/* 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/. */
//! Builds display lists from flows and fragments.
//!
//! Other browser engines sometimes call this "painting", but it is more accurately called display
//! list building, as the actual painting does not happen here—only deciding *what* we're going to
//! paint.
#![deny(unsafe_code)]
use azure::azure_hl::Color;
use block::BlockFlow;
use canvas::canvas_paint_task::CanvasMsg::SendPixelContents;
use context::LayoutContext;
use flow::{self, BaseFlow, Flow, IS_ABSOLUTELY_POSITIONED, NEEDS_LAYER};
use fragment::{CoordinateSystem, Fragment, IframeFragmentInfo, ImageFragmentInfo};
use fragment::{ScannedTextFragmentInfo, SpecificFragmentInfo};
use inline::InlineFlow;
use list_item::ListItemFlow;
use model::{self, MaybeAuto, ToGfxMatrix};
use opaque_node::OpaqueNodeMethods;
use geom::{Matrix2D, Point2D, Rect, Size2D, SideOffsets2D};
use gfx::color;
use gfx::display_list::{BLUR_INFLATION_FACTOR, BaseDisplayItem, BorderDisplayItem};
use gfx::display_list::{BorderRadii, BoxShadowClipMode, BoxShadowDisplayItem, ClippingRegion};
use gfx::display_list::{DisplayItem, DisplayList, DisplayItemMetadata};
use gfx::display_list::{GradientDisplayItem};
use gfx::display_list::{GradientStop, ImageDisplayItem, LineDisplayItem};
use gfx::display_list::{OpaqueNode, SolidColorDisplayItem};
use gfx::display_list::{StackingContext, TextDisplayItem, TextOrientation};
use gfx::paint_task::{PaintLayer, THREAD_TINT_COLORS};
use png::{self, PixelsByColorType};
use msg::compositor_msg::ScrollPolicy;
use msg::constellation_msg::Msg as ConstellationMsg;
use msg::constellation_msg::ConstellationChan;
use net::image::holder::ImageHolder;
use util::cursor::Cursor;
use util::geometry::{self, Au, ZERO_POINT, to_px, to_frac_px};
use util::logical_geometry::{LogicalPoint, LogicalRect, LogicalSize, WritingMode};
use util::opts;
use std::cmp;
use std::default::Default;
use std::iter::repeat;
use std::num::Float;
use style::values::specified::{AngleOrCorner, HorizontalDirection, VerticalDirection};
use style::values::computed::{Image, LinearGradient, LengthOrPercentage, LengthOrPercentageOrAuto};
use style::values::RGBA;
use style::computed_values::filter::Filter;
use style::computed_values::transform::ComputedMatrix;
use style::computed_values::{background_attachment, background_repeat, background_size};
use style::computed_values::{border_style, image_rendering, overflow_x, position, visibility};
use style::properties::style_structs::Border;
use style::properties::ComputedValues;
use std::num::ToPrimitive;
use std::sync::Arc;
use std::sync::mpsc::channel;
use url::Url;
/// The results of display list building for a single flow.
pub enum DisplayListBuildingResult {
None,
StackingContext(Arc<StackingContext>),
Normal(Box<DisplayList>),
}
impl DisplayListBuildingResult {
/// Adds the display list items contained within this display list building result to the given
/// display list, preserving stacking order. If this display list building result does not
/// consist of an entire stacking context, it will be emptied.
pub fn add_to(&mut self, display_list: &mut DisplayList) {
match *self {
DisplayListBuildingResult::None => return,
DisplayListBuildingResult::StackingContext(ref mut stacking_context) => {
display_list.children.push_back((*stacking_context).clone())
}
DisplayListBuildingResult::Normal(ref mut source_display_list) => {
display_list.append_from(&mut **source_display_list)
}
}
}
}
pub trait FragmentDisplayListBuilding {
/// Adds the display items necessary to paint the background of this fragment to the display
/// list if necessary.
fn build_display_list_for_background_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion);
/// Computes the background size for an image with the given background area according to the
/// rules in CSS-BACKGROUNDS § 3.9.
fn compute_background_image_size(&self,
style: &ComputedValues,
bounds: &Rect<Au>,
image: &png::Image)
-> Size2D<Au>;
/// Adds the display items necessary to paint the background image of this fragment to the
/// display list at the appropriate stacking level.
fn build_display_list_for_background_image(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion,
image_url: &Url);
/// Adds the display items necessary to paint the background linear gradient of this fragment
/// to the display list at the appropriate stacking level.
fn build_display_list_for_background_linear_gradient(&self,
display_list: &mut DisplayList,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion,
gradient: &LinearGradient,
style: &ComputedValues);
/// Adds the display items necessary to paint the borders of this fragment to a display list if
/// necessary.
fn build_display_list_for_borders_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
abs_bounds: &Rect<Au>,
level: StackingLevel,
clip: &ClippingRegion);
/// Adds the display items necessary to paint the outline of this fragment to the display list
/// if necessary.
fn build_display_list_for_outline_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
bounds: &Rect<Au>,
clip: &ClippingRegion);
/// Adds the display items necessary to paint the box shadow of this fragment to the display
/// list if necessary.
fn build_display_list_for_box_shadow_if_applicable(&self,
style: &ComputedValues,
list: &mut DisplayList,
layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion);
/// Adds display items necessary to draw debug boxes around a scanned text fragment.
fn build_debug_borders_around_text_fragments(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
stacking_relative_content_box: &Rect<Au>,
text_fragment: &ScannedTextFragmentInfo,
clip: &ClippingRegion);
/// Adds display items necessary to draw debug boxes around this fragment.
fn build_debug_borders_around_fragment(&self,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
clip: &ClippingRegion);
/// Adds the display items for this fragment to the given display list.
///
/// Arguments:
///
/// * `display_list`: The display list to add display items to.
/// * `layout_context`: The layout context.
/// * `dirty`: The dirty rectangle in the coordinate system of the owning flow.
/// * `stacking_relative_flow_origin`: Position of the origin of the owning flow with respect
/// to its nearest ancestor stacking context.
/// * `relative_containing_block_size`: The size of the containing block that
/// `position: relative` makes use of.
/// * `clip`: The region to clip the display items to.
fn build_display_list(&mut self,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
stacking_relative_flow_origin: &Point2D<Au>,
relative_containing_block_size: &LogicalSize<Au>,
relative_containing_block_mode: WritingMode,
background_and_border_level: BackgroundAndBorderLevel,
clip: &ClippingRegion);
/// Sends the size and position of this iframe fragment to the constellation. This is out of
/// line to guide inlining.
fn finalize_position_and_size_of_iframe(&self,
iframe_fragment: &IframeFragmentInfo,
offset: Point2D<Au>,
layout_context: &LayoutContext);
/// Returns the appropriate clipping region for descendants of this flow.
fn clipping_region_for_children(&self,
current_clip: &ClippingRegion,
stacking_relative_border_box: &Rect<Au>)
-> ClippingRegion;
/// Calculates the clipping rectangle for a fragment, taking the `clip` property into account
/// per CSS 2.1 § 11.1.2.
fn calculate_style_specified_clip(&self,
parent_clip: &ClippingRegion,
stacking_relative_border_box: &Rect<Au>)
-> ClippingRegion;
/// Creates the text display item for one text fragment. This can be called multiple times for
/// one fragment if there are text shadows.
