dom-tools/src/offset.js

A tiny collection of DOM helpers for IE8+.

var contains = require('./contains');
var getWindow = require('./utils/getWindow');
var ownerDocument = require('./utils/ownerDocument');

// Modified version of:
// react-bootstrap/dom-helpers 2.4.0 query/offset.js
function offset(node) {
  var doc = ownerDocument(node)
    , win = getWindow(doc)
    , docElem = doc && doc.documentElement
    , box = {top: 0, left: 0, height: 0, width: 0};

  if (!doc) return;

  // Make sure it's not a disconnected DOM node
  if (!contains(docElem, node)) return box;

  if (node.getBoundingClientRect !== undefined) {
    box = node.getBoundingClientRect();
  }

  if (box.width || box.height) {
    box = {
      top: box.top + (win.pageYOffset || docElem.scrollTop) - (docElem.clientTop || 0),
      left: box.left + (win.pageXOffset || docElem.scrollLeft) - (docElem.clientLeft || 0),
      width: (box.width == null ? node.offsetWidth : box.width) || 0,
      height: (box.height == null ? node.offsetHeight : box.height) || 0
    }
  }

  return box;
}

module.exports = offset;