2023-11-06 21:37:50 +01:00

958 lines
29 KiB
Rust

//! Text handling.
mod deco;
mod linebreak;
mod misc;
mod quote;
mod quotes;
mod raw;
mod shaping;
mod shift;
pub use self::deco::*;
pub(crate) use self::linebreak::*;
pub use self::misc::*;
pub use self::quote::*;
pub use self::quotes::*;
pub use self::raw::*;
pub use self::shaping::*;
pub use self::shift::*;
use rustybuzz::Tag;
use ttf_parser::Rect;
use typst::diag::{bail, error, SourceResult};
use typst::eval::Never;
use typst::font::{Font, FontStretch, FontStyle, FontWeight, VerticalFontMetric};
use crate::layout::ParElem;
use crate::prelude::*;
/// Hook up all text definitions.
pub(super) fn define(global: &mut Scope) {
global.category("text");
global.define_elem::<TextElem>();
global.define_elem::<LinebreakElem>();
global.define_elem::<SmartquoteElem>();
global.define_elem::<StrongElem>();
global.define_elem::<EmphElem>();
global.define_elem::<SubElem>();
global.define_elem::<SuperElem>();
global.define_elem::<UnderlineElem>();
global.define_elem::<OverlineElem>();
global.define_elem::<StrikeElem>();
global.define_elem::<HighlightElem>();
global.define_elem::<QuoteElem>();
global.define_elem::<RawElem>();
global.define_func::<lower>();
global.define_func::<upper>();
global.define_func::<smallcaps>();
global.define_func::<lorem>();
}
/// Customizes the look and layout of text in a variety of ways.
///
/// This function is used frequently, both with set rules and directly. While
/// the set rule is often the simpler choice, calling the `text` function
/// directly can be useful when passing text as an argument to another function.
///
/// # Example
/// ```example
/// #set text(18pt)
/// With a set rule.
///
/// #emph(text(blue)[
/// With a function call.
/// ])
/// ```
#[elem(Construct, PlainText, Repr)]
pub struct TextElem {
/// A font family name or priority list of font family names.
///
/// When processing text, Typst tries all specified font families in order
/// until it finds a font that has the necessary glyphs. In the example
/// below, the font `Inria Serif` is preferred, but since it does not
/// contain Arabic glyphs, the arabic text uses `Noto Sans Arabic` instead.
///
/// The collection of available fonts differs by platform:
///
/// - In the web app, you can see the list of available fonts by clicking on
/// the "Ag" button. You can provide additional fonts by uploading `.ttf`
/// or `.otf` files into your project. They will be discovered
/// automatically.
///
/// - Locally, Typst uses your installed system fonts. In addition, you can
/// use the `--font-path` argument or `TYPST_FONT_PATHS` environment
/// variable to add directories that should be scanned for fonts.
///
/// ```example
/// #set text(font: "PT Sans")
/// This is sans-serif.
///
/// #set text(font: (
/// "Inria Serif",
/// "Noto Sans Arabic",
/// ))
///
/// This is Latin. \
/// هذا عربي.
/// ```
#[default(FontList(vec![FontFamily::new("Linux Libertine")]))]
#[borrowed]
pub font: FontList,
/// Whether to allow last resort font fallback when the primary font list
/// contains no match. This lets Typst search through all available fonts
/// for the most similar one that has the necessary glyphs.
///
/// _Note:_ Currently, there are no warnings when fallback is disabled and
/// no glyphs are found. Instead, your text shows up in the form of "tofus":
/// Small boxes that indicate the lack of an appropriate glyph. In the
/// future, you will be able to instruct Typst to issue warnings so you know
/// something is up.
///
/// ```example
/// #set text(font: "Inria Serif")
/// هذا عربي
///
/// #set text(fallback: false)
/// هذا عربي
/// ```
#[default(true)]
pub fallback: bool,
/// The desired font style.
///
/// When an italic style is requested and only an oblique one is available,
/// it is used. Similarly, the other way around, an italic style can stand
/// in for an oblique one. When neither an italic nor an oblique style is
/// available, Typst selects the normal style. Since most fonts are only
/// available either in an italic or oblique style, the difference between
/// italic and oblique style is rarely observable.
///
/// If you want to emphasize your text, you should do so using the
/// [emph]($emph) function instead. This makes it easy to adapt the style
/// later if you change your mind about how to signify the emphasis.
