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servo/components/layout/fragment.rs
Ulf Nilsson c8db7da36a Fix inline size adjustment when stripping trailing whitespace from fragments 
The whitespace range was not properly shifted which caused us to adjust the fragment's inline size by the advance of a different set of characters.
This was causing justified text lines to be too long or too short.
2016-05-11 23:52:33 +02:00

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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! The `Fragment` type, which represents the leaves of the layout tree.
#![deny(unsafe_code)]
use app_units::Au;
use canvas_traits::CanvasMsg;
use context::LayoutContext;
use euclid::{Point2D, Rect, Size2D};
use floats::ClearType;
use flow::{self, Flow, ImmutableFlowUtils};
use flow_ref::{self, FlowRef};
use gfx;
use gfx::display_list::{BLUR_INFLATION_FACTOR, FragmentType, OpaqueNode, StackingContextId};
use gfx::text::glyph::ByteIndex;
use gfx::text::text_run::{TextRun, TextRunSlice};
use gfx_traits::{LayerId, LayerType};
use incremental::{RECONSTRUCT_FLOW, RestyleDamage};
use inline::{FIRST_FRAGMENT_OF_ELEMENT, InlineFragmentContext, InlineFragmentNodeInfo};
use inline::{InlineMetrics, LAST_FRAGMENT_OF_ELEMENT};
use ipc_channel::ipc::IpcSender;
use layout_debug;
use model::{self, IntrinsicISizes, IntrinsicISizesContribution, MaybeAuto, specified};
use msg::constellation_msg::PipelineId;
use net_traits::image::base::{Image, ImageMetadata};
use net_traits::image_cache_thread::{ImageOrMetadataAvailable, UsePlaceholder};
use range::*;
use rustc_serialize::{Encodable, Encoder};
use script::dom::htmlcanvaselement::HTMLCanvasData;
use std::borrow::ToOwned;
use std::cmp::{max, min};
use std::collections::LinkedList;
use std::fmt;
use std::sync::{Arc, Mutex};
use style::computed_values::content::ContentItem;
use style::computed_values::{border_collapse, clear, display, mix_blend_mode, overflow_wrap};
use style::computed_values::{overflow_x, position, text_decoration, transform_style};
use style::computed_values::{vertical_align, white_space, word_break, z_index};
use style::dom::TRestyleDamage;
use style::logical_geometry::{LogicalMargin, LogicalRect, LogicalSize, WritingMode};
use style::properties::{ComputedValues, ServoComputedValues};
use style::values::computed::{LengthOrPercentage, LengthOrPercentageOrAuto};
use style::values::computed::{LengthOrPercentageOrNone};
use text;
use text::TextRunScanner;
use url::Url;
use util;
use wrapper::{PseudoElementType, ThreadSafeLayoutElement, ThreadSafeLayoutNode};
/// Fragments (`struct Fragment`) are the leaves of the layout tree. They cannot position
/// themselves. In general, fragments do not have a simple correspondence with CSS fragments in the
/// specification:
///
/// * Several fragments may correspond to the same CSS box or DOM node. For example, a CSS text box
/// broken across two lines is represented by two fragments.
///
/// * Some CSS fragments are not created at all, such as some anonymous block fragments induced by
/// inline fragments with block-level sibling fragments. In that case, Servo uses an `InlineFlow`
/// with `BlockFlow` siblings; the `InlineFlow` is block-level, but not a block container. It is
/// positioned as if it were a block fragment, but its children are positioned according to
/// inline flow.
///
/// A `SpecificFragmentInfo::Generic` is an empty fragment that contributes only borders, margins,
/// padding, and backgrounds. It is analogous to a CSS nonreplaced content box.
///
/// A fragment's type influences how its styles are interpreted during layout. For example,
/// replaced content such as images are resized differently from tables, text, or other content.
/// Different types of fragments may also contain custom data; for example, text fragments contain
/// text.
///
/// Do not add fields to this structure unless they're really really mega necessary! Fragments get
/// moved around a lot and thus their size impacts performance of layout quite a bit.
///
/// FIXME(#2260, pcwalton): This can be slimmed down some by (at least) moving `inline_context`
/// to be on `InlineFlow` only.
#[derive(Clone)]
pub struct Fragment {
/// An opaque reference to the DOM node that this `Fragment` originates from.
pub node: OpaqueNode,
/// The CSS style of this fragment.
pub style: Arc<ServoComputedValues>,
/// The CSS style of this fragment when it's selected
pub selected_style: Arc<ServoComputedValues>,
/// The position of this fragment relative to its owning flow. The size includes padding and
/// border, but not margin.
///
/// NB: This does not account for relative positioning.
/// NB: Collapsed borders are not included in this.
pub border_box: LogicalRect<Au>,
/// The sum of border and padding; i.e. the distance from the edge of the border box to the
/// content edge of the fragment.
pub border_padding: LogicalMargin<Au>,
/// The margin of the content box.
pub margin: LogicalMargin<Au>,
/// Info specific to the kind of fragment. Keep this enum small.
pub specific: SpecificFragmentInfo,
/// Holds the style context information for fragments that are part of an inline formatting
/// context.
pub inline_context: Option<InlineFragmentContext>,
/// How damaged this fragment is since last reflow.
pub restyle_damage: RestyleDamage,
/// The pseudo-element that this fragment represents.
pub pseudo: PseudoElementType<()>,
/// Various flags for this fragment.
pub flags: FragmentFlags,
/// A debug ID that is consistent for the life of this fragment (via transform etc).
pub debug_id: u16,
/// The ID of the StackingContext that contains this fragment. This is initialized
/// to 0, but it assigned during the collect_stacking_contexts phase of display
/// list construction.
pub stacking_context_id: StackingContextId,
}
impl Encodable for Fragment {
fn encode<S: Encoder>(&self, e: &mut S) -> Result<(), S::Error> {
e.emit_struct("fragment", 0, |e| {
try!(e.emit_struct_field("id", 0, |e| self.debug_id().encode(e)));
try!(e.emit_struct_field("border_box", 1, |e| self.border_box.encode(e)));
e.emit_struct_field("margin", 2, |e| self.margin.encode(e))
})
}
}
/// Info specific to the kind of fragment.
///
/// Keep this enum small. As in, no more than one word. Or pcwalton will yell at you.
#[derive(Clone)]
pub enum SpecificFragmentInfo {
Generic,
/// A piece of generated content that cannot be resolved into `ScannedText` until the generated
/// content resolution phase (e.g. an ordered list item marker).
GeneratedContent(Box<GeneratedContentInfo>),
Iframe(IframeFragmentInfo),
Image(Box<ImageFragmentInfo>),
Canvas(Box<CanvasFragmentInfo>),
/// A hypothetical box (see CSS 2.1 § 10.3.7) for an absolutely-positioned block that was
/// declared with `display: inline;`.
InlineAbsoluteHypothetical(InlineAbsoluteHypotheticalFragmentInfo),
InlineBlock(InlineBlockFragmentInfo),
/// An inline fragment that establishes an absolute containing block for its descendants (i.e.
/// a positioned inline fragment).
InlineAbsolute(InlineAbsoluteFragmentInfo),
ScannedText(Box<ScannedTextFragmentInfo>),
Table,
TableCell,
TableColumn(TableColumnFragmentInfo),
TableRow,
TableWrapper,
Multicol,
MulticolColumn,
UnscannedText(Box<UnscannedTextFragmentInfo>),
}
impl SpecificFragmentInfo {
fn restyle_damage(&self) -> RestyleDamage {
let flow =
match *self {
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::ScannedText(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::UnscannedText(_) |
SpecificFragmentInfo::Generic => return RestyleDamage::empty(),
SpecificFragmentInfo::InlineAbsoluteHypothetical(ref info) => &info.flow_ref,
SpecificFragmentInfo::InlineAbsolute(ref info) => &info.flow_ref,
SpecificFragmentInfo::InlineBlock(ref info) => &info.flow_ref,
};
flow::base(&**flow).restyle_damage
}
pub fn get_type(&self) -> &'static str {
match *self {
SpecificFragmentInfo::Canvas(_) => "SpecificFragmentInfo::Canvas",
SpecificFragmentInfo::Generic => "SpecificFragmentInfo::Generic",
SpecificFragmentInfo::GeneratedContent(_) => "SpecificFragmentInfo::GeneratedContent",
SpecificFragmentInfo::Iframe(_) => "SpecificFragmentInfo::Iframe",
SpecificFragmentInfo::Image(_) => "SpecificFragmentInfo::Image",
SpecificFragmentInfo::InlineAbsolute(_) => "SpecificFragmentInfo::InlineAbsolute",
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => {
"SpecificFragmentInfo::InlineAbsoluteHypothetical"
}
SpecificFragmentInfo::InlineBlock(_) => "SpecificFragmentInfo::InlineBlock",
SpecificFragmentInfo::ScannedText(_) => "SpecificFragmentInfo::ScannedText",
SpecificFragmentInfo::Table => "SpecificFragmentInfo::Table",
SpecificFragmentInfo::TableCell => "SpecificFragmentInfo::TableCell",
SpecificFragmentInfo::TableColumn(_) => "SpecificFragmentInfo::TableColumn",
SpecificFragmentInfo::TableRow => "SpecificFragmentInfo::TableRow",
SpecificFragmentInfo::TableWrapper => "SpecificFragmentInfo::TableWrapper",
SpecificFragmentInfo::Multicol => "SpecificFragmentInfo::Multicol",
SpecificFragmentInfo::MulticolColumn => "SpecificFragmentInfo::MulticolColumn",
SpecificFragmentInfo::UnscannedText(_) => "SpecificFragmentInfo::UnscannedText",
}
}
}
impl fmt::Debug for SpecificFragmentInfo {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
SpecificFragmentInfo::ScannedText(ref info) => write!(f, "{:?}", info.text()),
SpecificFragmentInfo::UnscannedText(ref info) => write!(f, "{:?}", info.text),
_ => Ok(())
}
}
}
/// Clamp a value obtained from style_length, based on min / max lengths.
fn clamp_size(size: Au,
min_size: LengthOrPercentage,
max_size: LengthOrPercentageOrNone,
container_size: Au)
-> Au {
let min_size = model::specified(min_size, container_size);
let max_size = model::specified_or_none(max_size, container_size);
max(min_size, match max_size {
None => size,
Some(max_size) => min(size, max_size),
})
}
/// Information for generated content.
#[derive(Clone)]
pub enum GeneratedContentInfo {
ListItem,
ContentItem(ContentItem),
/// Placeholder for elements with generated content that did not generate any fragments.
Empty,
}
/// A hypothetical box (see CSS 2.1 § 10.3.7) for an absolutely-positioned block that was declared
/// with `display: inline;`.
///
/// FIXME(pcwalton): Stop leaking this `FlowRef` to layout; that is not memory safe because layout
/// can clone it.
#[derive(Clone)]
pub struct InlineAbsoluteHypotheticalFragmentInfo {
pub flow_ref: FlowRef,
}
impl InlineAbsoluteHypotheticalFragmentInfo {
pub fn new(flow_ref: FlowRef) -> InlineAbsoluteHypotheticalFragmentInfo {
InlineAbsoluteHypotheticalFragmentInfo {
flow_ref: flow_ref,
}
}
}
/// A fragment that represents an inline-block element.
///
/// FIXME(pcwalton): Stop leaking this `FlowRef` to layout; that is not memory safe because layout
/// can clone it.
#[derive(Clone)]
pub struct InlineBlockFragmentInfo {
pub flow_ref: FlowRef,
}
impl InlineBlockFragmentInfo {
pub fn new(flow_ref: FlowRef) -> InlineBlockFragmentInfo {
InlineBlockFragmentInfo {
flow_ref: flow_ref,
}
}
}
/// An inline fragment that establishes an absolute containing block for its descendants (i.e.
/// a positioned inline fragment).
///
/// FIXME(pcwalton): Stop leaking this `FlowRef` to layout; that is not memory safe because layout
/// can clone it.
