2024-10-27 18:04:55 +00:00

749 lines
20 KiB
Rust

use std::ops::Add;
use ecow::{eco_format, EcoString};
use crate::diag::{bail, HintedStrResult, SourceResult, StrResult};
use crate::engine::Engine;
use crate::foundations::{
cast, elem, func, scope, ty, CastInfo, Content, Fold, FromValue, IntoValue, Packed,
Reflect, Repr, Resolve, Show, StyleChain, Value,
};
use crate::layout::{Abs, Axes, Axis, Dir, Side};
use crate::text::TextElem;
/// Aligns content horizontally and vertically.
///
/// # Example
/// Let's start with centering our content horizontally:
/// ```example
/// #set page(height: 120pt)
/// #set align(center)
///
/// Centered text, a sight to see \
/// In perfect balance, visually \
/// Not left nor right, it stands alone \
/// A work of art, a visual throne
/// ```
///
/// To center something vertically, use _horizon_ alignment:
/// ```example
/// #set page(height: 120pt)
/// #set align(horizon)
///
/// Vertically centered, \
/// the stage had entered, \
/// a new paragraph.
/// ```
///
/// # Combining alignments
/// You can combine two alignments with the `+` operator. Let's also only apply
/// this to one piece of content by using the function form instead of a set
/// rule:
/// ```example
/// #set page(height: 120pt)
/// Though left in the beginning ...
///
/// #align(right + bottom)[
/// ... they were right in the end, \
/// and with addition had gotten, \
/// the paragraph to the bottom!
/// ]
/// ```
///
/// # Nested alignment
/// You can use varying alignments for layout containers and the elements within
/// them. This way, you can create intricate layouts:
///
/// ```example
/// #align(center, block[
/// #set align(left)
/// Though centered together \
/// alone \
/// we \
/// are \
/// left.
/// ])
/// ```
///
/// # Alignment within the same line
/// The `align` function performs block-level alignment and thus always
/// interrupts the current paragraph. To have different alignment for parts
/// of the same line, you should use [fractional spacing]($h) instead:
///
/// ```example
/// Start #h(1fr) End
/// ```
#[elem(Show)]
pub struct AlignElem {
/// The [alignment] along both axes.
///
/// ```example
/// #set page(height: 6cm)
/// #set text(lang: "ar")
///
/// مثال
/// #align(
/// end + horizon,
/// rect(inset: 12pt)[ركن]
/// )
/// ```
#[positional]
#[fold]
#[default]
pub alignment: Alignment,
/// The content to align.
#[required]
pub body: Content,
}
impl Show for Packed<AlignElem> {
#[typst_macros::time(name = "align", span = self.span())]
fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
Ok(self.body().clone().aligned(self.alignment(styles)))
}
}
/// Where to [align] something along an axis.
///
/// Possible values are:
/// - `start`: Aligns at the [start]($direction.start) of the [text
/// direction]($text.dir).
/// - `end`: Aligns at the [end]($direction.end) of the [text
/// direction]($text.dir).
/// - `left`: Align at the left.
/// - `center`: Aligns in the middle, horizontally.
/// - `right`: Aligns at the right.
/// - `top`: Aligns at the top.
/// - `horizon`: Aligns in the middle, vertically.
/// - `bottom`: Align at the bottom.
///
/// These values are available globally and also in the alignment type's scope,
/// so you can write either of the following two:
///
/// ```example
/// #align(center)[Hi]
/// #align(alignment.center)[Hi]
/// ```
///
/// # 2D alignments
/// To align along both axes at the same time, add the two alignments using the
/// `+` operator. For example, `top + right` aligns the content to the top right
/// corner.
///
/// ```example
/// #set page(height: 3cm)
/// #align(center + bottom)[Hi]
/// ```
///
/// # Fields
/// The `x` and `y` fields hold the alignment's horizontal and vertical
/// components, respectively (as yet another `alignment`). They may be `{none}`.
