diff options
Diffstat (limited to 'crates/typst-library/src/layout/mod.rs')
| -rw-r--r-- | crates/typst-library/src/layout/mod.rs | 709 |
1 files changed, 709 insertions, 0 deletions
diff --git a/crates/typst-library/src/layout/mod.rs b/crates/typst-library/src/layout/mod.rs new file mode 100644 index 00000000..41490eb8 --- /dev/null +++ b/crates/typst-library/src/layout/mod.rs @@ -0,0 +1,709 @@ +//! Composable layouts. + +mod align; +mod columns; +mod container; +#[path = "enum.rs"] +mod enum_; +mod flow; +mod fragment; +mod grid; +mod hide; +mod list; +mod measure; +mod pad; +mod page; +mod par; +mod place; +mod regions; +mod repeat; +mod spacing; +mod stack; +mod table; +mod terms; +mod transform; + +pub use self::align::*; +pub use self::columns::*; +pub use self::container::*; +pub use self::enum_::*; +pub use self::flow::*; +pub use self::fragment::*; +pub use self::grid::*; +pub use self::hide::*; +pub use self::list::*; +pub use self::measure::*; +pub use self::pad::*; +pub use self::page::*; +pub use self::par::*; +pub use self::place::*; +pub use self::regions::*; +pub use self::repeat::*; +pub use self::spacing::*; +pub use self::stack::*; +pub use self::table::*; +pub use self::terms::*; +pub use self::transform::*; + +use std::mem; + +use typed_arena::Arena; +use typst::diag::SourceResult; +use typst::eval::Tracer; +use typst::model::DelayedErrors; +use typst::model::{applicable, realize, StyleVecBuilder}; + +use crate::math::{EquationElem, LayoutMath}; +use crate::meta::DocumentElem; +use crate::prelude::*; +use crate::shared::BehavedBuilder; +use crate::text::{LinebreakElem, SmartQuoteElem, SpaceElem, TextElem}; +use crate::visualize::{ + CircleElem, EllipseElem, ImageElem, LineElem, PathElem, PolygonElem, RectElem, + SquareElem, +}; + +/// Hook up all layout definitions. +pub(super) fn define(global: &mut Scope) { + global.define("page", PageElem::func()); + global.define("pagebreak", PagebreakElem::func()); + global.define("v", VElem::func()); + global.define("par", ParElem::func()); + global.define("parbreak", ParbreakElem::func()); + global.define("h", HElem::func()); + global.define("box", BoxElem::func()); + global.define("block", BlockElem::func()); + global.define("list", ListElem::func()); + global.define("enum", EnumElem::func()); + global.define("terms", TermsElem::func()); + global.define("table", TableElem::func()); + global.define("stack", StackElem::func()); + global.define("grid", GridElem::func()); + global.define("columns", ColumnsElem::func()); + global.define("colbreak", ColbreakElem::func()); + global.define("place", PlaceElem::func()); + global.define("align", AlignElem::func()); + global.define("pad", PadElem::func()); + global.define("repeat", RepeatElem::func()); + global.define("move", MoveElem::func()); + global.define("scale", ScaleElem::func()); + global.define("rotate", RotateElem::func()); + global.define("hide", HideElem::func()); + global.define("measure", measure_func()); + global.define("ltr", Dir::LTR); + global.define("rtl", Dir::RTL); + global.define("ttb", Dir::TTB); + global.define("btt", Dir::BTT); + global.define("start", GenAlign::Start); + global.define("end", GenAlign::End); + global.define("left", GenAlign::Specific(Align::Left)); + global.define("center", GenAlign::Specific(Align::Center)); + global.define("right", GenAlign::Specific(Align::Right)); + global.define("top", GenAlign::Specific(Align::Top)); + global.define("horizon", GenAlign::Specific(Align::Horizon)); + global.define("bottom", GenAlign::Specific(Align::Bottom)); +} + +/// Root-level layout. +pub trait LayoutRoot { + /// Layout into one frame per page. + fn layout_root(&self, vt: &mut Vt, styles: StyleChain) -> SourceResult<Document>; +} + +impl LayoutRoot for Content { + #[tracing::instrument(name = "Content::layout_root", skip_all)] + fn layout_root(&self, vt: &mut Vt, styles: StyleChain) -> SourceResult<Document> { + #[comemo::memoize] + fn cached( + content: &Content, + world: Tracked<dyn World + '_>, + introspector: Tracked<Introspector>, + locator: Tracked<Locator>, + delayed: TrackedMut<DelayedErrors>, + tracer: TrackedMut<Tracer>, + styles: StyleChain, + ) -> SourceResult<Document> { + let mut locator = Locator::chained(locator); + let mut vt = Vt { + world, + introspector, + locator: &mut locator, + delayed, + tracer, + }; + let scratch = Scratch::default(); + let (realized, styles) = realize_root(&mut vt, &scratch, content, styles)?; + realized + .with::<dyn LayoutRoot>() + .unwrap() + .layout_root(&mut vt, styles) + } + + tracing::info!("Starting layout"); + cached( + self, + vt.world, + vt.introspector, + vt.locator.track(), + TrackedMut::reborrow_mut(&mut vt.delayed), + TrackedMut::reborrow_mut(&mut vt.tracer), + styles, + ) + } +} + +/// Layout into regions. +pub trait Layout { + /// Layout into one frame per region. + fn layout( + &self, + vt: &mut Vt, + styles: StyleChain, + regions: Regions, + ) -> SourceResult<Fragment>; + + /// Layout without side effects. + /// + /// This element must be layouted again in the same order for the results to + /// be valid. + #[tracing::instrument(name = "Layout::measure", skip_all)] + fn measure( + &self, + vt: &mut Vt, + styles: StyleChain, + regions: Regions, + ) -> SourceResult<Fragment> { + let mut locator = Locator::chained(vt.locator.track()); + let mut vt = Vt { + world: vt.world, + introspector: vt.introspector, + locator: &mut locator, + tracer: TrackedMut::reborrow_mut(&mut vt.tracer), + delayed: TrackedMut::reborrow_mut(&mut vt.delayed), + }; + self.layout(&mut vt, styles, regions) + } +} + +impl Layout for Content { + #[tracing::instrument(name = "Content::layout", skip_all)] + fn layout( + &self, + vt: &mut Vt, + styles: StyleChain, + regions: Regions, + ) -> SourceResult<Fragment> { + #[allow(clippy::too_many_arguments)] + #[comemo::memoize] + fn cached( + content: &Content, + world: Tracked<dyn World + '_>, + introspector: Tracked<Introspector>, + locator: Tracked<Locator>, + delayed: TrackedMut<DelayedErrors>, + tracer: TrackedMut<Tracer>, + styles: StyleChain, + regions: Regions, + ) -> SourceResult<Fragment> { + let mut locator = Locator::chained(locator); + let mut vt = Vt { + world, + introspector, + locator: &mut locator, + delayed, + tracer, + }; + let scratch = Scratch::default(); + let (realized, styles) = realize_block(&mut vt, &scratch, content, styles)?; + realized + .with::<dyn Layout>() + .unwrap() + .layout(&mut vt, styles, regions) + } + + tracing::info!("Layouting `Content`"); + + let fragment = cached( + self, + vt.world, + vt.introspector, + vt.locator.track(), + TrackedMut::reborrow_mut(&mut vt.delayed), + TrackedMut::reborrow_mut(&mut vt.tracer), + styles, + regions, + )?; + + vt.locator.visit_frames(&fragment); + Ok(fragment) + } +} + +/// Realize into an element that is capable of root-level layout. +#[tracing::instrument(skip_all)] +fn realize_root<'a>( + vt: &mut Vt, + scratch: &'a Scratch<'a>, + content: &'a Content, + styles: StyleChain<'a>, +) -> SourceResult<(Content, StyleChain<'a>)> { + if content.can::<dyn LayoutRoot>() && !applicable(content, styles) { + return Ok((content.clone(), styles)); + } + + let mut builder = Builder::new(vt, scratch, true); + builder.accept(content, styles)?; + builder.interrupt_page(Some(styles))?; + let (pages, shared) = builder.doc.unwrap().pages.finish(); + Ok((DocumentElem::new(pages.to_vec()).pack(), shared)) +} + +/// Realize into an element that is capable of block-level layout. +#[tracing::instrument(skip_all)] +fn