///
/// ```example
/// #text(font: "Linux Libertine", style: "italic")[Italic]
/// #text(font: "DejaVu Sans", style: "oblique")[Oblique]
/// ```
pub style: FontStyle,
/// The desired thickness of the font's glyphs. Accepts an integer between
/// `{100}` and `{900}` or one of the predefined weight names. When the
/// desired weight is not available, Typst selects the font from the family
/// that is closest in weight.
///
/// If you want to strongly emphasize your text, you should do so using the
/// [strong]($strong) function instead. This makes it easy to adapt the
/// style later if you change your mind about how to signify the strong
/// emphasis.
///
/// ```example
/// #set text(font: "IBM Plex Sans")
///
/// #text(weight: "light")[Light] \
/// #text(weight: "regular")[Regular] \
/// #text(weight: "medium")[Medium] \
/// #text(weight: 500)[Medium] \
/// #text(weight: "bold")[Bold]
/// ```
pub weight: FontWeight,
/// The desired width of the glyphs. Accepts a ratio between `{50%}` and
/// `{200%}`. When the desired width is not available, Typst selects the
/// font from the family that is closest in stretch. This will only stretch
/// the text if a condensed or expanded version of the font is available.
///
/// If you want to adjust the amount of space between characters instead of
/// stretching the glyphs itself, use the [`tracking`]($text.tracking)
/// property instead.
///
/// ```example
/// #text(stretch: 75%)[Condensed] \
/// #text(stretch: 100%)[Normal]
/// ```
pub stretch: FontStretch,
/// The size of the glyphs. This value forms the basis of the `em` unit:
/// `{1em}` is equivalent to the font size.
///
/// You can also give the font size itself in `em` units. Then, it is
/// relative to the previous font size.
///
/// ```example
/// #set text(size: 20pt)
/// very #text(1.5em)[big] text
/// ```
#[parse(args.named_or_find("size")?)]
#[fold]
#[default(Abs::pt(11.0))]
pub size: TextSize,
/// The glyph fill paint.
///
/// ```example
/// #set text(fill: red)
/// This text is red.
/// ```
#[parse({
let paint: Option<Spanned<Paint>> = args.named_or_find("fill")?;
if let Some(paint) = &paint {
if let Paint::Gradient(gradient) = &paint.v {
if gradient.relative() == Smart::Custom(Relative::Self_) {
bail!(
error!(
paint.span,
"gradients on text must be relative to the parent"
)
.with_hint("make sure to set `relative: auto` on your text fill")
);
}
}
}
paint.map(|paint| paint.v)
})]
#[default(Color::BLACK.into())]
pub fill: Paint,
/// The amount of space that should be added between characters.
///
/// ```example
/// #set text(tracking: 1.5pt)
/// Distant text.
/// ```
#[resolve]
pub tracking: Length,
/// The amount of space between words.
///
/// Can be given as an absolute length, but also relative to the width of
/// the space character in the font.
///
/// If you want to adjust the amount of space between characters rather than
/// words, use the [`tracking`]($text.tracking) property instead.
///
/// ```example
/// #set text(spacing: 200%)
/// Text with distant words.
/// ```
#[resolve]
#[default(Rel::one())]
pub spacing: Rel<Length>,
/// Whether to automatically insert spacing between CJK and Latin characters.
///
/// ```example
/// #set text(cjk-latin-spacing: auto)
/// 第4章介绍了基本的API。
///
/// #set text(cjk-latin-spacing: none)
/// 第4章介绍了基本的API。
/// ```
pub cjk_latin_spacing: Smart<Option<Never>>,
/// An amount to shift the text baseline by.
///
/// ```example
/// A #text(baseline: 3pt)[lowered]
/// word.
/// ```
#[resolve]
pub baseline: Length,
/// Whether certain glyphs can hang over into the margin in justified text.
/// This can make justification visually more pleasing.
///
/// ```example
/// #set par(justify: true)
/// This justified text has a hyphen in
/// the paragraph's first line. Hanging
/// the hyphen slightly into the margin
/// results in a clearer paragraph edge.
///
/// #set text(overhang: false)
/// This justified text has a hyphen in
/// the paragraph's first line. Hanging
/// the hyphen slightly into the margin
/// results in a clearer paragraph edge.
/// ```
#[default(true)]
pub overhang: bool,
/// The top end of the conceptual frame around the text used for layout and
/// positioning. This affects the size of containers that hold text.