///
/// ```example
/// #(top + right).x \
/// #left.x \
/// #left.y (none)
/// ```
#[ty(scope)]
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum Alignment {
H(HAlignment),
V(VAlignment),
Both(HAlignment, VAlignment),
}
impl Alignment {
/// The horizontal component.
pub const fn x(self) -> Option<HAlignment> {
match self {
Self::H(h) | Self::Both(h, _) => Some(h),
Self::V(_) => None,
}
}
/// The vertical component.
pub const fn y(self) -> Option<VAlignment> {
match self {
Self::V(v) | Self::Both(_, v) => Some(v),
Self::H(_) => None,
}
}
/// Normalize the alignment to a LTR-TTB space.
pub fn fix(self, text_dir: Dir) -> Axes<FixedAlignment> {
Axes::new(
self.x().unwrap_or_default().fix(text_dir),
self.y().unwrap_or_default().fix(text_dir),
)
}
}
#[scope]
impl Alignment {
pub const START: Self = Alignment::H(HAlignment::Start);
pub const LEFT: Self = Alignment::H(HAlignment::Left);
pub const CENTER: Self = Alignment::H(HAlignment::Center);
pub const RIGHT: Self = Alignment::H(HAlignment::Right);
pub const END: Self = Alignment::H(HAlignment::End);
pub const TOP: Self = Alignment::V(VAlignment::Top);
pub const HORIZON: Self = Alignment::V(VAlignment::Horizon);
pub const BOTTOM: Self = Alignment::V(VAlignment::Bottom);
/// The axis this alignment belongs to.
/// - `{"horizontal"}` for `start`, `left`, `center`, `right`, and `end`
/// - `{"vertical"}` for `top`, `horizon`, and `bottom`
/// - `{none}` for 2-dimensional alignments
///
/// ```example
/// #left.axis() \
/// #bottom.axis()
/// ```
#[func]
pub const fn axis(self) -> Option<Axis> {
match self {
Self::H(_) => Some(Axis::X),
Self::V(_) => Some(Axis::Y),
Self::Both(..) => None,
}
}
/// The inverse alignment.
///
/// ```example
/// #top.inv() \
/// #left.inv() \
/// #center.inv() \
/// #(left + bottom).inv()
/// ```
#[func(title = "Inverse")]
pub const fn inv(self) -> Alignment {
match self {
Self::H(h) => Self::H(h.inv()),
Self::V(v) => Self::V(v.inv()),
Self::Both(h, v) => Self::Both(h.inv(), v.inv()),
}
}
}
impl Default for Alignment {
fn default() -> Self {
HAlignment::default() + VAlignment::default()
}
}
impl Add for Alignment {
type Output = StrResult<Self>;
fn add(self, rhs: Self) -> Self::Output {
match (self, rhs) {
(Self::H(h), Self::V(v)) | (Self::V(v), Self::H(h)) => Ok(h + v),
(Self::H(_), Self::H(_)) => bail!("cannot add two horizontal alignments"),
(Self::V(_), Self::V(_)) => bail!("cannot add two vertical alignments"),
(Self::H(_), Self::Both(..)) | (Self::Both(..), Self::H(_)) => {
bail!("cannot add a horizontal and a 2D alignment")
}
(Self::V(_), Self::Both(..)) | (Self::Both(..), Self::V(_)) => {
bail!("cannot add a vertical and a 2D alignment")
}
(Self::Both(..), Self::Both(..)) => {
bail!("cannot add two 2D alignments")
}
}
}
}
impl Repr for Alignment {
fn repr(&self) -> EcoString {
match self {
Self::H(h) => h.repr(),
Self::V(v) => v.repr(),
Self::Both(h, v) => eco_format!("{} + {}", h.repr(), v.repr()),
}
}
}
impl Fold for Alignment {
fn fold(self, outer: Self) -> Self {
match (self, outer) {
(Self::H(h), Self::V(v) | Self::Both(_, v)) => Self::Both(h, v),
(Self::V(v), Self::H(h) | Self::Both(h, _)) => Self::Both(h, v),
_ => self,
}
}
}
impl Resolve for Alignment {
type Output = Axes<FixedAlignment>;
fn resolve(self, styles: StyleChain) -> Self::Output {
self.fix(TextElem::dir_in(styles))
}
}
impl From<Side> for Alignment {
fn from(side: Side) -> Self {
match side {
Side::Left => Self::LEFT,
Side::Top => Self::TOP,
Side::Right => Self::RIGHT,
Side::Bottom => Self::BOTTOM,
}
}
}
/// Alignment on this axis can be fixed to an absolute direction.