#[derive(Clone)]
pub struct InlineAbsoluteFragmentInfo {
pub flow_ref: FlowRef,
}
impl InlineAbsoluteFragmentInfo {
pub fn new(flow_ref: FlowRef) -> InlineAbsoluteFragmentInfo {
InlineAbsoluteFragmentInfo {
flow_ref: flow_ref,
}
}
}
#[derive(Clone)]
pub struct CanvasFragmentInfo {
pub replaced_image_fragment_info: ReplacedImageFragmentInfo,
pub ipc_renderer: Option<Arc<Mutex<IpcSender<CanvasMsg>>>>,
pub dom_width: Au,
pub dom_height: Au,
}
impl CanvasFragmentInfo {
pub fn new<N: ThreadSafeLayoutNode>(node: &N, data: HTMLCanvasData, ctx: &LayoutContext) -> CanvasFragmentInfo {
CanvasFragmentInfo {
replaced_image_fragment_info: ReplacedImageFragmentInfo::new(node, ctx),
ipc_renderer: data.ipc_renderer
.map(|renderer| Arc::new(Mutex::new(renderer))),
dom_width: Au::from_px(data.width as i32),
dom_height: Au::from_px(data.height as i32),
}
}
/// Returns the original inline-size of the canvas.
pub fn canvas_inline_size(&self) -> Au {
if self.replaced_image_fragment_info.writing_mode_is_vertical {
self.dom_height
} else {
self.dom_width
}
}
/// Returns the original block-size of the canvas.
pub fn canvas_block_size(&self) -> Au {
if self.replaced_image_fragment_info.writing_mode_is_vertical {
self.dom_width
} else {
self.dom_height
}
}
}
/// A fragment that represents a replaced content image and its accompanying borders, shadows, etc.
#[derive(Clone)]
pub struct ImageFragmentInfo {
/// The image held within this fragment.
pub replaced_image_fragment_info: ReplacedImageFragmentInfo,
pub image: Option<Arc<Image>>,
pub metadata: Option<ImageMetadata>,
}
impl ImageFragmentInfo {
/// Creates a new image fragment from the given URL and local image cache.
///
/// FIXME(pcwalton): The fact that image fragments store the cache in the fragment makes little
/// sense to me.
pub fn new<N: ThreadSafeLayoutNode>(node: &N, url: Option<Url>,
layout_context: &LayoutContext) -> ImageFragmentInfo {
let image_or_metadata = url.and_then(|url| {
layout_context.get_or_request_image_or_meta(url, UsePlaceholder::Yes)
});
let (image, metadata) = match image_or_metadata {
Some(ImageOrMetadataAvailable::ImageAvailable(i)) => {
(Some(i.clone()), Some(ImageMetadata { height: i.height, width: i.width } ))
}
Some(ImageOrMetadataAvailable::MetadataAvailable(m)) => {
(None, Some(m))
}
None => {
(None, None)
}
};
ImageFragmentInfo {
replaced_image_fragment_info: ReplacedImageFragmentInfo::new(node, layout_context),
image: image,
metadata: metadata,
}
}
/// Returns the original inline-size of the image.
pub fn image_inline_size(&mut self) -> Au {
match self.metadata {
Some(ref metadata) => {
Au::from_px(if self.replaced_image_fragment_info.writing_mode_is_vertical {
metadata.height
} else {
metadata.width
} as i32)
}
None => Au(0)
}
}
/// Returns the original block-size of the image.
pub fn image_block_size(&mut self) -> Au {
match self.metadata {
Some(ref metadata) => {
Au::from_px(if self.replaced_image_fragment_info.writing_mode_is_vertical {
metadata.width
} else {
metadata.height
} as i32)
}
None => Au(0)
}
}
/// Tile an image
pub fn tile_image(position: &mut Au, size: &mut Au, virtual_position: Au, image_size: u32) {
// Avoid division by zero below!
let image_size = image_size as i32;
if image_size == 0 {
return
}
let delta_pixels = (virtual_position - *position).to_px();
let tile_count = (delta_pixels + image_size - 1) / image_size;
let offset = Au::from_px(image_size * tile_count);
let new_position = virtual_position - offset;
*size = *position - new_position + *size;
*position = new_position;
}
}
#[derive(Clone)]
pub struct ReplacedImageFragmentInfo {
pub computed_inline_size: Option<Au>,
pub computed_block_size: Option<Au>,
pub writing_mode_is_vertical: bool,
}
impl ReplacedImageFragmentInfo {
pub fn new<N>(node: &N, ctx: &LayoutContext) -> ReplacedImageFragmentInfo
where N: ThreadSafeLayoutNode {
let is_vertical = node.style(ctx.style_context()).writing_mode.is_vertical();
ReplacedImageFragmentInfo {
computed_inline_size: None,
computed_block_size: None,
writing_mode_is_vertical: is_vertical,
}
}
/// Returns the calculated inline-size of the image, accounting for the inline-size attribute.
pub fn computed_inline_size(&self) -> Au {
self.computed_inline_size.expect("image inline_size is not computed yet!")
}
/// Returns the calculated block-size of the image, accounting for the block-size attribute.
pub fn computed_block_size(&self) -> Au {
self.computed_block_size.expect("image block_size is not computed yet!")
}
// Return used value for inline-size or block-size.
//
// `dom_length`: inline-size or block-size as specified in the `img` tag.
// `style_length`: inline-size as given in the CSS
pub fn style_length(style_length: LengthOrPercentageOrAuto,
container_size: Option<Au>) -> MaybeAuto {
match (style_length, container_size) {
(LengthOrPercentageOrAuto::Length(length), _) => MaybeAuto::Specified(length),
(LengthOrPercentageOrAuto::Percentage(pc), Some(container_size)) => {
MaybeAuto::Specified(container_size.scale_by(pc))
}
(LengthOrPercentageOrAuto::Percentage(_), None) => MaybeAuto::Auto,
(LengthOrPercentageOrAuto::Calc(calc), Some(container_size)) => {
MaybeAuto::Specified(calc.length() + container_size.scale_by(calc.percentage()))
}
(LengthOrPercentageOrAuto::Calc(_), None) => MaybeAuto::Auto,
(LengthOrPercentageOrAuto::Auto, _) => MaybeAuto::Auto,
}
}
pub fn calculate_replaced_inline_size(&mut self,
style: &ServoComputedValues,
noncontent_inline_size: Au,
container_inline_size: Au,
fragment_inline_size: Au,
fragment_block_size: Au)
-> Au {
let style_inline_size = style.content_inline_size();
let style_block_size = style.content_block_size();
let style_min_inline_size = style.min_inline_size();
let style_max_inline_size = style.max_inline_size();
let style_min_block_size = style.min_block_size();
let style_max_block_size = style.max_block_size();
// TODO(ksh8281): compute border,margin
let inline_size = ReplacedImageFragmentInfo::style_length(
style_inline_size,
Some(container_inline_size));
let inline_size = match inline_size {
MaybeAuto::Auto => {
let intrinsic_width = fragment_inline_size;
let intrinsic_height = fragment_block_size;
if intrinsic_height == Au(0) {
intrinsic_width
} else {
let ratio = intrinsic_width.to_f32_px() /
intrinsic_height.to_f32_px();
let specified_height = ReplacedImageFragmentInfo::style_length(
style_block_size,
None);
let specified_height = match specified_height {
MaybeAuto::Auto => intrinsic_height,
MaybeAuto::Specified(h) => h,
};
let specified_height = clamp_size(specified_height,
style_min_block_size,
style_max_block_size,
Au(0));
Au::from_f32_px(specified_height.to_f32_px() * ratio)
}
},
MaybeAuto::Specified(w) => w,
};
let inline_size = clamp_size(inline_size,
style_min_inline_size,
style_max_inline_size,
container_inline_size);
self.computed_inline_size = Some(inline_size);
inline_size + noncontent_inline_size
}
pub fn calculate_replaced_block_size(&mut self,
style: &ServoComputedValues,
noncontent_block_size: Au,
containing_block_block_size: Option<Au>,
fragment_inline_size: Au,
fragment_block_size: Au)
-> Au {
// TODO(ksh8281): compute border,margin,padding
let style_block_size = style.content_block_size();
let style_min_block_size = style.min_block_size();
let style_max_block_size = style.max_block_size();
let inline_size = self.computed_inline_size();
let block_size = ReplacedImageFragmentInfo::style_length(
style_block_size,
containing_block_block_size);
let block_size = match block_size {
MaybeAuto::Auto => {
let intrinsic_width = fragment_inline_size;
let intrinsic_height = fragment_block_size;
let scale = intrinsic_width.to_f32_px() / inline_size.to_f32_px();
Au::from_f32_px(intrinsic_height.to_f32_px() / scale)
},
MaybeAuto::Specified(h) => {
h
}
};
let block_size = clamp_size(block_size,
style_min_block_size,
style_max_block_size,
Au(0));
self.computed_block_size = Some(block_size);
block_size + noncontent_block_size
}
}
/// A fragment that represents an inline frame (iframe). This stores the pipeline ID so that the
/// size of this iframe can be communicated via the constellation to the iframe's own layout thread.
#[derive(Clone)]
pub struct IframeFragmentInfo {
/// The pipeline ID of this iframe.
pub pipeline_id: PipelineId,
}
impl IframeFragmentInfo {
/// Creates the information specific to an iframe fragment.
pub fn new<N: ThreadSafeLayoutNode>(node: &N) -> IframeFragmentInfo {
let pipeline_id = node.iframe_pipeline_id();
IframeFragmentInfo {
pipeline_id: pipeline_id,
}
}
#[inline]
pub fn calculate_replaced_inline_size(&self, style: &ServoComputedValues, containing_size: Au)
-> Au {
// Calculate the replaced inline size (or default) as per CSS 2.1 § 10.3.2
IframeFragmentInfo::calculate_replaced_size(style.content_inline_size(),
style.min_inline_size(),
style.max_inline_size(),
Some(containing_size),
Au::from_px(300))
}
#[inline]
pub fn calculate_replaced_block_size(&self, style: &ServoComputedValues, containing_size: Option<Au>)
-> Au {
// Calculate the replaced block size (or default) as per CSS 2.1 § 10.3.2
IframeFragmentInfo::calculate_replaced_size(style.content_block_size(),
style.min_block_size(),
style.max_block_size(),
containing_size,
Au::from_px(150))
}
fn calculate_replaced_size(content_size: LengthOrPercentageOrAuto,
style_min_size: LengthOrPercentage,
style_max_size: LengthOrPercentageOrNone,
containing_size: Option<Au>,
default_size: Au) -> Au {
let computed_size = match (content_size, containing_size) {
(LengthOrPercentageOrAuto::Length(length), _) => length,
(LengthOrPercentageOrAuto::Percentage(pc), Some(container_size)) => container_size.scale_by(pc),
(LengthOrPercentageOrAuto::Calc(calc), Some(container_size)) => {
container_size.scale_by(calc.percentage()) + calc.length()
},
(LengthOrPercentageOrAuto::Calc(calc), None) => calc.length(),
(LengthOrPercentageOrAuto::Percentage(_), None) => default_size,
(LengthOrPercentageOrAuto::Auto, _) => default_size,
};
let containing_size = containing_size.unwrap_or(Au(0));
clamp_size(computed_size,
style_min_size,
style_max_size,
containing_size)
}
}
/// A scanned text fragment represents a single run of text with a distinct style. A `TextFragment`
/// may be split into two or more fragments across line breaks. Several `TextFragment`s may
/// correspond to a single DOM text node. Split text fragments are implemented by referring to
/// subsets of a single `TextRun` object.
