Propagate text decoration where needed

components/layout_2020/display_list/mod.rs

@@ -133,7 +133,7 @@ impl Fragment {
 
         // Underline.
         if fragment
-            .text_decorations_in_effect
+            .text_decoration_line
             .contains(TextDecorationLine::UNDERLINE)
         {
             let mut rect = rect;
@@ -144,7 +144,7 @@ impl Fragment {
 
         // Overline.
         if fragment
-            .text_decorations_in_effect
+            .text_decoration_line
             .contains(TextDecorationLine::OVERLINE)
         {
             let mut rect = rect;
@@ -164,7 +164,7 @@ impl Fragment {
 
         // Line-through.
         if fragment
-            .text_decorations_in_effect
+            .text_decoration_line
             .contains(TextDecorationLine::LINE_THROUGH)
         {
             let mut rect = rect;

components/layout_2020/flow/construct.rs

@@ -19,6 +19,7 @@ use servo_arc::Arc;
 use std::convert::{TryFrom, TryInto};
 use style::properties::ComputedValues;
 use style::selector_parser::PseudoElement;
+use style::values::specified::text::TextDecorationLine;
 
 impl BlockFormattingContext {
     pub fn construct<'dom>(
@@ -27,9 +28,16 @@ impl BlockFormattingContext {
         style: &Arc<ComputedValues>,
         contents: NonReplacedContents,
         content_sizes: ContentSizesRequest,
+        propagated_text_decoration_line: TextDecorationLine,
     ) -> (Self, BoxContentSizes) {
-        let (contents, contains_floats, inline_content_sizes) =
+        let (contents, contains_floats, inline_content_sizes) = BlockContainer::construct(
-            BlockContainer::construct(context, node, style, contents, content_sizes);
+            context,
+            node,
+            style,
+            contents,
+            content_sizes,
+            propagated_text_decoration_line,
+        );
         // FIXME: add contribution to `inline_content_sizes` of floats in this formatting context
         // https://dbaron.org/css/intrinsic/#intrinsic
         let bfc = Self {
@@ -52,6 +60,7 @@ enum BlockLevelCreator {
     Independent {
         display_inside: DisplayInside,
         contents: Contents,
+        propagated_text_decoration_line: TextDecorationLine,
     },
     OutOfFlowAbsolutelyPositionedBox {
         display_inside: DisplayInside,
@@ -72,7 +81,7 @@ enum BlockLevelCreator {
 /// Deferring allows using rayon’s `into_par_iter`.
 enum IntermediateBlockContainer {
     InlineFormattingContext(InlineFormattingContext),
-    Deferred(NonReplacedContents),
+    Deferred(NonReplacedContents, TextDecorationLine),
 }
 
 /// A builder for a block container.
@@ -140,13 +149,16 @@ impl BlockContainer {
         block_container_style: &Arc<ComputedValues>,
         contents: NonReplacedContents,
         content_sizes: ContentSizesRequest,
+        propagated_text_decoration_line: TextDecorationLine,
     ) -> (BlockContainer, ContainsFloats, BoxContentSizes) {
+        let text_decoration_line =
+            propagated_text_decoration_line | block_container_style.clone_text_decoration_line();
         let mut builder = BlockContainerBuilder {
             context,
             root,
             block_container_style,
             block_level_boxes: Vec::new(),
-            ongoing_inline_formatting_context: InlineFormattingContext::default(),
+            ongoing_inline_formatting_context: InlineFormattingContext::new(text_decoration_line),
             ongoing_inline_boxes_stack: Vec::new(),
             anonymous_style: None,
             contains_floats: ContainsFloats::No,
@@ -439,6 +451,8 @@ where
                     display_inside,
                     contents,
                     ContentSizesRequest::inline_if(!style.inline_size_is_length()),
+                    // Text decorations are not propagated to atomic inline-level descendants.
+                    TextDecorationLine::NONE,
                 ),
             ))
         };
@@ -494,6 +508,9 @@ where
                 .push(ArcRefCell::new(fragmented_inline));
         }
 
