Import files from Victor

https://github.com/SimonSapin/victor/tree/fdb11f3e87f6d2d59170d10169fa6deb94e53b94

1 files changed, 116 insertions, 0 deletions

diff --git a/components/layout_2020/fragments.rs b/components/layout_2020/fragments.rs
new file mode 100644
index 00000000000..f2a4dcd2986
--- /dev/null
+++ b/components/layout_2020/fragments.rs
@@ -0,0 +1,116 @@
+use super::*;
+use crate::text::ShapedSegment;
+
+pub(crate) enum Fragment {
+    Box(BoxFragment),
+    Anonymous(AnonymousFragment),
+    Text(TextFragment),
+}
+
+pub(crate) struct BoxFragment {
+    pub style: Arc<ComputedValues>,
+    pub children: Vec<Fragment>,
+
+    /// From the containing block’s start corner…?
+    /// This might be broken when the containing block is in a different writing mode:
+    /// https://drafts.csswg.org/css-writing-modes/#orthogonal-flows
+    pub content_rect: Rect<Length>,
+
+    pub padding: Sides<Length>,
+    pub border: Sides<Length>,
+    pub margin: Sides<Length>,
+
+    pub block_margins_collapsed_with_children: CollapsedBlockMargins,
+}
+
+pub(crate) struct CollapsedBlockMargins {
+    pub collapsed_through: bool,
+    pub start: CollapsedMargin,
+    pub end: CollapsedMargin,
+}
+
+#[derive(Clone, Copy)]
+pub(crate) struct CollapsedMargin {
+    max_positive: Length,
+    min_negative: Length,
+}
+
+/// Can contain child fragments with relative coordinates, but does not contribute to painting itself.
+pub(crate) struct AnonymousFragment {
+    pub rect: Rect<Length>,
+    pub children: Vec<Fragment>,
+    pub mode: (WritingMode, Direction),
+}
+
+pub(crate) struct TextFragment {
+    pub parent_style: Arc<ComputedValues>,
+    pub content_rect: Rect<Length>,
+    pub text: ShapedSegment,
+}
+
+impl AnonymousFragment {
+    pub fn no_op(mode: (WritingMode, Direction)) -> Self {
+        Self {
+            children: vec![],
+            rect: Rect::zero(),
+            mode,
+        }
+    }
+}
+
+impl BoxFragment {
+    pub fn border_rect(&self) -> Rect<Length> {
+        self.content_rect
+            .inflate(&self.padding)
+            .inflate(&self.border)
+    }
+}
+
+impl CollapsedBlockMargins {
+    pub fn from_margin(margin: &Sides<Length>) -> Self {
+        Self {
+            collapsed_through: false,
+            start: CollapsedMargin::new(margin.block_start),
+            end: CollapsedMargin::new(margin.block_end),
+        }
+    }
+
+    pub fn zero() -> Self {
+        Self {
+            collapsed_through: false,
+            start: CollapsedMargin::zero(),
+            end: CollapsedMargin::zero(),
+        }
+    }
+}
+
+impl CollapsedMargin {
+    pub fn zero() -> Self {
+        Self {
+            max_positive: Length::zero(),
+            min_negative: Length::zero(),
+        }
+    }
+
+    pub fn new(margin: Length) -> Self {
+        Self {
+            max_positive: margin.max(Length::zero()),
+            min_negative: margin.min(Length::zero()),
+        }
+    }
+
+    pub fn adjoin(&self, other: &Self) -> Self {
+        Self {
+            max_positive: self.max_positive.max(other.max_positive),
+            min_negative: self.min_negative.min(other.min_negative),
+        }
+    }
+
+    pub fn adjoin_assign(&mut self, other: &Self) {
+        *self = self.adjoin(other);
+    }
+
+    pub fn solve(&self) -> Length {
+        self.max_positive + self.min_negative
+    }
+}