/* 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_msg::{CanvasMsg, CanvasCommonMsg}; 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 table_cell::CollapsedBordersForCell; 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 msg::compositor_msg::ScrollPolicy; use msg::constellation_msg::ConstellationChan; use msg::constellation_msg::Msg as ConstellationMsg; use png::{self, PixelsByColorType}; use std::cmp; use std::default::Default; use std::iter::repeat; use std::num::Float; use std::num::ToPrimitive; use std::sync::Arc; use std::sync::mpsc::channel; 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::ComputedValues; use style::properties::style_structs::Border; use style::values::RGBA; use style::values::computed::{Image, LinearGradient, LengthOrPercentage, LengthOrPercentageOrAuto}; use style::values::specified::{AngleOrCorner, HorizontalDirection, VerticalDirection}; use url::Url; 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; /// The results of display list building for a single flow. pub enum DisplayListBuildingResult { None, StackingContext(Arc), Normal(Box), } 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, 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, image: &png::Image) -> Size2D; /// 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, 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, 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, border_painting_mode: BorderPaintingMode, display_list: &mut DisplayList, bounds: &Rect, 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, 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, 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, stacking_relative_content_box: &Rect, 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, 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, relative_containing_block_size: &LogicalSize, relative_containing_block_mode: WritingMode, border_painting_mode: BorderPaintingMode, 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, 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) -> 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) -> 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, shadow_blur_radius: Option, offset: &Point2D, 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, 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, clip: &ClippingRegion); /// Creates a stacking context for associated fragment. fn create_stacking_context(&self, base_flow: &BaseFlow, display_list: Box, layer: Option>) -> Arc; } fn handle_overlapping_radii(size: &Size2D, radii: &BorderRadii) -> BorderRadii { // 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, border_style: &Border) -> BorderRadii { // 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, 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, image: &png::Image) -> Size2D { // 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 isize), Au::from_px(image.height as isize)); 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, clip: &ClippingRegion, image_url: &Url) { let background = style.get_background(); let image = layout_context.get_or_request_image(image_url.clone()); if let 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, 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, 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, border_painting_mode: BorderPaintingMode, display_list: &mut DisplayList, bounds: &Rect, level: StackingLevel, clip: &ClippingRegion) { let mut border = style.logical_border_width(); match border_painting_mode { BorderPaintingMode::Separate => {} BorderPaintingMode::Collapse(collapsed_borders) => { collapsed_borders.adjust_border_widths_for_painting(&mut border) } BorderPaintingMode::Hidden => return, } if border.is_zero() { return } let border_style_struct = style.get_border(); let mut colors = SideOffsets2D::new(border_style_struct.border_top_color, border_style_struct.border_right_color, border_style_struct.border_bottom_color, border_style_struct.border_left_color); let mut border_style = SideOffsets2D::new(border_style_struct.border_top_style, border_style_struct.border_right_style, border_style_struct.border_bottom_style, border_style_struct.border_left_style); if let BorderPaintingMode::Collapse(collapsed_borders) = border_painting_mode { collapsed_borders.adjust_border_colors_and_styles_for_painting(&mut colors, &mut border_style, style.writing_mode); } let colors = SideOffsets2D::new(style.resolve_color(colors.top), style.resolve_color(colors.right), style.resolve_color(colors.bottom), style.resolve_color(colors.left)); // If this border collapses, then we draw outside the boundaries we were given. let mut bounds = *bounds; if let BorderPaintingMode::Collapse(collapsed_borders) = border_painting_mode { collapsed_borders.adjust_border_bounds_for_painting(&mut bounds, style.writing_mode) } // Append the border to the display list. display_list.push(DisplayItem::BorderClass(box BorderDisplayItem { base: BaseDisplayItem::new(bounds, DisplayItemMetadata::new(self.node, style, Cursor::DefaultCursor), (*clip).clone()), border_widths: border.to_physical(style.writing_mode), color: SideOffsets2D::new(colors.top.to_gfx_color(), colors.right.to_gfx_color(), colors.bottom.to_gfx_color(), colors.left.to_gfx_color()), style: border_style, radius: build_border_radius(&bounds, border_style_struct), }), level); } fn build_display_list_for_outline_if_applicable(&self, style: &ComputedValues, display_list: &mut DisplayList, bounds: &Rect, 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, stacking_relative_content_box: &Rect, 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, 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) -> 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, relative_containing_block_size: &LogicalSize, relative_containing_block_mode: WritingMode, border_painting_mode: BorderPaintingMode, background_and_border_level: BackgroundAndBorderLevel, clip: &ClippingRegion) { if self.style().get_inheritedbox().visibility != visibility::T::visible { return } // 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 !