mirror of
https://github.com/servo/servo.git
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a4a9a46a87
first-class.
This implements the scheme described here:
https://groups.google.com/forum/#!topic/mozilla.dev.servo/sZVPSfPVfkg
This commit changes Servo to generate one display list per stacking
context instead of one display list per layer. This is purely a
refactoring; there are no functional changes. Performance is essentially
the same as before. However, there should be numerous future benefits
that this is intended to allow for:
* It makes the code simpler to understand because the "new layer needed"
vs. "no new layer needed" code paths are more consolidated.
* It makes it easy to support CSS properties that did not fit into our
previous flat display list model (without unconditionally layerizing
them):
o `opacity` should be easy to support because the stacking context
provides the higher-level grouping of display items to which opacity
is to be applied.
o `transform` can be easily supported because the stacking context
provides a place to stash the transformation matrix. This has the side
benefit of nicely separating the transformation matrix from the
clipping regions.
* The `flatten` logic is now O(1) instead of O(n) and now only needs to
be invoked for pseudo-stacking contexts (right now: just floats),
instead of for every stacking context.
* Layers are now a proper tree instead of a flat list as far as layout
is concerned, bringing us closer to a production-quality
compositing/layers framework.
* This commit opens the door to incremental display list construction at
the level of stacking contexts.
Future performance improvements could come from optimizing allocation of
display list items, and, of course, incremental display list
construction.
958 lines
46 KiB
Rust
958 lines
46 KiB
Rust
/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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//! Builds display lists from flows and fragments.
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//!
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//! Other browser engines sometimes call this "painting", but it is more accurately called display
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//! list building, as the actual painting does not happen here—only deciding *what* we're going to
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//! paint.
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#![deny(unsafe_blocks)]
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use block::BlockFlow;
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use context::LayoutContext;
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use flow::{mod, Flow};
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use fragment::{Fragment, GenericFragment, IframeFragment, IframeFragmentInfo, ImageFragment};
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use fragment::{ImageFragmentInfo, InlineAbsoluteHypotheticalFragment, InlineBlockFragment};
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use fragment::{ScannedTextFragment, ScannedTextFragmentInfo, TableFragment};
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use fragment::{TableCellFragment, TableColumnFragment, TableRowFragment, TableWrapperFragment};
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use fragment::{UnscannedTextFragment};
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use model;
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use util::{OpaqueNodeMethods, ToGfxColor};
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use geom::approxeq::ApproxEq;
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use geom::{Point2D, Rect, Size2D, SideOffsets2D};
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use gfx::color;
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use gfx::display_list::{BaseDisplayItem, BorderDisplayItem, BorderDisplayItemClass, DisplayItem};
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use gfx::display_list::{DisplayList, GradientDisplayItem, GradientDisplayItemClass, GradientStop};
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use gfx::display_list::{ImageDisplayItem, ImageDisplayItemClass, LineDisplayItem};
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use gfx::display_list::{LineDisplayItemClass, PseudoDisplayItemClass, SidewaysLeft, SidewaysRight};
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use gfx::display_list::{SolidColorDisplayItem, SolidColorDisplayItemClass, StackingContext};
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use gfx::display_list::{TextDisplayItem, TextDisplayItemClass, Upright};
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use gfx::render_task::RenderLayer;
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use servo_msg::compositor_msg::{FixedPosition, Scrollable};
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use servo_msg::constellation_msg::{ConstellationChan, FrameRectMsg};
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use servo_net::image::holder::ImageHolder;
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use servo_util::geometry::{mod, Au, ZERO_POINT, ZERO_RECT};
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use servo_util::logical_geometry::{LogicalRect, WritingMode};
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use servo_util::opts;
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use style::computed::{AngleAoc, CornerAoc, LP_Length, LP_Percentage, LengthOrPercentage};
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use style::computed::{LinearGradient, LinearGradientImage, UrlImage};
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use style::computed_values::{background_attachment, background_repeat, border_style, overflow};
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use style::computed_values::{visibility};
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use style::{ComputedValues, Bottom, Left, RGBA, Right, Top};
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use sync::Arc;
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use url::Url;
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/// The results of display list building for a single flow.
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pub enum DisplayListBuildingResult {
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NoDisplayListBuildingResult,
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StackingContextResult(Arc<StackingContext>),
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DisplayListResult(Box<DisplayList>),
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}
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impl DisplayListBuildingResult {
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/// Adds the display list items contained within this display list building result to the given
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/// display list, preserving stacking order. If this display list building result does not
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/// consist of an entire stacking context, it will be emptied.
