verge.js

/*!
 * verge 1.10.2+201705300050
 * http://npm.im/verge
 * MIT Ryan Van Etten
 */

!function(root, name, make) {
  if (typeof module != 'undefined' && module['exports']) module['exports'] = make();
  else root[name] = make();
}(this, 'verge', function() {

  var xports = {}
    , win = typeof window != 'undefined' && window
    , doc = typeof document != 'undefined' && document
    , docElem = doc && doc.documentElement
    , matchMedia = win['matchMedia'] || win['msMatchMedia']
    , mq = matchMedia ? function(q) {
        return !!matchMedia.call(win, q).matches;
      } : function() {
        return false;
      }
    , viewportW = xports['viewportW'] = function() {
        var a = docElem['clientWidth'], b = win['innerWidth'];
        return a < b ? b : a;
      }
    , viewportH = xports['viewportH'] = function() {
        var a = docElem['clientHeight'], b = win['innerHeight'];
        return a < b ? b : a;
      };

  /**
   * Test if a media query is active. Like Modernizr.mq
   * @since 1.6.0
   * @return {boolean}
   */
  xports['mq'] = mq;

  /**
   * Normalized matchMedia
   * @since 1.6.0
   * @return {MediaQueryList|Object}
   */
  xports['matchMedia'] = matchMedia ? function() {
    // matchMedia must be binded to window
    return matchMedia.apply(win, arguments);
  } : function() {
    // Gracefully degrade to plain object
    return {};
  };

  /**
   * @since 1.8.0
   * @return {{width:number, height:number}}
   */
  function viewport() {
    return {'width':viewportW(), 'height':viewportH()};
  }
  xports['viewport'] = viewport;

  /**
   * Cross-browser window.scrollX
   * @since 1.0.0
   * @return {number}
   */
  xports['scrollX'] = function() {
    return win.pageXOffset || docElem.scrollLeft;
  };

  /**
   * Cross-browser window.scrollY
   * @since 1.0.0
   * @return {number}
   */
  xports['scrollY'] = function() {
    return win.pageYOffset || docElem.scrollTop;
  };

  /**
   * @param {{top:number, right:number, bottom:number, left:number}} coords
   * @param {number=} cushion adjustment
   * @return {Object}
   */
  function calibrate(coords, cushion) {
    var o = {};
    cushion = +cushion || 0;
    o['width'] = (o['right'] = coords['right'] + cushion) - (o['left'] = coords['left'] - cushion);
    o['height'] = (o['bottom'] = coords['bottom'] + cushion) - (o['top'] = coords['top'] - cushion);
    return o;
  }

  /**
   * Cross-browser element.getBoundingClientRect plus optional cushion.
   * Coords are relative to the top-left corner of the viewport.
   * @since 1.0.0
   * @param {Element|Object} el element or stack (uses first item)
   * @param {number=} cushion +/- pixel adjustment amount
   * @return {Object|boolean}
   */
  function rectangle(el, cushion) {
    el = el && !el.nodeType ? el[0] : el;
    if (!el || 1 !== el.nodeType) return false;
    return calibrate(el.getBoundingClientRect(), cushion);
  }
  xports['rectangle'] = rectangle;

  /**
   * Get the viewport aspect ratio (or the aspect ratio of an object or element)
   * @since 1.7.0
   * @param {(Element|Object)=} o optional object with width/height props or methods
   * @return {number}
   * @link http://w3.org/TR/css3-mediaqueries/#orientation
   */
  function aspect(o) {
    o = null == o ? viewport() : 1 === o.nodeType ? rectangle(o) : o;
    var h = o['height'], w = o['width'];
    h = typeof h == 'function' ? h.call(o) : h;
    w = typeof w == 'function' ? w.call(o) : w;
    return w/h;
  }
  xports['aspect'] = aspect;

  /**
   * Test if an element is in the same x-axis section as the viewport.
   * @since 1.0.0
   * @param {Element|Object} el
   * @param {number=} cushion
   * @return {boolean}
   */
  xports['inX'] = function(el, cushion) {
    var r = rectangle(el, cushion);
    return !!r && r.right >= 0 && r.left <= viewportW();
  };

  /**
   * Test if an element is in the same y-axis section as the viewport.
   * @since 1.0.0
   * @param {Element|Object} el
   * @param {number=} cushion
   * @return {boolean}
   */
  xports['inY'] = function(el, cushion) {
    var r = rectangle(el, cushion);
    return !!r && r.bottom >= 0 && r.top <= viewportH();
  };

  /**
   * Test if an element is in the viewport.
   * @since 1.0.0
   * @param {Element|Object} el
   * @param {number=} cushion
   * @return {boolean}
   */
  xports['inViewport'] = function(el, cushion) {
    // Equiv to `inX(el, cushion) && inY(el, cushion)` but just manually do both
    // to avoid calling rectangle() twice. It gzips just as small like this.
    var r = rectangle(el, cushion);
    return !!r && r.bottom >= 0 && r.right >= 0 && r.top <= viewportH() && r.left <= viewportW();
  };

  return xports;
});