#[derive(Clone)]
pub struct ScannedTextFragmentInfo {
/// The text run that this represents.
pub run: Arc<TextRun>,
/// The intrinsic size of the text fragment.
pub content_size: LogicalSize<Au>,
/// The byte offset of the insertion point, if any.
pub insertion_point: Option<ByteIndex>,
/// The range within the above text run that this represents.
pub range: Range<ByteIndex>,
/// The endpoint of the above range, including whitespace that was stripped out. This exists
/// so that we can restore the range to its original value (before line breaking occurred) when
/// performing incremental reflow.
pub range_end_including_stripped_whitespace: ByteIndex,
pub flags: ScannedTextFlags,
}
bitflags! {
pub flags ScannedTextFlags: u8 {
/// Whether a line break is required after this fragment if wrapping on newlines (e.g. if
/// `white-space: pre` is in effect).
const REQUIRES_LINE_BREAK_AFTERWARD_IF_WRAPPING_ON_NEWLINES = 0x01,
/// Is this fragment selected?
const SELECTED = 0x02,
}
}
impl ScannedTextFragmentInfo {
/// Creates the information specific to a scanned text fragment from a range and a text run.
pub fn new(run: Arc<TextRun>,
range: Range<ByteIndex>,
content_size: LogicalSize<Au>,
insertion_point: Option<ByteIndex>,
flags: ScannedTextFlags)
-> ScannedTextFragmentInfo {
ScannedTextFragmentInfo {
run: run,
range: range,
insertion_point: insertion_point,
content_size: content_size,
range_end_including_stripped_whitespace: range.end(),
flags: flags,
}
}
pub fn text(&self) -> &str {
&self.run.text[self.range.begin().to_usize() .. self.range.end().to_usize()]
}
pub fn requires_line_break_afterward_if_wrapping_on_newlines(&self) -> bool {
self.flags.contains(REQUIRES_LINE_BREAK_AFTERWARD_IF_WRAPPING_ON_NEWLINES)
}
pub fn selected(&self) -> bool {
self.flags.contains(SELECTED)
}
}
/// Describes how to split a fragment. This is used during line breaking as part of the return
/// value of `find_split_info_for_inline_size()`.
#[derive(Debug, Clone)]
pub struct SplitInfo {
// TODO(bjz): this should only need to be a single character index, but both values are
// currently needed for splitting in the `inline::try_append_*` functions.
pub range: Range<ByteIndex>,
pub inline_size: Au,
}
impl SplitInfo {
fn new(range: Range<ByteIndex>, info: &ScannedTextFragmentInfo) -> SplitInfo {
let inline_size = info.run.advance_for_range(&range);
SplitInfo {
range: range,
inline_size: inline_size,
}
}
}
/// Describes how to split a fragment into two. This contains up to two `SplitInfo`s.
pub struct SplitResult {
/// The part of the fragment that goes on the first line.
pub inline_start: Option<SplitInfo>,
/// The part of the fragment that goes on the second line.
pub inline_end: Option<SplitInfo>,
/// The text run which is being split.
pub text_run: Arc<TextRun>,
}
/// Describes how a fragment should be truncated.
pub struct TruncationResult {
/// The part of the fragment remaining after truncation.
pub split: SplitInfo,
/// The text run which is being truncated.
pub text_run: Arc<TextRun>,
}
/// Data for an unscanned text fragment. Unscanned text fragments are the results of flow
/// construction that have not yet had their inline-size determined.
#[derive(Clone)]
pub struct UnscannedTextFragmentInfo {
/// The text inside the fragment.
pub text: Box<str>,
/// The selected text range. An empty range represents the insertion point.
pub selection: Option<Range<ByteIndex>>,
}
impl UnscannedTextFragmentInfo {
/// Creates a new instance of `UnscannedTextFragmentInfo` from the given text.
#[inline]
pub fn new(text: String, selection: Option<Range<ByteIndex>>) -> UnscannedTextFragmentInfo {
UnscannedTextFragmentInfo {
text: text.into_boxed_str(),
selection: selection,
}
}
}
/// A fragment that represents a table column.
#[derive(Copy, Clone)]
pub struct TableColumnFragmentInfo {
/// the number of columns a <col> element should span
pub span: u32,
}
impl TableColumnFragmentInfo {
/// Create the information specific to an table column fragment.
pub fn new<N: ThreadSafeLayoutNode>(node: &N) -> TableColumnFragmentInfo {
let element = node.as_element();
let span = element.get_attr(&ns!(), &atom!("span"))
.and_then(|string| string.parse().ok())
.unwrap_or(0);
TableColumnFragmentInfo {
span: span,
}
}
}
impl Fragment {
/// Constructs a new `Fragment` instance.
pub fn new<N: ThreadSafeLayoutNode>(node: &N, specific: SpecificFragmentInfo, ctx: &LayoutContext) -> Fragment {
let style_context = ctx.style_context();
let style = node.style(style_context).clone();
let writing_mode = style.writing_mode;
let mut restyle_damage = node.restyle_damage();
restyle_damage.remove(RECONSTRUCT_FLOW);
Fragment {
node: node.opaque(),
style: style,
selected_style: node.selected_style(style_context).clone(),
restyle_damage: restyle_damage,
border_box: LogicalRect::zero(writing_mode),
border_padding: LogicalMargin::zero(writing_mode),
margin: LogicalMargin::zero(writing_mode),
specific: specific,
inline_context: None,
pseudo: node.get_pseudo_element_type().strip(),
flags: FragmentFlags::empty(),
debug_id: layout_debug::generate_unique_debug_id(),
stacking_context_id: StackingContextId::new(0),
}
}
/// Constructs a new `Fragment` instance from an opaque node.
pub fn from_opaque_node_and_style(node: OpaqueNode,
pseudo: PseudoElementType<()>,
style: Arc<ServoComputedValues>,
selected_style: Arc<ServoComputedValues>,
mut restyle_damage: RestyleDamage,
specific: SpecificFragmentInfo)
-> Fragment {
let writing_mode = style.writing_mode;
restyle_damage.remove(RECONSTRUCT_FLOW);
Fragment {
node: node,
style: style,
selected_style: selected_style,
restyle_damage: restyle_damage,
border_box: LogicalRect::zero(writing_mode),
border_padding: LogicalMargin::zero(writing_mode),
margin: LogicalMargin::zero(writing_mode),
specific: specific,
inline_context: None,
pseudo: pseudo,
flags: FragmentFlags::empty(),
debug_id: layout_debug::generate_unique_debug_id(),
stacking_context_id: StackingContextId::new(0),
}
}
/// Returns a debug ID of this fragment. This ID should not be considered stable across
/// multiple layouts or fragment manipulations.
pub fn debug_id(&self) -> u16 {
self.debug_id
}
/// Transforms this fragment into another fragment of the given type, with the given size,
/// preserving all the other data.
pub fn transform(&self, size: LogicalSize<Au>, info: SpecificFragmentInfo)
-> Fragment {
let new_border_box = LogicalRect::from_point_size(self.style.writing_mode,
self.border_box.start,
size);
let mut restyle_damage = RestyleDamage::rebuild_and_reflow();
restyle_damage.remove(RECONSTRUCT_FLOW);
Fragment {
node: self.node,
style: self.style.clone(),
selected_style: self.selected_style.clone(),
restyle_damage: restyle_damage,
border_box: new_border_box,
border_padding: self.border_padding,
margin: self.margin,
specific: info,
inline_context: self.inline_context.clone(),
pseudo: self.pseudo.clone(),
flags: FragmentFlags::empty(),
debug_id: self.debug_id,
stacking_context_id: StackingContextId::new(0),
}
}
/// Transforms this fragment using the given `SplitInfo`, preserving all the other data.
pub fn transform_with_split_info(&self, split: &SplitInfo, text_run: Arc<TextRun>)
-> Fragment {
let size = LogicalSize::new(self.style.writing_mode,
split.inline_size,
self.border_box.size.block);
let flags = match self.specific {
SpecificFragmentInfo::ScannedText(ref info) => info.flags,
_ => ScannedTextFlags::empty()
};
// FIXME(pcwalton): This should modify the insertion point as necessary.
let info = box ScannedTextFragmentInfo::new(
text_run,
split.range,
size,
None,
flags);
self.transform(size, SpecificFragmentInfo::ScannedText(info))
}
/// Transforms this fragment into an ellipsis fragment, preserving all the other data.
pub fn transform_into_ellipsis(&self, layout_context: &LayoutContext) -> Fragment {
let mut unscanned_ellipsis_fragments = LinkedList::new();
unscanned_ellipsis_fragments.push_back(self.transform(
self.border_box.size,
SpecificFragmentInfo::UnscannedText(
box UnscannedTextFragmentInfo::new("…".to_owned(), None))));
let ellipsis_fragments = TextRunScanner::new().scan_for_runs(&mut layout_context.font_context(),
unscanned_ellipsis_fragments);
debug_assert!(ellipsis_fragments.len() == 1);
ellipsis_fragments.fragments.into_iter().next().unwrap()
}
pub fn restyle_damage(&self) -> RestyleDamage {
self.restyle_damage | self.specific.restyle_damage()
}
pub fn contains_node(&self, node_address: OpaqueNode) -> bool {
node_address == self.node ||
self.inline_context.as_ref().map_or(false, |ctx| {
ctx.contains_node(node_address)
})
}
/// Adds a style to the inline context for this fragment. If the inline context doesn't exist
/// yet, it will be created.
pub fn add_inline_context_style(&mut self, node_info: InlineFragmentNodeInfo) {
if self.inline_context.is_none() {
self.inline_context = Some(InlineFragmentContext::new());
}
self.inline_context.as_mut().unwrap().nodes.push(node_info);
}
/// Determines which quantities (border/padding/margin/specified) should be included in the
/// intrinsic inline size of this fragment.
fn quantities_included_in_intrinsic_inline_size(&self)
-> QuantitiesIncludedInIntrinsicInlineSizes {
match self.specific {
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::Multicol => {
QuantitiesIncludedInIntrinsicInlineSizes::all()
}
SpecificFragmentInfo::Table | SpecificFragmentInfo::TableCell => {
let base_quantities = INTRINSIC_INLINE_SIZE_INCLUDES_PADDING |
INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED;
if self.style.get_inheritedtable().border_collapse ==
border_collapse::T::separate {
base_quantities | INTRINSIC_INLINE_SIZE_INCLUDES_BORDER
} else {
base_quantities
}
}
SpecificFragmentInfo::TableWrapper => {
let base_quantities = INTRINSIC_INLINE_SIZE_INCLUDES_MARGINS |
INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED;
if self.style.get_inheritedtable().border_collapse ==
border_collapse::T::separate {
base_quantities | INTRINSIC_INLINE_SIZE_INCLUDES_BORDER
} else {
base_quantities
}
}
SpecificFragmentInfo::TableRow => {
let base_quantities = INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED;
if self.style.get_inheritedtable().border_collapse ==
border_collapse::T::separate {
base_quantities | INTRINSIC_INLINE_SIZE_INCLUDES_BORDER
} else {
base_quantities
}
}
SpecificFragmentInfo::ScannedText(_) |
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::UnscannedText(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::MulticolColumn => {
QuantitiesIncludedInIntrinsicInlineSizes::empty()
}
}
}
/// Returns the portion of the intrinsic inline-size that consists of borders, padding, and/or
/// margins.
///
/// FIXME(#2261, pcwalton): This won't work well for inlines: is this OK?
pub fn surrounding_intrinsic_inline_size(&self) -> Au {
let flags = self.quantities_included_in_intrinsic_inline_size();
let style = self.style();
// FIXME(pcwalton): Percentages should be relative to any definite size per CSS-SIZING.
// This will likely need to be done by pushing down definite sizes during selector
// cascading.
let margin = if flags.contains(INTRINSIC_INLINE_SIZE_INCLUDES_MARGINS) {
let margin = style.logical_margin();
(MaybeAuto::from_style(margin.inline_start, Au(0)).specified_or_zero() +
MaybeAuto::from_style(margin.inline_end, Au(0)).specified_or_zero())
} else {
Au(0)
};
// FIXME(pcwalton): Percentages should be relative to any definite size per CSS-SIZING.