pub trait FixAlignment {
/// Resolve to the absolute alignment.
fn fix(self, dir: Dir) -> FixedAlignment;
}
/// Where to align something horizontally.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub enum HAlignment {
#[default]
Start,
Left,
Center,
Right,
End,
}
impl HAlignment {
/// The inverse horizontal alignment.
pub const fn inv(self) -> Self {
match self {
Self::Start => Self::End,
Self::Left => Self::Right,
Self::Center => Self::Center,
Self::Right => Self::Left,
Self::End => Self::Start,
}
}
}
impl FixAlignment for HAlignment {
fn fix(self, dir: Dir) -> FixedAlignment {
match (self, dir.is_positive()) {
(Self::Start, true) | (Self::End, false) => FixedAlignment::Start,
(Self::Left, _) => FixedAlignment::Start,
(Self::Center, _) => FixedAlignment::Center,
(Self::Right, _) => FixedAlignment::End,
(Self::End, true) | (Self::Start, false) => FixedAlignment::End,
}
}
}
impl Repr for HAlignment {
fn repr(&self) -> EcoString {
match self {
Self::Start => "start".into(),
Self::Left => "left".into(),
Self::Center => "center".into(),
Self::Right => "right".into(),
Self::End => "end".into(),
}
}
}
impl Add<VAlignment> for HAlignment {
type Output = Alignment;
fn add(self, rhs: VAlignment) -> Self::Output {
Alignment::Both(self, rhs)
}
}
impl From<HAlignment> for Alignment {
fn from(align: HAlignment) -> Self {
Self::H(align)
}
}
impl TryFrom<Alignment> for HAlignment {
type Error = EcoString;
fn try_from(value: Alignment) -> StrResult<Self> {
match value {
Alignment::H(h) => Ok(h),
v => bail!(
"expected `start`, `left`, `center`, `right`, or `end`, found {}",
v.repr()
),
}
}
}
impl Resolve for HAlignment {
type Output = FixedAlignment;
fn resolve(self, styles: StyleChain) -> Self::Output {
self.fix(TextElem::dir_in(styles))
}
}
cast! {
HAlignment,
self => Alignment::H(self).into_value(),
align: Alignment => Self::try_from(align)?,
}
/// A horizontal alignment which only allows `left`/`right` and `start`/`end`,
/// thus excluding `center`.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub enum OuterHAlignment {
#[default]
Start,
Left,
Right,
End,
}
impl FixAlignment for OuterHAlignment {
fn fix(self, dir: Dir) -> FixedAlignment {
match (self, dir.is_positive()) {
(Self::Start, true) | (Self::End, false) => FixedAlignment::Start,
(Self::Left, _) => FixedAlignment::Start,
(Self::Right, _) => FixedAlignment::End,
(Self::End, true) | (Self::Start, false) => FixedAlignment::End,
}
}
}
impl Resolve for OuterHAlignment {
type Output = FixedAlignment;
fn resolve(self, styles: StyleChain) -> Self::Output {
self.fix(TextElem::dir_in(styles))
}
}
impl From<OuterHAlignment> for HAlignment {
fn from(value: OuterHAlignment) -> Self {
match value {
OuterHAlignment::Start => Self::Start,
OuterHAlignment::Left => Self::Left,
OuterHAlignment::Right => Self::Right,
OuterHAlignment::End => Self::End,
}
}
}
impl TryFrom<Alignment> for OuterHAlignment {
type Error = EcoString;
fn try_from(value: Alignment) -> StrResult<Self> {
match value {
Alignment::H(HAlignment::Start) => Ok(Self::Start),
Alignment::H(HAlignment::Left) => Ok(Self::Left),
Alignment::H(HAlignment::Right) => Ok(Self::Right),
Alignment::H(HAlignment::End) => Ok(Self::End),
v => bail!("expected `start`, `left`, `right`, or `end`, found {}", v.repr()),
}
}
}
cast! {
OuterHAlignment,
self => HAlignment::from(self).into_value(),
align: Alignment => Self::try_from(align)?,
}
/// Where to align something vertically.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum VAlignment {
#[default]
Top,
Horizon,
Bottom,
}
impl VAlignment {
/// The inverse vertical alignment.
