How to implement swipe gestures for mobile devices?

Question

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

Answer 1

I like your solution and implemented it on my site - however, with some little improvements. Just wanted to share my code:

function detectSwipe(id, f) {
    var detect = {
        startX: 0,
        startY: 0,
        endX: 0,
        endY: 0,
        minX: 30,   // min X swipe for horizontal swipe
        maxX: 30,   // max X difference for vertical swipe
        minY: 50,   // min Y swipe for vertial swipe
        maxY: 60    // max Y difference for horizontal swipe
    },
        direction = null,
        element = document.getElementById(id);

    element.addEventListener('touchstart', function (event) {
        var touch = event.touches[0];
        detect.startX = touch.screenX;
        detect.startY = touch.screenY;
    });

    element.addEventListener('touchmove', function (event) {
        event.preventDefault();
        var touch = event.touches[0];
        detect.endX = touch.screenX;
        detect.endY = touch.screenY;
    });

    element.addEventListener('touchend', function (event) {
        if (
            // Horizontal move.
            (Math.abs(detect.endX - detect.startX) > detect.minX)
                && (Math.abs(detect.endY - detect.startY) < detect.maxY)
        ) {
            direction = (detect.endX > detect.startX) ? 'right' : 'left';
        } else if (
            // Vertical move.
            (Math.abs(detect.endY - detect.startY) > detect.minY)
                && (Math.abs(detect.endX - detect.startX) < detect.maxX)
        ) {
            direction = (detect.endY > detect.startY) ? 'down' : 'up';
        }

        if ((direction !== null) && (typeof f === 'function')) {
            f(element, direction);
        }
    });
}

Use it like:

detectSwipe('an_element_id', myfunction);

Or

detectSwipe('another_element_id', my_other_function);

If a swipe is detected the function myfunction is called with parameter element-id and 'left', 'right', 'up' oder 'down'.

Answer 2

The simplest solution I've found that doesn't require a plugin:

document.addEventListener('touchstart', handleTouchStart, false);        
document.addEventListener('touchmove', handleTouchMove, false);
var xDown = null;                                                        
var yDown = null;  

function handleTouchStart(evt) {                                         
    xDown = evt.touches[0].clientX;                                      
    yDown = evt.touches[0].clientY;                                      
}; 

function handleTouchMove(evt) {
    if ( ! xDown || ! yDown ) {
        return;
    }
    var xUp = evt.touches[0].clientX;                                    
    var yUp = evt.touches[0].clientY;
    var xDiff = xDown - xUp;
    var yDiff = yDown - yUp;

    if ( Math.abs( xDiff ) > Math.abs( yDiff ) ) {/*most significant*/
        if ( xDiff > 0 ) {
        /* left swipe */ 
        } else {
        /* right swipe */
        }                       
    } else {
        if ( yDiff > 0 ) {
        /* up swipe */ 
        } else { 
        /* down swipe */
        }                                                                 
    }
    /* reset values */
    xDown = null;
    yDown = null;                                             
};

Answer 3

There is also an AngularJS module called angular-gestures which is based on hammer.js: https://github.com/wzr1337/angular-gestures

Answer 4

I looked at several solutions but all failed with scroll and select text being the biggest confusion. Instead of scrolling right I was closing boxes and such.

I just finished my implementation that does it all for me.

https://github.com/webdevelopers-eu/jquery-dna-gestures

It is MIT so do what you want - and yes, it is really simple - 800 bytes minified. You can check it out on my (under-development) site https://cyrex.tech - swiperight on touch-devices should dismiss popup windows.

Answer 5

Have you tried Hammerjs? It supports swipe gestures by using the velocity of the touch. http://eightmedia.github.com/hammer.js/

Answer 6

_{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%;
}

<div id='swipeme'>
  swipe me
</div>