// This will likely need to be done by pushing down definite sizes during selector
// cascading.
let padding = if flags.contains(INTRINSIC_INLINE_SIZE_INCLUDES_PADDING) {
let padding = style.logical_padding();
(model::specified(padding.inline_start, Au(0)) +
model::specified(padding.inline_end, Au(0)))
} else {
Au(0)
};
let border = if flags.contains(INTRINSIC_INLINE_SIZE_INCLUDES_BORDER) {
self.border_width().inline_start_end()
} else {
Au(0)
};
margin + padding + border
}
/// Uses the style only to estimate the intrinsic inline-sizes. These may be modified for text
/// or replaced elements.
fn style_specified_intrinsic_inline_size(&self) -> IntrinsicISizesContribution {
let flags = self.quantities_included_in_intrinsic_inline_size();
let style = self.style();
let mut specified = Au(0);
if flags.contains(INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED) {
specified = MaybeAuto::from_style(style.content_inline_size(),
Au(0)).specified_or_zero();
specified = max(model::specified(style.min_inline_size(), Au(0)), specified);
if let Some(max) = model::specified_or_none(style.max_inline_size(), Au(0)) {
specified = min(specified, max)
}
}
// FIXME(#2261, pcwalton): This won't work well for inlines: is this OK?
let surrounding_inline_size = self.surrounding_intrinsic_inline_size();
IntrinsicISizesContribution {
content_intrinsic_sizes: IntrinsicISizes {
minimum_inline_size: specified,
preferred_inline_size: specified,
},
surrounding_size: surrounding_inline_size,
}
}
/// Returns a guess as to the distances from the margin edge of this fragment to its content
/// in the inline direction. This will generally be correct unless percentages are involved.
///
/// This is used for the float placement speculation logic.
pub fn guess_inline_content_edge_offsets(&self) -> SpeculatedInlineContentEdgeOffsets {
let logical_margin = self.style.logical_margin();
let logical_padding = self.style.logical_padding();
let border_width = self.border_width();
SpeculatedInlineContentEdgeOffsets {
start: MaybeAuto::from_style(logical_margin.inline_start, Au(0)).specified_or_zero() +
model::specified(logical_padding.inline_start, Au(0)) +
border_width.inline_start,
end: MaybeAuto::from_style(logical_margin.inline_end, Au(0)).specified_or_zero() +
model::specified(logical_padding.inline_end, Au(0)) +
border_width.inline_end,
}
}
pub fn calculate_line_height(&self, layout_context: &LayoutContext) -> Au {
let font_style = self.style.get_font_arc();
let font_metrics = text::font_metrics_for_style(&mut layout_context.font_context(),
font_style);
text::line_height_from_style(&*self.style, &font_metrics)
}
/// Returns the sum of the inline-sizes of all the borders of this fragment. Note that this
/// can be expensive to compute, so if possible use the `border_padding` field instead.
#[inline]
pub fn border_width(&self) -> LogicalMargin<Au> {
let style_border_width = match self.specific {
SpecificFragmentInfo::ScannedText(_) |
SpecificFragmentInfo::InlineBlock(_) => LogicalMargin::zero(self.style.writing_mode),
_ => self.style().logical_border_width(),
};
match self.inline_context {
None => style_border_width,
Some(ref inline_fragment_context) => {
inline_fragment_context.nodes.iter().fold(style_border_width, |accumulator, node| {
let mut this_border_width = node.style.logical_border_width();
if !node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT) {
this_border_width.inline_start = Au(0)
}
if !node.flags.contains(LAST_FRAGMENT_OF_ELEMENT) {
this_border_width.inline_end = Au(0)
}
accumulator + this_border_width
})
}
}
}
/// Computes the margins in the inline direction from the containing block inline-size and the
/// style. After this call, the inline direction of the `margin` field will be correct.
///
/// Do not use this method if the inline direction margins are to be computed some other way
/// (for example, via constraint solving for blocks).
pub fn compute_inline_direction_margins(&mut self, containing_block_inline_size: Au) {
match self.specific {
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableColumn(_) => {
self.margin.inline_start = Au(0);
self.margin.inline_end = Au(0);
return
}
SpecificFragmentInfo::InlineBlock(_) => {
// Inline-blocks do not take self margins into account but do account for margins
// from outer inline contexts.
self.margin.inline_start = Au(0);
self.margin.inline_end = Au(0);
}
_ => {
let margin = self.style().logical_margin();
self.margin.inline_start =
MaybeAuto::from_style(margin.inline_start,
containing_block_inline_size).specified_or_zero();
self.margin.inline_end =
MaybeAuto::from_style(margin.inline_end,
containing_block_inline_size).specified_or_zero();
}
}
if let Some(ref inline_context) = self.inline_context {
for node in &inline_context.nodes {
let margin = node.style.logical_margin();
let this_inline_start_margin = if !node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT) {
Au(0)
} else {
MaybeAuto::from_style(margin.inline_start,
containing_block_inline_size).specified_or_zero()
};
let this_inline_end_margin = if !node.flags.contains(LAST_FRAGMENT_OF_ELEMENT) {
Au(0)
} else {
MaybeAuto::from_style(margin.inline_end,
containing_block_inline_size).specified_or_zero()
};
self.margin.inline_start = self.margin.inline_start + this_inline_start_margin;
self.margin.inline_end = self.margin.inline_end + this_inline_end_margin;
}
}
}
/// Computes the margins in the block direction from the containing block inline-size and the
/// style. After this call, the block direction of the `margin` field will be correct.
///
/// Do not use this method if the block direction margins are to be computed some other way
/// (for example, via constraint solving for absolutely-positioned flows).
pub fn compute_block_direction_margins(&mut self, containing_block_inline_size: Au) {
match self.specific {
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableColumn(_) => {
self.margin.block_start = Au(0);
self.margin.block_end = Au(0)
}
_ => {
// NB: Percentages are relative to containing block inline-size (not block-size)
// per CSS 2.1.
let margin = self.style().logical_margin();
self.margin.block_start =
MaybeAuto::from_style(margin.block_start, containing_block_inline_size)
.specified_or_zero();
self.margin.block_end =
MaybeAuto::from_style(margin.block_end, containing_block_inline_size)
.specified_or_zero();
}
}
}
/// Computes the border and padding in both inline and block directions from the containing
/// block inline-size and the style. After this call, the `border_padding` field will be
/// correct.
///
/// TODO(pcwalton): Remove `border_collapse`; we can figure it out from our style and specific
/// fragment info.
pub fn compute_border_and_padding(&mut self,
containing_block_inline_size: Au,
border_collapse: border_collapse::T) {
// Compute border.
let border = match border_collapse {
border_collapse::T::separate => self.border_width(),
border_collapse::T::collapse => LogicalMargin::zero(self.style.writing_mode),
};
// Compute padding from the fragment's style.
//
// This is zero in the case of `inline-block` because that padding is applied to the
// wrapped block, not the fragment.
let padding_from_style = match self.specific {
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::InlineBlock(_) => LogicalMargin::zero(self.style.writing_mode),
_ => model::padding_from_style(self.style(), containing_block_inline_size),
};
// Compute padding from the inline fragment context.
let padding_from_inline_fragment_context = match (&self.specific, &self.inline_context) {
(_, &None) |
(&SpecificFragmentInfo::TableColumn(_), _) |
(&SpecificFragmentInfo::TableRow, _) |
(&SpecificFragmentInfo::TableWrapper, _) => {
LogicalMargin::zero(self.style.writing_mode)
}
(_, &Some(ref inline_fragment_context)) => {
let zero_padding = LogicalMargin::zero(self.style.writing_mode);
inline_fragment_context.nodes.iter().fold(zero_padding, |accumulator, node| {
let mut padding = model::padding_from_style(&*node.style, Au(0));
if !node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT) {
padding.inline_start = Au(0)
}
if !node.flags.contains(LAST_FRAGMENT_OF_ELEMENT) {
padding.inline_end = Au(0)
}
accumulator + padding
})
}
};
self.border_padding = border + padding_from_style + padding_from_inline_fragment_context
}
// Return offset from original position because of `position: relative`.
pub fn relative_position(&self, containing_block_size: &LogicalSize<Au>) -> LogicalSize<Au> {
fn from_style(style: &ServoComputedValues, container_size: &LogicalSize<Au>)
-> LogicalSize<Au> {
let offsets = style.logical_position();
let offset_i = if offsets.inline_start != LengthOrPercentageOrAuto::Auto {
MaybeAuto::from_style(offsets.inline_start,
container_size.inline).specified_or_zero()
} else {
-MaybeAuto::from_style(offsets.inline_end,
container_size.inline).specified_or_zero()
};
let offset_b = if offsets.block_start != LengthOrPercentageOrAuto::Auto {
MaybeAuto::from_style(offsets.block_start,
container_size.inline).specified_or_zero()
} else {
-MaybeAuto::from_style(offsets.block_end,
container_size.inline).specified_or_zero()
};
LogicalSize::new(style.writing_mode, offset_i, offset_b)
}
// Go over the ancestor fragments and add all relative offsets (if any).
let mut rel_pos = if self.style().get_box().position == position::T::relative {
from_style(self.style(), containing_block_size)
} else {
LogicalSize::zero(self.style.writing_mode)
};
if let Some(ref inline_fragment_context) = self.inline_context {
for node in &inline_fragment_context.nodes {
if node.style.get_box().position == position::T::relative {
rel_pos = rel_pos + from_style(&*node.style, containing_block_size);
}
}
}
rel_pos
}
/// Always inline for SCCP.
///
/// FIXME(pcwalton): Just replace with the clear type from the style module for speed?
#[inline(always)]
pub fn clear(&self) -> Option<ClearType> {
let style = self.style();
match style.get_box().clear {
clear::T::none => None,
clear::T::left => Some(ClearType::Left),
clear::T::right => Some(ClearType::Right),
clear::T::both => Some(ClearType::Both),
}
}
#[inline(always)]
pub fn style(&self) -> &ServoComputedValues {
&*self.style
}
#[inline(always)]
pub fn selected_style(&self) -> &ServoComputedValues {
&*self.selected_style
}
pub fn white_space(&self) -> white_space::T {
self.style().get_inheritedtext().white_space
}
/// Returns the text decoration of this fragment, according to the style of the nearest ancestor
/// element.
///
/// NB: This may not be the actual text decoration, because of the override rules specified in
/// CSS 2.1 § 16.3.1. Unfortunately, computing this properly doesn't really fit into Servo's
/// model. Therefore, this is a best lower bound approximation, but the end result may actually
/// have the various decoration flags turned on afterward.
pub fn text_decoration(&self) -> text_decoration::T {
self.style().get_text().text_decoration
}
/// Returns the inline-start offset from margin edge to content edge.
