ratchet/js/toggles.js

/* ========================================================================
 * Ratchet: toggles.js v2.0.1
 * http://goratchet.com/components#toggles
 * ========================================================================
   Adapted from Brad Birdsall's swipe
 * Copyright 2014 Connor Sears
 * Licensed under MIT (https://github.com/twbs/ratchet/blob/master/LICENSE)
 * ======================================================================== */

!(function () {
  'use strict';

  var start     = {};
  var touchMove = false;
  var distanceX = false;
  var toggle    = false;

  var findToggle = function (target) {
    var i;
    var toggles = document.querySelectorAll('.toggle');

    for (; target && target !== document; target = target.parentNode) {
      for (i = toggles.length; i--;) {
        if (toggles[i] === target) {
          return target;
        }
      }
    }
  };

  window.addEventListener('touchstart', function (e) {
    e = e.originalEvent || e;

    toggle = findToggle(e.target);

    if (!toggle) {
      return;
    }

    var handle      = toggle.querySelector('.toggle-handle');
    var toggleWidth = toggle.clientWidth;
    var handleWidth = handle.clientWidth;
    var offset      = toggle.classList.contains('active') ? (toggleWidth - handleWidth) : 0;

    start     = { pageX : e.touches[0].pageX - offset, pageY : e.touches[0].pageY };
    touchMove = false;
  });

  window.addEventListener('touchmove', function (e) {
    e = e.originalEvent || e;

    if (e.touches.length > 1) {
      return; // Exit if a pinch
    }

    if (!toggle) {
      return;
    }

    var handle      = toggle.querySelector('.toggle-handle');
    var current     = e.touches[0];
    var toggleWidth = toggle.clientWidth;
    var handleWidth = handle.clientWidth;
    var offset      = toggleWidth - handleWidth;

    touchMove = true;
    distanceX = current.pageX - start.pageX;

    if (Math.abs(distanceX) < Math.abs(current.pageY - start.pageY)) {
      return;
    }

    e.preventDefault();

    if (distanceX < 0) {
      return (handle.style.webkitTransform = 'translate3d(0,0,0)');
    }
    if (distanceX > offset) {
      return (handle.style.webkitTransform = 'translate3d(' + offset + 'px,0,0)');
    }

    handle.style.webkitTransform = 'translate3d(' + distanceX + 'px,0,0)';

    toggle.classList[(distanceX > (toggleWidth / 2 - handleWidth / 2)) ? 'add' : 'remove']('active');
  });

  window.addEventListener('touchend', function (e) {
    if (!toggle) {
      return;
    }

    var handle      = toggle.querySelector('.toggle-handle');
    var toggleWidth = toggle.clientWidth;
    var handleWidth = handle.clientWidth;
    var offset      = (toggleWidth - handleWidth);
    var slideOn     = (!touchMove && !toggle.classList.contains('active')) || (touchMove && (distanceX > (toggleWidth / 2 - handleWidth / 2)));

    if (slideOn) {
      handle.style.webkitTransform = 'translate3d(' + offset + 'px,0,0)';
    } else {
      handle.style.webkitTransform = 'translate3d(0,0,0)';
    }

    toggle.classList[slideOn ? 'add' : 'remove']('active');

    e = new CustomEvent('toggle', {
      detail: { isActive: slideOn },
      bubbles: true,
      cancelable: true
    });

    toggle.dispatchEvent(e);

    touchMove = false;
    toggle    = false;
  });

}());