrolling,
/// Vector containing iframe sizes, used to inform the constellation about
/// new iframe sizes
pub iframe_sizes: FnvHashMap<BrowsingContextId, euclid::Size2D<f32, CSSPixel>>,
/// Stores text runs to answer text queries used to place a cursor inside text.
pub indexable_text: IndexableText,
}
impl<'a> DisplayListBuildState<'a> {
pub fn new(
layout_context: &'a LayoutContext,
state: StackingContextCollectionState,
) -> DisplayListBuildState<'a> {
DisplayListBuildState {
layout_context,
root_stacking_context: state.root_stacking_context,
items: FnvHashMap::default(),
stacking_context_info: state.stacking_context_info,
clip_scroll_nodes: state.clip_scroll_nodes,
processing_scrolling_overflow_element: false,
current_stacking_context_id: StackingContextId::root(),
current_clipping_and_scrolling: ClippingAndScrolling::simple(
ClipScrollNodeIndex::root_scroll_node(),
),
iframe_sizes: FnvHashMap::default(),
indexable_text: IndexableText::default(),
}
}
pub fn add_display_item(&mut self, display_item: DisplayItem) {
let items = self
.items
.entry(display_item.stacking_context_id())
.or_default();
items.push(display_item);
}
fn add_image_item(&mut self, base: BaseDisplayItem, item: webrender_api::ImageDisplayItem) {
self.add_display_item(DisplayItem::Image(CommonDisplayItem::new(base, item)))
}
fn parent_clip_scroll_node_index(&self, index: ClipScrollNodeIndex) -> ClipScrollNodeIndex {
if index.is_root_scroll_node() {
return index;
}
self.clip_scroll_nodes[index.to_index()].parent_index
}
fn is_background_or_border_of_clip_scroll_node(&self, section: DisplayListSection) -> bool {
(section == DisplayListSection::BackgroundAndBorders ||
section == DisplayListSection::BlockBackgroundsAndBorders) &&
self.processing_scrolling_overflow_element
}
pub fn create_base_display_item(
&self,
clip_rect: Rect<Au>,
node: OpaqueNode,
cursor: Option<Cursor>,
section: DisplayListSection,
) -> BaseDisplayItem {
let clipping_and_scrolling = if self.is_background_or_border_of_clip_scroll_node(section) {
ClippingAndScrolling::simple(
self.parent_clip_scroll_node_index(self.current_clipping_and_scrolling.scrolling),
)
} else {
self.current_clipping_and_scrolling
};
self.create_base_display_item_with_clipping_and_scrolling(
clip_rect,
node,
cursor,
section,
clipping_and_scrolling,
)
}
fn create_base_display_item_with_clipping_and_scrolling(
&self,
clip_rect: Rect<Au>,
node: OpaqueNode,
cursor: Option<Cursor>,
section: DisplayListSection,
clipping_and_scrolling: ClippingAndScrolling,
) -> BaseDisplayItem {
BaseDisplayItem::new(
DisplayItemMetadata { node, cursor },
clip_rect.to_layout(),
section,
self.current_stacking_context_id,
clipping_and_scrolling,
)
}
fn add_late_clip_node(&mut self, rect: LayoutRect, radii: BorderRadius) -> ClipScrollNodeIndex {
let node =
ClipScrollNode::rounded(rect, radii, self.current_clipping_and_scrolling.scrolling);
// We want the scroll root to be defined before any possible item that could use it,
// so we make sure that it is added to the beginning of the parent "real" (non-pseudo)
// stacking context. This ensures that item reordering will not result in an item using
// the scroll root before it is defined.
self.clip_scroll_nodes.push(node);
let index = ClipScrollNodeIndex::new(self.clip_scroll_nodes.len() - 1);
let real_stacking_context_id =
self.stacking_context_info[&self.current_stacking_context_id].real_stacking_context_id;
self.stacking_context_info
.get_mut(&real_stacking_context_id)
.unwrap()
.clip_scroll_nodes
.push(index);
index
}
pub fn to_display_list(mut self) -> DisplayList {
let mut list = Vec::new();
let root_context = mem::replace(&mut self.root_stacking_context, StackingContext::root());
self.to_display_list_for_stacking_context(&mut list, root_context);
DisplayList {
list,
clip_scroll_nodes: self.clip_scroll_nodes,
}
}
fn to_display_list_for_stacking_context(
&mut self,
list: &mut Vec<DisplayItem>,
stacking_context: StackingContext,
) {
let mut child_items = self.items.remove(&stacking_context.id).unwrap_or_default();
child_items.sort_by(|a, b| a.base().section.cmp(&b.base().section));
child_items.reverse();
let mut info = self
.stacking_context_info
.remove(&stacking_context.id)
.unwrap();
info.children.sort();
if stacking_context.context_type != StackingContextType::Real {
list.extend(
info.clip_scroll_nodes
.into_iter()
.map(|index| index.to_define_item()),
);
self.to_display_list_for_items(list, child_items, info.children);
} else {
let (push_item, pop_item) = stacking_context.to_display_list_items();
list.push(push_item);
list.extend(
info.clip_scroll_nodes
.into_iter()
.map(|index| index.to_define_item()),
);
self.to_display_list_for_items(list, child_items, info.children);
list.push(pop_item);
}
}
fn to_display_list_for_items(
&mut self,
list: &mut Vec<DisplayItem>,
mut child_items: Vec<DisplayItem>,
child_stacking_contexts: Vec<StackingContext>,
) {
// Properly order display items that make up a stacking context. "Steps" here
// refer to the steps in CSS 2.1 Appendix E.
// Steps 1 and 2: Borders and background for the root.
while child_items.last().map_or(false, |child| {
child.section() == DisplayListSection::BackgroundAndBorders
}) {
list.push(child_items.pop().unwrap());
}
// Step 3: Positioned descendants with negative z-indices.
let mut child_stacking_contexts = child_stacking_contexts.into_iter().peekable();
while child_stacking_contexts
.peek()
.map_or(false, |child| child.z_index < 0)
{
let context = child_stacking_contexts.next().unwrap();
self.to_display_list_for_stacking_context(list, context);
}
// Step 4: Block backgrounds and borders.
while child_items.last().map_or(false, |child| {
child.section() == DisplayListSection::BlockBackgroundsAndBorders
}) {
list.push(child_items.pop().unwrap());
}
// Step 5: Floats.
while child_stacking_contexts.peek().map_or(false, |child| {
child.context_type == StackingContextType::PseudoFloat
}) {
let context = child_stacking_contexts.next().unwrap();
self.to_display_list_for_stacking_context(list, context);
}
// Step 6 & 7: Content and inlines that generate stacking contexts.
while child_items.last().map_or(false, |child| {
child.section() == DisplayListSection::Content
}) {
list.push(child_items.pop().unwrap());
}
// Step 8 & 9: Positioned descendants with nonnegative, numeric z-indices.
for child in child_stacking_contexts {
self.to_display_list_for_stacking_context(list, child);
}
// Step 10: Outlines.
for item in child_items.drain(..) {
list.push(item);
}
}
fn clipping_and_scrolling_scope<R, F: FnOnce(&mut Self) -> R>(&mut self, function: F) -> R {
let previous_clipping_and_scrolling = self.current_clipping_and_scrolling;
let ret = function(self);
self.current_clipping_and_scrolling = previous_clipping_and_scrolling;
ret
}
}
/// The logical width of an insertion point: at the moment, a one-pixel-wide line.
const INSERTION_POINT_LOGICAL_WIDTH: Au = Au(AU_PER_PX);
/// Get the border radius for the rectangle inside of a rounded border. This is useful
/// for building the clip for the content inside the border.
fn build_border_radius_for_inner_rect(
outer_rect: Rect<Au>,
style: &ComputedValues,
) -> BorderRadius {
let radii = border::radii(outer_rect, style.get_border());
if radii.is_zero() {
return radii;
}
// Since we are going to using the inner rectangle (outer rectangle minus
// border width), we need to adjust to border radius so that we are smaller
// rectangle with the same border curve.
let border_widths = style.logical_border_width().to_physical(style.writing_mode);
border::inner_radii(radii, border_widths)
}
impl Fragment {
pub fn collect_stacking_contexts_for_blocklike_fragment(
&mut self,
state: &mut StackingContextCollectionState,
) -> bool {
match self.specific {
SpecificFragmentInfo::InlineBlock(ref mut block_flow) => {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
block_flow.collect_stacking_contexts(state);
true
},
SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut block_flow) => {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
block_flow.collect_stacking_contexts(state);
true
},
SpecificFragmentInfo::InlineAbsolute(ref mut block_flow) => {
let block_flow = FlowRef::deref_mut(&mut block_flow.flow_ref);
block_flow.collect_stacking_contexts(state);
true
},
// FIXME: In the future, if #15144 is fixed we can remove this case. See #18510.
SpecificFragmentInfo::TruncatedFragment(ref mut info) => {
let _ = info
.full
.collect_stacking_contexts_for_blocklike_fragment(state);
// To ensure the caller updates this fragment's stacking context
// appropriately based on the un-truncated fragment's status,
// we don't pass on the result of collecting stacking contexts.
false
},
_ => false,
}
}
pub fn create_stacking_context_for_inline_block(
&mut self,
base: &BaseFlow,
state: &mut StackingContextCollectionState,
) -> bool {
self.stacking_context_id = state.allocate_stacking_context_info(StackingContextType::Real);
let established_reference_frame = if self.can_establish_reference_frame() {
// WebRender currently creates reference frames automatically, so just add
// a placeholder node to allocate a ClipScrollNodeIndex for this reference frame.
self.established_reference_frame =
Some(state.add_clip_scroll_node(ClipScrollNode::placeholder()));
self.established_reference_frame
} else {
None
};
let current_stacking_context_id = state.current_stacking_context_id;
let stacking_context = self.create_stacking_context(
self.stacking_context_id,
base,
StackingContextType::Real,
established_reference_frame,
state.current_clipping_and_scrolling,
);
state.add_stacking_context(current_stacking_context_id, stacking_context);
true
}
/// Adds the display items necessary to paint the background of this fragment to the display
/// list if necessary.
fn build_display_list_for_background_if_applicable(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
display_list_section: DisplayListSection,
absolute_bounds: Rect<Au>,
) {
let background = style.get_background();
let background_color = style.resolve_color(background.background_color.clone());
// XXXManishearth the below method should ideally use an iterator over
// backgrounds
self.build_display_list_for_background_if_applicable_with_background(
state,
style,
background,
background_color,
display_list_section,
absolute_bounds,
)
}
/// Same as build_display_list_for_background_if_applicable, but lets you
/// override the actual background used
fn build_display_list_for_background_if_applicable_with_background(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
background: &style_structs::Background,
background_color: AbsoluteColor,
display_list_section: DisplayListSection,
absolute_bounds: Rect<Au>,
) {
// FIXME: This causes a lot of background colors to be displayed when they are clearly not
// needed. We could use display list optimization to clean this up, but it still seems
// inefficient. What we really want is something like "nearest ancestor element that
// doesn't have a fragment".
