coords-notnative.js

+function(exports){
  // exposed on this global object
  var exposed = 'notnative';
  
  /**!
   * @author Rhys Burnie
   * @description native js coordinates tool for scripts consumption.
   * @licence MIT
   * Copyright Rhys Burnie
   */
  function coords(el, precision)
  {
    var scroll = coords.scroll(),
        client = coords.client(),
        rect = coords.client(el),
        coordinates = {
          width: rect.right - rect.left,
          height: rect.bottom - rect.top,
          top: el.offsetTop,
          left: el.offsetLeft,
          offset: {
            top: rect.top + scroll.top - client.top,
            left: rect.left + scroll.left - client.left
          },
          client: {
            top: rect.top,
            left: rect.left
          }
        };

    coordinates = coordinates.util.precision(coordinates, precision);

    return coordinates;
  }

  coords.scroll = function(el)
  {
    if(el && el!==window) {
      return {
        top: el.scrollTop,
        left: el.scrollLeft
      };
    }
    return {
      top: window.pageYOffset || docEl.scrollTop || body.scrollTop,
      left: window.pageXOffset || docEl.scrollLeft || body.scrollLeft
    };
  };

  coords.client = function(el)
  {
    if(el && el!==window) {
      return el.getBoundingClientRect();
    }
    return {
      top: docEl.clientTop || body.clientTop || 0,
      left: docEl.clientLeft || body.clientLeft || 0
    };
  };

  coords.util = {
    precision: function(numbers, precision)
    {
      if(Math[precision]) { 
        for(var prop in numbers) {
          if(numbers.hasOwnProperty(prop)) {
            if(!isNaN(numbers[prop])) {
              numbers[prop] = Math[precision](numbers[prop]);
            } else if(typeof(numbers[prop]) === 'object') {
              numbers[prop] = coords.util.precision(numbers[prop], precision);
            }
          }
        }
      }

      return numbers;
    }
  };

  exports[exposed] = exports[exposed] || {};
  exports[exposed].coords = coords;
}(this);

var offset = notnative.coords(document.querySelector('#el')); ({top:0,left:0})