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use std::borrow::Cow;
use std::num::NonZeroUsize;
use std::str::FromStr;
use ecow::EcoString;
use typst_utils::NonZeroExt;
use crate::diag::{bail, SourceResult};
use crate::engine::Engine;
use crate::foundations::{
cast, elem, scope, select_where, Content, Element, NativeElement, Packed, Selector,
Show, ShowSet, Smart, StyleChain, Styles, Synthesize, TargetElem,
};
use crate::html::{tag, HtmlElem};
use crate::introspection::{
Count, Counter, CounterKey, CounterUpdate, Locatable, Location,
};
use crate::layout::{
AlignElem, Alignment, BlockBody, BlockElem, Em, HAlignment, Length, OuterVAlignment,
PlaceElem, PlacementScope, VAlignment, VElem,
};
use crate::model::{
Numbering, NumberingPattern, Outlinable, ParbreakElem, Refable, Supplement,
};
use crate::text::{Lang, Region, TextElem};
use crate::visualize::ImageElem;
/// A figure with an optional caption.
///
/// Automatically detects its kind to select the correct counting track. For
/// example, figures containing images will be numbered separately from figures
/// containing tables.
///
/// # Examples
/// The example below shows a basic figure with an image:
/// ```example
/// @glacier shows a glacier. Glaciers
/// are complex systems.
///
/// #figure(
/// image("glacier.jpg", width: 80%),
/// caption: [A curious figure.],
/// ) <glacier>
/// ```
///
/// You can also insert [tables]($table) into figures to give them a caption.
/// The figure will detect this and automatically use a separate counter.
///
/// ```example
/// #figure(
/// table(
/// columns: 4,
/// [t], [1], [2], [3],
/// [y], [0.3s], [0.4s], [0.8s],
/// ),
/// caption: [Timing results],
/// )
/// ```
///
/// This behaviour can be overridden by explicitly specifying the figure's
/// `kind`. All figures of the same kind share a common counter.
///
/// # Figure behaviour
/// By default, figures are placed within the flow of content. To make them
/// float to the top or bottom of the page, you can use the
/// [`placement`]($figure.placement) argument.
///
/// If your figure is too large and its contents are breakable across pages
/// (e.g. if it contains a large table), then you can make the figure itself
/// breakable across pages as well with this show rule:
/// ```typ
/// #show figure: set block(breakable: true)
/// ```
///
/// See the [block]($block.breakable) documentation for more information about
/// breakable and non-breakable blocks.
///
/// # Caption customization
/// You can modify the appearance of the figure's caption with its associated
/// [`caption`]($figure.caption) function. In the example below, we emphasize
/// all captions:
///
/// ```example
/// #show figure.caption: emph
///
/// #figure(
/// rect[Hello],
/// caption: [I am emphasized!],
/// )
/// ```
///
/// By using a [`where`]($function.where) selector, we can scope such rules to
/// specific kinds of figures. For example, to position the caption above
/// tables, but keep it below for all other kinds of figures, we could write the
/// following show-set rule:
///
/// ```example
/// #show figure.where(
/// kind: table
/// ): set figure.caption(position: top)
///
/// #figure(
/// table(columns: 2)[A][B][C][D],
/// caption: [I'm up here],
/// )
/// ```
#[elem(scope, Locatable, Synthesize, Count, Show, ShowSet, Refable, Outlinable)]
pub struct FigureElem {
/// The content of the figure. Often, an [image].
#[required]
pub body: Content,
/// The figure's placement on the page.
///
/// - `{none}`: The figure stays in-flow exactly where it was specified
/// like other content.
/// - `{auto}`: The figure picks `{top}` or `{bottom}` depending on which
/// is closer.
/// - `{top}`: The figure floats to the top of the page.
/// - `{bottom}`: The figure floats to the bottom of the page.
///
/// The gap between the main flow content and the floating figure is
/// controlled by the [`clearance`]($place.clearance) argument on the
/// `place` function.
///
/// ```example
/// #set page(height: 200pt)
///
/// = Introduction
/// #figure(
/// placement: bottom,
/// caption: [A glacier],
/// image("glacier.jpg", width: 60%),
/// )
/// #lorem(60)
/// ```
pub placement: Option<Smart<VAlignment>>,
/// Relative to which containing scope the figure is placed.
///
/// Set this to `{"parent"}` to create a full-width figure in a two-column
/// document.
///
/// Has no effect if `placement` is `{none}`.