// Quote from CSS Backgrounds and Borders Module Level 3:
//
// > The background color is clipped according to the background-clip value associated
// > with the bottom-most background image layer.
let last_background_image_index = background.background_image.0.len() - 1;
let color_clip = *get_cyclic(&background.background_clip.0, last_background_image_index);
let (bounds, border_radii) = background::clip(
color_clip,
absolute_bounds,
style.logical_border_width().to_physical(style.writing_mode),
self.border_padding.to_physical(self.style.writing_mode),
border::radii(absolute_bounds, style.get_border()),
);
state.clipping_and_scrolling_scope(|state| {
if !border_radii.is_zero() {
let clip_id = state.add_late_clip_node(bounds.to_layout(), border_radii);
state.current_clipping_and_scrolling = ClippingAndScrolling::simple(clip_id);
}
let base = state.create_base_display_item(
bounds,
self.node,
get_cursor(style, Cursor::Default),
display_list_section,
);
state.add_display_item(DisplayItem::Rectangle(CommonDisplayItem::new(
base,
webrender_api::RectangleDisplayItem {
color: PropertyBinding::Value(background_color.to_layout()),
common: items::empty_common_item_properties(),
bounds: bounds.to_layout(),
},
)));
});
// The background image is painted on top of the background color.
// Implements background image, per spec:
// http://www.w3.org/TR/CSS21/colors.html#background
let background = style.get_background();
for (i, background_image) in background.background_image.0.iter().enumerate().rev() {
match *background_image {
Image::None => {},
Image::Gradient(ref gradient) => {
self.build_display_list_for_background_gradient(
state,
display_list_section,
absolute_bounds,
gradient,
style,
i,
);
},
Image::Url(ref image_url) => {
if let Some(url) = image_url.url() {
let webrender_image = state.layout_context.get_webrender_image_for_url(
self.node,
url.clone().into(),
UsePlaceholder::No,
);
if let Some(webrender_image) = webrender_image {
self.build_display_list_for_webrender_image(
state,
style,
display_list_section,
absolute_bounds,
webrender_image,
i,
);
}
}
},
Image::PaintWorklet(ref paint_worklet) => {
let bounding_box = self.border_box - style.logical_border_width();
let bounding_box_size = bounding_box.size.to_physical(style.writing_mode);
let background_size =
get_cyclic(&style.get_background().background_size.0, i).clone();
let size = match background_size {
BackgroundSize::ExplicitSize { width, height } => Size2D::new(
width
.to_used_value(bounding_box_size.width)
.unwrap_or(bounding_box_size.width),
height
.to_used_value(bounding_box_size.height)
.unwrap_or(bounding_box_size.height),
),
_ => bounding_box_size,
};
let webrender_image = self.get_webrender_image_for_paint_worklet(
state,
style,
paint_worklet,
size,
);
if let Some(webrender_image) = webrender_image {
self.build_display_list_for_webrender_image(
state,
style,
display_list_section,
absolute_bounds,
webrender_image,
i,
);
}
},
Image::CrossFade(..) | Image::ImageSet(..) => {
unreachable!("Shouldn't be parsed by Servo for now")
},
Image::Rect(ref rect) => {
// This is a (boxed) empty enum on non-Gecko
match **rect {}
},
}
}
}
/// Adds the display items necessary to paint a webrender image of this fragment to the
/// appropriate section of the display list.
fn build_display_list_for_webrender_image(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
display_list_section: DisplayListSection,
absolute_bounds: Rect<Au>,
webrender_image: WebRenderImageInfo,
index: usize,
) {
debug!("(building display list) building background image");
if webrender_image.key.is_none() {
return;
}
let image = Size2D::new(
Au::from_px(webrender_image.width as i32),
Au::from_px(webrender_image.height as i32),
);
let placement = background::placement(
style.get_background(),
state.layout_context.shared_context().viewport_size(),
absolute_bounds,
Some(image),
style.logical_border_width().to_physical(style.writing_mode),
self.border_padding.to_physical(self.style.writing_mode),
border::radii(absolute_bounds, style.get_border()),
index,
);
let placement = match placement {
Some(placement) => placement,
None => return,
};
state.clipping_and_scrolling_scope(|state| {
if !placement.clip_radii.is_zero() {
let clip_id =
state.add_late_clip_node(placement.clip_rect.to_layout(), placement.clip_radii);
state.current_clipping_and_scrolling = ClippingAndScrolling::simple(clip_id);
}
// Create the image display item.
let base = state.create_base_display_item(
placement.clip_rect,
self.node,
get_cursor(style, Cursor::Default),
display_list_section,
);
debug!("(building display list) adding background image.");
let item = CommonDisplayItem::new(
base,
webrender_api::RepeatingImageDisplayItem {
bounds: placement.bounds.to_f32_px(),
common: items::empty_common_item_properties(),
image_key: webrender_image.key.unwrap(),
stretch_size: placement.tile_size.to_layout(),
tile_spacing: placement.tile_spacing.to_layout(),
image_rendering: style.get_inherited_box().image_rendering.to_layout(),
alpha_type: webrender_api::AlphaType::PremultipliedAlpha,
color: webrender_api::ColorF::WHITE,
},
);
state.add_display_item(DisplayItem::RepeatingImage(item))
});
}
/// Calculates the webrender image for a paint worklet.
/// Returns None if the worklet is not registered.
/// If the worklet has missing image URLs, it passes them to the image cache for loading.
fn get_webrender_image_for_paint_worklet(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
paint_worklet: &PaintWorklet,
size_in_au: Size2D<Au>,
) -> Option<WebRenderImageInfo> {
let device_pixel_ratio = state.layout_context.style_context.device_pixel_ratio();
let size_in_px =
euclid::Size2D::new(size_in_au.width.to_f32_px(), size_in_au.height.to_f32_px());
// TODO: less copying.
let name = paint_worklet.name.clone();
let arguments = paint_worklet
.arguments
.iter()
.map(|argument| argument.to_css_string())
.collect();
let draw_result = match state.layout_context.registered_painters.get(&name) {
Some(painter) => {
debug!(
"Drawing a paint image {}({},{}).",
name, size_in_px.width, size_in_px.height
);
let properties = painter
.properties()
.iter()
.filter_map(|(name, id)| id.as_shorthand().err().map(|id| (name, id)))
.map(|(name, id)| (name.clone(), style.computed_value_to_string(id)))
.collect();
painter.draw_a_paint_image(size_in_px, device_pixel_ratio, properties, arguments)
},
None => {
debug!("Worklet {} called before registration.", name);
return None;
},
};
if let Ok(draw_result) = draw_result {
let webrender_image = WebRenderImageInfo {
width: draw_result.width,
height: draw_result.height,
key: draw_result.image_key,
};
for url in draw_result.missing_image_urls.into_iter() {
debug!("Requesting missing image URL {}.", url);
state.layout_context.get_webrender_image_for_url(
self.node,
url,
UsePlaceholder::No,
);
}
Some(webrender_image)
} else {
None
}
}
/// Adds the display items necessary to paint the background linear gradient of this fragment
/// to the appropriate section of the display list.
fn build_display_list_for_background_gradient(
&self,
state: &mut DisplayListBuildState,
display_list_section: DisplayListSection,
absolute_bounds: Rect<Au>,
gradient: &Gradient,
style: &ComputedValues,
index: usize,
) {
let placement = background::placement(
style.get_background(),
state.layout_context.shared_context().viewport_size(),
absolute_bounds,
None,
style.logical_border_width().to_physical(style.writing_mode),
self.border_padding.to_physical(self.style.writing_mode),
border::radii(absolute_bounds, style.get_border()),
index,
);
let placement = match placement {
Some(placement) => placement,
None => return,
};
state.clipping_and_scrolling_scope(|state| {
if !placement.clip_radii.is_zero() {
let clip_id =
state.add_late_clip_node(placement.clip_rect.to_layout(), placement.clip_radii);
state.current_clipping_and_scrolling = ClippingAndScrolling::simple(clip_id);
}
let base = state.create_base_display_item(
placement.clip_rect,
self.node,
get_cursor(style, Cursor::Default),
display_list_section,
);
let display_item = match gradient {
Gradient::Linear {
ref direction,
ref items,
ref repeating,
compat_mode: _,
} => {
let (gradient, stops) =
gradient::linear(style, placement.tile_size, items, *direction, *repeating);
let item = webrender_api::GradientDisplayItem {
gradient,
bounds: placement.bounds.to_f32_px(),
common: items::empty_common_item_properties(),
tile_size: placement.tile_size.to_layout(),
tile_spacing: placement.tile_spacing.to_layout(),
};
DisplayItem::Gradient(CommonDisplayItem::with_data(base, item, stops))
},
Gradient::Radial {
ref shape,
ref position,
ref items,
ref repeating,
compat_mode: _,
} => {
let (gradient, stops) = gradient::radial(
style,
placement.tile_size,
items,
shape,
position,
*repeating,
);
let item = webrender_api::RadialGradientDisplayItem {
gradient,
bounds: placement.bounds.to_f32_px(),
common: items::empty_common_item_properties(),
tile_size: placement.tile_size.to_layout(),
tile_spacing: placement.tile_spacing.to_layout(),
};
DisplayItem::RadialGradient(CommonDisplayItem::with_data(base, item, stops))
},
Gradient::Conic { .. } => unimplemented!(),
};
state.add_display_item(display_item);
});
}
/// Adds the display items necessary to paint the box shadow of this fragment to the display
/// list if necessary.
fn build_display_list_for_box_shadow_if_applicable(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
display_list_section: DisplayListSection,
absolute_bounds: Rect<Au>,
clip: Rect<Au>,
) {
// NB: According to CSS-BACKGROUNDS, box shadows render in *reverse* order (front to back).