///
/// ```example
/// #set rect(inset: 0pt)
/// #set text(size: 20pt)
///
/// #set text(top-edge: "ascender")
/// #rect(fill: aqua)[Typst]
///
/// #set text(top-edge: "cap-height")
/// #rect(fill: aqua)[Typst]
/// ```
#[default(TopEdge::Metric(TopEdgeMetric::CapHeight))]
pub top_edge: TopEdge,
/// The bottom end of the conceptual frame around the text used for layout
/// and positioning. This affects the size of containers that hold text.
///
/// ```example
/// #set rect(inset: 0pt)
/// #set text(size: 20pt)
///
/// #set text(bottom-edge: "baseline")
/// #rect(fill: aqua)[Typst]
///
/// #set text(bottom-edge: "descender")
/// #rect(fill: aqua)[Typst]
/// ```
#[default(BottomEdge::Metric(BottomEdgeMetric::Baseline))]
pub bottom_edge: BottomEdge,
/// An [ISO 639-1/2/3 language code.](https://en.wikipedia.org/wiki/ISO_639)
///
/// Setting the correct language affects various parts of Typst:
///
/// - The text processing pipeline can make more informed choices.
/// - Hyphenation will use the correct patterns for the language.
/// - [Smart quotes]($smartquote) turns into the correct quotes for the
/// language.
/// - And all other things which are language-aware.
///
/// ```example
/// #set text(lang: "de")
/// #outline()
///
/// = Einleitung
/// In diesem Dokument, ...
/// ```
#[default(Lang::ENGLISH)]
pub lang: Lang,
/// An [ISO 3166-1 alpha-2 region code.](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2)
///
/// This lets the text processing pipeline make more informed choices.
pub region: Option<Region>,
/// The OpenType writing script.
///
/// The combination of `{lang}` and `{script}` determine how font features,
/// such as glyph substitution, are implemented. Frequently the value is a
/// modified (all-lowercase) ISO 15924 script identifier, and the `math`
/// writing script is used for features appropriate for mathematical
/// symbols.
///
/// When set to `{auto}`, the default and recommended setting, an
/// appropriate script is chosen for each block of characters sharing a
/// common Unicode script property.
///
/// ```example
/// #set text(
/// font: "Linux Libertine",
/// size: 20pt,
/// )
///
/// #let scedilla = [Ş]
/// #scedilla // S with a cedilla
///
/// #set text(lang: "ro", script: "latn")
/// #scedilla // S with a subscript comma
///
/// #set text(lang: "ro", script: "grek")
/// #scedilla // S with a cedilla
/// ```
pub script: Smart<WritingScript>,
/// The dominant direction for text and inline objects. Possible values are:
///
/// - `{auto}`: Automatically infer the direction from the `lang` property.
/// - `{ltr}`: Layout text from left to right.
/// - `{rtl}`: Layout text from right to left.
///
/// When writing in right-to-left scripts like Arabic or Hebrew, you should
/// set the [text language]($text.lang) or direction. While individual runs
/// of text are automatically layouted in the correct direction, setting the
/// dominant direction gives the bidirectional reordering algorithm the
/// necessary information to correctly place punctuation and inline objects.
/// Furthermore, setting the direction affects the alignment values `start`
/// and `end`, which are equivalent to `left` and `right` in `ltr` text and
/// the other way around in `rtl` text.
///
/// If you set this to `rtl` and experience bugs or in some way bad looking
/// output, please do get in touch with us through the
/// [contact form](https://typst.app/contact) or our
/// [Discord server]($community/#discord)!
///
/// ```example
/// #set text(dir: rtl)
/// هذا عربي.
/// ```
#[resolve]
pub dir: TextDir,
/// Whether to hyphenate text to improve line breaking. When `{auto}`, text
/// will be hyphenated if and only if justification is enabled.
///
/// Setting the [text language]($text.lang) ensures that the correct
/// hyphenation patterns are used.
///
/// ```example
/// #set page(width: 200pt)
///
/// #set par(justify: true)
/// This text illustrates how
/// enabling hyphenation can
/// improve justification.
///
/// #set text(hyphenate: false)
/// This text illustrates how
/// enabling hyphenation can
/// improve justification.
/// ```
#[resolve]
pub hyphenate: Hyphenate,
/// Whether to apply kerning.
///
/// When enabled, specific letter pairings move closer together or further
/// apart for a more visually pleasing result. The example below
/// demonstrates how decreasing the gap between the "T" and "o" results in a
/// more natural look. Setting this to `{false}` disables kerning by turning
/// off the OpenType `kern` font feature.
///
/// ```example
/// #set text(size: 25pt)
/// Totally
///
/// #set text(kerning: false)
/// Totally
/// ```
#[default(true)]
pub kerning: bool,
/// Whether to apply stylistic alternates.