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pub fn add_to(&mut self, display_list: &mut DisplayList) {
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match *self {
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NoDisplayListBuildingResult => return,
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StackingContextResult(ref mut stacking_context) => {
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display_list.children.push_back((*stacking_context).clone())
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}
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DisplayListResult(ref mut source_display_list) => {
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display_list.append_from(&mut **source_display_list)
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}
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}
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}
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}
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pub trait FragmentDisplayListBuilding {
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/// Adds the display items necessary to paint the background of this fragment to the display
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/// list if necessary.
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fn build_display_list_for_background_if_applicable(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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layout_context: &LayoutContext,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>);
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/// Adds the display items necessary to paint the background image of this fragment to the
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/// display list at the appropriate stacking level.
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fn build_display_list_for_background_image(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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layout_context: &LayoutContext,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>,
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image_url: &Url);
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/// Adds the display items necessary to paint the background linear gradient of this fragment
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/// to the display list at the appropriate stacking level.
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fn build_display_list_for_background_linear_gradient(&self,
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display_list: &mut DisplayList,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>,
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gradient: &LinearGradient,
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style: &ComputedValues);
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/// Adds the display items necessary to paint the borders of this fragment to a display list if
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/// necessary.
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fn build_display_list_for_borders_if_applicable(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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abs_bounds: &Rect<Au>,
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level: StackingLevel,
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clip_rect: &Rect<Au>);
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fn build_debug_borders_around_text_fragments(&self,
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display_list: &mut DisplayList,
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flow_origin: Point2D<Au>,
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text_fragment: &ScannedTextFragmentInfo,
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clip_rect: &Rect<Au>);
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fn build_debug_borders_around_fragment(&self,
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display_list: &mut DisplayList,
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flow_origin: Point2D<Au>,
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clip_rect: &Rect<Au>);
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/// Adds the display items for this fragment to the given display list.
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///
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/// Arguments:
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///
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/// * `display_list`: The display list to add display items to.
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/// * `layout_context`: The layout context.
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/// * `dirty`: The dirty rectangle in the coordinate system of the owning flow.
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/// * `flow_origin`: Position of the origin of the owning flow wrt the display list root flow.
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/// * `clip_rect`: The rectangle to clip the display items to.
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fn build_display_list(&mut self,
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display_list: &mut DisplayList,
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layout_context: &LayoutContext,
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flow_origin: Point2D<Au>,
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background_and_border_level: BackgroundAndBorderLevel,
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clip_rect: &Rect<Au>);
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/// Sends the size and position of this iframe fragment to the constellation. This is out of
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/// line to guide inlining.
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fn finalize_position_and_size_of_iframe(&self,
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iframe_fragment: &IframeFragmentInfo,
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offset: Point2D<Au>,
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layout_context: &LayoutContext);
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fn clip_rect_for_children(&self, current_clip_rect: Rect<Au>, flow_origin: Point2D<Au>)
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-> Rect<Au>;
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}
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impl FragmentDisplayListBuilding for Fragment {
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fn build_display_list_for_background_if_applicable(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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layout_context: &LayoutContext,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>) {
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// FIXME: This causes a lot of background colors to be displayed when they are clearly not
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// needed. We could use display list optimization to clean this up, but it still seems
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// inefficient. What we really want is something like "nearest ancestor element that
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// doesn't have a fragment".
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let background_color = style.resolve_color(style.get_background().background_color);
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if !background_color.alpha.approx_eq(&0.0) {
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display_list.push(SolidColorDisplayItemClass(box SolidColorDisplayItem {
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base: BaseDisplayItem::new(*absolute_bounds, self.node, *clip_rect),
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color: background_color.to_gfx_color(),
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}), level);
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}
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// The background image is painted on top of the background color.
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// Implements background image, per spec:
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// http://www.w3.org/TR/CSS21/colors.html#background
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let background = style.get_background();
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match background.background_image {
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None => {}
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Some(LinearGradientImage(ref gradient)) => {
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self.build_display_list_for_background_linear_gradient(display_list,
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level,
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absolute_bounds,
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clip_rect,
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gradient,
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style)
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}
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Some(UrlImage(ref image_url)) => {
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self.build_display_list_for_background_image(style,
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display_list,
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layout_context,
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level,
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absolute_bounds,
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clip_rect,
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image_url)
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}
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}
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}
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fn build_display_list_for_background_image(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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layout_context: &LayoutContext,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>,
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image_url: &Url) {
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let background = style.get_background();
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let mut holder = ImageHolder::new(image_url.clone(),
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layout_context.shared.image_cache.clone());
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let image = match holder.get_image(self.node.to_untrusted_node_address()) {
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None => {
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// No image data at all? Do nothing.