for box_shadow in style.get_effects().box_shadow.0.iter().rev() {
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(style, Cursor::Default),
display_list_section,
);
let border_radius = border::radii(absolute_bounds, style.get_border());
state.add_display_item(DisplayItem::BoxShadow(CommonDisplayItem::new(
base,
webrender_api::BoxShadowDisplayItem {
common: items::empty_common_item_properties(),
box_bounds: absolute_bounds.to_layout(),
color: style
.resolve_color(box_shadow.base.color.clone())
.to_layout(),
offset: LayoutVector2D::new(
box_shadow.base.horizontal.px(),
box_shadow.base.vertical.px(),
),
blur_radius: box_shadow.base.blur.px(),
spread_radius: box_shadow.spread.px(),
border_radius,
clip_mode: if box_shadow.inset {
BoxShadowClipMode::Inset
} else {
BoxShadowClipMode::Outset
},
},
)));
}
}
/// Adds the display items necessary to paint the borders of this fragment to a display list if
/// necessary.
fn build_display_list_for_borders_if_applicable(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
inline_info: Option<InlineNodeBorderInfo>,
border_painting_mode: BorderPaintingMode,
mut bounds: Rect<Au>,
display_list_section: DisplayListSection,
clip: Rect<Au>,
) {
let mut border = style.logical_border_width();
if let Some(inline_info) = inline_info {
modify_border_width_for_inline_sides(&mut border, inline_info);
}
match border_painting_mode {
BorderPaintingMode::Separate => {},
BorderPaintingMode::Collapse(collapsed_borders) => {
collapsed_borders.adjust_border_widths_for_painting(&mut border)
},
BorderPaintingMode::Hidden => return,
}
let border_style_struct = style.get_border();
let mut colors = SideOffsets2D::new(
border_style_struct.border_top_color.clone(),
border_style_struct.border_right_color.clone(),
border_style_struct.border_bottom_color.clone(),
border_style_struct.border_left_color.clone(),
);
let mut border_style = SideOffsets2D::new(
border_style_struct.border_top_style,
border_style_struct.border_right_style,
border_style_struct.border_bottom_style,
border_style_struct.border_left_style,
);
if let BorderPaintingMode::Collapse(collapsed_borders) = border_painting_mode {
collapsed_borders.adjust_border_colors_and_styles_for_painting(
&mut colors,
&mut border_style,
style.writing_mode,
);
}
// If this border collapses, then we draw outside the boundaries we were given.
if let BorderPaintingMode::Collapse(collapsed_borders) = border_painting_mode {
collapsed_borders.adjust_border_bounds_for_painting(&mut bounds, style.writing_mode)
}
// Append the border to the display list.
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(style, Cursor::Default),
display_list_section,
);
let border_radius = border::radii(bounds, border_style_struct);
let border_widths = border.to_physical(style.writing_mode);
if self
.build_display_list_for_border_image(
state,
style,
base.clone(),
bounds,
&border_style_struct.border_image_source,
border_widths,
)
.is_some()
{
return;
}
if border_widths == SideOffsets2D::zero() {
return;
}
let details = BorderDetails::Normal(NormalBorder {
left: BorderSide {
color: style.resolve_color(colors.left).to_layout(),
style: border_style.left.to_layout(),
},
right: BorderSide {
color: style.resolve_color(colors.right).to_layout(),
style: border_style.right.to_layout(),
},
top: BorderSide {
color: style.resolve_color(colors.top).to_layout(),
style: border_style.top.to_layout(),
},
bottom: BorderSide {
color: style.resolve_color(colors.bottom).to_layout(),
style: border_style.bottom.to_layout(),
},
radius: border_radius,
do_aa: true,
});
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: bounds.to_layout(),
common: items::empty_common_item_properties(),
widths: border_widths.to_layout(),
details,
},
Vec::new(),
)));
}
/// Add display item for image border.
///
/// Returns `Some` if the addition was successful.
fn build_display_list_for_border_image(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
base: BaseDisplayItem,
bounds: Rect<Au>,
image: &Image,
border_width: UntypedSideOffsets2D<Au>,
) -> Option<()> {
let border_style_struct = style.get_border();
let border_image_outset =
border::image_outset(border_style_struct.border_image_outset, border_width);
let border_image_area = bounds.outer_rect(border_image_outset);
let border_image_size = border_image_area.size;
let border_image_width = border::image_width(
&border_style_struct.border_image_width,
border_width.to_layout(),
border_image_size,
);
let border_image_repeat = &border_style_struct.border_image_repeat;
let border_image_fill = border_style_struct.border_image_slice.fill;
let border_image_slice = &border_style_struct.border_image_slice.offsets;
let mut stops = Vec::new();
let mut width = border_image_size.width.to_px() as u32;
let mut height = border_image_size.height.to_px() as u32;
let source = match image {
Image::Url(ref image_url) => {
let url = image_url.url()?;
let image = state.layout_context.get_webrender_image_for_url(
self.node,
url.clone().into(),
UsePlaceholder::No,
)?;
width = image.width;
height = image.height;
NinePatchBorderSource::Image(image.key?)
},
Image::PaintWorklet(ref paint_worklet) => {
let image = self.get_webrender_image_for_paint_worklet(
state,
style,
paint_worklet,
border_image_size,
)?;
width = image.width;
height = image.height;
NinePatchBorderSource::Image(image.key?)
},
Image::Gradient(ref gradient) => match **gradient {
Gradient::Linear {
ref direction,
ref items,
ref repeating,
compat_mode: _,
} => {
let (wr_gradient, linear_stops) =
gradient::linear(style, border_image_size, items, *direction, *repeating);
stops = linear_stops;
NinePatchBorderSource::Gradient(wr_gradient)
},
Gradient::Radial {
ref shape,
ref position,
ref items,
ref repeating,
compat_mode: _,
} => {
let (wr_gradient, radial_stops) = gradient::radial(
style,
border_image_size,
items,
shape,
position,
*repeating,
);
stops = radial_stops;
NinePatchBorderSource::RadialGradient(wr_gradient)
},
Gradient::Conic { .. } => unimplemented!(),
},
_ => return None,
};
// FIXME(emilio): WR expects device pixels here... somehow?
let size = euclid::Size2D::new(width as i32, height as i32);
let details = BorderDetails::NinePatch(NinePatchBorder {
source,
width: width as i32,
height: height as i32,
slice: border::image_slice(border_image_slice, size),
fill: border_image_fill,
repeat_horizontal: border_image_repeat.0.to_layout(),
repeat_vertical: border_image_repeat.1.to_layout(),
outset: SideOffsets2D::zero(),
});
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: border_image_area.to_layout(),
common: items::empty_common_item_properties(),
widths: border_image_width,
details,
},
stops,
)));
Some(())
}
/// Adds the display items necessary to paint the outline of this fragment to the display list
/// if necessary.
fn build_display_list_for_outline_if_applicable(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
mut bounds: Rect<Au>,
clip: Rect<Au>,
) {
use style::values::specified::outline::OutlineStyle;
let width = style.get_outline().outline_width;
if width == Au(0) {
return;
}
let outline_style = match style.get_outline().outline_style {
OutlineStyle::Auto => BorderStyle::Solid,
// FIXME(emilio): I don't think this border-style check is
// necessary, since border-style: none implies an outline-width of
// zero at computed value time.
OutlineStyle::BorderStyle(BorderStyle::None) => return,
OutlineStyle::BorderStyle(s) => s,
};
// Outlines are not accounted for in the dimensions of the border box, so adjust the
// absolute bounds.
let offset = width + Au::from(style.get_outline().outline_offset);
bounds = bounds.inflate(offset, offset);
// Append the outline to the display list.
let color = style
.resolve_color(style.get_outline().outline_color.clone())
.to_layout();
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(style, Cursor::Default),
DisplayListSection::Outlines,
);
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: bounds.to_layout(),
common: items::empty_common_item_properties(),
widths: SideOffsets2D::new_all_same(width).to_layout(),
details: BorderDetails::Normal(border::simple(color, outline_style.to_layout())),
},
Vec::new(),
)));
}
/// Adds display items necessary to draw debug boxes around a scanned text fragment.
fn build_debug_borders_around_text_fragments(
&self,
state: &mut DisplayListBuildState,
style: &ComputedValues,
stacking_relative_border_box: Rect<Au>,
stacking_relative_content_box: Rect<Au>,
text_fragment: &ScannedTextFragmentInfo,
clip: Rect<Au>,
) {
// FIXME(pcwalton, #2795): Get the real container size.
let container_size = Size2D::zero();
// Compute the text fragment bounds and draw a border surrounding them.
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(style, Cursor::Default),
DisplayListSection::Content,
);
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: stacking_relative_border_box.to_layout(),
common: items::empty_common_item_properties(),
widths: SideOffsets2D::new_all_same(Au::from_px(1)).to_layout(),
details: BorderDetails::Normal(border::simple(
ColorU::new(0, 0, 200, 1).into(),
webrender_api::BorderStyle::Solid,
)),
},
Vec::new(),
)));
// Draw a rectangle representing the baselines.
let mut baseline = LogicalRect::from_physical(
self.style.writing_mode,
stacking_relative_content_box,
container_size,
);
baseline.start.b += text_fragment.run.ascent();
baseline.size.block = Au(0);
let baseline = baseline.to_physical(self.style.writing_mode, container_size);
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(style, Cursor::Default),
DisplayListSection::Content,
);
// TODO(gw): Use a better estimate for wavy line thickness.
let area = baseline.to_layout();
let wavy_line_thickness = (0.33 * area.size.height).ceil();
state.add_display_item(DisplayItem::Line(CommonDisplayItem::new(
base,
webrender_api::LineDisplayItem {
common: items::empty_common_item_properties(),
area,
orientation: webrender_api::LineOrientation::Horizontal,
wavy_line_thickness,
color: ColorU::new(0, 200, 0, 1).into(),
style: LineStyle::Dashed,
},
)));
}
/// Adds display items necessary to draw debug boxes around this fragment.
fn build_debug_borders_around_fragment(
&self,
state: &mut DisplayListBuildState,
stacking_relative_border_box: Rect<Au>,
clip: Rect<Au>,
) {
// This prints a debug border around the border of this fragment.
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(&self.style, Cursor::Default),
DisplayListSection::Content,
);
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: stacking_relative_border_box.to_layout(),
common: items::empty_common_item_properties(),
widths: SideOffsets2D::new_all_same(Au::from_px(1)).to_layout(),
details: BorderDetails::Normal(border::simple(
ColorU::new(0, 0, 200, 1).into(),
webrender_api::BorderStyle::Solid,
)),
},
Vec::new(),
)));
}
/// Builds the display items necessary to paint the selection and/or caret for this fragment,
/// if any.
fn build_display_items_for_selection_if_necessary(
&self,
state: &mut DisplayListBuildState,
stacking_relative_border_box: Rect<Au>,
display_list_section: DisplayListSection,
) {
let scanned_text_fragment_info = match self.specific {
SpecificFragmentInfo::ScannedText(ref scanned_text_fragment_info) => {
scanned_text_fragment_info
},
_ => return,
};
// Draw a highlighted background if the text is selected.
