Files
ratatui/src/layout/rect.rs

292 lines
8.5 KiB
Rust

#![warn(missing_docs)]
use std::{
cmp::{max, min},
fmt,
};
use crate::prelude::*;
/// A simple rectangle used in the computation of the layout and to give widgets a hint about the
/// area they are supposed to render to.
#[derive(Debug, Default, Clone, Copy, Eq, PartialEq, Hash)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct Rect {
/// The x coordinate of the top left corner of the rect.
pub x: u16,
/// The y coordinate of the top left corner of the rect.
pub y: u16,
/// The width of the rect.
pub width: u16,
/// The height of the rect.
pub height: u16,
}
impl fmt::Display for Rect {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{}x{}+{}+{}", self.width, self.height, self.x, self.y)
}
}
impl Rect {
/// Creates a new rect, with width and height limited to keep the area under max u16. If
/// clipped, aspect ratio will be preserved.
pub fn new(x: u16, y: u16, width: u16, height: u16) -> Rect {
let max_area = u16::max_value();
let (clipped_width, clipped_height) =
if u32::from(width) * u32::from(height) > u32::from(max_area) {
let aspect_ratio = f64::from(width) / f64::from(height);
let max_area_f = f64::from(max_area);
let height_f = (max_area_f / aspect_ratio).sqrt();
let width_f = height_f * aspect_ratio;
(width_f as u16, height_f as u16)
} else {
(width, height)
};
Rect {
x,
y,
width: clipped_width,
height: clipped_height,
}
}
/// The area of the rect. If the area is larger than the maximum value of u16, it will be
/// clamped to u16::MAX.
pub const fn area(self) -> u16 {
self.width.saturating_mul(self.height)
}
/// Returns true if the rect has no area.
pub const fn is_empty(self) -> bool {
self.width == 0 || self.height == 0
}
/// Returns the left coordinate of the rect.
pub const fn left(self) -> u16 {
self.x
}
/// Returns the right coordinate of the rect. This is the first coordinate outside of the rect.
///
/// If the right coordinate is larger than the maximum value of u16, it will be clamped to
/// u16::MAX.
pub const fn right(self) -> u16 {
self.x.saturating_add(self.width)
}
/// Returns the top coordinate of the rect.
pub const fn top(self) -> u16 {
self.y
}
/// Returns the bottom coordinate of the rect. This is the first coordinate outside of the rect.
///
/// If the bottom coordinate is larger than the maximum value of u16, it will be clamped to
/// u16::MAX.
pub const fn bottom(self) -> u16 {
self.y.saturating_add(self.height)
}
/// Returns a new rect inside the current one, with the given margin on each side.
///
/// If the margin is larger than the rect, the returned rect will have no area.
pub fn inner(self, margin: &Margin) -> Rect {
let doubled_margin_horizontal = margin.horizontal.saturating_mul(2);
let doubled_margin_vertical = margin.vertical.saturating_mul(2);
if self.width < doubled_margin_horizontal || self.height < doubled_margin_vertical {
Rect::default()
} else {
Rect {
x: self.x.saturating_add(margin.horizontal),
y: self.y.saturating_add(margin.vertical),
width: self.width.saturating_sub(doubled_margin_horizontal),
height: self.height.saturating_sub(doubled_margin_vertical),
}
}
}
/// Returns a new rect that contains both the current one and the given one.
pub fn union(self, other: Rect) -> Rect {
let x1 = min(self.x, other.x);
let y1 = min(self.y, other.y);
let x2 = max(self.right(), other.right());
let y2 = max(self.bottom(), other.bottom());
Rect {
x: x1,
y: y1,
width: x2.saturating_sub(x1),
height: y2.saturating_sub(y1),
}
}
/// Returns a new rect that is the intersection of the current one and the given one.