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//
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// TODO: Add some kind of placeholder background image.
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debug!("(building display list) no background image :(");
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return
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}
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Some(image) => image,
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};
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debug!("(building display list) building background image");
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let image_width = Au::from_px(image.width as int);
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let image_height = Au::from_px(image.height as int);
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let mut bounds = *absolute_bounds;
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// Clip.
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//
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// TODO: Check the bounds to see if a clip item is actually required.
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let clip_rect = clip_rect.intersection(&bounds).unwrap_or(ZERO_RECT);
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// Use background-attachment to get the initial virtual origin
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let (virtual_origin_x, virtual_origin_y) = match background.background_attachment {
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background_attachment::scroll => {
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(absolute_bounds.origin.x, absolute_bounds.origin.y)
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}
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background_attachment::fixed => {
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(Au(0), Au(0))
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}
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};
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// Use background-position to get the offset
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let horizontal_position = model::specified(background.background_position.horizontal,
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bounds.size.width - image_width);
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let vertical_position = model::specified(background.background_position.vertical,
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bounds.size.height - image_height);
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let abs_x = virtual_origin_x + horizontal_position;
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let abs_y = virtual_origin_y + vertical_position;
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// Adjust origin and size based on background-repeat
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match background.background_repeat {
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background_repeat::no_repeat => {
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bounds.origin.x = abs_x;
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bounds.origin.y = abs_y;
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bounds.size.width = image_width;
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bounds.size.height = image_height;
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}
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background_repeat::repeat_x => {
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bounds.origin.y = abs_y;
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bounds.size.height = image_height;
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ImageFragmentInfo::tile_image(&mut bounds.origin.x, &mut bounds.size.width,
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abs_x, image.width);
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}
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background_repeat::repeat_y => {
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bounds.origin.x = abs_x;
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bounds.size.width = image_width;
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ImageFragmentInfo::tile_image(&mut bounds.origin.y, &mut bounds.size.height,
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abs_y, image.height);
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}
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background_repeat::repeat => {
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ImageFragmentInfo::tile_image(&mut bounds.origin.x, &mut bounds.size.width,
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abs_x, image.width);
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ImageFragmentInfo::tile_image(&mut bounds.origin.y, &mut bounds.size.height,
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abs_y, image.height);
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}
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};
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// Create the image display item.
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display_list.push(ImageDisplayItemClass(box ImageDisplayItem {
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base: BaseDisplayItem::new(bounds, self.node, clip_rect),
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image: image.clone(),
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stretch_size: Size2D(Au::from_px(image.width as int),
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Au::from_px(image.height as int)),
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}), level);
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}
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fn build_display_list_for_background_linear_gradient(&self,
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display_list: &mut DisplayList,
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level: StackingLevel,
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absolute_bounds: &Rect<Au>,
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clip_rect: &Rect<Au>,
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gradient: &LinearGradient,
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style: &ComputedValues) {
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let clip_rect = clip_rect.intersection(absolute_bounds).unwrap_or(ZERO_RECT);
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// This is the distance between the center and the ending point; i.e. half of the distance
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// between the starting point and the ending point.
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let delta = match gradient.angle_or_corner {
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AngleAoc(angle) => {
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Point2D(Au((angle.radians().sin() *
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absolute_bounds.size.width.to_f64().unwrap() / 2.0) as i32),
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Au((-angle.radians().cos() *
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absolute_bounds.size.height.to_f64().unwrap() / 2.0) as i32))
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}
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CornerAoc(horizontal, vertical) => {
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let x_factor = match horizontal {
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Left => -1,
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Right => 1,
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};
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let y_factor = match vertical {
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Top => -1,
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Bottom => 1,
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};
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Point2D(Au(x_factor * absolute_bounds.size.width.to_i32().unwrap() / 2),
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Au(y_factor * absolute_bounds.size.height.to_i32().unwrap() / 2))
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}
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};
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// This is the length of the gradient line.
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let length = Au((delta.x.to_f64().unwrap() * 2.0).hypot(delta.y.to_f64().unwrap() * 2.0)
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as i32);
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// Determine the position of each stop per CSS-IMAGES § 3.4.