pub const fn inv(self) -> Self {
match self {
Self::Top => Self::Bottom,
Self::Horizon => Self::Horizon,
Self::Bottom => Self::Top,
}
}
/// Returns the position of this alignment in a container with the given
/// extent.
pub fn position(self, extent: Abs) -> Abs {
match self {
Self::Top => Abs::zero(),
Self::Horizon => extent / 2.0,
Self::Bottom => extent,
}
}
}
impl FixAlignment for VAlignment {
fn fix(self, _: Dir) -> FixedAlignment {
// The vertical alignment does not depend on text direction.
match self {
Self::Top => FixedAlignment::Start,
Self::Horizon => FixedAlignment::Center,
Self::Bottom => FixedAlignment::End,
}
}
}
impl Repr for VAlignment {
fn repr(&self) -> EcoString {
match self {
Self::Top => "top".into(),
Self::Horizon => "horizon".into(),
Self::Bottom => "bottom".into(),
}
}
}
impl Add<HAlignment> for VAlignment {
type Output = Alignment;
fn add(self, rhs: HAlignment) -> Self::Output {
Alignment::Both(rhs, self)
}
}
impl Resolve for VAlignment {
type Output = FixedAlignment;
fn resolve(self, _: StyleChain) -> Self::Output {
self.fix(Dir::TTB)
}
}
impl From<VAlignment> for Alignment {
fn from(align: VAlignment) -> Self {
Self::V(align)
}
}
impl TryFrom<Alignment> for VAlignment {
type Error = EcoString;
fn try_from(value: Alignment) -> StrResult<Self> {
match value {
Alignment::V(v) => Ok(v),
v => bail!("expected `top`, `horizon`, or `bottom`, found {}", v.repr()),
}
}
}
cast! {
VAlignment,
self => Alignment::V(self).into_value(),
align: Alignment => Self::try_from(align)?,
}
/// A vertical alignment which only allows `top` and `bottom`, thus excluding
/// `horizon`.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum OuterVAlignment {
#[default]
Top,
Bottom,
}
impl FixAlignment for OuterVAlignment {
fn fix(self, _: Dir) -> FixedAlignment {
// The vertical alignment does not depend on text direction.
match self {
Self::Top => FixedAlignment::Start,
Self::Bottom => FixedAlignment::End,
}
}
}
impl From<OuterVAlignment> for VAlignment {
fn from(value: OuterVAlignment) -> Self {
match value {
OuterVAlignment::Top => Self::Top,
OuterVAlignment::Bottom => Self::Bottom,
}
}
}
impl TryFrom<Alignment> for OuterVAlignment {
type Error = EcoString;
fn try_from(value: Alignment) -> StrResult<Self> {
match value {
Alignment::V(VAlignment::Top) => Ok(Self::Top),
Alignment::V(VAlignment::Bottom) => Ok(Self::Bottom),
v => bail!("expected `top` or `bottom`, found {}", v.repr()),
}
}
}
cast! {
OuterVAlignment,
self => VAlignment::from(self).into_value(),
align: Alignment => Self::try_from(align)?,
}
/// An internal representation that combines horizontal or vertical alignments. The
/// allowed alignment positions are designated by the type parameter `H` and `V`.