//
// TODO: Allow non-text fragments to be selected too.
if scanned_text_fragment_info.selected() {
let style = self.selected_style();
let background_color =
style.resolve_color(style.get_background().background_color.clone());
let base = state.create_base_display_item(
stacking_relative_border_box,
self.node,
get_cursor(&self.style, Cursor::Default),
display_list_section,
);
state.add_display_item(DisplayItem::Rectangle(CommonDisplayItem::new(
base,
webrender_api::RectangleDisplayItem {
common: items::empty_common_item_properties(),
color: PropertyBinding::Value(background_color.to_layout()),
bounds: stacking_relative_border_box.to_layout(),
},
)));
}
// Draw a caret at the insertion point.
let insertion_point_index = match scanned_text_fragment_info.insertion_point {
Some(insertion_point_index) => insertion_point_index,
None => return,
};
let range = Range::new(
scanned_text_fragment_info.range.begin(),
insertion_point_index - scanned_text_fragment_info.range.begin(),
);
let advance = scanned_text_fragment_info.run.advance_for_range(&range);
let insertion_point_bounds;
let cursor;
if !self.style.writing_mode.is_vertical() {
insertion_point_bounds = rect(
stacking_relative_border_box.origin.x + advance,
stacking_relative_border_box.origin.y,
INSERTION_POINT_LOGICAL_WIDTH,
stacking_relative_border_box.size.height,
);
cursor = Cursor::Text;
} else {
insertion_point_bounds = rect(
stacking_relative_border_box.origin.x,
stacking_relative_border_box.origin.y + advance,
stacking_relative_border_box.size.width,
INSERTION_POINT_LOGICAL_WIDTH,
);
cursor = Cursor::VerticalText;
};
let base = state.create_base_display_item(
insertion_point_bounds,
self.node,
get_cursor(&self.style, cursor),
display_list_section,
);
state.add_display_item(DisplayItem::Rectangle(CommonDisplayItem::new(
base,
webrender_api::RectangleDisplayItem {
common: items::empty_common_item_properties(),
color: PropertyBinding::Value(self.style().get_inherited_text().color.to_layout()),
bounds: insertion_point_bounds.to_layout(),
},
)));
}
/// Adds the display items for this fragment to the given display list.
///
/// Arguments:
///
/// * `state`: The display building state, including the display list currently
/// under construction and other metadata useful for constructing it.
/// * `dirty`: The dirty rectangle in the coordinate system of the owning flow.
/// * `clip`: The region to clip the display items to.
/// * `overflow_content_size`: The size of content associated with this fragment
/// that must have overflow handling applied to it. For a scrollable block
/// flow, it is expected that this is the size of the child boxes.
pub fn build_display_list(
&mut self,
state: &mut DisplayListBuildState,
stacking_relative_border_box: Rect<Au>,
border_painting_mode: BorderPaintingMode,
display_list_section: DisplayListSection,
clip: Rect<Au>,
overflow_content_size: Option<Size2D<Au>>,
) {
let previous_clipping_and_scrolling = state.current_clipping_and_scrolling;
if let Some(index) = self.established_reference_frame {
state.current_clipping_and_scrolling = ClippingAndScrolling::simple(index);
}
self.restyle_damage.remove(ServoRestyleDamage::REPAINT);
self.build_display_list_no_damage(
state,
stacking_relative_border_box,
border_painting_mode,
display_list_section,
clip,
overflow_content_size,
);
state.current_clipping_and_scrolling = previous_clipping_and_scrolling;
}
/// build_display_list, but don't update the restyle damage
///
/// Must be paired with a self.restyle_damage.remove(REPAINT) somewhere
fn build_display_list_no_damage(
&self,
state: &mut DisplayListBuildState,
stacking_relative_border_box: Rect<Au>,
border_painting_mode: BorderPaintingMode,
display_list_section: DisplayListSection,
clip: Rect<Au>,
overflow_content_size: Option<Size2D<Au>>,
) {
if self.style().get_inherited_box().visibility != Visibility::Visible {
return;
}
// If this fragment takes up no space, we don't need to build any display items for it.
if self.has_non_invertible_transform_or_zero_scale() {
return;
}
debug!(
"Fragment::build_display_list at rel={:?}, abs={:?}: {:?}",
self.border_box, stacking_relative_border_box, self
);
// Check the clip rect. If there's nothing to render at all, don't even construct display
// list items.
let empty_rect = !clip.intersects(&stacking_relative_border_box);
if self.is_primary_fragment() && !empty_rect {
// Add shadows, background, borders, and outlines, if applicable.
if let Some(ref inline_context) = self.inline_context {
for node in inline_context.nodes.iter().rev() {
self.build_display_list_for_background_if_applicable(
state,
&node.style,
display_list_section,
stacking_relative_border_box,
);
self.build_display_list_for_box_shadow_if_applicable(
state,
&node.style,
display_list_section,
stacking_relative_border_box,
clip,
);
self.build_display_list_for_borders_if_applicable(
state,
&node.style,
Some(InlineNodeBorderInfo {
is_first_fragment_of_element: node
.flags
.contains(InlineFragmentNodeFlags::FIRST_FRAGMENT_OF_ELEMENT),
is_last_fragment_of_element: node
.flags
.contains(InlineFragmentNodeFlags::LAST_FRAGMENT_OF_ELEMENT),
}),
border_painting_mode,
stacking_relative_border_box,
display_list_section,
clip,
);
// FIXME(emilio): Why does outline not do the same width
// fixup as border?
self.build_display_list_for_outline_if_applicable(
state,
&node.style,
stacking_relative_border_box,
clip,
);
}
}
if !self.is_scanned_text_fragment() {
self.build_display_list_for_background_if_applicable(
state,
&self.style,
display_list_section,
stacking_relative_border_box,
);
self.build_display_list_for_box_shadow_if_applicable(
state,
&self.style,
display_list_section,
stacking_relative_border_box,
clip,
);
self.build_display_list_for_borders_if_applicable(
state,
&self.style,
/* inline_node_info = */ None,
border_painting_mode,
stacking_relative_border_box,
display_list_section,
clip,
);
self.build_display_list_for_outline_if_applicable(
state,
&self.style,
stacking_relative_border_box,
clip,
);
}
}
if self.is_primary_fragment() {
// Paint the selection point if necessary. Even an empty text fragment may have an
// insertion point, so we do this even if `empty_rect` is true.
self.build_display_items_for_selection_if_necessary(
state,
stacking_relative_border_box,
display_list_section,
);
}
if empty_rect {
return;
}
debug!("Fragment::build_display_list: intersected. Adding display item...");
if let Some(content_size) = overflow_content_size {
// Create a transparent rectangle for hit-testing purposes that exists in front
// of this fragment's background but behind its content. This ensures that any
// hit tests inside the content box but not on actual content target the current
// scrollable ancestor.
let content_size = Rect::new(stacking_relative_border_box.origin, content_size);
let base = state.create_base_display_item_with_clipping_and_scrolling(
content_size,
self.node,
// FIXME(emilio): Why does this ignore pointer-events?
get_cursor(&self.style, Cursor::Default).or(Some(Cursor::Default)),
display_list_section,
state.current_clipping_and_scrolling,
);
state.add_display_item(DisplayItem::Rectangle(CommonDisplayItem::new(
base,
webrender_api::RectangleDisplayItem {
common: items::empty_common_item_properties(),
color: PropertyBinding::Value(ColorF::TRANSPARENT),
bounds: content_size.to_layout(),
},
)));
}
// Create special per-fragment-type display items.
state.clipping_and_scrolling_scope(|state| {
self.build_fragment_type_specific_display_items(
state,
stacking_relative_border_box,
clip,
);
});
if opts::get().debug.show_fragment_borders {
self.build_debug_borders_around_fragment(state, stacking_relative_border_box, clip)
}
}
/// A helper method that `build_display_list` calls to create per-fragment-type display items.
fn build_fragment_type_specific_display_items(
&self,
state: &mut DisplayListBuildState,
stacking_relative_border_box: Rect<Au>,
clip: Rect<Au>,
) {
// Compute the context box position relative to the parent stacking context.
let stacking_relative_content_box =
self.stacking_relative_content_box(stacking_relative_border_box);
let create_base_display_item = |state: &mut DisplayListBuildState| {
// Adjust the clipping region as necessary to account for `border-radius`.
let radii =
build_border_radius_for_inner_rect(stacking_relative_border_box, &self.style);
if !radii.is_zero() {
// This is already calculated inside of build_border_radius_for_inner_rect(), it would be
// nice if it were only calculated once.
let border_widths = self
.style
.logical_border_width()
.to_physical(self.style.writing_mode);
let clip_id = state.add_late_clip_node(
stacking_relative_border_box
.inner_rect(border_widths)
.to_layout(),
radii,
);
state.current_clipping_and_scrolling = ClippingAndScrolling::simple(clip_id);
}
state.create_base_display_item(
stacking_relative_border_box,
self.node,
get_cursor(&self.style, Cursor::Default),
DisplayListSection::Content,
)
};
match self.specific {
SpecificFragmentInfo::TruncatedFragment(ref truncated_fragment)
if truncated_fragment.text_info.is_some() =>
{
let text_fragment = truncated_fragment.text_info.as_ref().unwrap();
// Create the main text display item.
self.build_display_list_for_text_fragment(
state,
text_fragment,
stacking_relative_content_box,
&self.style.get_inherited_text().text_shadow.0,
clip,
);
if opts::get().debug.show_fragment_borders {
self.build_debug_borders_around_text_fragments(
state,
self.style(),
stacking_relative_border_box,
stacking_relative_content_box,
text_fragment,
clip,
);
}
},
SpecificFragmentInfo::ScannedText(ref text_fragment) => {
// Create the main text display item.
self.build_display_list_for_text_fragment(
state,
text_fragment,
stacking_relative_content_box,
&self.style.get_inherited_text().text_shadow.0,
clip,
);
if opts::get().debug.show_fragment_borders {
self.build_debug_borders_around_text_fragments(
state,
self.style(),
stacking_relative_border_box,
stacking_relative_content_box,
text_fragment,
clip,
);
}
},
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(..) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::TruncatedFragment(_) |
SpecificFragmentInfo::Svg(_) => {
if opts::get().debug.show_fragment_borders {
self.build_debug_borders_around_fragment(
state,
stacking_relative_border_box,
clip,
);
}
},
SpecificFragmentInfo::Iframe(ref fragment_info) => {
if !stacking_relative_content_box.is_empty() {
let browsing_context_id = match fragment_info.browsing_context_id {
Some(browsing_context_id) => browsing_context_id,
None => return warn!("No browsing context id for iframe."),
};
let base = create_base_display_item(state);
let bounds = stacking_relative_content_box.to_layout();
// XXXjdm: This sleight-of-hand to convert LayoutRect -> Size2D<CSSPixel>
// looks bogus.