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//
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// FIXME(#3908, pcwalton): Make sure later stops can't be behind earlier stops.
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let (mut stops, mut stop_run) = (Vec::new(), None);
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for (i, stop) in gradient.stops.iter().enumerate() {
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let offset = match stop.position {
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None => {
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if stop_run.is_none() {
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// Initialize a new stop run.
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let start_offset = if i == 0 {
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0.0
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} else {
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// `unwrap()` here should never fail because this is the beginning of
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// a stop run, which is always bounded by a length or percentage.
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position_to_offset(gradient.stops[i - 1].position.unwrap(), length)
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};
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let (end_index, end_offset) =
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match gradient.stops
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.as_slice()
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.slice_from(i)
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.iter()
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.enumerate()
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.find(|&(_, ref stop)| stop.position.is_some()) {
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None => (gradient.stops.len() - 1, 1.0),
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Some((end_index, end_stop)) => {
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// `unwrap()` here should never fail because this is the end of
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// a stop run, which is always bounded by a length or
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// percentage.
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(end_index,
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position_to_offset(end_stop.position.unwrap(), length))
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}
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};
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stop_run = Some(StopRun {
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start_offset: start_offset,
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end_offset: end_offset,
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start_index: i,
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stop_count: end_index - i,
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})
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}
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let stop_run = stop_run.unwrap();
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let stop_run_length = stop_run.end_offset - stop_run.start_offset;
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if stop_run.stop_count == 0 {
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stop_run.end_offset
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} else {
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stop_run.start_offset +
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stop_run_length * (i - stop_run.start_index) as f32 /
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(stop_run.stop_count as f32)
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}
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}
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Some(position) => {
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stop_run = None;
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position_to_offset(position, length)
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}
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};
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stops.push(GradientStop {
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offset: offset,
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color: style.resolve_color(stop.color).to_gfx_color()
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})
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}
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let center = Point2D(absolute_bounds.origin.x + absolute_bounds.size.width / 2,
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absolute_bounds.origin.y + absolute_bounds.size.height / 2);
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let gradient_display_item = GradientDisplayItemClass(box GradientDisplayItem {
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base: BaseDisplayItem::new(*absolute_bounds, self.node, clip_rect),
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start_point: center - delta,
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end_point: center + delta,
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stops: stops,
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});
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display_list.push(gradient_display_item, level)
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}
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fn build_display_list_for_borders_if_applicable(&self,
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style: &ComputedValues,
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display_list: &mut DisplayList,
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abs_bounds: &Rect<Au>,
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level: StackingLevel,
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clip_rect: &Rect<Au>) {
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let border = style.logical_border_width();
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if border.is_zero() {
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return
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}
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let top_color = style.resolve_color(style.get_border().border_top_color);
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let right_color = style.resolve_color(style.get_border().border_right_color);
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let bottom_color = style.resolve_color(style.get_border().border_bottom_color);
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let left_color = style.resolve_color(style.get_border().border_left_color);
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// Append the border to the display list.
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display_list.push(BorderDisplayItemClass(box BorderDisplayItem {
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base: BaseDisplayItem::new(*abs_bounds, self.node, *clip_rect),
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border: border.to_physical(style.writing_mode),
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color: SideOffsets2D::new(top_color.to_gfx_color(),
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right_color.to_gfx_color(),
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bottom_color.to_gfx_color(),
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left_color.to_gfx_color()),
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style: SideOffsets2D::new(style.get_border().border_top_style,
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style.get_border().border_right_style,
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style.get_border().border_bottom_style,
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style.get_border().border_left_style)
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}), level);
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}
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fn build_debug_borders_around_text_fragments(&self,
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display_list: &mut DisplayList,
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flow_origin: Point2D<Au>,
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text_fragment: &ScannedTextFragmentInfo,
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clip_rect: &Rect<Au>) {
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// FIXME(#2795): Get the real container size
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let container_size = Size2D::zero();
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// Fragment position wrt to the owning flow.