///
/// ```example
/// #set page(height: 250pt, columns: 2)
///
/// = Introduction
/// #figure(
/// placement: bottom,
/// scope: "parent",
/// caption: [A glacier],
/// image("glacier.jpg", width: 60%),
/// )
/// #lorem(60)
/// ```
pub scope: PlacementScope,
/// The figure's caption.
#[borrowed]
pub caption: Option<Packed<FigureCaption>>,
/// The kind of figure this is.
///
/// All figures of the same kind share a common counter.
///
/// If set to `{auto}`, the figure will try to automatically determine its
/// kind based on the type of its body. Automatically detected kinds are
/// [tables]($table) and [code]($raw). In other cases, the inferred kind is
/// that of an [image].
///
/// Setting this to something other than `{auto}` will override the
/// automatic detection. This can be useful if
/// - you wish to create a custom figure type that is not an
/// [image], a [table] or [code]($raw),
/// - you want to force the figure to use a specific counter regardless of
/// its content.
///
/// You can set the kind to be an element function or a string. If you set
/// it to an element function other than [`{table}`]($table), [`{raw}`](raw)
/// or [`{image}`](image), you will need to manually specify the figure's
/// supplement.
///
/// ```example
/// #figure(
/// circle(radius: 10pt),
/// caption: [A curious atom.],
/// kind: "atom",
/// supplement: [Atom],
/// )
/// ```
pub kind: Smart<FigureKind>,
/// The figure's supplement.
///
/// If set to `{auto}`, the figure will try to automatically determine the
/// correct supplement based on the `kind` and the active
/// [text language]($text.lang). If you are using a custom figure type, you
/// will need to manually specify the supplement.
///
/// If a function is specified, it is passed the first descendant of the
/// specified `kind` (typically, the figure's body) and should return
/// content.
///
/// ```example
/// #figure(
/// [The contents of my figure!],
/// caption: [My custom figure],
/// supplement: [Bar],
/// kind: "foo",
/// )
/// ```
#[borrowed]
pub supplement: Smart<Option<Supplement>>,
/// How to number the figure. Accepts a
/// [numbering pattern or function]($numbering).
#[default(Some(NumberingPattern::from_str("1").unwrap().into()))]
#[borrowed]
pub numbering: Option<Numbering>,
/// The vertical gap between the body and caption.
#[default(Em::new(0.65).into())]
pub gap: Length,
/// Whether the figure should appear in an [`outline`] of figures.
#[default(true)]
pub outlined: bool,
/// Convenience field to get access to the counter for this figure.
///
/// The counter only depends on the `kind`:
/// - For (tables)[@table]: `{counter(figure.where(kind: table))}`
/// - For (images)[@image]: `{counter(figure.where(kind: image))}`
/// - For a custom kind: `{counter(figure.where(kind: kind))}`
///
/// These are the counters you'll need to modify if you want to skip a
/// number or reset the counter.
#[synthesized]
pub counter: Option<Counter>,
}
#[scope]
impl FigureElem {
#[elem]
type FigureCaption;
}
impl Synthesize for Packed<FigureElem> {
fn synthesize(
&mut self,
engine: &mut Engine,
styles: StyleChain,
) -> SourceResult<()> {
let span = self.span();
let location = self.location();
let elem = self.as_mut();
let numbering = elem.numbering(styles);
// Determine the figure's kind.
let kind = elem.kind(styles).unwrap_or_else(|| {
elem.body
.query_first(&Selector::can::<dyn Figurable>())
.map(|elem| FigureKind::Elem(elem.func()))
.unwrap_or_else(|| FigureKind::Elem(ImageElem::elem()))
});
// Resolve the supplement.
let supplement = match elem.supplement(styles).as_ref() {
Smart::Auto => {
// Default to the local name for the kind, if available.
let name = match &kind {
FigureKind::Elem(func) => func
.local_name(
TextElem::lang_in(styles),
TextElem::region_in(styles),
)
.map(TextElem::packed),
FigureKind::Name(_) => None,
};
if numbering.is_some() && name.is_none() {
bail!(span, "please specify the figure's supplement")
}
Some(name.unwrap_or_default())
}
Smart::Custom(None) => None,
Smart::Custom(Some(supplement)) => {
// Resolve the supplement with the first descendant of the kind or
// just the body, if none was found.
let descendant = match kind {
FigureKind::Elem(func) => {
elem.body.query_first(&Selector::Elem(func, None)).map(Cow::Owned)
}
FigureKind::Name(_) => None,
};
let target = descendant.unwrap_or_else(|| Cow::Borrowed(&elem.body));
Some(supplement.resolve(engine, styles, [target])?)