///
/// `shadow_blur_radius` will be `Some` if this is a shadow, even if the blur radius is zero.
fn build_display_list_for_text_fragment(&self,
display_list: &mut DisplayList,
text_fragment: &ScannedTextFragmentInfo,
text_color: RGBA,
stacking_relative_content_box: &Rect<Au>,
shadow_blur_radius: Option<Au>,
offset: &Point2D<Au>,
clip: &ClippingRegion);
/// Creates the display item for a text decoration: underline, overline, or line-through.
fn build_display_list_for_text_decoration(&self,
display_list: &mut DisplayList,
color: &RGBA,
stacking_relative_box: &LogicalRect<Au>,
clip: &ClippingRegion,
blur_radius: Au);
/// A helper method that `build_display_list` calls to create per-fragment-type display items.
fn build_fragment_type_specific_display_items(&mut self,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
clip: &ClippingRegion);
}
fn handle_overlapping_radii(size: &Size2D<Au>, radii: &BorderRadii<Au>) -> BorderRadii<Au> {
// No two corners' border radii may add up to more than the length of the edge
// between them. To prevent that, all radii are scaled down uniformly.
fn scale_factor(radius_a: Au, radius_b: Au, edge_length: Au) -> f64 {
let required = radius_a + radius_b;
if required <= edge_length {
1.0
} else {
to_frac_px(edge_length) / to_frac_px(required)
}
}
let top_factor = scale_factor(radii.top_left, radii.top_right, size.width);
let bottom_factor = scale_factor(radii.bottom_left, radii.bottom_right, size.width);
let left_factor = scale_factor(radii.top_left, radii.bottom_left, size.height);
let right_factor = scale_factor(radii.top_right, radii.bottom_right, size.height);
let min_factor = top_factor.min(bottom_factor).min(left_factor).min(right_factor);
if min_factor < 1.0 {
BorderRadii {
top_left: radii.top_left .scale_by(min_factor),
top_right: radii.top_right .scale_by(min_factor),
bottom_left: radii.bottom_left .scale_by(min_factor),
bottom_right: radii.bottom_right.scale_by(min_factor),
}
} else {
*radii
}
}
fn build_border_radius(abs_bounds: &Rect<Au>, border_style: &Border) -> BorderRadii<Au> {
// TODO(cgaebel): Support border radii even in the case of multiple border widths.
// This is an extension of supporting elliptical radii. For now, all percentage
// radii will be relative to the width.
handle_overlapping_radii(&abs_bounds.size, &BorderRadii {
top_left: model::specified(border_style.border_top_left_radius,
abs_bounds.size.width),
top_right: model::specified(border_style.border_top_right_radius,
abs_bounds.size.width),
bottom_right: model::specified(border_style.border_bottom_right_radius,
abs_bounds.size.width),
bottom_left: model::specified(border_style.border_bottom_left_radius,
abs_bounds.size.width),
})
}
impl FragmentDisplayListBuilding for Fragment {
fn build_display_list_for_background_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion) {
// Adjust the clipping region as necessary to account for `border-radius`.
let border_radii = build_border_radius(absolute_bounds, style.get_border());
let mut clip = (*clip).clone();
if !border_radii.is_square() {
clip = clip.intersect_with_rounded_rect(absolute_bounds, &border_radii)
}
// FIXME: This causes a lot of background colors to be displayed when they are clearly not
// needed. We could use display list optimization to clean this up, but it still seems
// inefficient. What we really want is something like "nearest ancestor element that
// doesn't have a fragment".
let background_color = style.resolve_color(style.get_background().background_color);
display_list.push(DisplayItem::SolidColorClass(box SolidColorDisplayItem {
base: BaseDisplayItem::new(*absolute_bounds,
DisplayItemMetadata::new(self.node,
style,
Cursor::DefaultCursor),
clip.clone()),
color: background_color.to_gfx_color(),
}), level);
// The background image is painted on top of the background color.
// Implements background image, per spec:
// http://www.w3.org/TR/CSS21/colors.html#background
let background = style.get_background();
match background.background_image {
None => {}
Some(Image::LinearGradient(ref gradient)) => {
self.build_display_list_for_background_linear_gradient(display_list,
level,
absolute_bounds,
&clip,
gradient,
style)
}
Some(Image::Url(ref image_url)) => {
self.build_display_list_for_background_image(style,
display_list,
layout_context,
level,
absolute_bounds,
&clip,
image_url)
}
}
}
fn compute_background_image_size(&self,
style: &ComputedValues,
bounds: &Rect<Au>,
image: &png::Image)
-> Size2D<Au> {
// If `image_aspect_ratio` < `bounds_aspect_ratio`, the image is tall; otherwise, it is
// wide.
let image_aspect_ratio = (image.width as f64) / (image.height as f64);
let bounds_aspect_ratio = bounds.size.width.to_subpx() / bounds.size.height.to_subpx();
let intrinsic_size = Size2D(Au::from_px(image.width as int),
Au::from_px(image.height as int));
match (style.get_background().background_size.clone(),
image_aspect_ratio < bounds_aspect_ratio) {
(background_size::T::Contain, false) | (background_size::T::Cover, true) => {
Size2D(bounds.size.width,
Au::from_frac_px(bounds.size.width.to_subpx() / image_aspect_ratio))
}
(background_size::T::Contain, true) | (background_size::T::Cover, false) => {
Size2D(Au::from_frac_px(bounds.size.height.to_subpx() * image_aspect_ratio),
bounds.size.height)
}
(background_size::T::Explicit(background_size::ExplicitSize {
width,
height: LengthOrPercentageOrAuto::Auto,
}), _) => {
let width = MaybeAuto::from_style(width, bounds.size.width)
.specified_or_default(intrinsic_size.width);
Size2D(width, Au::from_frac_px(width.to_subpx() / image_aspect_ratio))
}
(background_size::T::Explicit(background_size::ExplicitSize {
width: LengthOrPercentageOrAuto::Auto,
height
}), _) => {
let height = MaybeAuto::from_style(height, bounds.size.height)
.specified_or_default(intrinsic_size.height);
Size2D(Au::from_frac_px(height.to_subpx() * image_aspect_ratio), height)
}
(background_size::T::Explicit(background_size::ExplicitSize {
width,
height
}), _) => {
Size2D(MaybeAuto::from_style(width, bounds.size.width)
.specified_or_default(intrinsic_size.width),
MaybeAuto::from_style(height, bounds.size.height)
.specified_or_default(intrinsic_size.height))
}
}
}
fn build_display_list_for_background_image(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion,
image_url: &Url) {
let background = style.get_background();
let mut holder = ImageHolder::new(image_url.clone(),
layout_context.shared.image_cache.clone());
let image = match holder.get_image(self.node.to_untrusted_node_address()) {
None => {
// No image data at all? Do nothing.