///
/// Sometimes fonts contain alternative glyphs for the same codepoint.
/// Setting this to `{true}` switches to these by enabling the OpenType
/// `salt` font feature.
///
/// ```example
/// #set text(
/// font: "IBM Plex Sans",
/// size: 20pt,
/// )
///
/// 0, a, g, ß
///
/// #set text(alternates: true)
/// 0, a, g, ß
/// ```
#[default(false)]
pub alternates: bool,
/// Which stylistic set to apply. Font designers can categorize alternative
/// glyphs forms into stylistic sets. As this value is highly font-specific,
/// you need to consult your font to know which sets are available. When set
/// to an integer between `{1}` and `{20}`, enables the corresponding
/// OpenType font feature from `ss01`, ..., `ss20`.
pub stylistic_set: Option<StylisticSet>,
/// Whether standard ligatures are active.
///
/// Certain letter combinations like "fi" are often displayed as a single
/// merged glyph called a _ligature._ Setting this to `{false}` disables
/// these ligatures by turning off the OpenType `liga` and `clig` font
/// features.
///
/// ```example
/// #set text(size: 20pt)
/// A fine ligature.
///
/// #set text(ligatures: false)
/// A fine ligature.
/// ```
#[default(true)]
pub ligatures: bool,
/// Whether ligatures that should be used sparingly are active. Setting this
/// to `{true}` enables the OpenType `dlig` font feature.
#[default(false)]
pub discretionary_ligatures: bool,
/// Whether historical ligatures are active. Setting this to `{true}`
/// enables the OpenType `hlig` font feature.
#[default(false)]
pub historical_ligatures: bool,
/// Which kind of numbers / figures to select. When set to `{auto}`, the
/// default numbers for the font are used.
///
/// ```example
/// #set text(font: "Noto Sans", 20pt)
/// #set text(number-type: "lining")
/// Number 9.
///
/// #set text(number-type: "old-style")
/// Number 9.
/// ```
pub number_type: Smart<NumberType>,
/// The width of numbers / figures. When set to `{auto}`, the default
/// numbers for the font are used.
///
/// ```example
/// #set text(font: "Noto Sans", 20pt)
/// #set text(number-width: "proportional")
/// A 12 B 34. \
/// A 56 B 78.
///
/// #set text(number-width: "tabular")
/// A 12 B 34. \
/// A 56 B 78.
/// ```
pub number_width: Smart<NumberWidth>,
/// Whether to have a slash through the zero glyph. Setting this to `{true}`
/// enables the OpenType `zero` font feature.
///
/// ```example
/// 0, #text(slashed-zero: true)[0]
/// ```
#[default(false)]
pub slashed_zero: bool,
/// Whether to turn numbers into fractions. Setting this to `{true}`
/// enables the OpenType `frac` font feature.
///
/// It is not advisable to enable this property globally as it will mess
/// with all appearances of numbers after a slash (e.g., in URLs). Instead,
/// enable it locally when you want a fraction.
///
/// ```example
/// 1/2 \
/// #text(fractions: true)[1/2]
/// ```
#[default(false)]
pub fractions: bool,
/// Raw OpenType features to apply.
///
/// - If given an array of strings, sets the features identified by the
/// strings to `{1}`.
/// - If given a dictionary mapping to numbers, sets the features
/// identified by the keys to the values.
///
/// ```example
/// // Enable the `frac` feature manually.
/// #set text(features: ("frac",))
/// 1/2
/// ```
#[fold]
pub features: FontFeatures,
/// Content in which all text is styled according to the other arguments.
#[external]
#[required]
pub body: Content,
/// The text.
#[required]
#[variant(0)]
pub text: EcoString,
/// A delta to apply on the font weight.
#[internal]
#[fold]
pub delta: Delta,
/// Whether the font style should be inverted.
#[internal]
#[fold]
#[default(false)]
pub emph: Toggle,
/// Decorative lines.
#[internal]
#[fold]
pub deco: Decoration,
/// A case transformation that should be applied to the text.
#[internal]
pub case: Option<Case>,
/// Whether small capital glyphs should be used. ("smcp")
#[internal]
#[default(false)]
pub smallcaps: bool,
}
impl TextElem {
/// Create a new packed text element.
pub fn packed(text: impl Into<EcoString>) -> Content {
Self::new(text.into()).pack()
}
}
impl Repr for TextElem {
fn repr(&self) -> EcoString {
eco_format!("[{}]", self.text)
}
}
impl Construct for TextElem {
fn construct(vm: &mut Vm, args: &mut Args) -> SourceResult<Content> {
// The text constructor is special: It doesn't create a text element.