realize_block<'a>( + vt: &mut Vt, + scratch: &'a Scratch<'a>, + content: &'a Content, + styles: StyleChain<'a>, +) -> SourceResult<(Content, StyleChain<'a>)> { + if content.can::<dyn Layout>() + && !content.is::<LineElem>() + && !content.is::<RectElem>() + && !content.is::<SquareElem>() + && !content.is::<EllipseElem>() + && !content.is::<CircleElem>() + && !content.is::<ImageElem>() + && !content.is::<PolygonElem>() + && !content.is::<PathElem>() + && !applicable(content, styles) + { + return Ok((content.clone(), styles)); + } + + let mut builder = Builder::new(vt, scratch, false); + builder.accept(content, styles)?; + builder.interrupt_par()?; + let (children, shared) = builder.flow.0.finish(); + Ok((FlowElem::new(children.to_vec()).pack(), shared)) +} + +/// Builds a document or a flow element from content. +struct Builder<'a, 'v, 't> { + /// The virtual typesetter. + vt: &'v mut Vt<'t>, + /// Scratch arenas for building. + scratch: &'a Scratch<'a>, + /// The current document building state. + doc: Option<DocBuilder<'a>>, + /// The current flow building state. + flow: FlowBuilder<'a>, + /// The current paragraph building state. + par: ParBuilder<'a>, + /// The current list building state. + list: ListBuilder<'a>, +} + +/// Temporary storage arenas for building. +#[derive(Default)] +struct Scratch<'a> { + /// An arena where intermediate style chains are stored. + styles: Arena<StyleChain<'a>>, + /// An arena where intermediate content resulting from show rules is stored. + content: Arena<Content>, +} + +impl<'a, 'v, 't> Builder<'a, 'v, 't> { + fn new(vt: &'v mut Vt<'t>, scratch: &'a Scratch<'a>, top: bool) -> Self { + Self { + vt, + scratch, + doc: top.then(DocBuilder::default), + flow: FlowBuilder::default(), + par: ParBuilder::default(), + list: ListBuilder::default(), + } + } + + fn accept( + &mut self, + mut content: &'a Content, + styles: StyleChain<'a>, + ) -> SourceResult<()> { + if content.can::<dyn LayoutMath>() && !content.is::<EquationElem>() { + content = + self.scratch.content.alloc(EquationElem::new(content.clone()).pack()); + } + + if let Some(realized) = realize(self.vt, content, styles)? { + let stored = self.scratch.content.alloc(realized); + return self.accept(stored, styles); + } + + if let Some((elem, local)) = content.to_styled() { + return self.styled(elem, local, styles); + } + + if let Some(children) = content.to_sequence() { + for elem in children { + self.accept(elem, styles)?; + } + return Ok(()); + } + + if self.list.accept(content, styles) { + return Ok(()); + } + + self.interrupt_list()?; + + if self.list.accept(content, styles) { + return Ok(()); + } + + if self.par.accept(content, styles) { + return Ok(()); + } + + self.interrupt_par()?; + + if self.flow.accept(content, styles) { + return Ok(()); + } + + let keep = content + .to::<PagebreakElem>() + .map_or(false, |pagebreak| !pagebreak.weak(styles)); + + self.interrupt_page(keep.then_some(styles))?; + + if let Some(doc) = &mut self.doc { + if doc.accept(content, styles) { + return Ok(()); + } + } + + if content.is::<PagebreakElem>() { + bail!(content.span(), "pagebreaks are not allowed inside of containers"); + } else { + bail!(content.span(), "{} is not allowed here", content.func().name()); + } + } + + fn styled( + &mut self, + elem: &'a Content, + map: &'a Styles, + styles: StyleChain<'a>, + ) -> SourceResult<()> { + let stored = self.scratch.styles.alloc(styles); + let styles = stored.chain(map); + self.interrupt_style(map, None)?; + self.accept(elem, styles)?; + self.interrupt_style(map, Some(styles))?; + Ok(()) + } + + fn interrupt_style( + &mut self, + local: &Styles, + outer: Option<StyleChain<'a>>, + ) -> SourceResult<()> { + if let Some(Some(span)) = local.interruption::<DocumentElem>() { + if self.doc.is_none() { + bail!