rat_reloc/
lib.rs

1#![doc = include_str!("../readme.md")]
2
3use ratatui::layout::{Position, Rect};
4
5/// Widgets can be rendered to a temporary buffer using
6/// the buffers own coordinate system.
7///
8/// To adjust the Rects derived during rendering/layout to
9/// the actual screen coordinates a widget can implement this
10/// trait.
11///
12/// Container widgets that support this will call relocate()
13/// after rendering the widgets.
14pub trait RelocatableState {
15    /// Relocate the areas in this widgets state.
16    fn relocate(&mut self, shift: (i16, i16), clip: Rect);
17}
18
19/// Create the implementation of RelocatableState for the
20/// given list of struct members.
21#[macro_export]
22macro_rules! impl_relocatable_state {
23    ($($n:ident),* for $ty:ty) => {
24        impl $crate::RelocatableState for $ty {
25            fn relocate(&mut self, shift: (i16, i16), clip: Rect) {
26                $(self.$n.relocate(shift, clip);)*
27            }
28        }
29    };
30}
31
32impl RelocatableState for Rect {
33    fn relocate(&mut self, shift: (i16, i16), clip: Rect) {
34        *self = relocate_area(*self, shift, clip);
35    }
36}
37
38impl RelocatableState for [Rect] {
39    fn relocate(&mut self, shift: (i16, i16), clip: Rect) {
40        for rect in self {
41            rect.relocate(shift, clip);
42        }
43    }
44}
45
46/// Shift the area by offset and clip it.
47pub fn relocate_areas(area: &mut [Rect], shift: (i16, i16), clip: Rect) {
48    for a in area {
49        *a = relocate_area(*a, shift, clip)
50    }
51}
52
53/// Shift the area by offset and clip it.
54pub fn relocate_area(area: Rect, shift: (i16, i16), clip: Rect) -> Rect {
55    let relocated = relocate(area, shift);
56    let clipped = clipped(relocated, clip);
57
58    if !clipped.is_empty() {
59        clipped
60    } else {
61        // default on empty
62        Rect::default()
63    }
64}
65
66/// Shift the position by offset and clip it.
67/// Clipped positions are replaced with (0,0) for this function.
68pub fn relocate_positions(pos: &mut [Position], shift: (i16, i16), clip: Rect) {
69    for p in pos {
70        *p = relocate_position(*p, shift, clip).unwrap_or_default()
71    }
72}
73
74/// Shift the position by offset and clip it.
75/// Returns None if the position is clipped.
76pub fn relocate_position(pos: Position, shift: (i16, i16), clip: Rect) -> Option<Position> {
77    let reloc = relocate(Rect::new(pos.x, pos.y, 0, 0), shift);
78    let reloc_pos = Position::new(reloc.x, reloc.y);
79
80    if clip.contains(reloc_pos) {
81        Some(reloc_pos)
82    } else {
83        None
84    }
85}
86
87/// Clipping might introduce another offset by cutting away
88/// part of an area that a widgets internal offset refers to.
89///
90/// This calculates this dark, extra offset.
91pub fn relocate_dark_offset(area: Rect, shift: (i16, i16), clip: Rect) -> (u16, u16) {
92    let relocated = relocate(area, shift);
93    let clipped = clipped(relocated, clip);
94
95    (clipped.x - relocated.x, clipped.y - relocated.y)
96}
97
98pub fn rect_dbg(area: Rect) -> String {
99    use std::fmt::Write;
100    let mut buf = String::new();
101    _ = write!(buf, "{}:{}+{}+{}", area.x, area.y, area.width, area.height);
102    buf
103}
104
105#[inline]
106fn relocate(area: Rect, shift: (i16, i16)) -> Rect {
107    let x0 = area.left().saturating_add_signed(shift.0);
108    let x1 = area.right().saturating_add_signed(shift.0);
109    let y0 = area.top().saturating_add_signed(shift.1);
110    let y1 = area.bottom().saturating_add_signed(shift.1);
111
112    Rect::new(x0, y0, x1 - x0, y1 - y0)
113}
114
115#[inline]
116fn clipped(area: Rect, clip: Rect) -> Rect {
117    area.intersection(clip)
118}
rat_reloc/lib.rs

rat_reloc/
lib.rs