// Instead, it leaves the passed argument structurally unchanged, but
// styles all text in it.
let styles = Self::set(vm, args)?;
let body = args.expect::<Content>("body")?;
Ok(body.styled_with_map(styles))
}
}
impl PlainText for TextElem {
fn plain_text(&self, text: &mut EcoString) {
text.push_str(self.text());
}
}
/// A lowercased font family like "arial".
#[derive(Clone, Eq, PartialEq, Hash)]
pub struct FontFamily(EcoString);
impl FontFamily {
/// Create a named font family variant.
pub fn new(string: &str) -> Self {
Self(string.to_lowercase().into())
}
/// The lowercased family name.
pub fn as_str(&self) -> &str {
&self.0
}
}
impl Debug for FontFamily {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
self.0.fmt(f)
}
}
cast! {
FontFamily,
self => self.0.into_value(),
string: EcoString => Self::new(&string),
}
/// Font family fallback list.
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub struct FontList(pub Vec<FontFamily>);
impl<'a> IntoIterator for &'a FontList {
type IntoIter = std::slice::Iter<'a, FontFamily>;
type Item = &'a FontFamily;
fn into_iter(self) -> Self::IntoIter {
self.0.iter()
}
}
cast! {
FontList,
self => if self.0.len() == 1 {
self.0.into_iter().next().unwrap().0.into_value()
} else {
self.0.into_value()
},
family: FontFamily => Self(vec![family]),
values: Array => Self(values.into_iter().map(|v| v.cast()).collect::<StrResult<_>>()?),
}
/// The size of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct TextSize(pub Length);
impl Fold for TextSize {
type Output = Abs;
fn fold(self, outer: Self::Output) -> Self::Output {
self.0.em.at(outer) + self.0.abs
}
}
cast! {
TextSize,
self => self.0.into_value(),
v: Length => Self(v),
}
/// Specifies the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum TopEdge {
/// An edge specified via font metrics or bounding box.
Metric(TopEdgeMetric),
/// An edge specified as a length.
Length(Length),
}
impl TopEdge {
/// Determine if the edge is specified from bounding box info.
pub fn is_bounds(&self) -> bool {
matches!(self, Self::Metric(TopEdgeMetric::Bounds))
}
/// Resolve the value of the text edge given a font's metrics.
pub fn resolve(self, font_size: Abs, font: &Font, bbox: Option<Rect>) -> Abs {
match self {
TopEdge::Metric(metric) => {
if let Ok(metric) = metric.try_into() {
font.metrics().vertical(metric).at(font_size)
} else {
bbox.map(|bbox| (font.to_em(bbox.y_max)).at(font_size))
.unwrap_or_default()
}
}
TopEdge::Length(length) => length.at(font_size),
}
}
}
cast! {
TopEdge,
self => match self {
Self::Metric(metric) => metric.into_value(),
Self::Length(length) => length.into_value(),
},
v: TopEdgeMetric => Self::Metric(v),
v: Length => Self::Length(v),
}
/// Metrics that describe the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum TopEdgeMetric {
/// The font's ascender, which typically exceeds the height of all glyphs.
Ascender,
/// The approximate height of uppercase letters.
CapHeight,
/// The approximate height of non-ascending lowercase letters.
XHeight,
/// The baseline on which the letters rest.
Baseline,
/// The top edge of the glyph's bounding box.
Bounds,
}
impl TryInto<VerticalFontMetric> for TopEdgeMetric {
type Error = ();
fn try_into(self) -> Result<VerticalFontMetric, Self::Error> {
match self {
Self::Ascender => Ok(VerticalFontMetric::Ascender),
Self::CapHeight => Ok(VerticalFontMetric::CapHeight),
Self::XHeight => Ok(VerticalFontMetric::XHeight),
Self::Baseline => Ok(VerticalFontMetric::Baseline),
_ => Err(()),
}
}
}
/// Specifies the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum BottomEdge {
/// An edge specified via font metrics or bounding box.
Metric(BottomEdgeMetric),
/// An edge specified as a length.