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let fragment_bounds = self.border_box.to_physical(self.style.writing_mode, container_size);
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let absolute_fragment_bounds = Rect(
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fragment_bounds.origin + flow_origin,
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fragment_bounds.size);
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// Compute the text fragment bounds and draw a border surrounding them.
|
|
display_list.content.push_back(BorderDisplayItemClass(box BorderDisplayItem {
|
|
base: BaseDisplayItem::new(absolute_fragment_bounds, self.node, *clip_rect),
|
|
border: 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::solid)
|
|
}));
|
|
|
|
// Draw a rectangle representing the baselines.
|
|
let ascent = text_fragment.run.ascent();
|
|
let mut baseline = self.border_box.clone();
|
|
baseline.start.b = baseline.start.b + ascent;
|
|
baseline.size.block = Au(0);
|
|
let mut baseline = baseline.to_physical(self.style.writing_mode, container_size);
|
|
baseline.origin = baseline.origin + flow_origin;
|
|
|
|
let line_display_item = box LineDisplayItem {
|
|
base: BaseDisplayItem::new(baseline, self.node, *clip_rect),
|
|
color: color::rgb(0, 200, 0),
|
|
style: border_style::dashed,
|
|
};
|
|
display_list.content.push_back(LineDisplayItemClass(line_display_item));
|
|
}
|
|
|
|
fn build_debug_borders_around_fragment(&self,
|
|
display_list: &mut DisplayList,
|
|
flow_origin: Point2D<Au>,
|
|
clip_rect: &Rect<Au>) {
|
|
// FIXME(#2795): Get the real container size
|
|
let container_size = Size2D::zero();
|
|
// Fragment position wrt to the owning flow.
|
|
let fragment_bounds = self.border_box.to_physical(self.style.writing_mode, container_size);
|
|
let absolute_fragment_bounds = Rect(
|
|
fragment_bounds.origin + flow_origin,
|
|
fragment_bounds.size);
|
|
|
|
// This prints a debug border around the border of this fragment.
|
|
display_list.content.push_back(BorderDisplayItemClass(box BorderDisplayItem {
|
|
base: BaseDisplayItem::new(absolute_fragment_bounds, self.node, *clip_rect),
|
|
border: 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::solid)
|
|
}));
|
|
}
|
|
|
|
fn build_display_list(&mut self,
|
|
display_list: &mut DisplayList,
|
|
layout_context: &LayoutContext,
|
|
flow_origin: Point2D<Au>,
|
|
background_and_border_level: BackgroundAndBorderLevel,
|
|
clip_rect: &Rect<Au>) {
|
|
// 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_flow_origin = if self.establishes_stacking_context() {
|
|
ZERO_POINT
|
|
} else {
|
|
flow_origin
|
|
};
|
|
let absolute_fragment_bounds =
|
|
self.stacking_relative_bounds(&stacking_relative_flow_origin);
|
|
|
|
// FIXME(#2795): Get the real container size
|
|
let container_size = Size2D::zero();
|
|
let rect_to_absolute = |writing_mode: WritingMode, logical_rect: LogicalRect<Au>| {
|
|
let physical_rect = logical_rect.to_physical(writing_mode, container_size);
|
|
Rect(physical_rect.origin + stacking_relative_flow_origin, physical_rect.size)
|
|
};
|
|
|
|
debug!("Fragment::build_display_list at rel={}, abs={}: {}",
|
|
self.border_box,
|
|
absolute_fragment_bounds,
|
|
self);
|
|
debug!("Fragment::build_display_list: dirty={}, flow_origin={}",
|
|
layout_context.shared.dirty,
|
|
flow_origin);
|
|
|
|
if self.style().get_inheritedbox().visibility != visibility::visible {
|
|
return
|
|
}
|
|
|
|
if !absolute_fragment_bounds.intersects(&layout_context.shared.dirty) {
|
|
debug!("Fragment::build_display_list: Did not intersect...");
|
|
return
|
|
}
|
|
|
|
if !absolute_fragment_bounds.intersects(clip_rect) {
|
|
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 a pseudo-display item for content box queries. This is a very bogus thing to do.
|
|
let base_display_item = box BaseDisplayItem::new(absolute_fragment_bounds,
|
|
self.node,
|
|
*clip_rect);
|
|
display_list.push(PseudoDisplayItemClass(base_display_item), level);
|
|
|
|
// Add the background to the list, if applicable.
|
|
match self.inline_context {
|
|
Some(ref inline_context) => {
|
|
for style in inline_context.styles.iter().rev() {
|
|
self.build_display_list_for_background_if_applicable(
|
|
&**style,
|
|
display_list,
|
|
layout_context,
|
|
level,
|
|
&absolute_fragment_bounds,
|
|
clip_rect);
|
|
}
|
|
}
|
|
None => {}
|
|
}
|
|
match self.specific {
|
|
ScannedTextFragment(_) => {},
|
|
_ => {
|
|
self.build_display_list_for_background_if_applicable(
|
|
&*self.style,
|
|
display_list,
|
|
layout_context,
|
|
level,
|
|
&absolute_fragment_bounds,
|
|
clip_rect);
|
|
}
|
|
}
|
|
|
|
// Add a border, if applicable.
