Swipe left / right for mobile and desktop

gesture.js

el.addEventListener('touchstart', event => { start(event.touches[0].clientX, event.touches[0].clientY) }, false)
el.addEventListener('touchmove', event => { swipe(event.touches[0].clientX, event.touches[0].clientY) }, false)
el.addEventListener('mousedown', event => { start(event.clientX, event.clientY) }, false)
el.addEventListener('mousemove', event => { swipe(event.clientX, event.clientY) }, false)

let xDown = null
let yDown = null

function start (x, y) {
	xDown = x
	yDown = y
}

function swipe (xUp, yUp) {
	if (!xDown || !yDown) return

	const xDiff = xDown - xUp
	const yDiff = yDown - yUp

	if (Math.abs(xDiff) > Math.abs(yDiff)) {
		// Left swipe
		if (xDiff > 0) {
			console.log('left')
		}
		// Right swipe
		else {
			console.log('right')
		}
	}

	xDown = null
	yDown = null
}