state.iframe_sizes.insert(
browsing_context_id,
euclid::Size2D::new(bounds.size.width, bounds.size.height),
);
let pipeline_id = match fragment_info.pipeline_id {
Some(pipeline_id) => pipeline_id,
None => return warn!("No pipeline id for iframe {}.", browsing_context_id),
};
let item = DisplayItem::Iframe(Box::new(IframeDisplayItem {
base,
bounds,
iframe: pipeline_id,
}));
state.add_display_item(item);
}
},
SpecificFragmentInfo::Image(ref image_fragment) => {
// Place the image into the display list.
if let Some(ref image) = image_fragment.image {
if let Some(id) = image.id {
let base = create_base_display_item(state);
state.add_image_item(
base,
webrender_api::ImageDisplayItem {
bounds: stacking_relative_content_box.to_layout(),
common: items::empty_common_item_properties(),
image_key: id,
image_rendering: self
.style
.get_inherited_box()
.image_rendering
.to_layout(),
alpha_type: webrender_api::AlphaType::PremultipliedAlpha,
color: webrender_api::ColorF::WHITE,
},
);
}
}
},
SpecificFragmentInfo::Media(ref fragment_info) => {
if let Some((ref image_key, _, _)) = fragment_info.current_frame {
let base = create_base_display_item(state);
state.add_image_item(
base,
webrender_api::ImageDisplayItem {
bounds: stacking_relative_content_box.to_layout(),
common: items::empty_common_item_properties(),
image_key: *image_key,
image_rendering: ImageRendering::Auto,
alpha_type: webrender_api::AlphaType::PremultipliedAlpha,
color: webrender_api::ColorF::WHITE,
},
);
}
},
SpecificFragmentInfo::Canvas(ref canvas_fragment_info) => {
if canvas_fragment_info.dom_width == Au(0) ||
canvas_fragment_info.dom_height == Au(0)
{
return;
}
let image_key = match canvas_fragment_info.source {
CanvasFragmentSource::WebGL(image_key) => image_key,
CanvasFragmentSource::WebGPU(image_key) => image_key,
CanvasFragmentSource::Image(ref ipc_renderer) => match *ipc_renderer {
Some(ref ipc_renderer) => {
let ipc_renderer = ipc_renderer.lock().unwrap();
let (sender, receiver) = ipc::channel().unwrap();
ipc_renderer
.send(CanvasMsg::FromLayout(
FromLayoutMsg::SendData(sender),
canvas_fragment_info.canvas_id,
))
.unwrap();
receiver.recv().unwrap().image_key
},
None => return,
},
};
let base = create_base_display_item(state);
let display_item = webrender_api::ImageDisplayItem {
bounds: stacking_relative_border_box.to_layout(),
common: items::empty_common_item_properties(),
image_key,
image_rendering: ImageRendering::Auto,
alpha_type: webrender_api::AlphaType::PremultipliedAlpha,
color: webrender_api::ColorF::WHITE,
};
state.add_image_item(base, display_item);
},
SpecificFragmentInfo::UnscannedText(_) => {
panic!("Shouldn't see unscanned fragments here.")
},
SpecificFragmentInfo::TableColumn(_) => {
panic!("Shouldn't see table column fragments here.")
},
}
}
/// Creates a stacking context for associated fragment.
fn create_stacking_context(
&self,
id: StackingContextId,
base_flow: &BaseFlow,
context_type: StackingContextType,
established_reference_frame: Option<ClipScrollNodeIndex>,
parent_clipping_and_scrolling: ClippingAndScrolling,
) -> StackingContext {
let border_box = self.stacking_relative_border_box(
&base_flow.stacking_relative_position,
&base_flow
.early_absolute_position_info
.relative_containing_block_size,
base_flow
.early_absolute_position_info
.relative_containing_block_mode,
CoordinateSystem::Parent,
);
// First, compute the offset of our border box (including relative positioning)
// from our flow origin, since that is what `BaseFlow::overflow` is relative to.
let border_box_offset = border_box
.translate(-base_flow.stacking_relative_position)
.origin;
// Then, using that, compute our overflow region relative to our border box.
let overflow = base_flow
.overflow
.paint
.translate(-border_box_offset.to_vector());
// Create the filter pipeline.
let current_color = self.style().clone_color();
let effects = self.style().get_effects();
let mut filters: Vec<FilterOp> = effects
.filter
.0
.iter()
.map(|filter| FilterToLayout::to_layout(filter, &current_color))
.collect();
if effects.opacity != 1.0 {
filters.push(FilterOp::Opacity(effects.opacity.into(), effects.opacity));
}
StackingContext::new(
id,
context_type,
border_box.to_layout(),
overflow.to_layout(),
self.effective_z_index(),
self.style().get_box()._servo_top_layer,
filters,
self.style().get_effects().mix_blend_mode.to_layout(),
self.transform_matrix(&border_box),
self.style().get_used_transform_style().to_layout(),
self.perspective_matrix(&border_box),
parent_clipping_and_scrolling,
established_reference_frame,
)
}
/// Creates the text display item for one text fragment. This can be called multiple times for
/// one fragment if there are text shadows.
///
/// `text_shadow` will be `Some` if this is rendering a shadow.
fn build_display_list_for_text_fragment(
&self,
state: &mut DisplayListBuildState,
text_fragment: &ScannedTextFragmentInfo,
stacking_relative_content_box: Rect<Au>,
text_shadows: &[SimpleShadow],
clip: Rect<Au>,
) {
// NB: The order for painting text components (CSS Text Decoration Module Level 3) is:
// shadows, underline, overline, text, text-emphasis, and then line-through.
// TODO(emilio): Allow changing more properties by ::selection
// Paint the text with the color as described in its styling.
let text_color = if text_fragment.selected() {
self.selected_style().get_inherited_text().color
} else {
self.style().get_inherited_text().color
};
// Determine the orientation and cursor to use.
let (_orientation, cursor) = if self.style.writing_mode.is_vertical() {
// TODO: Distinguish between 'sideways-lr' and 'sideways-rl' writing modes in CSS
// Writing Modes Level 4.
(TextOrientation::SidewaysRight, Cursor::VerticalText)
} else {
(TextOrientation::Upright, Cursor::Text)
};
// Compute location of the baseline.
//
// FIXME(pcwalton): Get the real container size.
let container_size = Size2D::zero();
let metrics = &text_fragment.run.font_metrics;
let baseline_origin = stacking_relative_content_box.origin +
LogicalPoint::new(self.style.writing_mode, Au(0), metrics.ascent)
.to_physical(self.style.writing_mode, container_size)
.to_vector();
// Base item for all text/shadows
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(&self.style, cursor),
DisplayListSection::Content,
);
// NB: According to CSS-BACKGROUNDS, text shadows render in *reverse* order (front
// to back).
// Shadows
for shadow in text_shadows.iter().rev() {
state.add_display_item(DisplayItem::PushTextShadow(Box::new(
PushTextShadowDisplayItem {
base: base.clone(),
shadow: webrender_api::Shadow {
offset: LayoutVector2D::new(shadow.horizontal.px(), shadow.vertical.px()),
color: self.style.resolve_color(shadow.color.clone()).to_layout(),
blur_radius: shadow.blur.px(),
},
},
)));
}
// Create display items for text decorations.
let text_decorations = self.style().get_inherited_text().text_decorations_in_effect;
let dppx = state
.layout_context
.style_context
.device_pixel_ratio()
.get();
let round_to_nearest_device_pixel = |value: Au| -> Au {
// Round to the nearest integer device pixel, ensuring at least one device pixel.
Au::from_f32_px((value.to_f32_px() * dppx).round().max(1.0) / dppx)
};
let logical_stacking_relative_content_box = LogicalRect::from_physical(
self.style.writing_mode,
stacking_relative_content_box,
container_size,
);
// Underline
if text_decorations.underline {
let mut stacking_relative_box = logical_stacking_relative_content_box;
stacking_relative_box.start.b = logical_stacking_relative_content_box.start.b +
metrics.ascent -
metrics.underline_offset;
stacking_relative_box.size.block =
round_to_nearest_device_pixel(metrics.underline_size);
self.build_display_list_for_text_decoration(
state,
&text_color,
&stacking_relative_box,
clip,
);
}
// Overline
if text_decorations.overline {
let mut stacking_relative_box = logical_stacking_relative_content_box;
stacking_relative_box.size.block =
round_to_nearest_device_pixel(metrics.underline_size);
self.build_display_list_for_text_decoration(
state,
&text_color,
&stacking_relative_box,
clip,
);
}
// Text
let (largest_advance, mut glyphs) = convert_text_run_to_glyphs(
text_fragment.run.clone(),
text_fragment.range,
baseline_origin,
);
let indexable_text = IndexableTextItem {
origin: stacking_relative_content_box.origin,
text_run: text_fragment.run.clone(),
range: text_fragment.range,
baseline_origin,
};
state.indexable_text.insert(self.node, indexable_text);
// FIXME(mrobinson, #30313): This is a serious hack to enable a WebRender upgrade.
// Servo is not calculating glyph boundaries and is instead relying on the
// measured size of the content box here -- which is based on the positioning
// of the text. The issue is that glyphs can extend beyond the boundaries
// established by their brush origin and advance. Servo should be measuring
// the ink boundary rectangle based on the brush origin and the glyph extents
// instead.
//
// We don't yet have that information here, so in the meantime simply expand
// the boundary rectangle of the text by the largest character advance of the
// painted text run in all directions. This is used as a heuristic for a
// reasonable amount of "fudge" space to include the entire text run.
let inflated_bounds = stacking_relative_content_box
.inflate(largest_advance, largest_advance)
.to_layout();
// Process glyphs in chunks to avoid overflowing WebRender's internal limits (#17230).
while !glyphs.is_empty() {
let mut rest_of_glyphs = vec![];
if glyphs.len() > MAX_GLYPHS_PER_TEXT_RUN {
rest_of_glyphs = glyphs[MAX_GLYPHS_PER_TEXT_RUN..].to_vec();
glyphs.truncate(MAX_GLYPHS_PER_TEXT_RUN);
};
state.add_display_item(DisplayItem::Text(CommonDisplayItem::with_data(
base.clone(),
webrender_api::TextDisplayItem {
bounds: inflated_bounds,
common: items::empty_common_item_properties(),
font_key: text_fragment.run.font_key,
color: text_color.to_layout(),
glyph_options: None,
},
glyphs,
)));
glyphs = rest_of_glyphs;
}
// TODO(#17715): emit text-emphasis marks here.