///
/// If the two rects do not intersect, the returned rect will have no area.
pub fn intersection(self, other: Rect) -> Rect {
let x1 = max(self.x, other.x);
let y1 = max(self.y, other.y);
let x2 = min(self.right(), other.right());
let y2 = min(self.bottom(), other.bottom());
Rect {
x: x1,
y: y1,
width: x2 - x1,
height: y2 - y1,
}
}
/// Returns true if the two rects intersect.
pub const fn intersects(self, other: Rect) -> bool {
self.x < other.right()
&& self.right() > other.x
&& self.y < other.bottom()
&& self.bottom() > other.y
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn to_string() {
assert_eq!(Rect::new(1, 2, 3, 4).to_string(), "3x4+1+2");
}
#[test]
fn new() {
assert_eq!(
Rect::new(1, 2, 3, 4),
Rect {
x: 1,
y: 2,
width: 3,
height: 4
}
);
}
#[test]
fn area() {
assert_eq!(Rect::new(1, 2, 3, 4).area(), 12);
}
#[test]
fn is_empty() {
assert!(!Rect::new(1, 2, 3, 4).is_empty());
assert!(Rect::new(1, 2, 0, 4).is_empty());
assert!(Rect::new(1, 2, 3, 0).is_empty());
}
#[test]
fn left() {
assert_eq!(Rect::new(1, 2, 3, 4).left(), 1);
}
#[test]
fn right() {
assert_eq!(Rect::new(1, 2, 3, 4).right(), 4);
}
#[test]
fn top() {
assert_eq!(Rect::new(1, 2, 3, 4).top(), 2);
}
#[test]
fn bottom() {
assert_eq!(Rect::new(1, 2, 3, 4).bottom(), 6);
}
#[test]
fn inner() {
assert_eq!(
Rect::new(1, 2, 3, 4).inner(&Margin::new(1, 2)),
Rect::new(2, 4, 1, 0)
);
}
#[test]
fn union() {
assert_eq!(
Rect::new(1, 2, 3, 4).union(Rect::new(2, 3, 4, 5)),
Rect::new(1, 2, 5, 6)
);
}
#[test]
fn intersection() {
assert_eq!(
Rect::new(1, 2, 3, 4).intersection(Rect::new(2, 3, 4, 5)),
Rect::new(2, 3, 2, 3)
);
}
#[test]
fn intersects() {
assert!(Rect::new(1, 2, 3, 4).intersects(Rect::new(2, 3, 4, 5)));
assert!(!Rect::new(1, 2, 3, 4).intersects(Rect::new(5, 6, 7, 8)));
}
#[test]
fn size_truncation() {
for width in 256u16..300u16 {
for height in 256u16..300u16 {
let rect = Rect::new(0, 0, width, height);
rect.area(); // Should not panic.
assert!(rect.width < width || rect.height < height);
// The target dimensions are rounded down so the math will not be too precise
// but let's make sure the ratios don't diverge crazily.
assert!(
(f64::from(rect.width) / f64::from(rect.height)
- f64::from(width) / f64::from(height))
.abs()
< 1.0
);
}
}
// One dimension below 255, one above. Area above max u16.
let width = 900;
let height = 100;
let rect = Rect::new(0, 0, width, height);
assert_ne!(rect.width, 900);
assert_ne!(rect.height, 100);
assert!(rect.width < width || rect.height < height);
}
#[test]
fn size_preservation() {
for width in 0..256u16 {
for height in 0..256u16 {
let rect = Rect::new(0, 0, width, height);
rect.area(); // Should not panic.
assert_eq!(rect.width, width);
assert_eq!(rect.height, height);
}
}
// One dimension below 255, one above. Area below max u16.
let rect = Rect::new(0, 0, 300, 100);
assert_eq!(rect.width, 300);
assert_eq!(rect.height, 100);
}
#[test]
fn can_be_const() {
const RECT: Rect = Rect {
x: 0,
y: 0,
width: 10,
height: 10,
};
const _AREA: u16 = RECT.area();
const _LEFT: u16 = RECT.left();
const _RIGHT: u16 = RECT.right();
const _TOP: u16 = RECT.top();
const _BOTTOM: u16 = RECT.bottom();
assert!(RECT.intersects(RECT));
}
}