svelte/documentation/tutorial/12-actions/02-adding-parameters-to-actions/app-a/longpress.js

export function longpress(node, duration) {
	let timer;

	const handleMousedown = () => {
		timer = setTimeout(() => {
			node.dispatchEvent(new CustomEvent('longpress'));
		}, 500);
	};

	const handleMouseup = () => {
		clearTimeout(timer);
	};

	node.addEventListener('mousedown', handleMousedown);
	node.addEventListener('mouseup', handleMouseup);

	return {
		destroy() {
			clearTimeout(timer);
			node.removeEventListener('mousedown', handleMousedown);
			node.removeEventListener('mouseup', handleMouseup);
		}
	};
}