typst/library/src/layout/container.rs
2022-12-02 13:21:36 +01:00

105 lines
3.1 KiB
Rust

use super::VNode;
use crate::prelude::*;
/// An inline-level container that sizes content.
#[derive(Debug, Hash)]
pub struct BoxNode {
/// How to size the content horizontally and vertically.
pub sizing: Axes<Option<Rel<Length>>>,
/// The content to be sized.
pub child: Content,
}
#[node(Layout, Inline)]
impl BoxNode {
fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
let width = args.named("width")?;
let height = args.named("height")?;
let body = args.eat::<Content>()?.unwrap_or_default();
Ok(body.boxed(Axes::new(width, height)))
}
}
impl Layout for BoxNode {
fn layout(
&self,
vt: &mut Vt,
styles: StyleChain,
regions: &Regions,
) -> SourceResult<Fragment> {
// The "pod" is the region into which the child will be layouted.
let pod = {
// Resolve the sizing to a concrete size.
let size = self
.sizing
.resolve(styles)
.zip(regions.base)
.map(|(s, b)| s.map(|v| v.relative_to(b)))
.unwrap_or(regions.first);
// Select the appropriate base and expansion for the child depending
// on whether it is automatically or relatively sized.
let is_auto = self.sizing.as_ref().map(Option::is_none);
let base = is_auto.select(regions.base, size);
let expand = regions.expand | !is_auto;
Regions::one(size, base, expand)
};
// Layout the child.
let mut frame = self.child.layout(vt, styles, &pod)?.into_frame();
// Ensure frame size matches regions size if expansion is on.
let target = regions.expand.select(regions.first, frame.size());
frame.resize(target, Align::LEFT_TOP);
Ok(Fragment::frame(frame))
}
}
impl Inline for BoxNode {}
/// A block-level container that places content into a separate flow.
#[derive(Debug, Hash)]
pub struct BlockNode(pub Content);
#[node(Layout)]
impl BlockNode {
/// The spacing between the previous and this block.
#[property(skip)]
pub const ABOVE: VNode = VNode::block_spacing(Em::new(1.2).into());
/// The spacing between this and the following block.
#[property(skip)]
pub const BELOW: VNode = VNode::block_spacing(Em::new(1.2).into());
/// Whether this block must stick to the following one.
#[property(skip)]
pub const STICKY: bool = false;
fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
Ok(Self(args.eat()?.unwrap_or_default()).pack())
}
fn set(...) {
let spacing = args.named("spacing")?.map(VNode::block_spacing);
styles.set_opt(
Self::ABOVE,
args.named("above")?.map(VNode::block_around).or(spacing),
);
styles.set_opt(
Self::BELOW,
args.named("below")?.map(VNode::block_around).or(spacing),
);
}
}
impl Layout for BlockNode {
fn layout(
&self,
vt: &mut Vt,
styles: StyleChain,
regions: &Regions,
) -> SourceResult<Fragment> {
self.0.layout(vt, styles, regions)
}
}