//
// TODO: Add some kind of placeholder background image.
debug!("(building display list) no background image :(");
return
}
Some(image) => image,
};
debug!("(building display list) building background image");
// Use `background-size` to get the size.
let mut bounds = *absolute_bounds;
let image_size = self.compute_background_image_size(style, &bounds, &**image);
// Clip.
//
// TODO: Check the bounds to see if a clip item is actually required.
let clip = clip.clone().intersect_rect(&bounds);
// Use `background-attachment` to get the initial virtual origin
let (virtual_origin_x, virtual_origin_y) = match background.background_attachment {
background_attachment::T::scroll => {
(absolute_bounds.origin.x, absolute_bounds.origin.y)
}
background_attachment::T::fixed => {
(Au(0), Au(0))
}
};
// Use `background-position` to get the offset.
let horizontal_position = model::specified(background.background_position.horizontal,
bounds.size.width - image_size.width);
let vertical_position = model::specified(background.background_position.vertical,
bounds.size.height - image_size.height);
let abs_x = virtual_origin_x + horizontal_position;
let abs_y = virtual_origin_y + vertical_position;
// Adjust origin and size based on background-repeat
match background.background_repeat {
background_repeat::T::no_repeat => {
bounds.origin.x = abs_x;
bounds.origin.y = abs_y;
bounds.size.width = image_size.width;
bounds.size.height = image_size.height;
}
background_repeat::T::repeat_x => {
bounds.origin.y = abs_y;
bounds.size.height = image_size.height;
ImageFragmentInfo::tile_image(&mut bounds.origin.x,
&mut bounds.size.width,
abs_x,
image_size.width.to_nearest_px() as u32);
}
background_repeat::T::repeat_y => {
bounds.origin.x = abs_x;
bounds.size.width = image_size.width;
ImageFragmentInfo::tile_image(&mut bounds.origin.y,
&mut bounds.size.height,
abs_y,
image_size.height.to_nearest_px() as u32);
}
background_repeat::T::repeat => {
ImageFragmentInfo::tile_image(&mut bounds.origin.x,
&mut bounds.size.width,
abs_x,
image_size.width.to_nearest_px() as u32);
ImageFragmentInfo::tile_image(&mut bounds.origin.y,
&mut bounds.size.height,
abs_y,
image_size.height.to_nearest_px() as u32);
}
};
// Create the image display item.
display_list.push(DisplayItem::ImageClass(box ImageDisplayItem {
base: BaseDisplayItem::new(bounds,
DisplayItemMetadata::new(self.node,
style,
Cursor::DefaultCursor),
clip),
image: image.clone(),
stretch_size: Size2D(image_size.width, image_size.height),
image_rendering: style.get_effects().image_rendering.clone(),
}), level);
}
fn build_display_list_for_background_linear_gradient(&self,
display_list: &mut DisplayList,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion,
gradient: &LinearGradient,
style: &ComputedValues) {
let clip = clip.clone().intersect_rect(absolute_bounds);
// This is the distance between the center and the ending point; i.e. half of the distance
// between the starting point and the ending point.
let delta = match gradient.angle_or_corner {
AngleOrCorner::Angle(angle) => {
Point2D(Au((angle.radians().sin() *
absolute_bounds.size.width.to_f64().unwrap() / 2.0) as i32),
Au((-angle.radians().cos() *
absolute_bounds.size.height.to_f64().unwrap() / 2.0) as i32))
}
AngleOrCorner::Corner(horizontal, vertical) => {
let x_factor = match horizontal {
HorizontalDirection::Left => -1,
HorizontalDirection::Right => 1,
};
let y_factor = match vertical {
VerticalDirection::Top => -1,
VerticalDirection::Bottom => 1,
};
Point2D(Au(x_factor * absolute_bounds.size.width.to_i32().unwrap() / 2),
Au(y_factor * absolute_bounds.size.height.to_i32().unwrap() / 2))
}
};
// This is the length of the gradient line.
let length = Au((delta.x.to_f64().unwrap() * 2.0).hypot(delta.y.to_f64().unwrap() * 2.0)
as i32);
// Determine the position of each stop per CSS-IMAGES § 3.4.
//
// FIXME(#3908, pcwalton): Make sure later stops can't be behind earlier stops.
let (mut stops, mut stop_run) = (Vec::new(), None);
for (i, stop) in gradient.stops.iter().enumerate() {
let offset = match stop.position {
None => {
if stop_run.is_none() {
// Initialize a new stop run.
let start_offset = if i == 0 {
0.0
} else {
// `unwrap()` here should never fail because this is the beginning of
// a stop run, which is always bounded by a length or percentage.
position_to_offset(gradient.stops[i - 1].position.unwrap(), length)
};
let (end_index, end_offset) =
match gradient.stops[i..]
.iter()
.enumerate()
.find(|&(_, ref stop)| stop.position.is_some()) {
None => (gradient.stops.len() - 1, 1.0),
Some((end_index, end_stop)) => {
// `unwrap()` here should never fail because this is the end of
// a stop run, which is always bounded by a length or
// percentage.
(end_index,
position_to_offset(end_stop.position.unwrap(), length))
}
};
stop_run = Some(StopRun {
start_offset: start_offset,
end_offset: end_offset,
start_index: i,
stop_count: end_index - i,
})
}
let stop_run = stop_run.unwrap();
let stop_run_length = stop_run.end_offset - stop_run.start_offset;
if stop_run.stop_count == 0 {
stop_run.end_offset
} else {
stop_run.start_offset +
stop_run_length * (i - stop_run.start_index) as f32 /
(stop_run.stop_count as f32)
}
}
Some(position) => {
stop_run = None;
position_to_offset(position, length)
}
};
stops.push(GradientStop {
offset: offset,
color: style.resolve_color(stop.color).to_gfx_color()
})
}
let center = Point2D(absolute_bounds.origin.x + absolute_bounds.size.width / 2,
absolute_bounds.origin.y + absolute_bounds.size.height / 2);
let gradient_display_item = DisplayItem::GradientClass(box GradientDisplayItem {
base: BaseDisplayItem::new(*absolute_bounds,
DisplayItemMetadata::new(self.node,
style,
Cursor::DefaultCursor),
clip),
start_point: center - delta,
end_point: center + delta,
stops: stops,
});
display_list.push(gradient_display_item, level)
}
fn build_display_list_for_box_shadow_if_applicable(&self,
style: &ComputedValues,
list: &mut DisplayList,
_layout_context: &LayoutContext,
level: StackingLevel,
absolute_bounds: &Rect<Au>,
clip: &ClippingRegion) {
// NB: According to CSS-BACKGROUNDS, box shadows render in *reverse* order (front to back).