(span, "document set rules are not allowed inside of containers"); + } + if outer.is_none() + && (!self.flow.0.is_empty() + || !self.par.0.is_empty() + || !self.list.items.is_empty()) + { + bail!(span, "document set rules must appear before any content"); + } + } else if let Some(Some(span)) = local.interruption::<PageElem>() { + if self.doc.is_none() { + bail!(span, "page configuration is not allowed inside of containers"); + } + self.interrupt_page(outer)?; + } else if local.interruption::<ParElem>().is_some() + || local.interruption::<AlignElem>().is_some() + { + self.interrupt_par()?; + } else if local.interruption::<ListElem>().is_some() + || local.interruption::<EnumElem>().is_some() + || local.interruption::<TermsElem>().is_some() + { + self.interrupt_list()?; + } + Ok(()) + } + + fn interrupt_list(&mut self) -> SourceResult<()> { + if !self.list.items.is_empty() { + let staged = mem::take(&mut self.list.staged); + let (list, styles) = mem::take(&mut self.list).finish(); + let stored = self.scratch.content.alloc(list); + self.accept(stored, styles)?; + for (content, styles) in staged { + self.accept(content, styles)?; + } + } + Ok(()) + } + + fn interrupt_par(&mut self) -> SourceResult<()> { + self.interrupt_list()?; + if !self.par.0.is_empty() { + let (par, styles) = mem::take(&mut self.par).finish(); + let stored = self.scratch.content.alloc(par); + self.accept(stored, styles)?; + } + + Ok(()) + } + + fn interrupt_page(&mut self, styles: Option<StyleChain<'a>>) -> SourceResult<()> { + self.interrupt_par()?; + let Some(doc) = &mut self.doc else { return Ok(()) }; + if !self.flow.0.is_empty() || (doc.keep_next && styles.is_some()) { + let (flow, shared) = mem::take(&mut self.flow).0.finish(); + let styles = if shared == StyleChain::default() { + styles.unwrap_or_default() + } else { + shared + }; + let page = PageElem::new(FlowElem::new(flow.to_vec()).pack()); + let stored = self.scratch.content.alloc(page.pack()); + self.accept(stored, styles)?; + } + Ok(()) + } +} + +/// Accepts pagebreaks and pages. +struct DocBuilder<'a> { + /// The page runs built so far. + pages: StyleVecBuilder<'a, Content>, + /// Whether to keep a following page even if it is empty. + keep_next: bool, + /// Whether the next page should be cleared to an even or odd number. + clear_next: Option<Parity>, +} + +impl<'a> DocBuilder<'a> { + fn accept(&mut self, content: &Content, styles: StyleChain<'a>) -> bool { + if let Some(pagebreak) = content.to::<PagebreakElem>() { + self.keep_next = !pagebreak.weak(styles); + self.clear_next = pagebreak.to(styles); + return true; + } + + if let Some(page) = content.to::<PageElem>() { + let elem = if let Some(clear_to) = self.clear_next.take() { + let mut page = page.clone(); + page.push_clear_to(Some(clear_to)); + page.pack() + } else { + content.clone() + }; + + self.pages.push(elem, styles); + self.keep_next = false; + return true; + } + + false + } +} + +impl Default for DocBuilder<'_> { + fn default() -> Self { + Self { + pages: StyleVecBuilder::new(), + keep_next: true, + clear_next: None, + } + } +} + +/// Accepts flow content. +#[derive(Default)] +struct FlowBuilder<'a>(BehavedBuilder<'a>, bool); + +impl<'a> FlowBuilder<'a> { + fn accept(&mut self, content: &'a Content, styles: StyleChain<'a>) -> bool { + if content.is::<ParbreakElem>() { + self.1 = true; + return true; + } + + let last_was_parbreak = self.1; + self.1 = false; + + if content.is::<VElem>() + || content.is::<ColbreakElem>() + || content.is::<MetaElem>() + { + self.0.push(content.clone(), styles); + return true; + } + + if content.can::<dyn Layout>() || content.is::<ParElem>() { + let is_tight_list = if let Some(elem) = content.to::<ListElem>() { + elem.tight(styles) + } else if let