yazi/yazi-widgets/src/clear.rs

use std::sync::atomic::{AtomicBool, Ordering};

use ratatui::{buffer::{Buffer, CellDiffOption}, layout::Rect, widgets::Widget};
use yazi_adapter::ADAPTOR;

pub static COLLISION: AtomicBool = AtomicBool::new(false);

#[derive(Clone, Copy, Debug)]
pub struct Clear;

impl Widget for Clear {
	fn render(self, area: Rect, buf: &mut Buffer)
	where
		Self: Sized,
	{
		ratatui::widgets::Clear.render(area, buf);

		let Some(r) = ADAPTOR.get().shown_load().and_then(|r| overlap(area, r)) else {
			return;
		};

		ADAPTOR.get().image_erase(r).ok();
		COLLISION.store(true, Ordering::Relaxed);
		for y in r.top()..r.bottom() {
			for x in r.left()..r.right() {
				buf[(x, y)].set_diff_option(CellDiffOption::AlwaysUpdate);
			}
		}
	}
}

const fn is_overlapping(a: Rect, b: Rect) -> bool {
	a.x < b.right() && a.right() > b.x && a.y < b.y + b.height && a.y + a.height > b.y
}

fn overlap(a: Rect, b: Rect) -> Option<Rect> {
	if !is_overlapping(a, b) {
		return None;
	}

	let x = a.x.max(b.x);
	let y = a.y.max(b.y);
	let width = a.right().min(b.right()) - x;
	let height = (a.y + a.height).min(b.y + b.height) - y;
	Some(Rect { x, y, width, height })
}