jquery-smoove/dist/jquery.smoove.js

/*!
* jQuery Smoove v0.2.11 (http://smoove.js.org/)
* Copyright (c) 2017 Adam Bouqdib
* Licensed under GPL-2.0 (http://abemedia.co.uk/license) 
*/

(function($, window, document) {

  // function for adding vendor prefixes
  function crossBrowser(property, value, prefix) {

    function ucase(string) {
      return string.charAt(0).toUpperCase() + string.slice(1);
    }

    var vendor = ['webkit', 'moz', 'ms', 'o'],
      properties = {};

    for (var i = 0; i < vendor.length; i++) {
      if (prefix) {
        value = value.replace(prefix, '-' + vendor[i] + '-' + prefix);
      }
      properties[ucase(vendor[i]) + ucase(property)] = value;
    }
    properties[property] = value;

    return properties;
  }

  function smooveIt(direction) {
    var height = $(window).height(),
      width = $(window).width();

    for (var i = 0; i < $.fn.smoove.items.length; i++) {
      var $item = $.fn.smoove.items[i],
        params = $item.params;

      // disable smoove on small screens
      if (params.min_width > width || params.min_height > height) {
        return false;
      }

      // if direction isn't set, set offset to 0 to avoid hiding objects that are above the fold
      var offset = (!direction || direction === 'down' && $item.css('opacity') === '1') ? 0 : params.offset,
        itemtop = $(window).scrollTop() + height - $item.data('top');

      // offset in %
      if (typeof offset === 'string' && offset.indexOf('%')) {
        offset = parseInt(offset) / 100 * height;
      }

      if (itemtop < offset) {
        if (params.opacity !== false) {
          $item.css({
            opacity: params.opacity
          });
        }

        var transforms = [],
          properties = ['move', 'move3D', 'moveX', 'moveY', 'moveZ', 'rotate', 'rotate3d', 'rotateX', 'rotateY', 'rotateZ', 'scale', 'scale3d', 'scaleX', 'scaleY', 'skew', 'skewX', 'skewY'];

        for (var p = 0; p < properties.length; p++) {
          if (typeof params[properties[p]] !== "undefined") {
            transforms[properties[p]] = params[properties[p]];
          }
        }

        var transform = '';
        for (var t in transforms) {
          transform += t.replace('move', 'translate') + '(' + transforms[t] + ') ';
        }
        if (transform) {
          $item.css(crossBrowser('transform', transform));
          $item.parent().css(crossBrowser('perspective', params.perspective));
          //$item.parent().css(crossBrowser('transformStyle', params.transformstyle));

          if (params.transformOrigin) {
            $item.css(crossBrowser('transformOrigin', params.transformOrigin));
          }
        }
      } else {
        $item.css('opacity', 1).css(crossBrowser('transform', ''));
      }
    }
  }

  function throttle(fn, threshhold, scope) {
    threshhold = threshhold || 250;
    var last, deferTimer;
    return function() {
      var context = scope || this,
        now = +new Date(),
        args = arguments;
      if (last && now < last + threshhold) {
        // hold on to it
        clearTimeout(deferTimer);
        deferTimer = setTimeout(function() {
          last = now;
          fn.apply(context, args);
        }, threshhold);
      } else {
        last = now;
        fn.apply(context, args);
      }
    };
  }

  $.fn.smoove = function(options) {
    $.fn.smoove.init(this, $.extend({}, $.fn.smoove.defaults, options));
    return this;
  };

  $.fn.smoove.items = [];
  $.fn.smoove.loaded = false;

  $.fn.smoove.defaults = {
    offset: 150,
    opacity: 0,
    transition: "all 1s ease, opacity 1.5s ease",
    transformStyle: 'preserve-3d',
    transformOrigin: false,
    perspective: 1000,
    min_width: 768,
    min_height: false
  };

  $.fn.smoove.init = function(items, settings) {
    items.each(function() {
      var $item = $(this),
        params = $item.params = $.extend({}, settings, $item.data());

      $item.params.opacity = $item.params.opacity / 100;
      $item.data('top', $item.offset().top);

      params.transition = crossBrowser('transition', params.transition, 'transform');
      $item.css(params.transition);

      $.fn.smoove.items.push($item);
    });

    // add event handlers
    if (!$.fn.smoove.loaded) {
      $.fn.smoove.loaded = true;

      var oldScroll = 0,
        oldHeight = $(window).height(),
        oldWidth = $(window).width(),
        oldDocHeight = $(document).height(),
        resizing;

      // naughty way of avoiding vertical scrollbars when items slide in/out from the side
      if ($('body').width() === $(window).width()) {
        $('body').css('overflow-x', 'hidden');
      }

      $(window).on("orientationchange resize", function() {
        clearTimeout(resizing);
        resizing = setTimeout(function() {
          var height = $(window).height(),
            width = $(window).width(),
            direction = (oldHeight > height) ? direction = 'up' : 'down',
            items = $.fn.smoove.items;

          oldHeight = height;

          // responsive support - reassign position values on resize
          if (oldWidth !== width) {
            for (var i = 0; i < items.length; i++) {
              items[i].css(crossBrowser('transform', '')).css(crossBrowser('transition', ''));
            }

            // wait for responsive magic to finish
            var stillResizing = setInterval(function() {
              var docHeight = $(document).height();
              if (docHeight === oldDocHeight) {
                window.clearInterval(stillResizing);
                for (var i = 0; i < items.length; i++) {
                  items[i].data('top', items[i].offset().top);
                  items[i].css(items[i].params.transition);
                }
                smooveIt(direction);
              }
              oldDocHeight = docHeight;
            }, 500);
          } else {
            smooveIt(direction);
          }
          oldWidth = width;
        }, 500);
      });

      $(window).on('load', function() {
        smooveIt();

        // throttle scroll handler
        $(window).on('scroll', throttle(function() {
          var scrolltop = $(window).scrollTop(),
            direction = (scrolltop < oldScroll) ? direction = 'up' : 'down';
          oldScroll = scrolltop;
          smooveIt(direction);
        }, 250));
      });
    }
  };

}(jQuery, window, document));