Split out four new crates (#5302)

1 files changed, 401 insertions, 0 deletions

diff --git a/crates/typst-library/src/text/deco.rs b/crates/typst-library/src/text/deco.rs
new file mode 100644
index 00000000..5da7ecec
--- /dev/null
+++ b/crates/typst-library/src/text/deco.rs
@@ -0,0 +1,401 @@
+use smallvec::smallvec;
+
+use crate::diag::SourceResult;
+use crate::engine::Engine;
+use crate::foundations::{elem, Content, Packed, Show, Smart, StyleChain};
+use crate::layout::{Abs, Corners, Length, Rel, Sides};
+use crate::text::{BottomEdge, BottomEdgeMetric, TextElem, TopEdge, TopEdgeMetric};
+use crate::visualize::{Color, FixedStroke, Paint, Stroke};
+
+/// Underlines text.
+///
+/// # Example
+/// ```example
+/// This is #underline[important].
+/// ```
+#[elem(Show)]
+pub struct UnderlineElem {
+    /// How to [stroke] the line.
+    ///
+    /// If set to `{auto}`, takes on the text's color and a thickness defined in
+    /// the current font.
+    ///
+    /// ```example
+    /// Take #underline(
+    ///   stroke: 1.5pt + red,
+    ///   offset: 2pt,
+    ///   [care],
+    /// )
+    /// ```
+    #[resolve]
+    #[fold]
+    pub stroke: Smart<Stroke>,
+
+    /// The position of the line relative to the baseline, read from the font
+    /// tables if `{auto}`.
+    ///
+    /// ```example
+    /// #underline(offset: 5pt)[
+    ///   The Tale Of A Faraway Line I
+    /// ]
+    /// ```
+    #[resolve]
+    pub offset: Smart<Length>,
+
+    /// The amount by which to extend the line beyond (or within if negative)
+    /// the content.
+    ///
+    /// ```example
+    /// #align(center,
+    ///   underline(extent: 2pt)[Chapter 1]
+    /// )
+    /// ```
+    #[resolve]
+    pub extent: Length,
+
+    /// Whether the line skips sections in which it would collide with the
+    /// glyphs.
+    ///
+    /// ```example
+    /// This #underline(evade: true)[is great].
+    /// This #underline(evade: false)[is less great].
+    /// ```
+    #[default(true)]
+    pub evade: bool,
+
+    /// Whether the line is placed behind the content it underlines.
+    ///
+    /// ```example
+    /// #set underline(stroke: (thickness: 1em, paint: maroon, cap: "round"))
+    /// #underline(background: true)[This is stylized.] \
+    /// #underline(background: false)[This is partially hidden.]
+    /// ```
+    #[default(false)]
+    pub background: bool,
+
+    /// The content to underline.
+    #[required]
+    pub body: Content,
+}
+
+impl Show for Packed<UnderlineElem> {
+    #[typst_macros::time(name = "underline", span = self.span())]
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.body().clone().styled(TextElem::set_deco(smallvec![Decoration {
+            line: DecoLine::Underline {
+                stroke: self.stroke(styles).unwrap_or_default(),
+                offset: self.offset(styles),
+                evade: self.evade(styles),
+                background: self.background(styles),
+            },
+            extent: self.extent(styles),
+        }])))
+    }
+}
+
+/// Adds a line over text.
+///
+/// # Example
+/// ```example
+/// #overline[A line over text.]
+/// ```
+#[elem(Show)]
+pub struct OverlineElem {
+    /// How to [stroke] the line.
+    ///
+    /// If set to `{auto}`, takes on the text's color and a thickness defined in
+    /// the current font.
+    ///
+    /// ```example
+    /// #set text(fill: olive)
+    /// #overline(
+    ///   stroke: green.darken(20%),
+    ///   offset: -12pt,
+    ///   [The Forest Theme],
+    /// )
+    /// ```
+    #[resolve]
+    #[fold]
+    pub stroke: Smart<Stroke>,
+
+    /// The position of the line relative to the baseline. Read from the font
+    /// tables if `{auto}`.