for box_shadow in style.get_effects().box_shadow.iter().rev() {
let bounds = shadow_bounds(&absolute_bounds.translate(&Point2D(box_shadow.offset_x,
box_shadow.offset_y)),
box_shadow.blur_radius,
box_shadow.spread_radius);
list.push(DisplayItem::BoxShadowClass(box BoxShadowDisplayItem {
base: BaseDisplayItem::new(bounds,
DisplayItemMetadata::new(self.node,
style,
Cursor::DefaultCursor),
(*clip).clone()),
box_bounds: *absolute_bounds,
color: style.resolve_color(box_shadow.color).to_gfx_color(),
offset: Point2D(box_shadow.offset_x, box_shadow.offset_y),
blur_radius: box_shadow.blur_radius,
spread_radius: box_shadow.spread_radius,
clip_mode: if box_shadow.inset {
BoxShadowClipMode::Inset
} else {
BoxShadowClipMode::Outset
},
}), level);
}
}
fn build_display_list_for_borders_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
abs_bounds: &Rect<Au>,
level: StackingLevel,
clip: &ClippingRegion) {
let border = style.logical_border_width();
if border.is_zero() {
return
}
let top_color = style.resolve_color(style.get_border().border_top_color);
let right_color = style.resolve_color(style.get_border().border_right_color);
let bottom_color = style.resolve_color(style.get_border().border_bottom_color);
let left_color = style.resolve_color(style.get_border().border_left_color);
// Append the border to the display list.
display_list.push(DisplayItem::BorderClass(box BorderDisplayItem {
base: BaseDisplayItem::new(*abs_bounds,
DisplayItemMetadata::new(self.node, style, Cursor::DefaultCursor),
(*clip).clone()),
border_widths: border.to_physical(style.writing_mode),
color: SideOffsets2D::new(top_color.to_gfx_color(),
right_color.to_gfx_color(),
bottom_color.to_gfx_color(),
left_color.to_gfx_color()),
style: SideOffsets2D::new(style.get_border().border_top_style,
style.get_border().border_right_style,
style.get_border().border_bottom_style,
style.get_border().border_left_style),
radius: build_border_radius(abs_bounds, style.get_border()),
}), level);
}
fn build_display_list_for_outline_if_applicable(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
bounds: &Rect<Au>,
clip: &ClippingRegion) {
let width = style.get_outline().outline_width;
if width == Au(0) {
return
}
let outline_style = style.get_outline().outline_style;
if outline_style == border_style::T::none {
return
}
// Outlines are not accounted for in the dimensions of the border box, so adjust the
// absolute bounds.
let mut bounds = *bounds;
let offset = width + style.get_outline().outline_offset;
bounds.origin.x = bounds.origin.x - offset;
bounds.origin.y = bounds.origin.y - offset;
bounds.size.width = bounds.size.width + offset + offset;
bounds.size.height = bounds.size.height + offset + offset;
// Append the outline to the display list.
let color = style.resolve_color(style.get_outline().outline_color).to_gfx_color();
display_list.outlines.push_back(DisplayItem::BorderClass(box BorderDisplayItem {
base: BaseDisplayItem::new(bounds,
DisplayItemMetadata::new(self.node, style, Cursor::DefaultCursor),
(*clip).clone()),
border_widths: SideOffsets2D::new_all_same(width),
color: SideOffsets2D::new_all_same(color),
style: SideOffsets2D::new_all_same(outline_style),
radius: Default::default(),
}))
}
fn build_debug_borders_around_text_fragments(&self,
style: &ComputedValues,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
stacking_relative_content_box: &Rect<Au>,
text_fragment: &ScannedTextFragmentInfo,
clip: &ClippingRegion) {
// FIXME(pcwalton, #2795): Get the real container size.
let container_size = Size2D::zero();
// Compute the text fragment bounds and draw a border surrounding them.
display_list.content.push_back(DisplayItem::BorderClass(box BorderDisplayItem {
base: BaseDisplayItem::new(*stacking_relative_border_box,
DisplayItemMetadata::new(self.node, style, Cursor::DefaultCursor),
(*clip).clone()),
border_widths: SideOffsets2D::new_all_same(Au::from_px(1)),
color: SideOffsets2D::new_all_same(color::rgb(0, 0, 200)),
style: SideOffsets2D::new_all_same(border_style::T::solid),
radius: Default::default(),
}));
// Draw a rectangle representing the baselines.
let mut baseline = LogicalRect::from_physical(self.style.writing_mode,
*stacking_relative_content_box,
container_size);
baseline.start.b = baseline.start.b + text_fragment.run.ascent();
baseline.size.block = Au(0);
let baseline = baseline.to_physical(self.style.writing_mode, container_size);
let line_display_item = box LineDisplayItem {
base: BaseDisplayItem::new(baseline,
DisplayItemMetadata::new(self.node, style, Cursor::DefaultCursor),
(*clip).clone()),
color: color::rgb(0, 200, 0),
style: border_style::T::dashed,
};
display_list.content.push_back(DisplayItem::LineClass(line_display_item));
}
fn build_debug_borders_around_fragment(&self,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
clip: &ClippingRegion) {
// This prints a debug border around the border of this fragment.
display_list.content.push_back(DisplayItem::BorderClass(box BorderDisplayItem {
base: BaseDisplayItem::new(*stacking_relative_border_box,
DisplayItemMetadata::new(self.node,
&*self.style,
Cursor::DefaultCursor),
(*clip).clone()),
border_widths: SideOffsets2D::new_all_same(Au::from_px(1)),
color: SideOffsets2D::new_all_same(color::rgb(0, 0, 200)),
style: SideOffsets2D::new_all_same(border_style::T::solid),
radius: Default::default(),
}));
}
fn calculate_style_specified_clip(&self,
parent_clip: &ClippingRegion,
stacking_relative_border_box: &Rect<Au>)
-> ClippingRegion {
// Account for `clip` per CSS 2.1 § 11.1.2.
let style_clip_rect = match (self.style().get_box().position,
self.style().get_effects().clip) {
(position::T::absolute, Some(style_clip_rect)) => style_clip_rect,
_ => return (*parent_clip).clone(),
};
// FIXME(pcwalton, #2795): Get the real container size.
let clip_origin = Point2D(stacking_relative_border_box.origin.x + style_clip_rect.left,
stacking_relative_border_box.origin.y + style_clip_rect.top);
let right = style_clip_rect.right.unwrap_or(stacking_relative_border_box.size.width);
let bottom = style_clip_rect.bottom.unwrap_or(stacking_relative_border_box.size.height);
let clip_size = Size2D(right - clip_origin.x, bottom - clip_origin.y);
(*parent_clip).clone().intersect_rect(&Rect(clip_origin, clip_size))
}
fn build_display_list(&mut self,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
stacking_relative_flow_origin: &Point2D<Au>,
relative_containing_block_size: &LogicalSize<Au>,
relative_containing_block_mode: WritingMode,
background_and_border_level: BackgroundAndBorderLevel,
clip: &ClippingRegion) {
// Compute the fragment position relative to the parent stacking context. If the fragment
// itself establishes a stacking context, then the origin of its position will be (0, 0)
// for the purposes of this computation.
