typst_library/layout/
dir.rs

1use ecow::EcoString;
2
3use crate::foundations::{func, scope, ty, Repr};
4use crate::layout::{Axis, Side};
5
6/// The four directions into which content can be laid out.
7///
8///  Possible values are:
9/// - `{ltr}`: Left to right.
10/// - `{rtl}`: Right to left.
11/// - `{ttb}`: Top to bottom.
12/// - `{btt}`: Bottom to top.
13///
14/// These values are available globally and
15/// also in the direction type's scope, so you can write either of the following
16/// two:
17/// ```example
18/// #stack(dir: rtl)[A][B][C]
19/// #stack(dir: direction.rtl)[A][B][C]
20/// ```
21#[ty(scope, name = "direction")]
22#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
23pub enum Dir {
24    /// Left to right.
25    LTR,
26    /// Right to left.
27    RTL,
28    /// Top to bottom.
29    TTB,
30    /// Bottom to top.
31    BTT,
32}
33
34impl Dir {
35    /// Whether this direction points into the positive coordinate direction.
36    ///
37    /// The positive directions are left-to-right and top-to-bottom.
38    pub const fn is_positive(self) -> bool {
39        match self {
40            Self::LTR | Self::TTB => true,
41            Self::RTL | Self::BTT => false,
42        }
43    }
44}
45
46#[scope]
47impl Dir {
48    pub const LTR: Self = Self::LTR;
49    pub const RTL: Self = Self::RTL;
50    pub const TTB: Self = Self::TTB;
51    pub const BTT: Self = Self::BTT;
52
53    /// The axis this direction belongs to, either `{"horizontal"}` or
54    /// `{"vertical"}`.
55    ///
56    /// ```example
57    /// #ltr.axis() \
58    /// #ttb.axis()
59    /// ```
60    #[func]
61    pub const fn axis(self) -> Axis {
62        match self {
63            Self::LTR | Self::RTL => Axis::X,
64            Self::TTB | Self::BTT => Axis::Y,
65        }
66    }
67
68    /// The start point of this direction, as an alignment.
69    ///
70    /// ```example
71    /// #ltr.start() \
72    /// #rtl.start() \
73    /// #ttb.start() \
74    /// #btt.start()
75    /// ```
76    #[func]
77    pub const fn start(self) -> Side {
78        match self {
79            Self::LTR => Side::Left,
80            Self::RTL => Side::Right,
81            Self::TTB => Side::Top,
82            Self::BTT => Side::Bottom,
83        }
84    }
85
86    /// The end point of this direction, as an alignment.
87    ///
88    /// ```example
89    /// #ltr.end() \
90    /// #rtl.end() \
91    /// #ttb.end() \
92    /// #btt.end()
93    /// ```
94    #[func]
95    pub const fn end(self) -> Side {
96        match self {
97            Self::LTR => Side::Right,
98            Self::RTL => Side::Left,
99            Self::TTB => Side::Bottom,
100            Self::BTT => Side::Top,
101        }
102    }
103
104    /// The inverse direction.
105    ///
106    /// ```example
107    /// #ltr.inv() \
108    /// #rtl.inv() \
109    /// #ttb.inv() \
110    /// #btt.inv()
111    /// ```
112    #[func(title = "Inverse")]
113    pub const fn inv(self) -> Dir {
114        match self {
115            Self::LTR => Self::RTL,
116            Self::RTL => Self::LTR,
117            Self::TTB => Self::BTT,
118            Self::BTT => Self::TTB,
119        }
120    }
121}
122
123impl Repr for Dir {
124    fn repr(&self) -> EcoString {
125        match self {
126            Self::LTR => "ltr".into(),
127            Self::RTL => "rtl".into(),
128            Self::TTB => "ttb".into(),
129            Self::BTT => "btt".into(),
130        }
131    }
132}
typst_library/layout/dir.rs

typst_library/layout/
dir.rs