// (just push another TextDisplayItem?)
// Line-Through
if text_decorations.line_through {
let mut stacking_relative_box = logical_stacking_relative_content_box;
stacking_relative_box.start.b =
stacking_relative_box.start.b + metrics.ascent - metrics.strikeout_offset;
stacking_relative_box.size.block =
round_to_nearest_device_pixel(metrics.strikeout_size);
self.build_display_list_for_text_decoration(
state,
&text_color,
&stacking_relative_box,
clip,
);
}
// Pop all the PushTextShadows
if !text_shadows.is_empty() {
state.add_display_item(DisplayItem::PopAllTextShadows(Box::new(
PopAllTextShadowsDisplayItem { base },
)));
}
}
/// Creates the display item for a text decoration: underline, overline, or line-through.
fn build_display_list_for_text_decoration(
&self,
state: &mut DisplayListBuildState,
color: &AbsoluteColor,
stacking_relative_box: &LogicalRect<Au>,
clip: Rect<Au>,
) {
// FIXME(pcwalton, #2795): Get the real container size.
let container_size = Size2D::zero();
let stacking_relative_box =
stacking_relative_box.to_physical(self.style.writing_mode, container_size);
let base = state.create_base_display_item(
clip,
self.node,
get_cursor(&self.style, Cursor::Default),
DisplayListSection::Content,
);
// TODO(gw): Use a better estimate for wavy line thickness.
let area = stacking_relative_box.to_layout();
let wavy_line_thickness = (0.33 * area.size.height).ceil();
state.add_display_item(DisplayItem::Line(CommonDisplayItem::new(
base,
webrender_api::LineDisplayItem {
common: items::empty_common_item_properties(),
area,
orientation: webrender_api::LineOrientation::Horizontal,
wavy_line_thickness,
color: color.to_layout(),
style: LineStyle::Solid,
},
)));
}
fn unique_id(&self) -> u64 {
let fragment_type = self.fragment_type();
let id = self.node.id();
combine_id_with_fragment_type(id, fragment_type) as u64
}
fn fragment_type(&self) -> FragmentType {
self.pseudo.fragment_type()
}
}
bitflags! {
#[derive(Clone, Copy)]
pub struct StackingContextCollectionFlags: u8 {
/// This flow never establishes a containing block.
const POSITION_NEVER_CREATES_CONTAINING_BLOCK = 0b001;
/// This flow never creates a ClipScrollNode.
const NEVER_CREATES_CLIP_SCROLL_NODE = 0b010;
/// This flow never creates a stacking context.
const NEVER_CREATES_STACKING_CONTEXT = 0b100;
}
}
/// This structure manages ensuring that modification to StackingContextCollectionState is
/// only temporary. It's useful for moving recursively down the flow tree and ensuring
/// that the state is restored for siblings. To use this structure, we must call
/// SavedStackingContextCollectionState::restore in order to restore the state.
/// TODO(mrobinson): It would be nice to use RAII here to avoid having to call restore.
pub struct SavedStackingContextCollectionState {
stacking_context_id: StackingContextId,
real_stacking_context_id: StackingContextId,
parent_reference_frame_id: ClipScrollNodeIndex,
clipping_and_scrolling: ClippingAndScrolling,
containing_block_clipping_and_scrolling: ClippingAndScrolling,
clips_pushed: usize,
containing_block_clips_pushed: usize,
stacking_relative_content_box: Rect<Au>,
}
impl SavedStackingContextCollectionState {
fn new(state: &mut StackingContextCollectionState) -> SavedStackingContextCollectionState {
SavedStackingContextCollectionState {
stacking_context_id: state.current_stacking_context_id,
real_stacking_context_id: state.current_real_stacking_context_id,
parent_reference_frame_id: state.current_parent_reference_frame_id,
clipping_and_scrolling: state.current_clipping_and_scrolling,
containing_block_clipping_and_scrolling: state.containing_block_clipping_and_scrolling,
clips_pushed: 0,
containing_block_clips_pushed: 0,
stacking_relative_content_box: state.parent_stacking_relative_content_box,
}
}
fn switch_to_containing_block_clip(&mut self, state: &mut StackingContextCollectionState) {
let clip = state
.containing_block_clip_stack
.last()
.cloned()
.unwrap_or_else(MaxRect::max_rect);
state.clip_stack.push(clip);
self.clips_pushed += 1;
}
fn restore(self, state: &mut StackingContextCollectionState) {
state.current_stacking_context_id = self.stacking_context_id;
state.current_real_stacking_context_id = self.real_stacking_context_id;
state.current_parent_reference_frame_id = self.parent_reference_frame_id;
state.current_clipping_and_scrolling = self.clipping_and_scrolling;
state.containing_block_clipping_and_scrolling =
self.containing_block_clipping_and_scrolling;
state.parent_stacking_relative_content_box = self.stacking_relative_content_box;
let truncate_length = state.clip_stack.len() - self.clips_pushed;
state.clip_stack.truncate(truncate_length);
let truncate_length =
state.containing_block_clip_stack.len() - self.containing_block_clips_pushed;
state.containing_block_clip_stack.truncate(truncate_length);
}
fn push_clip(
&mut self,
state: &mut StackingContextCollectionState,
mut clip: Rect<Au>,
positioning: StylePosition,
) {
if positioning != StylePosition::Fixed {
if let Some(old_clip) = state.clip_stack.last() {
clip = old_clip.intersection(&clip).unwrap_or_else(Rect::zero);
}
}
state.clip_stack.push(clip);
self.clips_pushed += 1;
if StylePosition::Absolute == positioning {
state.containing_block_clip_stack.push(clip);
self.containing_block_clips_pushed += 1;
}
}
}
impl BlockFlow {
fn transform_clip_to_coordinate_space(
&mut self,
state: &mut StackingContextCollectionState,
preserved_state: &mut SavedStackingContextCollectionState,
) {
if state.clip_stack.is_empty() {
return;
}
let border_box = self.stacking_relative_border_box(CoordinateSystem::Parent);
let transform = match self.fragment.transform_matrix(&border_box) {
Some(transform) => transform,
None => return,
};
let perspective = self
.fragment
.perspective_matrix(&border_box)
.unwrap_or(LayoutTransform::identity());
let transform = perspective.then(&transform).inverse();
let origin = border_box.origin;
let transform_clip = |clip: Rect<Au>| {
if clip == Rect::max_rect() {
return clip;
}
match transform {
Some(transform) if transform.m13 != 0.0 || transform.m23 != 0.0 => {
// We cannot properly handle perspective transforms, because there may be a
// situation where an element is transformed from outside the clip into the
// clip region. Here we don't have enough information to detect when that is
// happening. For the moment we just punt on trying to optimize the display
// list for those cases.
Rect::max_rect()
},
Some(transform) => {
let clip = rect(
(clip.origin.x - origin.x).to_f32_px(),
(clip.origin.y - origin.y).to_f32_px(),
clip.size.width.to_f32_px(),
clip.size.height.to_f32_px(),
);
let clip = transform.outer_transformed_rect(&clip).unwrap();
rect(
Au::from_f32_px(clip.origin.x),
Au::from_f32_px(clip.origin.y),
Au::from_f32_px(clip.size.width),
Au::from_f32_px(clip.size.height),
)
},
None => Rect::zero(),
}
};
if let Some(clip) = state.clip_stack.last().cloned() {
state.clip_stack.push(transform_clip(clip));
preserved_state.clips_pushed += 1;
}
if let Some(clip) = state.containing_block_clip_stack.last().cloned() {
state.containing_block_clip_stack.push(transform_clip(clip));
preserved_state.containing_block_clips_pushed += 1;
}
}
/// Returns true if this fragment may establish a reference frame and this block
/// creates a stacking context. Both are necessary in order to establish a reference
/// frame.
fn is_reference_frame(&self, context_type: Option<StackingContextType>) -> bool {
match context_type {
Some(StackingContextType::Real) => self.fragment.can_establish_reference_frame(),
_ => false,
}
}
pub fn collect_stacking_contexts_for_block(
&mut self,
state: &mut StackingContextCollectionState,
flags: StackingContextCollectionFlags,
) {
// This block flow produces no stacking contexts if it takes up no space.
if self.has_non_invertible_transform_or_zero_scale() {
return;
}
let mut preserved_state = SavedStackingContextCollectionState::new(state);
let stacking_context_type = self.stacking_context_type(flags);
self.base.stacking_context_id = match stacking_context_type {
None => state.current_stacking_context_id,
Some(sc_type) => state.allocate_stacking_context_info(sc_type),
};
state.current_stacking_context_id = self.base.stacking_context_id;
if stacking_context_type == Some(StackingContextType::Real) {
state.current_real_stacking_context_id = self.base.stacking_context_id;
}
let established_reference_frame = if self.is_reference_frame(stacking_context_type) {
// WebRender currently creates reference frames automatically, so just add
// a placeholder node to allocate a ClipScrollNodeIndex for this reference frame.
Some(state.add_clip_scroll_node(ClipScrollNode::placeholder()))
} else {
None
};
// We are getting the id of the scroll root that contains us here, not the id of
// any scroll root that we create. If we create a scroll root, its index will be
// stored in state.current_clipping_and_scrolling. If we create a stacking context,
// we don't want it to be contained by its own scroll root.
let containing_clipping_and_scrolling = self.setup_clipping_for_block(
state,
&mut preserved_state,
stacking_context_type,
established_reference_frame,
flags,
);
let creates_containing_block = !flags
.contains(StackingContextCollectionFlags::POSITION_NEVER_CREATES_CONTAINING_BLOCK);
let abspos_containing_block = established_reference_frame.is_some() ||
(creates_containing_block && self.positioning() != StylePosition::Static);
if abspos_containing_block {
state.containing_block_clipping_and_scrolling = state.current_clipping_and_scrolling;
}
match stacking_context_type {
None => self.base.collect_stacking_contexts_for_children(state),
Some(StackingContextType::Real) => {
self.create_real_stacking_context_for_block(
preserved_state.stacking_context_id,
containing_clipping_and_scrolling,
established_reference_frame,
state,
);
},
Some(stacking_context_type) => {
self.create_pseudo_stacking_context_for_block(
stacking_context_type,
preserved_state.stacking_context_id,
containing_clipping_and_scrolling,
state,
);
},
}
preserved_state.restore(state);
}
fn setup_clipping_for_block(
&mut self,
state: &mut StackingContextCollectionState,
preserved_state: &mut SavedStackingContextCollectionState,
stacking_context_type: Option<StackingContextType>,
established_reference_frame: Option<ClipScrollNodeIndex>,
flags: StackingContextCollectionFlags,
) -> ClippingAndScrolling {
// If this block is absolutely positioned, we should be clipped and positioned by
// the scroll root of our nearest ancestor that establishes a containing block.