+    ///
+    /// ```example
+    /// #overline(offset: -1.2em)[
+    ///   The Tale Of A Faraway Line II
+    /// ]
+    /// ```
+    #[resolve]
+    pub offset: Smart<Length>,
+
+    /// The amount by which to extend the line beyond (or within if negative)
+    /// the content.
+    ///
+    /// ```example
+    /// #set overline(extent: 4pt)
+    /// #set underline(extent: 4pt)
+    /// #overline(underline[Typography Today])
+    /// ```
+    #[resolve]
+    pub extent: Length,
+
+    /// Whether the line skips sections in which it would collide with the
+    /// glyphs.
+    ///
+    /// ```example
+    /// #overline(
+    ///   evade: false,
+    ///   offset: -7.5pt,
+    ///   stroke: 1pt,
+    ///   extent: 3pt,
+    ///   [Temple],
+    /// )
+    /// ```
+    #[default(true)]
+    pub evade: bool,
+
+    /// Whether the line is placed behind the content it overlines.
+    ///
+    /// ```example
+    /// #set overline(stroke: (thickness: 1em, paint: maroon, cap: "round"))
+    /// #overline(background: true)[This is stylized.] \
+    /// #overline(background: false)[This is partially hidden.]
+    /// ```
+    #[default(false)]
+    pub background: bool,
+
+    /// The content to add a line over.
+    #[required]
+    pub body: Content,
+}
+
+impl Show for Packed<OverlineElem> {
+    #[typst_macros::time(name = "overline", span = self.span())]
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.body().clone().styled(TextElem::set_deco(smallvec![Decoration {
+            line: DecoLine::Overline {
+                stroke: self.stroke(styles).unwrap_or_default(),
+                offset: self.offset(styles),
+                evade: self.evade(styles),
+                background: self.background(styles),
+            },
+            extent: self.extent(styles),
+        }])))
+    }
+}
+
+/// Strikes through text.
+///
+/// # Example
+/// ```example
+/// This is #strike[not] relevant.
+/// ```
+#[elem(title = "Strikethrough", Show)]
+pub struct StrikeElem {
+    /// How to [stroke] the line.
+    ///
+    /// If set to `{auto}`, takes on the text's color and a thickness defined in
+    /// the current font.
+    ///
+    /// _Note:_ Please don't use this for real redaction as you can still copy
+    /// paste the text.
+    ///
+    /// ```example
+    /// This is #strike(stroke: 1.5pt + red)[very stricken through]. \
+    /// This is #strike(stroke: 10pt)[redacted].
+    /// ```
+    #[resolve]
+    #[fold]
+    pub stroke: Smart<Stroke>,
+
+    /// The position of the line relative to the baseline. Read from the font
+    /// tables if `{auto}`.
+    ///
+    /// This is useful if you are unhappy with the offset your font provides.
+    ///
+    /// ```example
+    /// #set text(font: "Inria Serif")
+    /// This is #strike(offset: auto)[low-ish]. \
+    /// This is #strike(offset: -3.5pt)[on-top].
+    /// ```
+    #[resolve]
+    pub offset: Smart<Length>,
+
+    /// The amount by which to extend the line beyond (or within if negative)
+    /// the content.
+    ///
+    /// ```example
+    /// This #strike(extent: -2pt)[skips] parts of the word.
+    /// This #strike(extent: 2pt)[extends] beyond the word.
+    /// ```
+    #[resolve]
+    pub extent: Length,
+
+    /// Whether the line is placed behind the content.
+    ///
+    /// ```example
+    /// #set strike(stroke: red)
+    /// #strike(background: true)[This is behind.] \
+    /// #strike(background: false)[This is in front.]
+    /// ```
+    #[default(false)]
+    pub background: bool,
+
+    /// The content to strike through.
+    #[required]
+    pub body: Content,
+}
+
+impl Show for Packed<StrikeElem> {
+    #[typst_macros::time(name = "strike", span = self.span())]
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.body().clone().styled(TextElem::set_deco(smallvec![Decoration {
+            // Note that we do not support evade option for strikethrough.
+            line: DecoLine::Strikethrough {
+                stroke: self.stroke(styles).unwrap_or_default(),
+                offset: self.offset(styles),
+                background: self.background(styles),
+            },
+            extent: self.extent(styles),
+        }])))
+    }
+}
+
+/// Highlights text with a background color.