let stacking_relative_border_box =
self.stacking_relative_border_box(stacking_relative_flow_origin,
relative_containing_block_size,
relative_containing_block_mode,
CoordinateSystem::Own);
debug!("Fragment::build_display_list at rel={:?}, abs={:?}, dirty={:?}, flow origin={:?}: \
{:?}",
self.border_box,
stacking_relative_border_box,
layout_context.shared.dirty,
stacking_relative_flow_origin,
self);
if self.style().get_inheritedbox().visibility != visibility::T::visible {
return
}
if !stacking_relative_border_box.intersects(&layout_context.shared.dirty) {
debug!("Fragment::build_display_list: Did not intersect...");
return
}
// Calculate the clip rect. If there's nothing to render at all, don't even construct
// display list items.
let clip = self.calculate_style_specified_clip(clip, &stacking_relative_border_box);
if !clip.might_intersect_rect(&stacking_relative_border_box) {
return;
}
debug!("Fragment::build_display_list: intersected. Adding display item...");
if self.is_primary_fragment() {
let level =
StackingLevel::from_background_and_border_level(background_and_border_level);
// Add shadows, background, borders, and outlines, if applicable.
if let Some(ref inline_context) = self.inline_context {
for style in inline_context.styles.iter().rev() {
self.build_display_list_for_box_shadow_if_applicable(
&**style,
display_list,
layout_context,
level,
&stacking_relative_border_box,
&clip);
self.build_display_list_for_background_if_applicable(
&**style,
display_list,
layout_context,
level,
&stacking_relative_border_box,
&clip);
self.build_display_list_for_borders_if_applicable(
&**style,
display_list,
&stacking_relative_border_box,
level,
&clip);
self.build_display_list_for_outline_if_applicable(
&**style,
display_list,
&stacking_relative_border_box,
&clip);
}
}
if !self.is_scanned_text_fragment() {
self.build_display_list_for_box_shadow_if_applicable(&*self.style,
display_list,
layout_context,
level,
&stacking_relative_border_box,
&clip);
self.build_display_list_for_background_if_applicable(&*self.style,
display_list,
layout_context,
level,
&stacking_relative_border_box,
&clip);
self.build_display_list_for_borders_if_applicable(&*self.style,
display_list,
&stacking_relative_border_box,
level,
&clip);
self.build_display_list_for_outline_if_applicable(&*self.style,
display_list,
&stacking_relative_border_box,
&clip);
}
}
// Create special per-fragment-type display items.
self.build_fragment_type_specific_display_items(display_list,
&stacking_relative_border_box,
&clip);
if opts::get().show_debug_fragment_borders {
self.build_debug_borders_around_fragment(display_list,
&stacking_relative_border_box,
&clip)
}
// If this is an iframe, then send its position and size up to the constellation.
//
// FIXME(pcwalton): Doing this during display list construction seems potentially
// problematic if iframes are outside the area we're computing the display list for, since
// they won't be able to reflow at all until the user scrolls to them. Perhaps we should
// separate this into two parts: first we should send the size only to the constellation
// once that's computed during assign-block-sizes, and second we should should send the
// origin to the constellation here during display list construction. This should work
// because layout for the iframe only needs to know size, and origin is only relevant if
// the iframe is actually going to be displayed.
if let SpecificFragmentInfo::Iframe(ref iframe_fragment) = self.specific {
self.finalize_position_and_size_of_iframe(&**iframe_fragment,
stacking_relative_border_box.origin,
layout_context)
}
}
fn build_fragment_type_specific_display_items(&mut self,
display_list: &mut DisplayList,
stacking_relative_border_box: &Rect<Au>,
clip: &ClippingRegion) {
// Compute the context box position relative to the parent stacking context.
let stacking_relative_content_box =
self.stacking_relative_content_box(stacking_relative_border_box);
match self.specific {
SpecificFragmentInfo::ScannedText(ref text_fragment) => {
// Create items for shadows.
//
// NB: According to CSS-BACKGROUNDS, text shadows render in *reverse* order (front
// to back).
let text_color = self.style().get_color().color;
for text_shadow in self.style.get_effects().text_shadow.0.iter().rev() {
let offset = &Point2D(text_shadow.offset_x, text_shadow.offset_y);
let color = self.style().resolve_color(text_shadow.color);
self.build_display_list_for_text_fragment(display_list,
&**text_fragment,
color,
&stacking_relative_content_box,
Some(text_shadow.blur_radius),
offset,
clip);
}
// Create the main text display item.
self.build_display_list_for_text_fragment(display_list,
&**text_fragment,
text_color,
&stacking_relative_content_box,
None,
&Point2D(Au(0), Au(0)),
clip);
if opts::get().show_debug_fragment_borders {
self.build_debug_borders_around_text_fragments(self.style(),
display_list,
stacking_relative_border_box,
&stacking_relative_content_box,
&**text_fragment,
clip)
}
}
SpecificFragmentInfo::Generic |
SpecificFragmentInfo::GeneratedContent(..) |
SpecificFragmentInfo::Iframe(..) |
SpecificFragmentInfo::Table |
SpecificFragmentInfo::TableCell |
SpecificFragmentInfo::TableRow |
SpecificFragmentInfo::TableWrapper |
SpecificFragmentInfo::InlineBlock(_) |
SpecificFragmentInfo::InlineAbsoluteHypothetical(_) => {
if opts::get().show_debug_fragment_borders {
self.build_debug_borders_around_fragment(display_list,
stacking_relative_border_box,
clip);
}
}
SpecificFragmentInfo::Image(ref mut image_fragment) => {
let image_ref = &mut image_fragment.image;
if let Some(image) = image_ref.get_image(self.node.to_untrusted_node_address()) {
debug!("(building display list) building image fragment");
// Place the image into the display list.
display_list.content.push_back(DisplayItem::ImageClass(box ImageDisplayItem {
base: BaseDisplayItem::new(stacking_relative_content_box,
DisplayItemMetadata::new(self.node,
&*self.style,
Cursor::DefaultCursor),
(*clip).clone()),
image: image.clone(),
stretch_size: stacking_relative_content_box.size,
image_rendering: self.style.get_effects().image_rendering.clone(),
}));
} else {
// No image data at all? Do nothing.
//
// TODO: Add some kind of placeholder image.
debug!("(building display list) no image :(");
}
}
SpecificFragmentInfo::Canvas(ref canvas_fragment_info) => {
let width = canvas_fragment_info.replaced_image_fragment_info
.computed_inline_size.map_or(0, |w| to_px(w) as uint);
let height = canvas_fragment_info.replaced_image_fragment_info
.computed_block_size.map_or(0, |h| to_px(h) as uint);
let (sender, receiver) = channel::<Vec<u8>>();
let canvas_data = match canvas_fragment_info.renderer {
Some(ref renderer) => {
renderer.lock().unwrap().send(SendPixelContents(sender)).unwrap();
receiver.recv().unwrap()
},
None => repeat(0xFFu8).take(width * height * 4).collect(),
};
let canvas_display_item = box ImageDisplayItem {
base: BaseDisplayItem::new(stacking_relative_content_box,
DisplayItemMetadata::new(self.node,
&*self.style,
Cursor::DefaultCursor),
(*clip).clone()),
image: Arc::new(box png::Image {
width: width as u32,
height: height as u32,
pixels: PixelsByColorType::RGBA8(canvas_data),
}),
stretch_size: stacking_relative_content_box.size,
image_rendering: image_rendering::T::Auto,
};
display_list.content.push_back(DisplayItem::ImageClass(canvas_display_item));
}
SpecificFragmentInfo::UnscannedText(_) => {
panic!("Shouldn't see unscanned fragments here.")