let containing_clipping_and_scrolling = match self.positioning() {
StylePosition::Absolute => {
preserved_state.switch_to_containing_block_clip(state);
state.current_clipping_and_scrolling =
state.containing_block_clipping_and_scrolling;
state.containing_block_clipping_and_scrolling
},
StylePosition::Fixed => {
// If we are a fixed positioned stacking context, we want to be scrolled by
// our reference frame instead of the clip scroll node that we are inside.
preserved_state.push_clip(state, Rect::max_rect(), StylePosition::Fixed);
state.current_clipping_and_scrolling.scrolling =
state.current_parent_reference_frame_id;
state.current_clipping_and_scrolling
},
_ => state.current_clipping_and_scrolling,
};
self.base.clipping_and_scrolling = Some(containing_clipping_and_scrolling);
if let Some(reference_frame_index) = established_reference_frame {
let clipping_and_scrolling = ClippingAndScrolling::simple(reference_frame_index);
state.current_clipping_and_scrolling = clipping_and_scrolling;
self.base.clipping_and_scrolling = Some(clipping_and_scrolling);
}
let stacking_relative_border_box = if self.fragment.establishes_stacking_context() {
self.stacking_relative_border_box(CoordinateSystem::Own)
} else {
self.stacking_relative_border_box(CoordinateSystem::Parent)
};
if stacking_context_type == Some(StackingContextType::Real) {
self.transform_clip_to_coordinate_space(state, preserved_state);
}
if !flags.contains(StackingContextCollectionFlags::NEVER_CREATES_CLIP_SCROLL_NODE) {
self.setup_clip_scroll_node_for_position(state, stacking_relative_border_box);
self.setup_clip_scroll_node_for_overflow(state, stacking_relative_border_box);
self.setup_clip_scroll_node_for_css_clip(
state,
preserved_state,
stacking_relative_border_box,
);
}
self.base.clip = state
.clip_stack
.last()
.cloned()
.unwrap_or_else(Rect::max_rect);
// We keep track of our position so that any stickily positioned elements can
// properly determine the extent of their movement relative to scrolling containers.
if !flags.contains(StackingContextCollectionFlags::POSITION_NEVER_CREATES_CONTAINING_BLOCK)
{
let border_box = if self.fragment.establishes_stacking_context() {
stacking_relative_border_box
} else {
self.stacking_relative_border_box(CoordinateSystem::Own)
};
state.parent_stacking_relative_content_box =
self.fragment.stacking_relative_content_box(border_box)
}
match self.positioning() {
StylePosition::Absolute | StylePosition::Relative | StylePosition::Fixed => {
state.containing_block_clipping_and_scrolling = state.current_clipping_and_scrolling
},
_ => {},
}
containing_clipping_and_scrolling
}
fn setup_clip_scroll_node_for_position(
&mut self,
state: &mut StackingContextCollectionState,
border_box: Rect<Au>,
) {
if self.positioning() != StylePosition::Sticky {
return;
}
let sticky_position = self.sticky_position();
if sticky_position.left == MaybeAuto::Auto &&
sticky_position.right == MaybeAuto::Auto &&
sticky_position.top == MaybeAuto::Auto &&
sticky_position.bottom == MaybeAuto::Auto
{
return;
}
// Since position: sticky elements always establish a stacking context, we will
// have previously calculated our border box in our own coordinate system. In
// order to properly calculate max offsets we need to compare our size and
// position in our parent's coordinate system.
let border_box_in_parent = self.stacking_relative_border_box(CoordinateSystem::Parent);
let margins = self
.fragment
.margin
.to_physical(self.fragment.style.writing_mode);
// Position:sticky elements are always restricted based on the size and position of
// their containing block, which for sticky items is like relative and statically
// positioned items: just the parent block.
let constraint_rect = state.parent_stacking_relative_content_box;
let to_offset_bound = |constraint_edge: Au, moving_edge: Au| -> f32 {
(constraint_edge - moving_edge).to_f32_px()
};
// This is the minimum negative offset and then the maximum positive offset. We just
// specify every edge, but if the corresponding margin is None, that offset has no effect.
let vertical_offset_bounds = StickyOffsetBounds::new(
to_offset_bound(
constraint_rect.min_y(),
border_box_in_parent.min_y() - margins.top,
),
to_offset_bound(constraint_rect.max_y(), border_box_in_parent.max_y()),
);
let horizontal_offset_bounds = StickyOffsetBounds::new(
to_offset_bound(
constraint_rect.min_x(),
border_box_in_parent.min_x() - margins.left,
),
to_offset_bound(constraint_rect.max_x(), border_box_in_parent.max_x()),
);
// The margins control which edges have sticky behavior.
let sticky_frame_data = StickyFrameData {
margins: SideOffsets2D::new(
sticky_position.top.to_option().map(|v| v.to_f32_px()),
sticky_position.right.to_option().map(|v| v.to_f32_px()),
sticky_position.bottom.to_option().map(|v| v.to_f32_px()),
sticky_position.left.to_option().map(|v| v.to_f32_px()),
),
vertical_offset_bounds,
horizontal_offset_bounds,
};
let new_clip_scroll_index = state.add_clip_scroll_node(ClipScrollNode {
parent_index: self.clipping_and_scrolling().scrolling,
clip: ClippingRegion::from_rect(border_box.to_layout()),
content_rect: LayoutRect::zero(),
node_type: ClipScrollNodeType::StickyFrame(sticky_frame_data),
scroll_node_id: None,
clip_chain_id: None,
});
let new_clipping_and_scrolling = ClippingAndScrolling::simple(new_clip_scroll_index);
self.base.clipping_and_scrolling = Some(new_clipping_and_scrolling);
state.current_clipping_and_scrolling = new_clipping_and_scrolling;
}
fn setup_clip_scroll_node_for_overflow(
&mut self,
state: &mut StackingContextCollectionState,
border_box: Rect<Au>,
) {
if !self.overflow_style_may_require_clip_scroll_node() {
return;
}
let content_box = self.fragment.stacking_relative_content_box(border_box);
let has_scrolling_overflow = self.base.overflow.scroll.origin != Point2D::zero() ||
self.base.overflow.scroll.size.width > content_box.size.width ||
self.base.overflow.scroll.size.height > content_box.size.height ||
StyleOverflow::Hidden == self.fragment.style.get_box().overflow_x ||
StyleOverflow::Hidden == self.fragment.style.get_box().overflow_y;
self.mark_scrolling_overflow(has_scrolling_overflow);
if !has_scrolling_overflow {
return;
}
let sensitivity = if StyleOverflow::Hidden == self.fragment.style.get_box().overflow_x &&
StyleOverflow::Hidden == self.fragment.style.get_box().overflow_y
{
ScrollSensitivity::Script
} else {
ScrollSensitivity::ScriptAndInputEvents
};
let border_widths = self
.fragment
.style
.logical_border_width()
.to_physical(self.fragment.style.writing_mode);
let clip_rect = border_box.inner_rect(border_widths);
let clip = ClippingRegion::from_rect(clip_rect.to_layout());
let radii = build_border_radius_for_inner_rect(border_box, &self.fragment.style);
if !radii.is_zero() {
let node = ClipScrollNode::rounded(
clip_rect.to_layout(),
radii,
state.current_clipping_and_scrolling.scrolling,
);
let clip_id = state.add_clip_scroll_node(node);
let new_clipping_and_scrolling = ClippingAndScrolling::simple(clip_id);
self.base.clipping_and_scrolling = Some(new_clipping_and_scrolling);
state.current_clipping_and_scrolling = new_clipping_and_scrolling;
}
let content_size = self.base.overflow.scroll.origin + self.base.overflow.scroll.size;
let content_size = Size2D::new(content_size.x, content_size.y);
let external_id =
ExternalScrollId(self.fragment.unique_id(), state.pipeline_id.to_webrender());
let new_clip_scroll_index = state.add_clip_scroll_node(ClipScrollNode {
parent_index: self.clipping_and_scrolling().scrolling,
clip,
content_rect: Rect::new(content_box.origin, content_size).to_layout(),
node_type: ClipScrollNodeType::ScrollFrame(sensitivity, external_id),
scroll_node_id: None,
clip_chain_id: None,
});
let new_clipping_and_scrolling = ClippingAndScrolling::simple(new_clip_scroll_index);
self.base.clipping_and_scrolling = Some(new_clipping_and_scrolling);
state.current_clipping_and_scrolling = new_clipping_and_scrolling;
}
/// Adds a scroll root for a block to take the `clip` property into account
/// per CSS 2.1 § 11.1.2.
fn setup_clip_scroll_node_for_css_clip(
&mut self,
state: &mut StackingContextCollectionState,
preserved_state: &mut SavedStackingContextCollectionState,
stacking_relative_border_box: Rect<Au>,
) {
// Account for `clip` per CSS 2.1 § 11.1.2.
let style_clip_rect = match self.fragment.style().get_effects().clip {
ClipRectOrAuto::Rect(ref r) => r,
ClipRectOrAuto::Auto => return,
};
// CSS `clip` should only apply to position:absolute or positione:fixed elements.