|
|
//
|
|
// TODO: Outlines.
|
|
match self.inline_context {
|
|
Some(ref inline_context) => {
|
|
for style in inline_context.styles.iter().rev() {
|
|
self.build_display_list_for_borders_if_applicable(
|
|
&**style,
|
|
display_list,
|
|
&absolute_fragment_bounds,
|
|
level,
|
|
clip_rect);
|
|
}
|
|
}
|
|
None => {}
|
|
}
|
|
match self.specific {
|
|
ScannedTextFragment(_) => {},
|
|
_ => {
|
|
self.build_display_list_for_borders_if_applicable(
|
|
&*self.style,
|
|
display_list,
|
|
&absolute_fragment_bounds,
|
|
level,
|
|
clip_rect);
|
|
}
|
|
}
|
|
}
|
|
|
|
let content_box = self.content_box();
|
|
let absolute_content_box = rect_to_absolute(self.style.writing_mode, content_box);
|
|
|
|
// Create special per-fragment-type display items.
|
|
match self.specific {
|
|
UnscannedTextFragment(_) => panic!("Shouldn't see unscanned fragments here."),
|
|
TableColumnFragment(_) => panic!("Shouldn't see table column fragments here."),
|
|
ScannedTextFragment(ref text_fragment) => {
|
|
// Create the text display item.
|
|
let orientation = if self.style.writing_mode.is_vertical() {
|
|
if self.style.writing_mode.is_sideways_left() {
|
|
SidewaysLeft
|
|
} else {
|
|
SidewaysRight
|
|
}
|
|
} else {
|
|
Upright
|
|
};
|
|
|
|
let metrics = &text_fragment.run.font_metrics;
|
|
let baseline_origin = {
|
|
let mut content_box_start = content_box.start;
|
|
content_box_start.b = content_box_start.b + metrics.ascent;
|
|
content_box_start.to_physical(self.style.writing_mode, container_size)
|
|
+ flow_origin
|
|
};
|
|
|
|
display_list.content.push_back(TextDisplayItemClass(box TextDisplayItem {
|
|
base: BaseDisplayItem::new(absolute_content_box, self.node, *clip_rect),
|
|
text_run: text_fragment.run.clone(),
|
|
range: text_fragment.range,
|
|
text_color: self.style().get_color().color.to_gfx_color(),
|
|
orientation: orientation,
|
|
baseline_origin: baseline_origin,
|
|
}));
|
|
|
|
// Create display items for text decoration
|
|
{
|
|
let line = |maybe_color: Option<RGBA>, rect: || -> LogicalRect<Au>| {
|
|
match maybe_color {
|
|
None => {}
|
|
Some(color) => {
|
|
let bounds = rect_to_absolute(self.style.writing_mode, rect());
|
|
display_list.content.push_back(SolidColorDisplayItemClass(
|
|
box SolidColorDisplayItem {
|
|
base: BaseDisplayItem::new(bounds, self.node, *clip_rect),
|
|
color: color.to_gfx_color(),
|
|
}))
|
|
}
|
|
}
|
|
};
|
|
|
|
let text_decorations =
|
|
self.style().get_inheritedtext()._servo_text_decorations_in_effect;
|
|
line(text_decorations.underline, || {
|
|
let mut rect = content_box.clone();
|
|
rect.start.b = rect.start.b + metrics.ascent - metrics.underline_offset;
|
|
rect.size.block = metrics.underline_size;
|
|
rect
|
|
});
|
|
|
|
line(text_decorations.overline, || {
|
|
let mut rect = content_box.clone();
|
|
rect.size.block = metrics.underline_size;
|
|
rect
|
|
});
|
|
|
|
line(text_decorations.line_through, || {
|
|
let mut rect = content_box.clone();
|
|
rect.start.b = rect.start.b + metrics.ascent - metrics.strikeout_offset;
|
|
rect.size.block = metrics.strikeout_size;
|
|
rect
|
|
});
|
|
}
|
|
|
|
if opts::get().show_debug_fragment_borders {
|
|
self.build_debug_borders_around_text_fragments(display_list,
|
|
flow_origin,
|
|
&**text_fragment,
|
|
clip_rect);
|
|
}
|
|
}
|
|
GenericFragment | IframeFragment(..) | TableFragment | TableCellFragment |
|
|
TableRowFragment | TableWrapperFragment | InlineBlockFragment(_) |
|
|
InlineAbsoluteHypotheticalFragment(_) => {
|
|
if opts::get().show_debug_fragment_borders {
|
|
self.build_debug_borders_around_fragment(display_list,
|
|
flow_origin,
|
|
clip_rect);
|
|
}
|
|
}
|
|
ImageFragment(ref mut image_fragment) => {
|
|
let image_ref = &mut image_fragment.image;
|
|
match image_ref.get_image(self.node.to_untrusted_node_address()) {
|
|
Some(image) => {
|
|
debug!("(building display list) building image fragment");
|
|
|
|
// Place the image into the display list.