}
SpecificFragmentInfo::TableColumn(_) => {
panic!("Shouldn't see table column fragments here.")
}
}
}
#[inline(never)]
fn finalize_position_and_size_of_iframe(&self,
iframe_fragment: &IframeFragmentInfo,
offset: Point2D<Au>,
layout_context: &LayoutContext) {
let border_padding = (self.border_padding).to_physical(self.style.writing_mode);
let content_size = self.content_box().size.to_physical(self.style.writing_mode);
let iframe_rect = Rect(Point2D(geometry::to_frac_px(offset.x + border_padding.left) as f32,
geometry::to_frac_px(offset.y + border_padding.top) as f32),
Size2D(geometry::to_frac_px(content_size.width) as f32,
geometry::to_frac_px(content_size.height) as f32));
debug!("finalizing position and size of iframe for {:?},{:?}",
iframe_fragment.pipeline_id,
iframe_fragment.subpage_id);
let ConstellationChan(ref chan) = layout_context.shared.constellation_chan;
chan.send(ConstellationMsg::FrameRect(iframe_fragment.pipeline_id,
iframe_fragment.subpage_id,
iframe_rect)).unwrap();
}
fn clipping_region_for_children(&self,
current_clip: &ClippingRegion,
stacking_relative_border_box: &Rect<Au>)
-> ClippingRegion {
// Don't clip if we're text.
if self.is_scanned_text_fragment() {
return (*current_clip).clone()
}
// Account for style-specified `clip`.
let mut current_clip = self.calculate_style_specified_clip(current_clip,
stacking_relative_border_box);
// Clip according to the values of `overflow-x` and `overflow-y`.
//
// TODO(pcwalton): Support scrolling.
// FIXME(pcwalton): This may be more complex than it needs to be, since it seems to be
// impossible with the computed value rules as they are to have `overflow-x: visible` with
// `overflow-y: <scrolling>` or vice versa!
match self.style.get_box().overflow_x {
overflow_x::T::hidden | overflow_x::T::auto | overflow_x::T::scroll => {
let mut bounds = current_clip.bounding_rect();
let max_x = cmp::min(bounds.max_x(), stacking_relative_border_box.max_x());
bounds.origin.x = cmp::max(bounds.origin.x, stacking_relative_border_box.origin.x);
bounds.size.width = max_x - bounds.origin.x;
current_clip = current_clip.intersect_rect(&bounds)
}
_ => {}
}
match self.style.get_box().overflow_y.0 {
overflow_x::T::hidden | overflow_x::T::auto | overflow_x::T::scroll => {
let mut bounds = current_clip.bounding_rect();
let max_y = cmp::min(bounds.max_y(), stacking_relative_border_box.max_y());
bounds.origin.y = cmp::max(bounds.origin.y, stacking_relative_border_box.origin.y);
bounds.size.height = max_y - bounds.origin.y;
current_clip = current_clip.intersect_rect(&bounds)
}
_ => {}
}
current_clip
}
fn build_display_list_for_text_fragment(&self,
display_list: &mut DisplayList,
text_fragment: &ScannedTextFragmentInfo,
text_color: RGBA,
stacking_relative_content_box: &Rect<Au>,
shadow_blur_radius: Option<Au>,
offset: &Point2D<Au>,
clip: &ClippingRegion) {
// Determine the orientation and cursor to use.
let (orientation, cursor) = if self.style.writing_mode.is_vertical() {
if self.style.writing_mode.is_sideways_left() {
(TextOrientation::SidewaysLeft, Cursor::VerticalTextCursor)
} else {
(TextOrientation::SidewaysRight, Cursor::VerticalTextCursor)
}
} else {
(TextOrientation::Upright, Cursor::TextCursor)
};
// Compute location of the baseline.
//
// FIXME(pcwalton): Get the real container size.
let container_size = Size2D::zero();
let metrics = &text_fragment.run.font_metrics;
let stacking_relative_content_box = stacking_relative_content_box.translate(offset);
let baseline_origin = stacking_relative_content_box.origin +
LogicalPoint::new(self.style.writing_mode,
Au(0),
metrics.ascent).to_physical(self.style.writing_mode,
container_size);
// Create the text display item.
display_list.content.push_back(DisplayItem::TextClass(box TextDisplayItem {
base: BaseDisplayItem::new(stacking_relative_content_box,
DisplayItemMetadata::new(self.node, self.style(), cursor),
(*clip).clone()),
text_run: text_fragment.run.clone(),
range: text_fragment.range,
text_color: text_color.to_gfx_color(),
orientation: orientation,
baseline_origin: baseline_origin,
blur_radius: shadow_blur_radius.unwrap_or(Au(0)),
}));
// Create display items for text decorations.
let mut text_decorations = self.style()
.get_inheritedtext()
._servo_text_decorations_in_effect;
if shadow_blur_radius.is_some() {
// If we're painting a shadow, paint the decorations the same color as the shadow.
text_decorations.underline = text_decorations.underline.map(|_| text_color);
text_decorations.overline = text_decorations.overline.map(|_| text_color);
text_decorations.line_through = text_decorations.line_through.map(|_| text_color);
}
let stacking_relative_content_box =
LogicalRect::from_physical(self.style.writing_mode,
stacking_relative_content_box,
container_size);
if let Some(ref underline_color) = text_decorations.underline {
let mut stacking_relative_box = stacking_relative_content_box;
stacking_relative_box.start.b = stacking_relative_content_box.start.b +
metrics.ascent - metrics.underline_offset;
stacking_relative_box.size.block = metrics.underline_size;
self.build_display_list_for_text_decoration(display_list,
underline_color,
&stacking_relative_box,
clip,
shadow_blur_radius.unwrap_or(Au(0)))
}
if let Some(ref overline_color) = text_decorations.overline {
let mut stacking_relative_box = stacking_relative_content_box;
stacking_relative_box.size.block = metrics.underline_size;
self.build_display_list_for_text_decoration(display_list,
overline_color,
&stacking_relative_box,
clip,
shadow_blur_radius.unwrap_or(Au(0)))
}
if let Some(ref line_through_color) = text_decorations.line_through {
let mut stacking_relative_box = stacking_relative_content_box;
stacking_relative_box.start.b = stacking_relative_box.start.b + metrics.ascent -
metrics.strikeout_offset;
stacking_relative_box.size.block = metrics.strikeout_size;
self.build_display_list_for_text_decoration(display_list,
line_through_color,
&stacking_relative_box,
clip,
shadow_blur_radius.unwrap_or(Au(0)))
}
}
fn build_display_list_for_text_decoration(&self,
display_list: &mut DisplayList,
color: &RGBA,
stacking_relative_box: &LogicalRect<Au>,
clip: &ClippingRegion,
blur_radius: Au) {
// Perhaps surprisingly, text decorations are box shadows. This is because they may need
// to have blur in the case of `text-shadow`, and this doesn't hurt performance because box
// shadows are optimized into essentially solid colors if there is no need for the blur.