Some(elem) = content.to::<EnumElem>() { + elem.tight(styles) + } else if let Some(elem) = content.to::<TermsElem>() { + elem.tight(styles) + } else { + false + }; + + if !last_was_parbreak && is_tight_list { + let leading = ParElem::leading_in(styles); + let spacing = VElem::list_attach(leading.into()); + self.0.push(spacing.pack(), styles); + } + + let (above, below) = if let Some(block) = content.to::<BlockElem>() { + (block.above(styles), block.below(styles)) + } else { + (BlockElem::above_in(styles), BlockElem::below_in(styles)) + }; + + self.0.push(above.pack(), styles); + self.0.push(content.clone(), styles); + self.0.push(below.pack(), styles); + return true; + } + + false + } +} + +/// Accepts paragraph content. +#[derive(Default)] +struct ParBuilder<'a>(BehavedBuilder<'a>); + +impl<'a> ParBuilder<'a> { + fn accept(&mut self, content: &'a Content, styles: StyleChain<'a>) -> bool { + if content.is::<MetaElem>() { + if !self.0.is_basically_empty() { + self.0.push(content.clone(), styles); + return true; + } + } else if content.is::<SpaceElem>() + || content.is::<TextElem>() + || content.is::<HElem>() + || content.is::<LinebreakElem>() + || content.is::<SmartQuoteElem>() + || content.to::<EquationElem>().map_or(false, |elem| !elem.block(styles)) + || content.is::<BoxElem>() + { + self.0.push(content.clone(), styles); + return true; + } + + false + } + + fn finish(self) -> (Content, StyleChain<'a>) { + let (children, shared) = self.0.finish(); + (ParElem::new(children.to_vec()).pack(), shared) + } +} + +/// Accepts list / enum items, spaces, paragraph breaks. +struct ListBuilder<'a> { + /// The list items collected so far. + items: StyleVecBuilder<'a, Content>, + /// Whether the list contains no paragraph breaks. + tight: bool, + /// Trailing content for which it is unclear whether it is part of the list. + staged: Vec<(&'a Content, StyleChain<'a>)>, +} + +impl<'a> ListBuilder<'a> { + fn accept(&mut self, content: &'a Content, styles: StyleChain<'a>) -> bool { + if !self.items.is_empty() + && (content.is::<SpaceElem>() || content.is::<ParbreakElem>()) + { + self.staged.push((content, styles)); + return true; + } + + if (content.is::<ListItem>() + || content.is::<EnumItem>() + || content.is::<TermItem>()) + && self + .items + .elems() + .next() + .map_or(true, |first| first.func() == content.func()) + { + self.items.push(content.clone(), styles); + self.tight &= self.staged.drain(..).all(|(t, _)| !t.is::<ParbreakElem>()); + return true; + } + + false + } + + fn finish(self) -> (Content, StyleChain<'a>) { + let (items, shared) = self.items.finish(); + let item = items.items().next().unwrap(); + let output = if item.is::<ListItem>() { + ListElem::new( + items + .iter() + .map(|(item, local)| { + let item = item.to::<ListItem>().unwrap(); + item.clone().with_body(item.body().styled_with_map(local.clone())) + }) + .collect::<Vec<_>>(), + ) + .with_tight(self.tight) + .pack() + } else if item.is::<EnumItem>() { + EnumElem::new( + items + .iter() + .map(|(item, local)| { + let item = item.to::<EnumItem>().unwrap(); + item.clone().with_body(item.body().styled_with_map(local.clone())) + }) + .collect::<Vec<_>>(), + ) + .with_tight(self.tight) + .pack() + } else if item.is::<TermItem>() { + TermsElem::new( + items + .iter() + .map(|(item, local)| { + let item = item.to::<TermItem>().unwrap(); + item.clone() + .with_term(item.term().styled_with_map(local.clone())) + .with_description( + item.description().styled_with_map(local.clone()), + ) + }) + .collect::<Vec<_>>(), + ) + .with_tight(self.tight) + .pack() + } else { + unreachable!() + }; + (output, shared) + } +} + +impl Default for ListBuilder<'_> { + fn default() -> Self { + Self { + items: StyleVecBuilder::default(), + tight: true, + staged: vec![], + } + } +} |