|
|
display_list.content.push_back(ImageDisplayItemClass(box ImageDisplayItem {
|
|
base: BaseDisplayItem::new(absolute_content_box,
|
|
self.node,
|
|
*clip_rect),
|
|
image: image.clone(),
|
|
stretch_size: absolute_content_box.size,
|
|
}));
|
|
}
|
|
None => {
|
|
// No image data at all? Do nothing.
|
|
//
|
|
// TODO: Add some kind of placeholder image.
|
|
debug!("(building display list) no image :(");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if opts::get().show_debug_fragment_borders {
|
|
self.build_debug_borders_around_fragment(display_list,
|
|
flow_origin,
|
|
clip_rect)
|
|
}
|
|
|
|
// 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.
|
|
match self.specific {
|
|
IframeFragment(ref iframe_fragment) => {
|
|
self.finalize_position_and_size_of_iframe(&**iframe_fragment,
|
|
absolute_fragment_bounds.origin,
|
|
layout_context)
|
|
}
|
|
_ => {}
|
|
}
|
|
}
|
|
|
|
#[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(FrameRectMsg(iframe_fragment.pipeline_id,
|
|
iframe_fragment.subpage_id,
|
|
iframe_rect));
|
|
}
|
|
|
|
fn clip_rect_for_children(&self, current_clip_rect: Rect<Au>, flow_origin: Point2D<Au>)
|
|
-> Rect<Au> {
|
|
// Don't clip if we're text.
|
|
match self.specific {
|
|
ScannedTextFragment(_) => return current_clip_rect,
|
|
_ => {}
|
|
}
|
|
|
|
// Only clip if `overflow` tells us to.
|
|
match self.style.get_box().overflow {
|
|
overflow::hidden | overflow::auto | overflow::scroll => {}
|
|
_ => return current_clip_rect,
|
|
}
|
|
|
|
// Create a new clip rect.
|
|
//
|
|
// FIXME(#2795): Get the real container size.
|
|
let physical_rect = self.border_box.to_physical(self.style.writing_mode, Size2D::zero());
|
|
current_clip_rect.intersection(&Rect(physical_rect.origin + flow_origin,
|
|
physical_rect.size)).unwrap_or(ZERO_RECT)
|
|
}
|
|
}
|
|
|
|
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_block(&mut self,
|
|
layout_context: &LayoutContext,
|
|
background_border_level: BackgroundAndBorderLevel);
|
|
fn build_display_list_for_absolutely_positioned_block(&mut self,
|
|
layout_context: &LayoutContext);
|
|
fn build_display_list_for_floating_block(&mut self, layout_context: &LayoutContext);
|
|
}
|
|
|
|
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.
|
|
let stacking_relative_fragment_origin =
|
|
self.base.stacking_relative_position_of_child_fragment(&self.fragment);
|
|
self.fragment.build_display_list(display_list,
|
|
layout_context,
|
|
stacking_relative_fragment_origin,
|
|
background_border_level,
|
|
&self.base.clip_rect);
|
|
|
|
for kid in self.base.children.iter_mut() {
|
|
if flow::base(kid).flags.is_absolutely_positioned() {
|
|
// All absolute flows will be handled by their containing block.
|
|
continue
|
|
}
|
|
|
|
flow::mut_base(kid).display_list_building_result.add_to(display_list);
|
|
}
|
|
|
|
// Process absolute descendant links.
|
|
for abs_descendant_link in self.base.abs_descendants.iter() {
|
|
// TODO(pradeep): Send in our absolute position directly.