///
/// FIXME(#2262, pcwalton): I think this method is pretty bogus, because it won't work for
/// inlines.
pub fn inline_start_offset(&self) -> Au {
match self.specific {
SpecificFragmentInfo::TableWrapper => self.margin.inline_start,
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow => self.border_padding.inline_start,
SpecificFragmentInfo::TableColumn(_) => Au(0),
_ => self.margin.inline_start + self.border_padding.inline_start,
}
}
/// Returns true if this element can be split. This is true for text fragments, unless
/// `white-space: pre` or `white-space: nowrap` is set.
pub fn can_split(&self) -> bool {
self.is_scanned_text_fragment() && self.white_space().allow_wrap()
}
/// Returns true if and only if this fragment is a generated content fragment.
pub fn is_unscanned_generated_content(&self) -> bool {
match self.specific {
SpecificFragmentInfo::GeneratedContent(box GeneratedContentInfo::Empty) => false,
SpecificFragmentInfo::GeneratedContent(..) => true,
_ => false,
}
}
/// Returns true if and only if this is a scanned text fragment.
pub fn is_scanned_text_fragment(&self) -> bool {
match self.specific {
SpecificFragmentInfo::ScannedText(..) => true,
_ => false,
}
}
/// Computes the intrinsic inline-sizes of this fragment.
pub fn compute_intrinsic_inline_sizes(&mut self) -> IntrinsicISizesContribution {
let mut result = self.style_specified_intrinsic_inline_size();
match self.specific {
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => {}
SpecificFragmentInfo::InlineBlock(ref info) => {
let block_flow = info.flow_ref.as_block();
result.union_block(&block_flow.base.intrinsic_inline_sizes)
}
SpecificFragmentInfo::InlineAbsolute(ref info) => {
let block_flow = info.flow_ref.as_block();
result.union_block(&block_flow.base.intrinsic_inline_sizes)
}
SpecificFragmentInfo::Image(ref mut image_fragment_info) => {
let mut image_inline_size = match self.style.content_inline_size() {
LengthOrPercentageOrAuto::Auto |
LengthOrPercentageOrAuto::Percentage(_) => {
image_fragment_info.image_inline_size()
}
LengthOrPercentageOrAuto::Length(length) => length,
LengthOrPercentageOrAuto::Calc(calc) => calc.length(),
};
image_inline_size = max(model::specified(self.style.min_inline_size(), Au(0)), image_inline_size);
if let Some(max) = model::specified_or_none(self.style.max_inline_size(), Au(0)) {
image_inline_size = min(image_inline_size, max)
}
result.union_block(&IntrinsicISizes {
minimum_inline_size: image_inline_size,
preferred_inline_size: image_inline_size,
});
}
SpecificFragmentInfo::Canvas(ref mut canvas_fragment_info) => {
let mut canvas_inline_size = match self.style.content_inline_size() {
LengthOrPercentageOrAuto::Auto |
LengthOrPercentageOrAuto::Percentage(_) => {
canvas_fragment_info.canvas_inline_size()
}
LengthOrPercentageOrAuto::Length(length) => length,
LengthOrPercentageOrAuto::Calc(calc) => calc.length(),
};
canvas_inline_size = max(model::specified(self.style.min_inline_size(), Au(0)), canvas_inline_size);
if let Some(max) = model::specified_or_none(self.style.max_inline_size(), Au(0)) {
canvas_inline_size = min(canvas_inline_size, max)
}
result.union_block(&IntrinsicISizes {
minimum_inline_size: canvas_inline_size,
preferred_inline_size: canvas_inline_size,
});
}
SpecificFragmentInfo::ScannedText(ref text_fragment_info) => {
let range = &text_fragment_info.range;
// See http://dev.w3.org/csswg/css-sizing/#max-content-inline-size.
// TODO: Account for soft wrap opportunities.
let max_line_inline_size = text_fragment_info.run
.metrics_for_range(range)
.advance_width;
let min_line_inline_size = if self.white_space().allow_wrap() {
text_fragment_info.run.min_width_for_range(range)
} else {
max_line_inline_size
};
result.union_block(&IntrinsicISizes {
minimum_inline_size: min_line_inline_size,
preferred_inline_size: max_line_inline_size,
})
}
SpecificFragmentInfo::UnscannedText(..) => {
panic!("Unscanned text fragments should have been scanned by now!")
}
};
// Take borders and padding for parent inline fragments into account, if necessary.
if self.is_primary_fragment() {
if let Some(ref context) = self.inline_context {
for node in &context.nodes {
let mut border_width = node.style.logical_border_width();
let mut padding = model::padding_from_style(&*node.style, Au(0));
let mut margin = model::specified_margin_from_style(&*node.style);
if !node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT) {
border_width.inline_start = Au(0);
padding.inline_start = Au(0);
margin.inline_start = Au(0);
}
if !node.flags.contains(LAST_FRAGMENT_OF_ELEMENT) {
border_width.inline_end = Au(0);
padding.inline_end = Au(0);
margin.inline_end = Au(0);
}
result.surrounding_size =
result.surrounding_size +
border_width.inline_start_end() +
padding.inline_start_end() +
margin.inline_start_end();
}
}
}
result
}
/// Returns the narrowest inline-size that the first splittable part of this fragment could
/// possibly be split to. (In most cases, this returns the inline-size of the first word in
/// this fragment.)
pub fn minimum_splittable_inline_size(&self) -> Au {
match self.specific {
SpecificFragmentInfo::ScannedText(ref text) => {
text.run.minimum_splittable_inline_size(&text.range)
}
_ => Au(0),
}
}
/// TODO: What exactly does this function return? Why is it Au(0) for
/// `SpecificFragmentInfo::Generic`?
pub fn content_inline_size(&self) -> Au {
match self.specific {
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) => Au(0),
SpecificFragmentInfo::Canvas(ref canvas_fragment_info) => {
canvas_fragment_info.replaced_image_fragment_info.computed_inline_size()
}
SpecificFragmentInfo::Image(ref image_fragment_info) => {
image_fragment_info.replaced_image_fragment_info.computed_inline_size()
}
SpecificFragmentInfo::ScannedText(ref text_fragment_info) => {
let (range, run) = (&text_fragment_info.range, &text_fragment_info.run);
let text_bounds = run.metrics_for_range(range).bounding_box;
text_bounds.size.width
}
SpecificFragmentInfo::TableColumn(_) => {
panic!("Table column fragments do not have inline_size")
}
SpecificFragmentInfo::UnscannedText(_) => {
panic!("Unscanned text fragments should have been scanned by now!")
}
}
}
/// Returns the dimensions of the content box.
///
/// This is marked `#[inline]` because it is frequently called when only one or two of the
/// values are needed and that will save computation.
#[inline]
pub fn content_box(&self) -> LogicalRect<Au> {
self.border_box - self.border_padding
}
/// Attempts to find the split positions of a text fragment so that its inline-size is no more
/// than `max_inline_size`.
///
/// A return value of `None` indicates that the fragment could not be split. Otherwise the
/// information pertaining to the split is returned. The inline-start and inline-end split
/// information are both optional due to the possibility of them being whitespace.
pub fn calculate_split_position(&self, max_inline_size: Au, starts_line: bool)
-> Option<SplitResult> {
let text_fragment_info =
if let SpecificFragmentInfo::ScannedText(ref text_fragment_info) = self.specific {
text_fragment_info
} else {
return None
};
let mut flags = SplitOptions::empty();
if starts_line {
flags.insert(STARTS_LINE);
if self.style().get_inheritedtext().overflow_wrap == overflow_wrap::T::break_word {
flags.insert(RETRY_AT_CHARACTER_BOUNDARIES)
}
}
match self.style().get_inheritedtext().word_break {
word_break::T::normal => {
// Break at normal word boundaries.
let natural_word_breaking_strategy =
text_fragment_info.run.natural_word_slices_in_range(&text_fragment_info.range);
self.calculate_split_position_using_breaking_strategy(
natural_word_breaking_strategy,
max_inline_size,
flags)
}
word_break::T::break_all => {
// Break at character boundaries.
let character_breaking_strategy =
text_fragment_info.run.character_slices_in_range(&text_fragment_info.range);
flags.remove(RETRY_AT_CHARACTER_BOUNDARIES);
self.calculate_split_position_using_breaking_strategy(
character_breaking_strategy,
max_inline_size,
flags)
}
}
}
/// Truncates this fragment to the given `max_inline_size`, using a character-based breaking
/// strategy. If no characters could fit, returns `None`.
pub fn truncate_to_inline_size(&self, max_inline_size: Au) -> Option<TruncationResult> {
let text_fragment_info =
if let SpecificFragmentInfo::ScannedText(ref text_fragment_info) = self.specific {
text_fragment_info
} else {
return None
};
let character_breaking_strategy =
text_fragment_info.run.character_slices_in_range(&text_fragment_info.range);
match self.calculate_split_position_using_breaking_strategy(character_breaking_strategy,
max_inline_size,
SplitOptions::empty()) {
None => None,
Some(split_info) => {
match split_info.inline_start {
None => None,
Some(split) => {
Some(TruncationResult {
split: split,
text_run: split_info.text_run.clone(),
})
}
}
}
}
}
/// A helper method that uses the breaking strategy described by `slice_iterator` (at present,
/// either natural word breaking or character breaking) to split this fragment.
fn calculate_split_position_using_breaking_strategy<'a, I>(
&self,
slice_iterator: I,
max_inline_size: Au,
flags: SplitOptions)
-> Option<SplitResult>
where I: Iterator<Item=TextRunSlice<'a>> {
let text_fragment_info =
if let SpecificFragmentInfo::ScannedText(ref text_fragment_info) = self.specific {
text_fragment_info
} else {
return None
};
let mut remaining_inline_size = max_inline_size;
let mut inline_start_range = Range::new(text_fragment_info.range.begin(), ByteIndex(0));
let mut inline_end_range = None;
let mut overflowing = false;
debug!("calculate_split_position_using_breaking_strategy: splitting text fragment \
(strlen={}, range={:?}, max_inline_size={:?})",
text_fragment_info.run.text.len(),
text_fragment_info.range,
max_inline_size);
for slice in slice_iterator {
debug!("calculate_split_position_using_breaking_strategy: considering slice \
(offset={:?}, slice range={:?}, remaining_inline_size={:?})",
slice.offset,
slice.range,
remaining_inline_size);
// Use the `remaining_inline_size` to find a split point if possible. If not, go around
// the loop again with the next slice.
let metrics = text_fragment_info.run.metrics_for_slice(slice.glyphs, &slice.range);
let advance = metrics.advance_width;
// Have we found the split point?
if advance <= remaining_inline_size || slice.glyphs.is_whitespace() {
// Keep going; we haven't found the split point yet.
debug!("calculate_split_position_using_breaking_strategy: enlarging span");
remaining_inline_size = remaining_inline_size - advance;
inline_start_range.extend_by(slice.range.length());
continue
}
// The advance is more than the remaining inline-size, so split here. First, check to
// see if we're going to overflow the line. If so, perform a best-effort split.
let mut remaining_range = slice.text_run_range();
let split_is_empty = inline_start_range.is_empty() &&
!self.requires_line_break_afterward_if_wrapping_on_newlines();
if split_is_empty {
// We're going to overflow the line.
overflowing = true;
inline_start_range = slice.text_run_range();
remaining_range = Range::new(slice.text_run_range().end(), ByteIndex(0));
remaining_range.extend_to(text_fragment_info.range.end());
}
// Check to see if we need to create an inline-end chunk.
let slice_begin = remaining_range.begin();
if slice_begin < text_fragment_info.range.end() {
// There still some things left over at the end of the line, so create the
// inline-end chunk.
let mut inline_end = remaining_range;
inline_end.extend_to(text_fragment_info.range.end());
inline_end_range = Some(inline_end);
debug!("calculate_split_position: splitting remainder with inline-end range={:?}",
inline_end);
}
// If we failed to find a suitable split point, we're on the verge of overflowing the
// line.
if split_is_empty || overflowing {
// If we've been instructed to retry at character boundaries (probably via
// `overflow-wrap: break-word`), do so.
if flags.contains(RETRY_AT_CHARACTER_BOUNDARIES) {
let character_breaking_strategy =
text_fragment_info.run
.character_slices_in_range(&text_fragment_info.range);
let mut flags = flags;
flags.remove(RETRY_AT_CHARACTER_BOUNDARIES);
return self.calculate_split_position_using_breaking_strategy(
character_breaking_strategy,
max_inline_size,
flags)
}
// We aren't at the start of the line, so don't overflow. Let inline layout wrap to
// the next line instead.
if !flags.contains(STARTS_LINE) {
return None
}
}
break
}
let split_is_empty = inline_start_range.is_empty() &&
!self.requires_line_break_afterward_if_wrapping_on_newlines();
let inline_start = if !split_is_empty {
Some(SplitInfo::new(inline_start_range, &**text_fragment_info))
} else {
None
};
let inline_end = inline_end_range.map(|inline_end_range| {
SplitInfo::new(inline_end_range, &**text_fragment_info)
});
Some(SplitResult {
inline_start: inline_start,
inline_end: inline_end,
text_run: text_fragment_info.run.clone(),
})
}
/// The opposite of `calculate_split_position_using_breaking_strategy`: merges this fragment
/// with the next one.