//
// FIXME(pcwalton, #2795): Get the real container size.
let container_size = Size2D::zero();
let stacking_relative_box = stacking_relative_box.to_physical(self.style.writing_mode,
container_size);
let metadata = DisplayItemMetadata::new(self.node, &*self.style, Cursor::DefaultCursor);
display_list.content.push_back(DisplayItem::BoxShadowClass(box BoxShadowDisplayItem {
base: BaseDisplayItem::new(shadow_bounds(&stacking_relative_box, blur_radius, Au(0)),
metadata,
(*clip).clone()),
box_bounds: stacking_relative_box,
color: color.to_gfx_color(),
offset: ZERO_POINT,
blur_radius: blur_radius,
spread_radius: Au(0),
clip_mode: BoxShadowClipMode::None,
}))
}
}
pub trait BlockFlowDisplayListBuilding {
fn build_display_list_for_block_base(&mut self,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
background_border_level: BackgroundAndBorderLevel);
fn build_display_list_for_static_block(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext,
background_border_level: BackgroundAndBorderLevel);
fn build_display_list_for_absolutely_positioned_block(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext);
fn build_display_list_for_floating_block(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext);
fn build_display_list_for_block(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext);
fn create_stacking_context(&self,
display_list: Box<DisplayList>,
layer: Option<Arc<PaintLayer>>)
-> Arc<StackingContext>;
}
impl BlockFlowDisplayListBuilding for BlockFlow {
fn build_display_list_for_block_base(&mut self,
display_list: &mut DisplayList,
layout_context: &LayoutContext,
background_border_level: BackgroundAndBorderLevel) {
// Add the box that starts the block context.
self.fragment.build_display_list(display_list,
layout_context,
&self.base.stacking_relative_position,
&self.base
.absolute_position_info
.relative_containing_block_size,
self.base
.absolute_position_info
.relative_containing_block_mode,
background_border_level,
&self.base.clip);
// Add children.
for kid in self.base.children.iter_mut() {
flow::mut_base(kid).display_list_building_result.add_to(display_list);
}
self.base.build_display_items_for_debugging_tint(display_list, self.fragment.node);
}
fn build_display_list_for_static_block(&mut self,
mut display_list: Box<DisplayList>,
layout_context: &LayoutContext,
background_border_level: BackgroundAndBorderLevel) {
self.build_display_list_for_block_base(&mut *display_list,
layout_context,
background_border_level);
self.base.display_list_building_result = if self.fragment.establishes_stacking_context() {
DisplayListBuildingResult::StackingContext(self.create_stacking_context(display_list,
None))
} else {
DisplayListBuildingResult::Normal(display_list)
}
}
fn build_display_list_for_absolutely_positioned_block(&mut self,
mut display_list: Box<DisplayList>,
layout_context: &LayoutContext) {
self.build_display_list_for_block_base(&mut *display_list,
layout_context,
BackgroundAndBorderLevel::RootOfStackingContext);
if !self.base.absolute_position_info.layers_needed_for_positioned_flows &&
!self.base.flags.contains(NEEDS_LAYER) {
// We didn't need a layer.
self.base.display_list_building_result =
DisplayListBuildingResult::StackingContext(self.create_stacking_context(
display_list,
None));
return
}
// If we got here, then we need a new layer.
let scroll_policy = if self.is_fixed() {
ScrollPolicy::FixedPosition
} else {
ScrollPolicy::Scrollable
};
let transparent = color::rgba(1.0, 1.0, 1.0, 0.0);
let stacking_context =
self.create_stacking_context(display_list,
Some(Arc::new(PaintLayer::new(self.layer_id(0),
transparent,
scroll_policy))));
self.base.display_list_building_result =
DisplayListBuildingResult::StackingContext(stacking_context)
}
fn build_display_list_for_floating_block(&mut self,
mut display_list: Box<DisplayList>,
layout_context: &LayoutContext) {
self.build_display_list_for_block_base(&mut *display_list,
layout_context,
BackgroundAndBorderLevel::RootOfStackingContext);
display_list.form_float_pseudo_stacking_context();
self.base.display_list_building_result = if self.fragment.establishes_stacking_context() {
DisplayListBuildingResult::StackingContext(self.create_stacking_context(display_list,
None))
} else {
DisplayListBuildingResult::Normal(display_list)
}
}
fn build_display_list_for_block(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext) {
if self.base.flags.is_float() {
// TODO(#2009, pcwalton): This is a pseudo-stacking context. We need to merge `z-index:
// auto` kids into the parent stacking context, when that is supported.
self.build_display_list_for_floating_block(display_list, layout_context);
} else if self.base.flags.contains(IS_ABSOLUTELY_POSITIONED) {
self.build_display_list_for_absolutely_positioned_block(display_list, layout_context);
} else {
self.build_display_list_for_static_block(display_list,
layout_context,
BackgroundAndBorderLevel::Block);
}
}
fn create_stacking_context(&self,
display_list: Box<DisplayList>,
layer: Option<Arc<PaintLayer>>)
-> Arc<StackingContext> {
debug_assert!(self.fragment.establishes_stacking_context());
let border_box = self.fragment
.stacking_relative_border_box(&self.base.stacking_relative_position,
&self.base
.absolute_position_info
.relative_containing_block_size,
self.base
.absolute_position_info
.relative_containing_block_mode,
CoordinateSystem::Parent);
let transform_origin = self.fragment.style().get_effects().transform_origin;
let transform_origin =
Point2D(model::specified(transform_origin.horizontal,
border_box.size.width).to_frac32_px(),
model::specified(transform_origin.vertical,
border_box.size.height).to_frac32_px());
let transform = self.fragment
.style()
.get_effects()
.transform
.unwrap_or(ComputedMatrix::identity())
.to_gfx_matrix(&border_box.size);
let transform = Matrix2D::identity().translate(transform_origin.x, transform_origin.y)
.mul(&transform)
.translate(-transform_origin.x, -transform_origin.y);
// FIXME(pcwalton): Is this vertical-writing-direction-safe?
let margin = self.fragment.margin.to_physical(self.base.writing_mode);
let overflow = self.base.overflow.translate(&-Point2D(margin.left, Au(0)));
// Create the filter pipeline.