|
|
flow::mut_base(abs_descendant_link).display_list_building_result.add_to(display_list);
|
|
}
|
|
}
|
|
|
|
fn build_display_list_for_block(&mut self,
|
|
layout_context: &LayoutContext,
|
|
background_border_level: BackgroundAndBorderLevel) {
|
|
let mut display_list = box DisplayList::new();
|
|
self.build_display_list_for_block_base(&mut *display_list,
|
|
layout_context,
|
|
background_border_level);
|
|
self.base.display_list_building_result = DisplayListResult(display_list);
|
|
}
|
|
|
|
fn build_display_list_for_absolutely_positioned_block(&mut self,
|
|
layout_context: &LayoutContext) {
|
|
let mut display_list = box DisplayList::new();
|
|
self.build_display_list_for_block_base(&mut *display_list,
|
|
layout_context,
|
|
RootOfStackingContextLevel);
|
|
|
|
let bounds = Rect(self.base.stacking_relative_position,
|
|
self.base.overflow.size.to_physical(self.base.writing_mode));
|
|
let z_index = self.fragment.style().get_box().z_index.number_or_zero();
|
|
|
|
if !self.base.absolute_position_info.layers_needed_for_positioned_flows &&
|
|
!self.base.flags.needs_layer() {
|
|
// We didn't need a layer.
|
|
self.base.display_list_building_result =
|
|
StackingContextResult(Arc::new(StackingContext::new(display_list,
|
|
bounds,
|
|
z_index,
|
|
None)));
|
|
return
|
|
}
|
|
|
|
// If we got here, then we need a new layer.
|
|
let scroll_policy = if self.is_fixed() {
|
|
FixedPosition
|
|
} else {
|
|
Scrollable
|
|
};
|
|
|
|
let transparent = color::rgba(1.0, 1.0, 1.0, 0.0);
|
|
let stacking_context =
|
|
Arc::new(StackingContext::new(display_list,
|
|
bounds,
|
|
z_index,
|
|
Some(Arc::new(RenderLayer::new(self.layer_id(0),
|
|
transparent,
|
|
scroll_policy)))));
|
|
|
|
self.base.display_list_building_result = StackingContextResult(stacking_context)
|
|
}
|
|
|
|
fn build_display_list_for_floating_block(&mut self, layout_context: &LayoutContext) {
|
|
let mut display_list = box DisplayList::new();
|
|
self.build_display_list_for_block_base(&mut *display_list,
|
|
layout_context,
|
|
RootOfStackingContextLevel);
|
|
display_list.form_float_pseudo_stacking_context();
|
|
self.base.display_list_building_result = DisplayListResult(display_list);
|
|
}
|
|
}
|
|
|
|
// A helper data structure for gradients.
|
|
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 {
|
|
LP_Length(Au(length)) => fmin(1.0, (length as f32) / (total_length as f32)),
|
|
LP_Percentage(percentage) => percentage as f32,
|
|
}
|
|
}
|
|
|
|
/// "Steps" as defined by CSS 2.1 § E.2.
|
|
#[deriving(Clone, PartialEq, Show)]
|
|
pub enum StackingLevel {
|
|
/// The border and backgrounds for the root of this stacking context: steps 1 and 2.
|
|
BackgroundAndBordersStackingLevel,
|
|
/// Borders and backgrounds for block-level descendants: step 4.
|
|
BlockBackgroundsAndBordersStackingLevel,
|
|
/// All other content.
|
|
ContentStackingLevel,
|
|
}
|
|
|
|
impl StackingLevel {
|
|
#[inline]
|
|
pub fn from_background_and_border_level(level: BackgroundAndBorderLevel) -> StackingLevel {
|
|
match level {
|
|
RootOfStackingContextLevel => BackgroundAndBordersStackingLevel,
|
|
BlockLevel => BlockBackgroundsAndBordersStackingLevel,
|
|
ContentLevel => ContentStackingLevel,
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Which level to place backgrounds and borders in.
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pub enum BackgroundAndBorderLevel {
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RootOfStackingContextLevel,
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BlockLevel,
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ContentLevel,
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}
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trait StackingContextConstruction {
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/// Adds the given display item at the specified level to this display list.
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fn push(&mut self, display_item: DisplayItem, level: StackingLevel);
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}
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impl StackingContextConstruction for DisplayList {
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fn push(&mut self, display_item: DisplayItem, level: StackingLevel) {
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match level {
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BackgroundAndBordersStackingLevel => {
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self.background_and_borders.push_back(display_item)
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}
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BlockBackgroundsAndBordersStackingLevel => {
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self.block_backgrounds_and_borders.push_back(display_item)
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}
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ContentStackingLevel => self.content.push_back(display_item),
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}
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}
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}
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