pub fn merge_with(&mut self, next_fragment: Fragment) {
match (&mut self.specific, &next_fragment.specific) {
(&mut SpecificFragmentInfo::ScannedText(ref mut this_info),
&SpecificFragmentInfo::ScannedText(ref other_info)) => {
debug_assert!(util::arc_ptr_eq(&this_info.run, &other_info.run));
this_info.range_end_including_stripped_whitespace =
other_info.range_end_including_stripped_whitespace;
if other_info.requires_line_break_afterward_if_wrapping_on_newlines() {
this_info.flags.insert(REQUIRES_LINE_BREAK_AFTERWARD_IF_WRAPPING_ON_NEWLINES);
}
if other_info.insertion_point.is_some() {
this_info.insertion_point = other_info.insertion_point;
}
self.border_padding.inline_end = next_fragment.border_padding.inline_end;
self.margin.inline_end = next_fragment.margin.inline_end;
}
_ => panic!("Can only merge two scanned-text fragments!"),
}
self.reset_text_range_and_inline_size();
self.meld_with_next_inline_fragment(&next_fragment);
}
/// Restore any whitespace that was stripped from a text fragment, and recompute inline metrics
/// if necessary.
pub fn reset_text_range_and_inline_size(&mut self) {
if let SpecificFragmentInfo::ScannedText(ref mut info) = self.specific {
if info.run.extra_word_spacing != Au(0) {
Arc::make_mut(&mut info.run).extra_word_spacing = Au(0);
}
// FIXME (mbrubeck): Do we need to restore leading too?
let range_end = info.range_end_including_stripped_whitespace;
if info.range.end() == range_end {
return
}
info.range.extend_to(range_end);
info.content_size.inline = info.run.metrics_for_range(&info.range).advance_width;
self.border_box.size.inline = info.content_size.inline +
self.border_padding.inline_start_end();
}
}
/// Assigns replaced inline-size, padding, and margins for this fragment only if it is replaced
/// content per CSS 2.1 § 10.3.2.
pub fn assign_replaced_inline_size_if_necessary(&mut self, container_inline_size: Au) {
match self.specific {
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn => return,
SpecificFragmentInfo::TableColumn(_) => {
panic!("Table column fragments do not have inline size")
}
SpecificFragmentInfo::UnscannedText(_) => {
panic!("Unscanned text fragments should have been scanned by now!")
}
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::ScannedText(_) => {}
};
let style = &*self.style;
let noncontent_inline_size = self.border_padding.inline_start_end();
match self.specific {
SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut info) => {
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_mut_block();
block_flow.base.position.size.inline =
block_flow.base.intrinsic_inline_sizes.preferred_inline_size;
// This is a hypothetical box, so it takes up no space.
self.border_box.size.inline = Au(0);
}
SpecificFragmentInfo::InlineBlock(ref mut info) => {
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_mut_block();
self.border_box.size.inline =
max(block_flow.base.intrinsic_inline_sizes.minimum_inline_size,
block_flow.base.intrinsic_inline_sizes.preferred_inline_size);
block_flow.base.block_container_inline_size = self.border_box.size.inline;
block_flow.base.block_container_writing_mode = self.style.writing_mode;
}
SpecificFragmentInfo::InlineAbsolute(ref mut info) => {
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_mut_block();
self.border_box.size.inline =
max(block_flow.base.intrinsic_inline_sizes.minimum_inline_size,
block_flow.base.intrinsic_inline_sizes.preferred_inline_size);
block_flow.base.block_container_inline_size = self.border_box.size.inline;
block_flow.base.block_container_writing_mode = self.style.writing_mode;
}
SpecificFragmentInfo::ScannedText(ref info) => {
// Scanned text fragments will have already had their content inline-sizes assigned
// by this point.
self.border_box.size.inline = info.content_size.inline + noncontent_inline_size
}
SpecificFragmentInfo::Image(ref mut image_fragment_info) => {
let fragment_inline_size = image_fragment_info.image_inline_size();
let fragment_block_size = image_fragment_info.image_block_size();
self.border_box.size.inline =
image_fragment_info.replaced_image_fragment_info
.calculate_replaced_inline_size(style,
noncontent_inline_size,
container_inline_size,
fragment_inline_size,
fragment_block_size);
}
SpecificFragmentInfo::Canvas(ref mut canvas_fragment_info) => {
let fragment_inline_size = canvas_fragment_info.canvas_inline_size();
let fragment_block_size = canvas_fragment_info.canvas_block_size();
self.border_box.size.inline =
canvas_fragment_info.replaced_image_fragment_info
.calculate_replaced_inline_size(style,
noncontent_inline_size,
container_inline_size,
fragment_inline_size,
fragment_block_size);
}
SpecificFragmentInfo::Iframe(ref iframe_fragment_info) => {
self.border_box.size.inline =
iframe_fragment_info.calculate_replaced_inline_size(style,
container_inline_size) +
noncontent_inline_size;
}
_ => panic!("this case should have been handled above"),
}
}
/// Assign block-size for this fragment if it is replaced content. The inline-size must have
/// been assigned first.
///
/// Ideally, this should follow CSS 2.1 § 10.6.2.
pub fn assign_replaced_block_size_if_necessary(&mut self, containing_block_block_size: Option<Au>) {
match self.specific {
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn => return,
SpecificFragmentInfo::TableColumn(_) => {
panic!("Table column fragments do not have block size")
}
SpecificFragmentInfo::UnscannedText(_) => {
panic!("Unscanned text fragments should have been scanned by now!")
}
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::ScannedText(_) => {}
}
let style = &*self.style;
let noncontent_block_size = self.border_padding.block_start_end();
match self.specific {
SpecificFragmentInfo::Image(ref mut image_fragment_info) => {
let fragment_inline_size = image_fragment_info.image_inline_size();
let fragment_block_size = image_fragment_info.image_block_size();
self.border_box.size.block =
image_fragment_info.replaced_image_fragment_info
.calculate_replaced_block_size(style,
noncontent_block_size,
containing_block_block_size,
fragment_inline_size,
fragment_block_size);
}
SpecificFragmentInfo::Canvas(ref mut canvas_fragment_info) => {
let fragment_inline_size = canvas_fragment_info.canvas_inline_size();
let fragment_block_size = canvas_fragment_info.canvas_block_size();
self.border_box.size.block =
canvas_fragment_info.replaced_image_fragment_info
.calculate_replaced_block_size(style,
noncontent_block_size,
containing_block_block_size,
fragment_inline_size,
fragment_block_size);
}
SpecificFragmentInfo::ScannedText(ref info) => {
// Scanned text fragments' content block-sizes are calculated by the text run
// scanner during flow construction.
self.border_box.size.block = info.content_size.block + noncontent_block_size
}
SpecificFragmentInfo::InlineBlock(ref mut info) => {
// Not the primary fragment, so we do not take the noncontent size into account.
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_block();
self.border_box.size.block = block_flow.base.position.size.block +
block_flow.fragment.margin.block_start_end()
}
SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut info) => {
// Not the primary fragment, so we do not take the noncontent size into account.
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_block();
self.border_box.size.block = block_flow.base.position.size.block;
}
SpecificFragmentInfo::InlineAbsolute(ref mut info) => {
// Not the primary fragment, so we do not take the noncontent size into account.
let block_flow = flow_ref::deref_mut(&mut info.flow_ref).as_block();
self.border_box.size.block = block_flow.base.position.size.block +
block_flow.fragment.margin.block_start_end()
}
SpecificFragmentInfo::Iframe(ref info) => {
self.border_box.size.block =
info.calculate_replaced_block_size(style, containing_block_block_size) +
noncontent_block_size;
}
_ => panic!("should have been handled above"),
}
}
/// Calculates block-size above baseline, depth below baseline, and ascent for this fragment
/// when used in an inline formatting context. See CSS 2.1 § 10.8.1.
pub fn inline_metrics(&self, layout_context: &LayoutContext) -> InlineMetrics {
match self.specific {
SpecificFragmentInfo::Image(ref image_fragment_info) => {
let computed_block_size = image_fragment_info.replaced_image_fragment_info
.computed_block_size();
InlineMetrics {
block_size_above_baseline: computed_block_size +
self.border_padding.block_start,
depth_below_baseline: self.border_padding.block_end,
ascent: computed_block_size + self.border_padding.block_start,
}
}
SpecificFragmentInfo::Canvas(ref canvas_fragment_info) => {
let computed_block_size = canvas_fragment_info.replaced_image_fragment_info
.computed_block_size();
InlineMetrics {
block_size_above_baseline: computed_block_size +
self.border_padding.block_start,
depth_below_baseline: self.border_padding.block_end,
ascent: computed_block_size + self.border_padding.block_start,
}
}
SpecificFragmentInfo::ScannedText(ref text_fragment) => {
// See CSS 2.1 § 10.8.1.
let line_height = self.calculate_line_height(layout_context);
let font_derived_metrics =
InlineMetrics::from_font_metrics(&text_fragment.run.font_metrics, line_height);
InlineMetrics {
block_size_above_baseline: font_derived_metrics.block_size_above_baseline +
self.border_padding.block_start,
depth_below_baseline: font_derived_metrics.depth_below_baseline +
self.border_padding.block_end,
ascent: font_derived_metrics.ascent + self.border_padding.block_start,
}
}
SpecificFragmentInfo::InlineBlock(ref info) => {
// See CSS 2.1 § 10.8.1.
let flow = &info.flow_ref;
let block_flow = flow.as_block();
let baseline_offset = match flow.baseline_offset_of_last_line_box_in_flow() {
Some(baseline_offset) => baseline_offset,
None => block_flow.fragment.border_box.size.block,
};
let start_margin = block_flow.fragment.margin.block_start;
let end_margin = block_flow.fragment.margin.block_end;
let depth_below_baseline = flow::base(&**flow).position.size.block -
baseline_offset + end_margin;
InlineMetrics::new(baseline_offset + start_margin,
depth_below_baseline,
baseline_offset)
}
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) => {
// Hypothetical boxes take up no space.
InlineMetrics {
block_size_above_baseline: Au(0),
depth_below_baseline: Au(0),
ascent: Au(0),
}
}
_ => {
InlineMetrics {
block_size_above_baseline: self.border_box.size.block,
depth_below_baseline: Au(0),
ascent: self.border_box.size.block,
}
}
}
}
/// Returns true if this fragment is a hypothetical box. See CSS 2.1 § 10.3.7.
pub fn is_hypothetical(&self) -> bool {
match self.specific {
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => true,
_ => false,
}
}
/// Returns true if this fragment can merge with another immediately-following fragment or
/// false otherwise.
pub fn can_merge_with_fragment(&self, other: &Fragment) -> bool {
match (&self.specific, &other.specific) {
(&SpecificFragmentInfo::UnscannedText(ref first_unscanned_text),
&SpecificFragmentInfo::UnscannedText(_)) => {
// FIXME: Should probably use a whitelist of styles that can safely differ (#3165)
if self.style().get_font() != other.style().get_font() ||
self.text_decoration() != other.text_decoration() ||
self.white_space() != other.white_space() {
return false
}
if first_unscanned_text.text.ends_with('\n') {
return false
}
// If this node has any styles that have border/padding/margins on the following
// side, then we can't merge with the next fragment.
if let Some(ref inline_context) = self.inline_context {
for inline_context_node in inline_context.nodes.iter() {
if !inline_context_node.flags.contains(LAST_FRAGMENT_OF_ELEMENT) {
continue
}
if inline_context_node.style.logical_margin().inline_end !=
LengthOrPercentageOrAuto::Length(Au(0)) {
return false
}
if inline_context_node.style.logical_padding().inline_end !=
LengthOrPercentage::Length(Au(0)) {
return false
}
if inline_context_node.style.logical_border_width().inline_end != Au(0) {
return false
}
}
}
// If the next fragment has any styles that have border/padding/margins on the
// preceding side, then it can't merge with us.
if let Some(ref inline_context) = other.inline_context {
for inline_context_node in inline_context.nodes.iter() {
if !inline_context_node.flags.contains(FIRST_FRAGMENT_OF_ELEMENT) {
continue
}
if inline_context_node.style.logical_margin().inline_start !=
LengthOrPercentageOrAuto::Length(Au(0)) {
return false
}
if inline_context_node.style.logical_padding().inline_start !=
LengthOrPercentage::Length(Au(0)) {
return false
}
if inline_context_node.style.logical_border_width().inline_start != Au(0) {
return false
}
}
}
true
}
_ => false,
}
}
/// Returns true if and only if this is the *primary fragment* for the fragment's style object
/// (conceptually, though style sharing makes this not really true, of course). The primary
/// fragment is the one that draws backgrounds, borders, etc., and takes borders, padding and
/// margins into account. Every style object has at most one primary fragment.