let effects = self.fragment.style().get_effects();
let mut filters = effects.filter.clone();
if effects.opacity != 1.0 {
filters.push(Filter::Opacity(effects.opacity))
}
Arc::new(StackingContext::new(display_list,
&border_box,
&overflow,
self.fragment.style().get_box().z_index.number_or_zero(),
&transform,
filters,
self.fragment.style().get_effects().mix_blend_mode,
layer))
}
}
pub trait InlineFlowDisplayListBuilding {
fn build_display_list_for_inline(&mut self, layout_context: &LayoutContext);
}
impl InlineFlowDisplayListBuilding for InlineFlow {
fn build_display_list_for_inline(&mut self, layout_context: &LayoutContext) {
// TODO(#228): Once we form lines and have their cached bounds, we can be smarter and
// not recurse on a line if nothing in it can intersect the dirty region.
debug!("Flow: building display list for {} inline fragments", self.fragments.len());
let mut display_list = box DisplayList::new();
for fragment in self.fragments.fragments.iter_mut() {
fragment.build_display_list(&mut *display_list,
layout_context,
&self.base.stacking_relative_position,
&self.base
.absolute_position_info
.relative_containing_block_size,
self.base
.absolute_position_info
.relative_containing_block_mode,
BackgroundAndBorderLevel::Content,
&self.base.clip);
match fragment.specific {
SpecificFragmentInfo::InlineBlock(ref mut block_flow) => {
let block_flow = &mut *block_flow.flow_ref;
flow::mut_base(block_flow).display_list_building_result
.add_to(&mut *display_list)
}
SpecificFragmentInfo::InlineAbsoluteHypothetical(ref mut block_flow) => {
let block_flow = &mut *block_flow.flow_ref;
flow::mut_base(block_flow).display_list_building_result
.add_to(&mut *display_list)
}
_ => {}
}
}
if !self.fragments.fragments.is_empty() {
self.base.build_display_items_for_debugging_tint(&mut *display_list,
self.fragments.fragments[0].node);
}
self.base.display_list_building_result = DisplayListBuildingResult::Normal(display_list);
if opts::get().validate_display_list_geometry {
self.base.validate_display_list_geometry();
}
}
}
pub trait ListItemFlowDisplayListBuilding {
fn build_display_list_for_list_item(&mut self,
display_list: Box<DisplayList>,
layout_context: &LayoutContext);
}
impl ListItemFlowDisplayListBuilding for ListItemFlow {
fn build_display_list_for_list_item(&mut self,
mut display_list: Box<DisplayList>,
layout_context: &LayoutContext) {
// Draw the marker, if applicable.
if let Some(ref mut marker) = self.marker {
marker.build_display_list(&mut *display_list,
layout_context,
&self.block_flow.base.stacking_relative_position,
&self.block_flow
.base
.absolute_position_info
.relative_containing_block_size,
self.block_flow
.base
.absolute_position_info
.relative_containing_block_mode,
BackgroundAndBorderLevel::Content,
&self.block_flow.base.clip);
}
// Draw the rest of the block.
self.block_flow.build_display_list_for_block(display_list, layout_context)
}
}
trait BaseFlowDisplayListBuilding {
fn build_display_items_for_debugging_tint(&self,
display_list: &mut DisplayList,
node: OpaqueNode);
}
impl BaseFlowDisplayListBuilding for BaseFlow {
fn build_display_items_for_debugging_tint(&self,
display_list: &mut DisplayList,
node: OpaqueNode) {
if !opts::get().show_debug_parallel_layout {
return
}
let thread_id = self.thread_id;
let stacking_context_relative_bounds =
Rect(self.stacking_relative_position,
self.position.size.to_physical(self.writing_mode));
let mut color = THREAD_TINT_COLORS[thread_id as usize % THREAD_TINT_COLORS.len()];
color.a = 1.0;
display_list.push(DisplayItem::BorderClass(box BorderDisplayItem {
base: BaseDisplayItem::new(stacking_context_relative_bounds.inflate(Au::from_px(2),
Au::from_px(2)),
DisplayItemMetadata {
node: node,
pointing: None,
},
self.clip.clone()),
border_widths: SideOffsets2D::new_all_same(Au::from_px(2)),
color: SideOffsets2D::new_all_same(color),
style: SideOffsets2D::new_all_same(border_style::T::solid),
radius: BorderRadii::all_same(Au(0)),
}), StackingLevel::Content);
}
}
// A helper data structure for gradients.
#[derive(Copy)]
struct StopRun {
start_offset: f32,
end_offset: f32,
start_index: uint,
stop_count: uint,
}
fn fmin(a: f32, b: f32) -> f32 {
if a < b {
a
} else {
b
}
}
fn position_to_offset(position: LengthOrPercentage, Au(total_length): Au) -> f32 {
match position {
LengthOrPercentage::Length(Au(length)) => fmin(1.0, (length as f32) / (total_length as f32)),
LengthOrPercentage::Percentage(percentage) => percentage as f32,
}
}
/// "Steps" as defined by CSS 2.1 § E.2.
#[derive(Clone, PartialEq, Debug, Copy)]
pub enum StackingLevel {
/// The border and backgrounds for the root of this stacking context: steps 1 and 2.
BackgroundAndBorders,
/// Borders and backgrounds for block-level descendants: step 4.
BlockBackgroundsAndBorders,
/// All other content.
Content,
}
impl StackingLevel {
#[inline]
pub fn from_background_and_border_level(level: BackgroundAndBorderLevel) -> StackingLevel {
match level {
BackgroundAndBorderLevel::RootOfStackingContext => StackingLevel::BackgroundAndBorders,
BackgroundAndBorderLevel::Block => StackingLevel::BlockBackgroundsAndBorders,
BackgroundAndBorderLevel::Content => StackingLevel::Content,
}
}
}
/// Which level to place backgrounds and borders in.
pub enum BackgroundAndBorderLevel {
RootOfStackingContext,
Block,
Content,
}
trait StackingContextConstruction {
/// Adds the given display item at the specified level to this display list.
fn push(&mut self, display_item: DisplayItem, level: StackingLevel);
}
impl StackingContextConstruction for DisplayList {
fn push(&mut self, display_item: DisplayItem, level: StackingLevel) {
match level {
StackingLevel::BackgroundAndBorders => {
self.background_and_borders.push_back(display_item)
}
StackingLevel::BlockBackgroundsAndBorders => {
self.block_backgrounds_and_borders.push_back(display_item)
}
StackingLevel::Content => self.content.push_back(display_item),
}
}
}
/// Adjusts `content_rect` as necessary for the given spread, and blur so that the resulting
/// bounding rect contains all of a shadow's ink.
fn shadow_bounds(content_rect: &Rect<Au>, blur_radius: Au, spread_radius: Au) -> Rect<Au> {
let inflation = spread_radius + blur_radius * BLUR_INFLATION_FACTOR;
content_rect.inflate(inflation, inflation)
}
/// Allows a CSS color to be converted into a graphics color.
pub trait ToGfxColor {
/// Converts a CSS color to a graphics color.
fn to_gfx_color(&self) -> Color;
}
impl ToGfxColor for RGBA {
fn to_gfx_color(&self) -> Color {
color::rgba(self.red, self.green, self.blue, self.alpha)
}
}