I have an application made in AngularJS which has arrow key navigation to switch views.
I want to implement this navigation using swipe for touch devices. I tried jG
NOTE: Greatly inspired by EscapeNetscape's answer, I've made an edit of his script using modern javascript in a comment. I made an answer of this due to user interest and a massive 4h jsfiddle.net downtime. I chose not to edit the original answer since it would change everything...
Here is a detectSwipe function, working pretty well (used on one of my websites). I'd suggest you read it before you use it. Feel free to review it/edit the answer.
// usage example
detectSwipe('swipeme', (el, dir) => alert(`you swiped on element with id ${el.id} to ${dir} direction`))
// source code
// Tune deltaMin according to your needs. Near 0 it will almost
// always trigger, with a big value it can never trigger.
function detectSwipe(id, func, deltaMin = 90) {
const swipe_det = {
sX: 0,
sY: 0,
eX: 0,
eY: 0
}
// Directions enumeration
const directions = Object.freeze({
UP: 'up',
DOWN: 'down',
RIGHT: 'right',
LEFT: 'left'
})
let direction = null
const el = document.getElementById(id)
el.addEventListener('touchstart', function(e) {
const t = e.touches[0]
swipe_det.sX = t.screenX
swipe_det.sY = t.screenY
}, false)
el.addEventListener('touchmove', function(e) {
// Prevent default will stop user from scrolling, use with care
// e.preventDefault();
const t = e.touches[0]
swipe_det.eX = t.screenX
swipe_det.eY = t.screenY
}, false)
el.addEventListener('touchend', function(e) {
const deltaX = swipe_det.eX - swipe_det.sX
const deltaY = swipe_det.eY - swipe_det.sY
// Min swipe distance, you could use absolute value rather
// than square. It just felt better for personnal use
if (deltaX ** 2 + deltaY ** 2 < deltaMin ** 2) return
// horizontal
if (deltaY === 0 || Math.abs(deltaX / deltaY) > 1)
direction = deltaX > 0 ? directions.RIGHT : directions.LEFT
else // vertical
direction = deltaY > 0 ? directions.UP : directions.DOWN
if (direction && typeof func === 'function') func(el, direction)
direction = null
}, false)
}
#swipeme {
width: 100%;
height: 100%;
background-color: orange;
color: black;
text-align: center;
padding-top: 20%;
padding-bottom: 20%;
}
swipe me