///
/// At present, all fragments are primary fragments except for inline-block and table wrapper
/// fragments. Inline-block fragments are not primary fragments because the corresponding block
/// flow is the primary fragment, while table wrapper fragments are not primary fragments
/// because the corresponding table flow is the primary fragment.
pub fn is_primary_fragment(&self) -> bool {
match self.specific {
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::TableWrapper => false,
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::ScannedText(_) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::UnscannedText(_) => true,
}
}
/// Determines the inline sizes of inline-block fragments. These cannot be fully computed until
/// inline size assignment has run for the child flow: thus it is computed "late", during
/// block size assignment.
pub fn update_late_computed_replaced_inline_size_if_necessary(&mut self) {
if let SpecificFragmentInfo::InlineBlock(ref mut inline_block_info) = self.specific {
let block_flow = flow_ref::deref_mut(&mut inline_block_info.flow_ref).as_block();
let margin = block_flow.fragment.style.logical_margin();
self.border_box.size.inline = block_flow.fragment.border_box.size.inline +
MaybeAuto::from_style(margin.inline_start, Au(0)).specified_or_zero() +
MaybeAuto::from_style(margin.inline_end, Au(0)).specified_or_zero()
}
}
pub fn update_late_computed_inline_position_if_necessary(&mut self) {
if let SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut info) = self.specific {
let position = self.border_box.start.i;
flow_ref::deref_mut(&mut info.flow_ref)
.update_late_computed_inline_position_if_necessary(position)
}
}
pub fn update_late_computed_block_position_if_necessary(&mut self) {
if let SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut info) = self.specific {
let position = self.border_box.start.b;
flow_ref::deref_mut(&mut info.flow_ref)
.update_late_computed_block_position_if_necessary(position)
}
}
pub fn repair_style(&mut self, new_style: &Arc<ServoComputedValues>) {
self.style = (*new_style).clone()
}
/// Given the stacking-context-relative position of the containing flow, returns the border box
/// of this fragment relative to the parent stacking context. This takes `position: relative`
/// into account.
///
/// If `coordinate_system` is `Parent`, this returns the border box in the parent stacking
/// context's coordinate system. Otherwise, if `coordinate_system` is `Own` and this fragment
/// establishes a stacking context itself, this returns a border box anchored at (0, 0). (If
/// this fragment does not establish a stacking context, then it always belongs to its parent
/// stacking context and thus `coordinate_system` is ignored.)
///
/// This is the method you should use for display list construction as well as
/// `getBoundingClientRect()` and so forth.
pub fn stacking_relative_border_box(&self,
stacking_relative_flow_origin: &Point2D<Au>,
relative_containing_block_size: &LogicalSize<Au>,
relative_containing_block_mode: WritingMode,
coordinate_system: CoordinateSystem)
-> Rect<Au> {
let container_size =
relative_containing_block_size.to_physical(relative_containing_block_mode);
let border_box = self.border_box.to_physical(self.style.writing_mode, container_size);
if coordinate_system == CoordinateSystem::Own && self.establishes_stacking_context() {
return Rect::new(Point2D::zero(), border_box.size)
}
// FIXME(pcwalton): This can double-count relative position sometimes for inlines (e.g.
// `<div style="position:relative">x</div>`, because the `position:relative` trickles down
// to the inline flow. Possibly we should extend the notion of "primary fragment" to fix
// this.
let relative_position = self.relative_position(relative_containing_block_size);
border_box.translate_by_size(&relative_position.to_physical(self.style.writing_mode))
.translate(stacking_relative_flow_origin)
}
/// Given the stacking-context-relative border box, returns the stacking-context-relative
/// content box.
pub fn stacking_relative_content_box(&self, stacking_relative_border_box: &Rect<Au>)
-> Rect<Au> {
let border_padding = self.border_padding.to_physical(self.style.writing_mode);
Rect::new(Point2D::new(stacking_relative_border_box.origin.x + border_padding.left,
stacking_relative_border_box.origin.y + border_padding.top),
Size2D::new(stacking_relative_border_box.size.width - border_padding.horizontal(),
stacking_relative_border_box.size.height - border_padding.vertical()))
}
/// Returns true if this fragment establishes a new stacking context and false otherwise.
pub fn establishes_stacking_context(&self) -> bool {
if self.flags.contains(HAS_LAYER) {
return true
}
if self.style().get_effects().opacity != 1.0 {
return true
}
if !self.style().get_effects().filter.is_empty() {
return true
}
if self.style().get_effects().mix_blend_mode != mix_blend_mode::T::normal {
return true
}
if self.style().get_effects().transform.0.is_some() {
return true
}
match self.style().get_used_transform_style() {
transform_style::T::flat | transform_style::T::preserve_3d => {
return true
}
transform_style::T::auto => {}
}
// FIXME(pcwalton): Don't unconditionally form stacking contexts for `overflow_x: scroll`
// and `overflow_y: scroll`. This needs multiple layers per stacking context.
match (self.style().get_box().position,
self.style().get_position().z_index,
self.style().get_box().overflow_x,
self.style().get_box().overflow_y.0) {
(position::T::absolute,
z_index::T::Auto,
overflow_x::T::visible,
overflow_x::T::visible) |
(position::T::fixed,
z_index::T::Auto,
overflow_x::T::visible,
overflow_x::T::visible) |
(position::T::relative,
z_index::T::Auto,
overflow_x::T::visible,
overflow_x::T::visible) => false,
(position::T::absolute, _, _, _) |
(position::T::fixed, _, _, _) |
(position::T::relative, _, _, _) |
(_, _, overflow_x::T::auto, _) |
(_, _, overflow_x::T::scroll, _) |
(_, _, _, overflow_x::T::auto) |
(_, _, _, overflow_x::T::scroll) => true,
(position::T::static_, _, _, _) => false
}
}
// Get the effective z-index of this fragment. Z-indices only apply to positioned element
// per CSS 2 9.9.1 (http://www.w3.org/TR/CSS2/visuren.html#z-index), so this value may differ
// from the value specified in the style.
pub fn effective_z_index(&self) -> i32 {
match self.style().get_box().position {
position::T::static_ => {},
_ => return self.style().get_position().z_index.number_or_zero(),
}
if self.style().get_effects().transform.0.is_some() {
return self.style().get_position().z_index.number_or_zero();
}
match self.style().get_box().display {
display::T::flex => self.style().get_position().z_index.number_or_zero(),
_ => 0,
}
}
/// Computes the overflow rect of this fragment relative to the start of the flow.
pub fn compute_overflow(&self,
flow_size: &Size2D<Au>,
relative_containing_block_size: &LogicalSize<Au>)
-> Overflow {
let mut border_box = self.border_box.to_physical(self.style.writing_mode, *flow_size);
// Relative position can cause us to draw outside our border box.
//
// FIXME(pcwalton): I'm not a fan of the way this makes us crawl though so many styles all
// the time. Can't we handle relative positioning by just adjusting `border_box`?
let relative_position = self.relative_position(relative_containing_block_size);
border_box =
border_box.translate_by_size(&relative_position.to_physical(self.style.writing_mode));
let mut overflow = Overflow::from_rect(&border_box);
// Box shadows cause us to draw outside our border box.
for box_shadow in &self.style().get_effects().box_shadow.0 {
let offset = Point2D::new(box_shadow.offset_x, box_shadow.offset_y);
let inflation = box_shadow.spread_radius + box_shadow.blur_radius *
BLUR_INFLATION_FACTOR;
overflow.paint = overflow.paint.union(&border_box.translate(&offset)
.inflate(inflation, inflation))
}
// Outlines cause us to draw outside our border box.
let outline_width = self.style.get_outline().outline_width;
if outline_width != Au(0) {
overflow.paint = overflow.paint.union(&border_box.inflate(outline_width,
outline_width))
}
// Include the overflow of the block flow, if any.
match self.specific {
SpecificFragmentInfo::InlineBlock(ref info) => {
let block_flow = info.flow_ref.as_block();
overflow.union(&flow::base(block_flow).overflow);
}
SpecificFragmentInfo::InlineAbsolute(ref info) => {
let block_flow = info.flow_ref.as_block();
overflow.union(&flow::base(block_flow).overflow);
}
_ => (),
}
// FIXME(pcwalton): Sometimes excessively fancy glyphs can make us draw outside our border
// box too.
overflow
}
pub fn requires_line_break_afterward_if_wrapping_on_newlines(&self) -> bool {
match self.specific {
SpecificFragmentInfo::ScannedText(ref scanned_text) => {
scanned_text.requires_line_break_afterward_if_wrapping_on_newlines()
}
_ => false,
}
}
pub fn strip_leading_whitespace_if_necessary(&mut self) -> WhitespaceStrippingResult {
if self.white_space().preserve_spaces() {
return WhitespaceStrippingResult::RetainFragment
}
match self.specific {
SpecificFragmentInfo::ScannedText(ref mut scanned_text_fragment_info) => {
let leading_whitespace_byte_count = scanned_text_fragment_info.text()
.find(|c| !util::str::char_is_whitespace(c))
.unwrap_or(scanned_text_fragment_info.text().len());
let whitespace_len = ByteIndex(leading_whitespace_byte_count as isize);
let whitespace_range = Range::new(scanned_text_fragment_info.range.begin(),
whitespace_len);
let text_bounds =
scanned_text_fragment_info.run.metrics_for_range(&whitespace_range).bounding_box;
self.border_box.size.inline = self.border_box.size.inline - text_bounds.size.width;
scanned_text_fragment_info.content_size.inline =
scanned_text_fragment_info.content_size.inline - text_bounds.size.width;
scanned_text_fragment_info.range.adjust_by(whitespace_len, -whitespace_len);
WhitespaceStrippingResult::RetainFragment
}
SpecificFragmentInfo::UnscannedText(ref mut unscanned_text_fragment_info) => {
let mut new_text_string = String::new();
let mut modified = false;
for (i, character) in unscanned_text_fragment_info.text.char_indices() {
if gfx::text::util::is_bidi_control(character) {
new_text_string.push(character);
continue
}
if util::str::char_is_whitespace(character) {
modified = true;
continue
}
// Finished processing leading control chars and whitespace.
if modified {
new_text_string.push_str(&unscanned_text_fragment_info.text[i..]);
}
break
}
if modified {
unscanned_text_fragment_info.text = new_text_string.into_boxed_str();
}
WhitespaceStrippingResult::from_unscanned_text_fragment_info(
&unscanned_text_fragment_info)
}
_ => WhitespaceStrippingResult::RetainFragment,
}
}
/// Returns true if the entire fragment was stripped.
