index.js

/**
 * Module dependencies.
 */

var getDocument = require('get-document');

/**
 * Module exports.
 */

module.exports = getWindow;

var needsIEFallback = require('./needs-ie-fallback');

/**
 * Returns `true` if `w` is a Window object, or `false` otherwise.
 *
 * @param {Mixed} w - Window object, maybe
 * @return {Boolean}
 * @private
 */

function isWindow (w) {
  return w && w.window === w;
}

/**
 * Returns the `window` object associated with the given `node`, which may be
 * a DOM element, the Window object, a Selection, a Range. Basically any DOM
 * object that references the Window in some way, this function will find it.
 *
 * @param {Mixed} node - DOM node, selection, or range in which to find the `window` object
 * @return {Window} the `window` object associated with `node`
 * @public
 */

function getWindow(node) {
  if (isWindow(node)) {
    return node;
  }

  var doc = getDocument(node);

  if (needsIEFallback) {
    // In IE 6-8, only the variable 'window' can be used to connect events (others
    // may be only copies).
    doc.parentWindow.execScript('document._parentWindow = window;', 'Javascript');
    var win = doc._parentWindow;
    // to prevent memory leak, unset it after use
    // another possibility is to add an onUnload handler,
    // (which seems overkill to @liucougar)
    doc._parentWindow = null;
    return win;
  } else {
    // standards-compliant and newer IE
    return doc.defaultView || doc.parentWindow;
  }
}