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, border_painting_mode, 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, border_painting_mode, 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, 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) => { // Place the image into the display list. if let Some(ref image) = image_fragment.image { 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(), })); } } 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 usize); let height = canvas_fragment_info.replaced_image_fragment_info .computed_block_size.map_or(0, |h| to_px(h) as usize); let (sender, receiver) = channel::>(); let canvas_data = match canvas_fragment_info.renderer { Some(ref renderer) => { renderer.lock().unwrap().send(CanvasMsg::Common(CanvasCommonMsg::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(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.") } } } fn create_stacking_context(&self, base_flow: &BaseFlow, display_list: Box, layer: Option>) -> Arc { let border_box = self.stacking_relative_border_box(&base_flow.stacking_relative_position, &base_flow.absolute_position_info .relative_containing_block_size, base_flow.absolute_position_info .relative_containing_block_mode, CoordinateSystem::Parent); let transform_origin = self.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.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.margin.to_physical(base_flow.writing_mode); let overflow = base_flow.overflow.translate(&-Point2D(margin.left, Au(0))); // Create the filter pipeline. let effects = self.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.style().get_box().z_index.number_or_zero(), &transform, filters, self.style().get_effects().mix_blend_mode, layer)) } #[inline(never)] fn finalize_position_and_size_of_iframe(&self, iframe_fragment: &IframeFragmentInfo, offset: Point2D, 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) -> 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: ` 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, shadow_blur_radius: Option, offset: &Point2D, 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, 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, border_painting_mode: BorderPaintingMode, background_border_level: BackgroundAndBorderLevel); fn build_display_list_for_static_block(&mut self, display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode, background_border_level: BackgroundAndBorderLevel); fn build_display_list_for_absolutely_positioned_block( &mut self, display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode); fn build_display_list_for_floating_block(&mut self, display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode); fn build_display_list_for_block(&mut self, display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode); } impl BlockFlowDisplayListBuilding for BlockFlow { fn build_display_list_for_block_base(&mut self, display_list: &mut DisplayList, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode, background_border_level: BackgroundAndBorderLevel) { // Add the box that starts the block context. let clip = if self.fragment.establishes_stacking_context() { self.base.clip.translate(&-self.base.stacking_relative_position) } else { self.base.clip.clone() }; 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, border_painting_mode, background_border_level, &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, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode, background_border_level: BackgroundAndBorderLevel) { self.build_display_list_for_block_base(&mut *display_list, layout_context, border_painting_mode, background_border_level); self.base.display_list_building_result = if self.fragment.establishes_stacking_context() { DisplayListBuildingResult::StackingContext(self.fragment.create_stacking_context(&self.base, display_list, None)) } else { DisplayListBuildingResult::Normal(display_list) } } fn build_display_list_for_absolutely_positioned_block( &mut self, mut display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode) { self.build_display_list_for_block_base(&mut *display_list, layout_context, border_painting_mode, 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.fragment .create_stacking_context(&self.base, 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::transparent(); let stacking_context = self.fragment.create_stacking_context(&self.base, 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, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode) { self.build_display_list_for_block_base(&mut *display_list, layout_context, border_painting_mode, BackgroundAndBorderLevel::RootOfStackingContext); display_list.form_float_pseudo_stacking_context(); self.base.display_list_building_result = if self.fragment.establishes_stacking_context() { DisplayListBuildingResult::StackingContext(self.fragment .create_stacking_context(&self.base, display_list, None)) } else { DisplayListBuildingResult::Normal(display_list) } } fn build_display_list_for_block(&mut self, display_list: Box, layout_context: &LayoutContext, border_painting_mode: BorderPaintingMode) { 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, border_painting_mode); } else if self.base.flags.contains(IS_ABSOLUTELY_POSITIONED) { self.build_display_list_for_absolutely_positioned_block(display_list, layout_context, border_painting_mode); } else { self.build_display_list_for_static_block(display_list, layout_context, border_painting_mode, BackgroundAndBorderLevel::Block); } } } 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(); let mut has_stacking_context = false; 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, BorderPaintingMode::Separate, BackgroundAndBorderLevel::Content, &self.base.clip); has_stacking_context = fragment.establishes_stacking_context(); 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); } // FIXME(Savago): fix Fragment::establishes_stacking_context() for absolute positioned item // and remove the check for filter presence. Further details on #5812. if has_stacking_context && !self.fragments.fragments[0].style().get_effects().filter.is_empty() { self.base.display_list_building_result = DisplayListBuildingResult::StackingContext(self.fragments.fragments[0].create_stacking_context(&self.base, display_list, None)); } else { 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, layout_context: &LayoutContext); } impl ListItemFlowDisplayListBuilding for ListItemFlow { fn build_display_list_for_list_item(&mut self, mut display_list: Box, 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, BorderPaintingMode::Separate, 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, BorderPaintingMode::Separate) } } 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: usize, stop_count: usize, } 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, blur_radius: Au, spread_radius: Au) -> Rect { 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) } } /// Describes how to paint the borders. #[derive(Copy, Clone)] pub enum BorderPaintingMode<'a> { /// Paint borders separately (`border-collapse: separate`). Separate, /// Paint collapsed borders. Collapse(&'a CollapsedBordersForCell), /// Paint no borders. Hidden, }