pub fn strip_trailing_whitespace_if_necessary(&mut self) -> WhitespaceStrippingResult {
if self.white_space().preserve_spaces() {
return WhitespaceStrippingResult::RetainFragment
}
match self.specific {
SpecificFragmentInfo::ScannedText(ref mut scanned_text_fragment_info) => {
let mut trailing_whitespace_start_byte = 0;
for (i, c) in scanned_text_fragment_info.text().char_indices().rev() {
if !util::str::char_is_whitespace(c) {
trailing_whitespace_start_byte = i + c.len_utf8();
break;
}
}
let whitespace_start = ByteIndex(trailing_whitespace_start_byte as isize);
let whitespace_len = scanned_text_fragment_info.range.length() - whitespace_start;
let mut whitespace_range = Range::new(whitespace_start, whitespace_len);
whitespace_range.shift_by(scanned_text_fragment_info.range.begin());
let text_bounds = scanned_text_fragment_info.run
.metrics_for_range(&whitespace_range)
.bounding_box;
self.border_box.size.inline -= text_bounds.size.width;
scanned_text_fragment_info.content_size.inline -= text_bounds.size.width;
scanned_text_fragment_info.range.extend_by(-whitespace_len);
WhitespaceStrippingResult::RetainFragment
}
SpecificFragmentInfo::UnscannedText(ref mut unscanned_text_fragment_info) => {
let mut trailing_bidi_control_characters_to_retain = Vec::new();
let (mut modified, mut last_character_index) = (true, 0);
for (i, character) in unscanned_text_fragment_info.text.char_indices().rev() {
if gfx::text::util::is_bidi_control(character) {
trailing_bidi_control_characters_to_retain.push(character);
continue
}
if util::str::char_is_whitespace(character) {
modified = true;
continue
}
last_character_index = i + character.len_utf8();
break
}
if modified {
let mut text = unscanned_text_fragment_info.text.to_string();
text.truncate(last_character_index);
for character in trailing_bidi_control_characters_to_retain.iter().rev() {
text.push(*character);
}
unscanned_text_fragment_info.text = text.into_boxed_str();
}
WhitespaceStrippingResult::from_unscanned_text_fragment_info(
&unscanned_text_fragment_info)
}
_ => WhitespaceStrippingResult::RetainFragment,
}
}
pub fn inline_styles(&self) -> InlineStyleIterator {
InlineStyleIterator::new(self)
}
/// Returns the inline-size of this fragment's margin box.
pub fn margin_box_inline_size(&self) -> Au {
self.border_box.size.inline + self.margin.inline_start_end()
}
/// Returns true if this node *or any of the nodes within its inline fragment context* have
/// non-`static` `position`.
pub fn is_positioned(&self) -> bool {
if self.style.get_box().position != position::T::static_ {
return true
}
if let Some(ref inline_context) = self.inline_context {
for node in inline_context.nodes.iter() {
if node.style.get_box().position != position::T::static_ {
return true
}
}
}
false
}
/// Returns true if this node is absolutely positioned.
pub fn is_absolutely_positioned(&self) -> bool {
self.style.get_box().position == position::T::absolute
}
pub fn is_inline_absolute(&self) -> bool {
match self.specific {
SpecificFragmentInfo::InlineAbsolute(..) => true,
_ => false,
}
}
pub fn meld_with_next_inline_fragment(&mut self, next_fragment: &Fragment) {
if let Some(ref mut inline_context_of_this_fragment) = self.inline_context {
if let Some(ref inline_context_of_next_fragment) = next_fragment.inline_context {
for (inline_context_node_from_this_fragment,
inline_context_node_from_next_fragment)
in inline_context_of_this_fragment.nodes.iter_mut().rev()
.zip(inline_context_of_next_fragment.nodes.iter().rev())
{
if !inline_context_node_from_next_fragment.flags.contains(
LAST_FRAGMENT_OF_ELEMENT) {
continue
}
if inline_context_node_from_next_fragment.address !=
inline_context_node_from_this_fragment.address {
continue
}
inline_context_node_from_this_fragment.flags.insert(LAST_FRAGMENT_OF_ELEMENT);
}
}
}
}
pub fn meld_with_prev_inline_fragment(&mut self, prev_fragment: &Fragment) {
if let Some(ref mut inline_context_of_this_fragment) = self.inline_context {
if let Some(ref inline_context_of_prev_fragment) = prev_fragment.inline_context {
for (inline_context_node_from_prev_fragment,
inline_context_node_from_this_fragment)
in inline_context_of_prev_fragment.nodes.iter().rev().zip(
inline_context_of_this_fragment.nodes.iter_mut().rev())
{
if !inline_context_node_from_prev_fragment.flags.contains(
FIRST_FRAGMENT_OF_ELEMENT) {
continue
}
if inline_context_node_from_prev_fragment.address !=
inline_context_node_from_this_fragment.address {
continue
}
inline_context_node_from_this_fragment.flags.insert(
FIRST_FRAGMENT_OF_ELEMENT);
}
}
}
}
pub fn fragment_id(&self) -> usize {
return self as *const Fragment as usize;
}
pub fn fragment_type(&self) -> FragmentType {
match self.pseudo {
PseudoElementType::Normal => FragmentType::FragmentBody,
PseudoElementType::Before(_) => FragmentType::BeforePseudoContent,
PseudoElementType::After(_) => FragmentType::AfterPseudoContent,
PseudoElementType::DetailsSummary(_) => FragmentType::FragmentBody,
PseudoElementType::DetailsContent(_) => FragmentType::FragmentBody,
}
}
pub fn layer_id(&self) -> LayerId {
let layer_type = match self.pseudo {
PseudoElementType::Normal => LayerType::FragmentBody,
PseudoElementType::Before(_) => LayerType::BeforePseudoContent,
PseudoElementType::After(_) => LayerType::AfterPseudoContent,
PseudoElementType::DetailsSummary(_) => LayerType::FragmentBody,
PseudoElementType::DetailsContent(_) => LayerType::FragmentBody,
};
LayerId::new_of_type(layer_type, self.node.id() as usize)
}
pub fn layer_id_for_overflow_scroll(&self) -> LayerId {
LayerId::new_of_type(LayerType::OverflowScroll, self.node.id() as usize)
}
/// Returns true if any of the inline styles associated with this fragment have
/// `vertical-align` set to `top` or `bottom`.
pub fn is_vertically_aligned_to_top_or_bottom(&self) -> bool {
match self.style.get_box().vertical_align {
vertical_align::T::top | vertical_align::T::bottom => return true,
_ => {}
}
if let Some(ref inline_context) = self.inline_context {
for node in &inline_context.nodes {
match node.style.get_box().vertical_align {
vertical_align::T::top | vertical_align::T::bottom => return true,
_ => {}
}
}
}
false
}
pub fn is_text_or_replaced(&self) -> bool {
match self.specific {
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::InlineAbsolute(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::Multicol |
SpecificFragmentInfo::MulticolColumn |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableColumn(_) |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper => false,
SpecificFragmentInfo::Canvas(_) |
SpecificFragmentInfo::GeneratedContent(_) |
SpecificFragmentInfo::Iframe(_) |
SpecificFragmentInfo::Image(_) |
SpecificFragmentInfo::ScannedText(_) |
SpecificFragmentInfo::UnscannedText(_) => true
}
}
}
impl fmt::Debug for Fragment {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let border_padding_string = if !self.border_padding.is_zero() {
format!(" border_padding={:?}", self.border_padding)
} else {
"".to_owned()
};
let margin_string = if !self.margin.is_zero() {
format!(" margin={:?}", self.margin)
} else {
"".to_owned()
};
let damage_string = if self.restyle_damage != RestyleDamage::empty() {
format!(" damage={:?}", self.restyle_damage)
} else {
"".to_owned()
};
write!(f, "{}({}) [{:?}] border_box={:?}{}{}{}",
self.specific.get_type(),
self.debug_id(),
self.specific,
self.border_box,
border_padding_string,
margin_string,
damage_string)
}
}
bitflags! {
flags QuantitiesIncludedInIntrinsicInlineSizes: u8 {
const INTRINSIC_INLINE_SIZE_INCLUDES_MARGINS = 0x01,
const INTRINSIC_INLINE_SIZE_INCLUDES_PADDING = 0x02,
const INTRINSIC_INLINE_SIZE_INCLUDES_BORDER = 0x04,
const INTRINSIC_INLINE_SIZE_INCLUDES_SPECIFIED = 0x08,
}
}
bitflags! {
// Various flags we can use when splitting fragments. See
// `calculate_split_position_using_breaking_strategy()`.
flags SplitOptions: u8 {
#[doc = "True if this is the first fragment on the line."]
const STARTS_LINE = 0x01,
#[doc = "True if we should attempt to split at character boundaries if this split fails. \
This is used to implement `overflow-wrap: break-word`."]
const RETRY_AT_CHARACTER_BOUNDARIES = 0x02,
}
}
/// A top-down fragment border box iteration handler.
pub trait FragmentBorderBoxIterator {
/// The operation to perform.
fn process(&mut self, fragment: &Fragment, level: i32, overflow: &Rect<Au>);
/// Returns true if this fragment must be processed in-order. If this returns false,
/// we skip the operation for this fragment, but continue processing siblings.
fn should_process(&mut self, fragment: &Fragment) -> bool;
}
/// The coordinate system used in `stacking_relative_border_box()`. See the documentation of that
/// method for details.
#[derive(Clone, PartialEq, Debug)]
pub enum CoordinateSystem {
/// The border box returned is relative to the fragment's parent stacking context.
Parent,
/// The border box returned is relative to the fragment's own stacking context, if applicable.
Own,
}
pub struct InlineStyleIterator<'a> {
fragment: &'a Fragment,
inline_style_index: usize,
primary_style_yielded: bool,
}
impl<'a> Iterator for InlineStyleIterator<'a> {
type Item = &'a ServoComputedValues;
fn next(&mut self) -> Option<&'a ServoComputedValues> {
if !self.primary_style_yielded {
self.primary_style_yielded = true;
return Some(&*self.fragment.style)
}
let inline_context = match self.fragment.inline_context {
None => return None,
Some(ref inline_context) => inline_context,
};
let inline_style_index = self.inline_style_index;
if inline_style_index == inline_context.nodes.len() {
return None
}
self.inline_style_index += 1;
Some(&*inline_context.nodes[inline_style_index].style)
}
}
impl<'a> InlineStyleIterator<'a> {
fn new(fragment: &Fragment) -> InlineStyleIterator {
InlineStyleIterator {
fragment: fragment,
inline_style_index: 0,
primary_style_yielded: false,
}
}
}
#[derive(Copy, Clone, Debug, PartialEq)]
pub enum WhitespaceStrippingResult {
RetainFragment,
FragmentContainedOnlyBidiControlCharacters,
FragmentContainedOnlyWhitespace,
}
impl WhitespaceStrippingResult {
fn from_unscanned_text_fragment_info(info: &UnscannedTextFragmentInfo)
-> WhitespaceStrippingResult {
if info.text.is_empty() {
WhitespaceStrippingResult::FragmentContainedOnlyWhitespace
} else if info.text.chars().all(gfx::text::util::is_bidi_control) {
WhitespaceStrippingResult::FragmentContainedOnlyBidiControlCharacters
} else {
WhitespaceStrippingResult::RetainFragment
}
}
}
/// The overflow area. We need two different notions of overflow: paint overflow and scrollable
/// overflow.
#[derive(Copy, Clone, Debug)]
pub struct Overflow {
pub scroll: Rect<Au>,
pub paint: Rect<Au>,
}
impl Overflow {
pub fn new() -> Overflow {
Overflow {
scroll: Rect::zero(),
paint: Rect::zero(),
}
}
pub fn from_rect(border_box: &Rect<Au>) -> Overflow {
Overflow {
scroll: *border_box,
paint: *border_box,
}
}
pub fn union(&mut self, other: &Overflow) {
self.scroll = self.scroll.union(&other.scroll);
self.paint = self.paint.union(&other.paint);
}
pub fn translate(&mut self, point: &Point2D<Au>) {
self.scroll = self.scroll.translate(point);
self.paint = self.paint.translate(point);
}
}
bitflags! {
pub flags FragmentFlags: u8 {
/// Whether this fragment has a layer.
const HAS_LAYER = 0x01,
}
}
/// Specified distances from the margin edge of a block to its content in the inline direction.
/// These are returned by `guess_inline_content_edge_offsets()` and are used in the float placement
/// speculation logic.
#[derive(Copy, Clone, Debug)]
pub struct SpeculatedInlineContentEdgeOffsets {
pub start: Au,
pub end: Au,
}
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