}
};
// Construct the figure's counter.
let counter = Counter::new(CounterKey::Selector(
select_where!(FigureElem, Kind => kind.clone()),
));
// Fill the figure's caption.
let mut caption = elem.caption(styles).clone();
if let Some(caption) = &mut caption {
caption.synthesize(engine, styles)?;
caption.push_kind(kind.clone());
caption.push_supplement(supplement.clone());
caption.push_numbering(numbering.clone());
caption.push_counter(Some(counter.clone()));
caption.push_figure_location(location);
}
elem.push_kind(Smart::Custom(kind));
elem.push_supplement(Smart::Custom(supplement.map(Supplement::Content)));
elem.push_counter(Some(counter));
elem.push_caption(caption);
Ok(())
}
}
impl Show for Packed<FigureElem> {
#[typst_macros::time(name = "figure", span = self.span())]
fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
let span = self.span();
let target = TargetElem::target_in(styles);
let mut realized = self.body.clone();
// Build the caption, if any.
if let Some(caption) = self.caption(styles).clone() {
let (first, second) = match caption.position(styles) {
OuterVAlignment::Top => (caption.pack(), realized),
OuterVAlignment::Bottom => (realized, caption.pack()),
};
let mut seq = Vec::with_capacity(3);
seq.push(first);
if !target.is_html() {
let v = VElem::new(self.gap(styles).into()).with_weak(true);
seq.push(v.pack().spanned(span))
}
seq.push(second);
realized = Content::sequence(seq)
}
// Ensure that the body is considered a paragraph.
realized += ParbreakElem::shared().clone().spanned(span);
if target.is_html() {
return Ok(HtmlElem::new(tag::figure)
.with_body(Some(realized))
.pack()
.spanned(span));
}
// Wrap the contents in a block.
realized = BlockElem::new()
.with_body(Some(BlockBody::Content(realized)))
.pack()
.spanned(span);
// Wrap in a float.
if let Some(align) = self.placement(styles) {
realized = PlaceElem::new(realized)
.with_alignment(align.map(|align| HAlignment::Center + align))
.with_scope(self.scope(styles))
.with_float(true)
.pack()
.spanned(span);
} else if self.scope(styles) == PlacementScope::Parent {
bail!(
span,
"parent-scoped placement is only available for floating figures";
hint: "you can enable floating placement with `figure(placement: auto, ..)`"
);
}
Ok(realized)
}
}
impl ShowSet for Packed<FigureElem> {
fn show_set(&self, _: StyleChain) -> Styles {
// Still allows breakable figures with
// `show figure: set block(breakable: true)`.
let mut map = Styles::new();
map.set(BlockElem::set_breakable(false));
map.set(AlignElem::set_alignment(Alignment::CENTER));
map
}
}
impl Count for Packed<FigureElem> {
fn update(&self) -> Option<CounterUpdate> {
// If the figure is numbered, step the counter by one.
// This steps the `counter(figure)` which is global to all numbered figures.
self.numbering()
.is_some()
.then(|| CounterUpdate::Step(NonZeroUsize::ONE))
}
}
impl Refable for Packed<FigureElem> {
fn supplement(&self) -> Content {
// After synthesis, this should always be custom content.
match (**self).supplement(StyleChain::default()).as_ref() {
Smart::Custom(Some(Supplement::Content(content))) => content.clone(),
_ => Content::empty(),
}
}
fn counter(&self) -> Counter {
(**self)
.counter()
.cloned()
.flatten()
.unwrap_or_else(|| Counter::of(FigureElem::elem()))
}
fn numbering(&self) -> Option<&Numbering> {
(**self).numbering(StyleChain::default()).as_ref()
}
}
impl Outlinable for Packed<FigureElem> {
fn outlined(&self) -> bool {
(**self).outlined(StyleChain::default())
&& (self.caption(StyleChain::default()).is_some()
|| self.numbering().is_some())
}
fn prefix(&self, numbers: Content) -> Content {
let supplement = self.supplement();
if !supplement.is_empty() {
supplement + TextElem::packed('\u{a0}') + numbers
} else {
numbers
}
}
fn body(&self) -> Content {
self.caption(StyleChain::default())
.as_ref()
.map(|caption| caption.body.clone())
.unwrap_or_default()
}
}
/// The caption of a figure. This element can be used in set and show rules to
/// customize the appearance of captions for all figures or figures of a
/// specific kind.
///
/// In addition to its `position` and `body`, the `caption` also provides the
/// figure's `kind`, `supplement`, `counter`, and `numbering` as fields. These
/// parts can be used in [`where`]($function.where) selectors and show rules to
/// build a completely custom caption.