///
/// This is not user-visible, but an internal type to impose type safety. For example,
/// `SpecificAlignment<HAlignment, OuterVAlignment>` does not allow vertical alignment
/// position "center", because `V = OuterVAlignment` doesn't have it.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum SpecificAlignment<H, V> {
H(H),
V(V),
Both(H, V),
}
impl<H, V> SpecificAlignment<H, V>
where
H: Default + Copy + FixAlignment,
V: Default + Copy + FixAlignment,
{
/// The horizontal component.
pub const fn x(self) -> Option<H> {
match self {
Self::H(h) | Self::Both(h, _) => Some(h),
Self::V(_) => None,
}
}
/// The vertical component.
pub const fn y(self) -> Option<V> {
match self {
Self::V(v) | Self::Both(_, v) => Some(v),
Self::H(_) => None,
}
}
/// Normalize the alignment to a LTR-TTB space.
pub fn fix(self, text_dir: Dir) -> Axes<FixedAlignment> {
Axes::new(
self.x().unwrap_or_default().fix(text_dir),
self.y().unwrap_or_default().fix(text_dir),
)
}
}
impl<H, V> Resolve for SpecificAlignment<H, V>
where
H: Default + Copy + FixAlignment,
V: Default + Copy + FixAlignment,
{
type Output = Axes<FixedAlignment>;
fn resolve(self, styles: StyleChain) -> Self::Output {
self.fix(TextElem::dir_in(styles))
}
}
impl<H, V> From<SpecificAlignment<H, V>> for Alignment
where
HAlignment: From<H>,
VAlignment: From<V>,
{
fn from(value: SpecificAlignment<H, V>) -> Self {
type FromType<H, V> = SpecificAlignment<H, V>;
match value {
FromType::H(h) => Self::H(HAlignment::from(h)),
FromType::V(v) => Self::V(VAlignment::from(v)),
FromType::Both(h, v) => Self::Both(HAlignment::from(h), VAlignment::from(v)),
}
}
}
impl<H, V> Reflect for SpecificAlignment<H, V>
where
H: Reflect,
V: Reflect,
{
fn input() -> CastInfo {
Alignment::input()
}
fn output() -> CastInfo {
Alignment::output()
}
fn castable(value: &Value) -> bool {
H::castable(value) || V::castable(value)
}
}
impl<H, V> IntoValue for SpecificAlignment<H, V>
where
HAlignment: From<H>,
VAlignment: From<V>,
{
fn into_value(self) -> Value {
Alignment::from(self).into_value()
}
}
impl<H, V> FromValue for SpecificAlignment<H, V>
where
H: Reflect + TryFrom<Alignment, Error = EcoString>,
V: Reflect + TryFrom<Alignment, Error = EcoString>,
{
fn from_value(value: Value) -> HintedStrResult<Self> {
if Alignment::castable(&value) {
let align = Alignment::from_value(value)?;
let result = match align {
Alignment::H(_) => Self::H(H::try_from(align)?),
Alignment::V(_) => Self::V(V::try_from(align)?),
Alignment::Both(h, v) => {
Self::Both(H::try_from(h.into())?, V::try_from(v.into())?)
}
};
return Ok(result);
}
Err(Self::error(&value))
}
}
/// A fixed alignment in the global coordinate space.
///
/// For horizontal alignment, start is globally left and for vertical alignment
/// it is globally top.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub enum FixedAlignment {
Start,
Center,
End,
}
impl FixedAlignment {
/// Returns the position of this alignment in a container with the given
/// extent.
pub fn position(self, extent: Abs) -> Abs {
match self {
Self::Start => Abs::zero(),
Self::Center => extent / 2.0,
Self::End => extent,
}
}
/// The inverse alignment.
pub const fn inv(self) -> Self {
match self {
Self::Start => Self::End,
Self::Center => Self::Center,
Self::End => Self::Start,
}
}
}
impl From<Side> for FixedAlignment {
fn from(side: Side) -> Self {
match side {
Side::Left => Self::Start,
Side::Top => Self::Start,
Side::Right => Self::End,
Side::Bottom => Self::End,
}
}
}