+        let propagated_text_decoration_line =
+            self.ongoing_inline_formatting_context.text_decoration_line;
+
         // We found a block level element, so the ongoing inline formatting
         // context needs to be ended.
         self.end_ongoing_inline_formatting_context();
@@ -501,11 +518,12 @@ where
         let kind = match contents.try_into() {
             Ok(contents) => match display_inside {
                 DisplayInside::Flow => BlockLevelCreator::SameFormattingContextBlock(
-                    IntermediateBlockContainer::Deferred(contents),
+                    IntermediateBlockContainer::Deferred(contents, propagated_text_decoration_line),
                 ),
                 _ => BlockLevelCreator::Independent {
                     display_inside,
                     contents: contents.into(),
+                    propagated_text_decoration_line,
                 },
             },
             Err(contents) => {
@@ -513,6 +531,7 @@ where
                 BlockLevelCreator::Independent {
                     display_inside,
                     contents,
+                    propagated_text_decoration_line,
                 }
             },
         };
@@ -680,6 +699,7 @@ where
             BlockLevelCreator::Independent {
                 display_inside,
                 contents,
+                propagated_text_decoration_line,
             } => {
                 let content_sizes = ContentSizesRequest::inline_if(
                     max_assign_in_flow_outer_content_sizes_to.is_some() &&
@@ -692,6 +712,7 @@ where
                     display_inside,
                     contents,
                     content_sizes,
+                    propagated_text_decoration_line,
                 );
                 if let Some(to) = max_assign_in_flow_outer_content_sizes_to {
                     to.max_assign(&contents.content_sizes.outer_inline(&contents.style))
@@ -742,8 +763,15 @@ impl IntermediateBlockContainer {
         content_sizes: ContentSizesRequest,
     ) -> (BlockContainer, ContainsFloats, BoxContentSizes) {
         match self {
-            IntermediateBlockContainer::Deferred(contents) => {
+            IntermediateBlockContainer::Deferred(contents, propagated_text_decoration_line) => {
-                BlockContainer::construct(context, node, style, contents, content_sizes)
+                BlockContainer::construct(
+                    context,
+                    node,
+                    style,
+                    contents,
+                    content_sizes,
+                    propagated_text_decoration_line,
+                )
             },
             IntermediateBlockContainer::InlineFormattingContext(ifc) => {
                 let content_sizes = content_sizes.compute(|| ifc.inline_content_sizes(context));

components/layout_2020/flow/float.rs

@@ -9,6 +9,7 @@ use crate::sizing::ContentSizesRequest;
 use crate::style_ext::{ComputedValuesExt, DisplayInside};
 use servo_arc::Arc;
 use style::properties::ComputedValues;
+use style::values::specified::text::TextDecorationLine;
 
 #[derive(Debug, Serialize)]
 pub(crate) struct FloatBox {
@@ -43,6 +44,8 @@ impl FloatBox {
                 display_inside,
                 contents,
                 content_sizes,
+                // Text decorations are not propagated to any out-of-flow descendants
+                TextDecorationLine::NONE,
             ),
         }
     }

components/layout_2020/flow/inline.rs

@@ -33,6 +33,7 @@ use webrender_api::FontInstanceKey;
 #[derive(Debug, Default, Serialize)]
 pub(crate) struct InlineFormattingContext {
     pub(super) inline_level_boxes: Vec<ArcRefCell<InlineLevelBox>>,
+    pub(super) text_decoration_line: TextDecorationLine,
 }
 
 #[derive(Debug, Serialize)]
@@ -69,6 +70,11 @@ struct InlineNestingLevelState<'box_tree> {
     inline_start: Length,
     max_block_size_of_fragments_so_far: Length,
     positioning_context: Option<PositioningContext>,
+    /// Indicates whether this nesting level have text decorations in effect.
+    /// From https://drafts.csswg.org/css-text-decor/#line-decoration
+    // "When specified on or propagated to a block container that establishes
+    //  an IFC..."
+    text_decoration_line: TextDecorationLine,
 }
 
 struct PartialInlineBoxFragment<'box_tree> {
@@ -123,6 +129,13 @@ struct Lines {
 }
 
 impl InlineFormattingContext {
+    pub(super) fn new(text_decoration_line: TextDecorationLine) -> InlineFormattingContext {
+        InlineFormattingContext {
+            inline_level_boxes: Default::default(),
+            text_decoration_line,
+        }
+    }
+
     // This works on an already-constructed `InlineFormattingContext`,
     // Which would have to change if/when
     // `BlockContainer::construct` parallelize their construction.
@@ -257,8 +270,10 @@ impl InlineFormattingContext {
                 inline_start: Length::zero(),
                 max_block_size_of_fragments_so_far: Length::zero(),
                 positioning_context: None,
+                text_decoration_line: self.text_decoration_line,
             },
         };
+
         loop {
             if let Some(child) = ifc.current_nesting_level.remaining_boxes.next() {
                 match &*child.borrow() {
@@ -387,17 +402,6 @@ impl Lines {
         };
         self.next_line_block_position += size.block;
 