///
/// ```example
/// #show figure.caption: emph
///
/// #figure(
/// rect[Hello],
/// caption: [A rectangle],
/// )
/// ```
#[elem(name = "caption", Synthesize, Show)]
pub struct FigureCaption {
/// The caption's position in the figure. Either `{top}` or `{bottom}`.
///
/// ```example
/// #show figure.where(
/// kind: table
/// ): set figure.caption(position: top)
///
/// #figure(
/// table(columns: 2)[A][B],
/// caption: [I'm up here],
/// )
///
/// #figure(
/// rect[Hi],
/// caption: [I'm down here],
/// )
///
/// #figure(
/// table(columns: 2)[A][B],
/// caption: figure.caption(
/// position: bottom,
/// [I'm down here too!]
/// )
/// )
/// ```
#[default(OuterVAlignment::Bottom)]
pub position: OuterVAlignment,
/// The separator which will appear between the number and body.
///
/// If set to `{auto}`, the separator will be adapted to the current
/// [language]($text.lang) and [region]($text.region).
///
/// ```example
/// #set figure.caption(separator: [ --- ])
///
/// #figure(
/// rect[Hello],
/// caption: [A rectangle],
/// )
/// ```
pub separator: Smart<Content>,
/// The caption's body.
///
/// Can be used alongside `kind`, `supplement`, `counter`, `numbering`, and
/// `location` to completely customize the caption.
///
/// ```example
/// #show figure.caption: it => [
/// #underline(it.body) |
/// #it.supplement
/// #context it.counter.display(it.numbering)
/// ]
///
/// #figure(
/// rect[Hello],
/// caption: [A rectangle],
/// )
/// ```
#[required]
pub body: Content,
/// The figure's supplement.
#[synthesized]
pub kind: FigureKind,
/// The figure's supplement.
#[synthesized]
pub supplement: Option<Content>,
/// How to number the figure.
#[synthesized]
pub numbering: Option<Numbering>,
/// The counter for the figure.
#[synthesized]
pub counter: Option<Counter>,
/// The figure's location.
#[internal]
#[synthesized]
pub figure_location: Option<Location>,
}
impl FigureCaption {
/// Gets the default separator in the given language and (optionally)
/// region.
fn local_separator(lang: Lang, _: Option<Region>) -> &'static str {
match lang {
Lang::CHINESE => "\u{2003}",
Lang::FRENCH => ".\u{a0} ",
Lang::RUSSIAN => ". ",
Lang::ENGLISH | _ => ": ",
}
}
fn get_separator(&self, styles: StyleChain) -> Content {
self.separator(styles).unwrap_or_else(|| {
TextElem::packed(Self::local_separator(
TextElem::lang_in(styles),
TextElem::region_in(styles),
))
})
}
}
impl Synthesize for Packed<FigureCaption> {
fn synthesize(&mut self, _: &mut Engine, styles: StyleChain) -> SourceResult<()> {
let elem = self.as_mut();
elem.push_separator(Smart::Custom(elem.get_separator(styles)));
Ok(())
}
}
impl Show for Packed<FigureCaption> {
#[typst_macros::time(name = "figure.caption", span = self.span())]
fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
let mut realized = self.body.clone();
if let (
Some(Some(mut supplement)),
Some(Some(numbering)),
Some(Some(counter)),
Some(Some(location)),
) = (
self.supplement().cloned(),
self.numbering(),
self.counter(),
self.figure_location(),
) {
let numbers = counter.display_at_loc(engine, *location, styles, numbering)?;
if !supplement.is_empty() {
supplement += TextElem::packed('\u{a0}');
}
realized = supplement + numbers + self.get_separator(styles) + realized;
}
Ok(if TargetElem::target_in(styles).is_html() {
HtmlElem::new(tag::figcaption)
.with_body(Some(realized))
.pack()
.spanned(self.span())
} else {
BlockElem::new()
.with_body(Some(BlockBody::Content(realized)))
.pack()
.spanned(self.span())
})
}
}
cast! {
FigureCaption,
v: Content => v.unpack::<Self>().unwrap_or_else(Self::new),
}
/// The `kind` parameter of a [`FigureElem`].
#[derive(Debug, Clone, PartialEq, Hash)]
pub enum FigureKind {
/// The kind is an element function.
Elem(Element),
/// The kind is a name.
Name(EcoString),
}
cast! {
FigureKind,
self => match self {
Self::Elem(v) => v.into_value(),
Self::Name(v) => v.into_value(),
},
v: Element => Self::Elem(v),
v: EcoString => Self::Name(v),
}
/// An element that can be auto-detected in a figure.
///
/// This trait is used to determine the type of a figure.
pub trait Figurable {}