Length(Length),
}
impl BottomEdge {
/// Determine if the edge is specified from bounding box info.
pub fn is_bounds(&self) -> bool {
matches!(self, Self::Metric(BottomEdgeMetric::Bounds))
}
/// Resolve the value of the text edge given a font's metrics.
pub fn resolve(self, font_size: Abs, font: &Font, bbox: Option<Rect>) -> Abs {
match self {
BottomEdge::Metric(metric) => {
if let Ok(metric) = metric.try_into() {
font.metrics().vertical(metric).at(font_size)
} else {
bbox.map(|bbox| (font.to_em(bbox.y_min)).at(font_size))
.unwrap_or_default()
}
}
BottomEdge::Length(length) => length.at(font_size),
}
}
}
cast! {
BottomEdge,
self => match self {
Self::Metric(metric) => metric.into_value(),
Self::Length(length) => length.into_value(),
},
v: BottomEdgeMetric => Self::Metric(v),
v: Length => Self::Length(v),
}
/// Metrics that describe the bottom edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum BottomEdgeMetric {
/// The baseline on which the letters rest.
Baseline,
/// The font's descender, which typically exceeds the depth of all glyphs.
Descender,
/// The bottom edge of the glyph's bounding box.
Bounds,
}
impl TryInto<VerticalFontMetric> for BottomEdgeMetric {
type Error = ();
fn try_into(self) -> Result<VerticalFontMetric, Self::Error> {
match self {
Self::Baseline => Ok(VerticalFontMetric::Baseline),
Self::Descender => Ok(VerticalFontMetric::Descender),
_ => Err(()),
}
}
}
/// The direction of text and inline objects in their line.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct TextDir(pub Smart<Dir>);
cast! {
TextDir,
self => self.0.into_value(),
v: Smart<Dir> => {
if v.map_or(false, |dir| dir.axis() == Axis::Y) {
bail!("text direction must be horizontal");
}
Self(v)
},
}
impl Resolve for TextDir {
type Output = Dir;
fn resolve(self, styles: StyleChain) -> Self::Output {
match self.0 {
Smart::Auto => TextElem::lang_in(styles).dir(),
Smart::Custom(dir) => dir,
}
}
}
/// Whether to hyphenate text.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct Hyphenate(pub Smart<bool>);
cast! {
Hyphenate,
self => self.0.into_value(),
v: Smart<bool> => Self(v),
}
impl Resolve for Hyphenate {
type Output = bool;
fn resolve(self, styles: StyleChain) -> Self::Output {
match self.0 {
Smart::Auto => ParElem::justify_in(styles),
Smart::Custom(v) => v,
}
}
}
/// A stylistic set in a font.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct StylisticSet(u8);
impl StylisticSet {
/// Create a new set, clamping to 1-20.
pub fn new(index: u8) -> Self {
Self(index.clamp(1, 20))
}
/// Get the value, guaranteed to be 1-20.
pub fn get(self) -> u8 {
self.0
}
}
cast! {
StylisticSet,
self => self.0.into_value(),
v: i64 => match v {
1 ..= 20 => Self::new(v as u8),
_ => bail!("stylistic set must be between 1 and 20"),
},
}
/// Which kind of numbers / figures to select.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum NumberType {
/// Numbers that fit well with capital text (the OpenType `lnum`
/// font feature).
Lining,
/// Numbers that fit well into a flow of upper- and lowercase text (the
/// OpenType `onum` font feature).
OldStyle,
}
/// The width of numbers / figures.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum NumberWidth {
/// Numbers with glyph-specific widths (the OpenType `pnum` font feature).
Proportional,
/// Numbers of equal width (the OpenType `tnum` font feature).
Tabular,
}
/// OpenType font features settings.
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub struct FontFeatures(pub Vec<(Tag, u32)>);
cast! {
FontFeatures,
self => self.0
.into_iter()
.map(|(tag, num)| {
let bytes = tag.to_bytes();
let key = std::str::from_utf8(&bytes).unwrap_or_default();
(key.into(), num.into_value())
})
.collect::<Dict>()
.into_value(),
values: Array => Self(values
.into_iter()
.map(|v| {
let tag = v.cast::<EcoString>()?;
Ok((Tag::from_bytes_lossy(tag.as_bytes()), 1))
})
.collect::<StrResult<_>>()?),
values: Dict => Self(values
.into_iter()
.map(|(k, v)| {
let num = v.cast::<u32>()?;
let tag = Tag::from_bytes_lossy(k.as_bytes());
Ok((tag, num))
})
.collect::<StrResult<_>>()?),
}
impl Fold for FontFeatures {
type Output = Self;
fn fold(mut self, outer: Self::Output) -> Self::Output {
self.0.extend(outer.0);
self
}
}