// CSS Masking Appendix A: "Applies to: Absolutely positioned elements."
match self.positioning() {
StylePosition::Absolute | StylePosition::Fixed => {},
_ => return,
}
let clip_rect = style_clip_rect.for_border_rect(stacking_relative_border_box);
preserved_state.push_clip(state, clip_rect, self.positioning());
let new_index = state.add_clip_scroll_node(ClipScrollNode {
parent_index: self.clipping_and_scrolling().scrolling,
clip: ClippingRegion::from_rect(clip_rect.to_layout()),
content_rect: LayoutRect::zero(), // content_rect isn't important for clips.
node_type: ClipScrollNodeType::Clip(ClipType::Rect),
scroll_node_id: None,
clip_chain_id: None,
});
let new_indices = ClippingAndScrolling::new(new_index, new_index);
self.base.clipping_and_scrolling = Some(new_indices);
state.current_clipping_and_scrolling = new_indices;
}
fn create_pseudo_stacking_context_for_block(
&mut self,
stacking_context_type: StackingContextType,
parent_stacking_context_id: StackingContextId,
parent_clipping_and_scrolling: ClippingAndScrolling,
state: &mut StackingContextCollectionState,
) {
let new_context = self.fragment.create_stacking_context(
self.base.stacking_context_id,
&self.base,
stacking_context_type,
None,
parent_clipping_and_scrolling,
);
state.add_stacking_context(parent_stacking_context_id, new_context);
self.base.collect_stacking_contexts_for_children(state);
let children = state
.stacking_context_info
.get_mut(&self.base.stacking_context_id)
.map(|info| info.take_children());
if let Some(children) = children {
for child in children {
if child.context_type == StackingContextType::PseudoFloat {
state.add_stacking_context(self.base.stacking_context_id, child);
} else {
state.add_stacking_context(parent_stacking_context_id, child);
}
}
}
}
fn create_real_stacking_context_for_block(
&mut self,
parent_stacking_context_id: StackingContextId,
parent_clipping_and_scrolling: ClippingAndScrolling,
established_reference_frame: Option<ClipScrollNodeIndex>,
state: &mut StackingContextCollectionState,
) {
let stacking_context = self.fragment.create_stacking_context(
self.base.stacking_context_id,
&self.base,
StackingContextType::Real,
established_reference_frame,
parent_clipping_and_scrolling,
);
state.add_stacking_context(parent_stacking_context_id, stacking_context);
self.base.collect_stacking_contexts_for_children(state);
}
pub fn build_display_list_for_block_no_damage(
&self,
state: &mut DisplayListBuildState,
border_painting_mode: BorderPaintingMode,
) {
let background_border_section = self.background_border_section();
state.processing_scrolling_overflow_element = self.has_scrolling_overflow();
let content_size = if state.processing_scrolling_overflow_element {
let content_size = self.base.overflow.scroll.origin + self.base.overflow.scroll.size;
Some(Size2D::new(content_size.x, content_size.y))
} else {
None
};
let stacking_relative_border_box = self
.base
.stacking_relative_border_box_for_display_list(&self.fragment);
// Add the box that starts the block context.
self.fragment.build_display_list_no_damage(
state,
stacking_relative_border_box,
border_painting_mode,
background_border_section,
self.base.clip,
content_size,
);
self.base
.build_display_items_for_debugging_tint(state, self.fragment.node);
state.processing_scrolling_overflow_element = false;
}
pub fn build_display_list_for_block(
&mut self,
state: &mut DisplayListBuildState,
border_painting_mode: BorderPaintingMode,
) {
self.fragment
.restyle_damage
.remove(ServoRestyleDamage::REPAINT);
self.build_display_list_for_block_no_damage(state, border_painting_mode);
}
pub fn build_display_list_for_background_if_applicable_with_background(
&self,
state: &mut DisplayListBuildState,
background: &style_structs::Background,
background_color: AbsoluteColor,
) {
let stacking_relative_border_box = self
.base
.stacking_relative_border_box_for_display_list(&self.fragment);
let background_border_section = self.background_border_section();
self.fragment
.build_display_list_for_background_if_applicable_with_background(
state,
self.fragment.style(),
background,
background_color,
background_border_section,
stacking_relative_border_box,
)
}
#[inline]
fn stacking_context_type(
&self,
flags: StackingContextCollectionFlags,
) -> Option<StackingContextType> {
if flags.contains(StackingContextCollectionFlags::NEVER_CREATES_STACKING_CONTEXT) {
return None;
}
if self.fragment.establishes_stacking_context() {
return Some(StackingContextType::Real);
}
if self
.base
.flags
.contains(FlowFlags::IS_ABSOLUTELY_POSITIONED)
{
return Some(StackingContextType::PseudoPositioned);
}
if self.fragment.style.get_box().position != StylePosition::Static {
return Some(StackingContextType::PseudoPositioned);
}
if self.base.flags.is_float() {
return Some(StackingContextType::PseudoFloat);
}
None
}
}
impl BaseFlow {
pub fn build_display_items_for_debugging_tint(
&self,
state: &mut DisplayListBuildState,
node: OpaqueNode,
) {
if !opts::get().debug.show_parallel_layout {
return;
}
let thread_id = self.thread_id;
let stacking_context_relative_bounds = Rect::new(
self.stacking_relative_position.to_point(),
self.position.size.to_physical(self.writing_mode),
);
let mut color = THREAD_TINT_COLORS[thread_id as usize % THREAD_TINT_COLORS.len()];
color.a = 1.0;
let base =
state.create_base_display_item(self.clip, node, None, DisplayListSection::Content);
let bounds = stacking_context_relative_bounds.inflate(Au::from_px(2), Au::from_px(2));
state.add_display_item(DisplayItem::Border(CommonDisplayItem::with_data(
base,
webrender_api::BorderDisplayItem {
bounds: bounds.to_layout(),
common: items::empty_common_item_properties(),
widths: SideOffsets2D::new_all_same(Au::from_px(2)).to_layout(),
details: BorderDetails::Normal(border::simple(
color,
webrender_api::BorderStyle::Solid,
)),
},
Vec::new(),
)));
}
}
/// Gets the cursor to use given the specific ComputedValues. `default_cursor` specifies
/// the cursor to use if `cursor` is `auto`. Typically, this will be `PointerCursor`, but for
/// text display items it may be `TextCursor` or `VerticalTextCursor`.
#[inline]
fn get_cursor(values: &ComputedValues, default_cursor: Cursor) -> Option<Cursor> {
let inherited_ui = values.get_inherited_ui();
if inherited_ui.pointer_events == PointerEvents::None {
return None;
}
Some(match inherited_ui.cursor.keyword {
CursorKind::Auto => default_cursor,
CursorKind::None => Cursor::None,
CursorKind::Default => Cursor::Default,
CursorKind::Pointer => Cursor::Pointer,
CursorKind::ContextMenu => Cursor::ContextMenu,
CursorKind::Help => Cursor::Help,
CursorKind::Progress => Cursor::Progress,
CursorKind::Wait => Cursor::Wait,
CursorKind::Cell => Cursor::Cell,
CursorKind::Crosshair => Cursor::Crosshair,
CursorKind::Text => Cursor::Text,
CursorKind::VerticalText => Cursor::VerticalText,
CursorKind::Alias => Cursor::Alias,
CursorKind::Copy => Cursor::Copy,
CursorKind::Move => Cursor::Move,
CursorKind::NoDrop => Cursor::NoDrop,
CursorKind::NotAllowed => Cursor::NotAllowed,
CursorKind::Grab => Cursor::Grab,
CursorKind::Grabbing => Cursor::Grabbing,
CursorKind::EResize => Cursor::EResize,
CursorKind::NResize => Cursor::NResize,
CursorKind::NeResize => Cursor::NeResize,
CursorKind::NwResize => Cursor::NwResize,
CursorKind::SResize => Cursor::SResize,
CursorKind::SeResize => Cursor::SeResize,
CursorKind::SwResize => Cursor::SwResize,
CursorKind::WResize => Cursor::WResize,
CursorKind::EwResize => Cursor::EwResize,
CursorKind::NsResize => Cursor::NsResize,
CursorKind::NeswResize => Cursor::NeswResize,
CursorKind::NwseResize => Cursor::NwseResize,
CursorKind::ColResize => Cursor::ColResize,
CursorKind::RowResize => Cursor::RowResize,
CursorKind::AllScroll => Cursor::AllScroll,
CursorKind::ZoomIn => Cursor::ZoomIn,
CursorKind::ZoomOut => Cursor::ZoomOut,
})
}
/// Adjusts borders as appropriate to account for a fragment's status as the
/// first or last fragment within the range of an element.
///
/// Specifically, this function sets border widths to zero on the sides for
/// which the fragment is not outermost.
fn modify_border_width_for_inline_sides(
border_width: &mut LogicalMargin<Au>,
inline_border_info: InlineNodeBorderInfo,
) {
if !inline_border_info.is_first_fragment_of_element {
border_width.inline_start = Au(0);
}
if !inline_border_info.is_last_fragment_of_element {
border_width.inline_end = Au(0);
}
}
/// Describes how to paint the borders.
#[derive(Clone, Copy)]
pub enum BorderPaintingMode<'a> {
/// Paint borders separately (`border-collapse: separate`).
Separate,
/// Paint collapsed borders.
Collapse(&'a CollapsedBordersForCell),
/// Paint no borders.
Hidden,
}
fn convert_text_run_to_glyphs(
text_run: Arc<TextRun>,
range: Range<ByteIndex>,
mut origin: Point2D<Au>,
) -> (Au, Vec<GlyphInstance>) {
let mut largest_advance = Au(0);
let mut glyphs = vec![];
for slice in text_run.natural_word_slices_in_visual_order(&range) {
for glyph in slice.glyphs.iter_glyphs_for_byte_range(&slice.range) {
let glyph_advance = if glyph.char_is_word_separator() {
glyph.advance() + text_run.extra_word_spacing
} else {
glyph.advance()
};
largest_advance = largest_advance.max(glyph.advance());
if !slice.glyphs.is_whitespace() {
let glyph_offset = glyph.offset().unwrap_or(Point2D::zero());
let point = origin + glyph_offset.to_vector();
let glyph = GlyphInstance {
index: glyph.id(),
point: point.to_layout(),
};
glyphs.push(glyph);
}
origin.x += glyph_advance;
}
}
(largest_advance, glyphs)
}
pub struct IndexableTextItem {
/// The placement of the text item on the plane.
pub origin: Point2D<Au>,
/// The text run.
pub text_run: Arc<TextRun>,
/// The range of text within the text run.
pub range: Range<ByteIndex>,
/// The position of the start of the baseline of this text.
pub baseline_origin: Point2D<Au>,
}
#[derive(Default)]
pub struct IndexableText {
inner: FnvHashMap<OpaqueNode, Vec<IndexableTextItem>>,
}
impl IndexableText {
fn insert(&mut self, node: OpaqueNode, item: IndexableTextItem) {
let entries = self.inner.entry(node).or_default();
entries.push(item);
}
pub fn get(&self, node: OpaqueNode) -> Option<&[IndexableTextItem]> {
self.inner.get(&node).map(|x| x.as_slice())
}
// Returns the text index within a node for the point of interest.
pub fn text_index(&self, node: OpaqueNode, point_in_item: Point2D<Au>) -> Option<usize> {
let item = self.inner.get(&node)?;
// TODO(#20020): access all elements
let point = point_in_item + item[0].origin.to_vector();
let offset = point - item[0].baseline_origin;
Some(
item[0]
.text_run
.range_index_of_advance(&item[0].range, offset.x),
)
}
}
trait ToF32Px {
type Output;
fn to_f32_px(&self) -> Self::Output;
}
impl ToF32Px for Rect<Au> {
type Output = LayoutRect;
fn to_f32_px(&self) -> LayoutRect {
LayoutRect::from_untyped(&servo_geometry::au_rect_to_f32_rect(*self))
}
}
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