+///
+/// # Example
+/// ```example
+/// This is #highlight[important].
+/// ```
+#[elem(Show)]
+pub struct HighlightElem {
+    /// The color to highlight the text with.
+    ///
+    /// ```example
+    /// This is #highlight(
+    ///   fill: blue
+    /// )[highlighted with blue].
+    /// ```
+    #[default(Some(Color::from_u8(0xFF, 0xFD, 0x11, 0xA1).into()))]
+    pub fill: Option<Paint>,
+
+    /// The highlight's border color. See the
+    /// [rectangle's documentation]($rect.stroke) for more details.
+    ///
+    /// ```example
+    /// This is a #highlight(
+    ///   stroke: fuchsia
+    /// )[stroked highlighting].
+    /// ```
+    #[resolve]
+    #[fold]
+    pub stroke: Sides<Option<Option<Stroke>>>,
+
+    /// The top end of the background rectangle.
+    ///
+    /// ```example
+    /// #set highlight(top-edge: "ascender")
+    /// #highlight[a] #highlight[aib]
+    ///
+    /// #set highlight(top-edge: "x-height")
+    /// #highlight[a] #highlight[aib]
+    /// ```
+    #[default(TopEdge::Metric(TopEdgeMetric::Ascender))]
+    pub top_edge: TopEdge,
+
+    /// The bottom end of the background rectangle.
+    ///
+    /// ```example
+    /// #set highlight(bottom-edge: "descender")
+    /// #highlight[a] #highlight[ap]
+    ///
+    /// #set highlight(bottom-edge: "baseline")
+    /// #highlight[a] #highlight[ap]
+    /// ```
+    #[default(BottomEdge::Metric(BottomEdgeMetric::Descender))]
+    pub bottom_edge: BottomEdge,
+
+    /// The amount by which to extend the background to the sides beyond
+    /// (or within if negative) the content.
+    ///
+    /// ```example
+    /// A long #highlight(extent: 4pt)[background].
+    /// ```
+    #[resolve]
+    pub extent: Length,
+
+    /// How much to round the highlight's corners. See the
+    /// [rectangle's documentation]($rect.radius) for more details.
+    ///
+    /// ```example
+    /// Listen #highlight(
+    ///   radius: 5pt, extent: 2pt
+    /// )[carefully], it will be on the test.
+    /// ```
+    #[resolve]
+    #[fold]
+    pub radius: Corners<Option<Rel<Length>>>,
+
+    /// The content that should be highlighted.
+    #[required]
+    pub body: Content,
+}
+
+impl Show for Packed<HighlightElem> {
+    #[typst_macros::time(name = "highlight", span = self.span())]
+    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
+        Ok(self.body().clone().styled(TextElem::set_deco(smallvec![Decoration {
+            line: DecoLine::Highlight {
+                fill: self.fill(styles),
+                stroke: self
+                    .stroke(styles)
+                    .unwrap_or_default()
+                    .map(|stroke| stroke.map(Stroke::unwrap_or_default)),
+                top_edge: self.top_edge(styles),
+                bottom_edge: self.bottom_edge(styles),
+                radius: self.radius(styles).unwrap_or_default(),
+            },
+            extent: self.extent(styles),
+        }])))
+    }
+}
+
+/// A text decoration.
+///
+/// Can be positioned over, under, or on top of text, or highlight the text with
+/// a background.
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub struct Decoration {
+    pub line: DecoLine,
+    pub extent: Abs,
+}
+
+/// A kind of decorative line.
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+pub enum DecoLine {
+    Underline {
+        stroke: Stroke<Abs>,
+        offset: Smart<Abs>,
+        evade: bool,
+        background: bool,
+    },
+    Strikethrough {
+        stroke: Stroke<Abs>,
+        offset: Smart<Abs>,
+        background: bool,
+    },
+    Overline {
+        stroke: Stroke<Abs>,
+        offset: Smart<Abs>,
+        evade: bool,
+        background: bool,
+    },
+    Highlight {
+        fill: Option<Paint>,
+        stroke: Sides<Option<FixedStroke>>,
+        top_edge: TopEdge,
+        bottom_edge: BottomEdge,
+        radius: Corners<Rel<Abs>>,
+    },
+}