-        // From https://drafts.csswg.org/css-text-decor/#line-decoration
-        // "When specified on or propagated to an inline box,
-        // that box becomes a decorating box for that decoration,
-        // applying the decoration to all its fragments..."
-        let text_decoration_line = containing_block.style.clone_text_decoration_line();
-        if text_decoration_line != TextDecorationLine::NONE {
-            for fragment in &mut line_contents {
-                fragment.set_text_decorations_in_effect(text_decoration_line);
-            }
-        }
-
         self.fragments
             .push(Fragment::Anonymous(AnonymousFragment::new(
                 Rect { start_corner, size },
@@ -436,6 +440,8 @@ impl InlineBox {
             start_corner += &relative_adjustement(&style, ifc.containing_block)
         }
         let positioning_context = PositioningContext::new_for_style(&style);
+        let text_decoration_line =
+            ifc.current_nesting_level.text_decoration_line | style.clone_text_decoration_line();
         PartialInlineBoxFragment {
             tag: self.tag,
             style,
@@ -454,6 +460,7 @@ impl InlineBox {
                     inline_start: ifc.inline_position,
                     max_block_size_of_fragments_so_far: Length::zero(),
                     positioning_context,
+                    text_decoration_line: text_decoration_line,
                 },
             ),
         }
@@ -788,7 +795,7 @@ impl TextRun {
                     font_metrics,
                     font_key,
                     glyphs,
-                    text_decorations_in_effect: TextDecorationLine::NONE,
+                    text_decoration_line: ifc.current_nesting_level.text_decoration_line,
                 }));
             if runs.is_empty() {
                 break;

components/layout_2020/flow/root.rs

@@ -104,6 +104,7 @@ fn construct_for_root_element<'dom>(
             ))],
         )
     } else {
+        let propagated_text_decoration_line = style.clone_text_decoration_line();
         (
             ContainsFloats::No,
             vec![ArcRefCell::new(BlockLevelBox::Independent(
@@ -114,6 +115,7 @@ fn construct_for_root_element<'dom>(
                     display_inside,
                     contents,
                     ContentSizesRequest::None,
+                    propagated_text_decoration_line,
                 ),
             ))],
         )

components/layout_2020/formatting_contexts.rs

@@ -16,6 +16,7 @@ use std::convert::TryInto;
 use style::dom::OpaqueNode;
 use style::properties::ComputedValues;
 use style::values::computed::Length;
+use style::values::specified::text::TextDecorationLine;
 
 /// https://drafts.csswg.org/css-display/#independent-formatting-context
 #[derive(Debug, Serialize)]
@@ -62,6 +63,7 @@ impl IndependentFormattingContext {
         display_inside: DisplayInside,
         contents: Contents,
         content_sizes: ContentSizesRequest,
+        propagated_text_decoration_line: TextDecorationLine,
     ) -> Self {
         match contents.try_into() {
             Ok(non_replaced) => match display_inside {
@@ -72,6 +74,7 @@ impl IndependentFormattingContext {
                         &style,
                         non_replaced,
                         content_sizes,
+                        propagated_text_decoration_line,
                     );
                     Self {
                         tag: node.as_opaque(),

components/layout_2020/fragments.rs

@@ -123,7 +123,7 @@ pub(crate) struct TextFragment {
     pub font_key: FontInstanceKey,
     pub glyphs: Vec<Arc<GlyphStore>>,
     /// A flag that represents the _used_ value of the text-decoration property.
-    pub text_decorations_in_effect: TextDecorationLine,
+    pub text_decoration_line: TextDecorationLine,
 }
 
 #[derive(Serialize)]
@@ -195,23 +195,6 @@ impl AbsoluteOrFixedPositionedFragment {
     pub fn print(&self, tree: &mut PrintTree) {
         tree.add_item(format!("AbsoluteOrFixedPositionedFragment({:?})", self.0));
     }
-    
-    pub fn set_text_decorations_in_effect(&mut self, text_decorations: TextDecorationLine) {
-        match self {
-            Fragment::Text(fragment) => fragment.text_decorations_in_effect = text_decorations,
-            Fragment::Box(fragment) => {
-                for child in &mut fragment.children {
-                    child.set_text_decorations_in_effect(text_decorations);
-                }
-            },
-            Fragment::Anonymous(fragment) => {
-                for child in &mut fragment.children {
-                    child.set_text_decorations_in_effect(text_decorations);
-                }
-            },
-            _ => (),
-        }
-    }
 }
 
 impl AnonymousFragment {

components/layout_2020/positioned.rs

@@ -17,6 +17,7 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 use style::computed_values::position::T as Position;
 use style::properties::ComputedValues;
 use style::values::computed::{Length, LengthOrAuto, LengthPercentage, LengthPercentageOrAuto};
+use style::values::specified::text::TextDecorationLine;
 use style::Zero;
 
 static HOISTED_FRAGMENT_ID_COUNTER: AtomicUsize = AtomicUsize::new(0);
@@ -104,6 +105,8 @@ impl AbsolutelyPositionedBox {
                 display_inside,
                 contents,
                 content_sizes,
+                // Text decorations are not propagated to any out-of-flow descendants.
+                TextDecorationLine::NONE,
             ),
         }
     }

components/style/values/specified/text.rs

@@ -244,6 +244,12 @@ bitflags! {
     }
 }
 
+impl Default for TextDecorationLine {
+    fn default() -> Self {
+        TextDecorationLine::NONE
+    }
+}
+
 impl Parse for TextDecorationLine {
     /// none | [ underline || overline || line-through || blink ]
     fn parse<'i, 't>(