Function getOffsets

lib/assets/react-source/development/react.js:10419–10449

* @param {DOMElement} outerNode * @return {?object}

(outerNode)

	 */

	function getOffsets(outerNode) {
	  var ownerDocument = outerNode.ownerDocument;
	  var win = ownerDocument && ownerDocument.defaultView || window;
	  var selection = win.getSelection && win.getSelection();

	  if (!selection || selection.rangeCount === 0) {
	    return null;
	  }

	  var anchorNode = selection.anchorNode,
	      anchorOffset = selection.anchorOffset,
	      focusNode = selection.focusNode,
	      focusOffset = selection.focusOffset; // In Firefox, anchorNode and focusNode can be "anonymous divs", e.g. the
	  // up/down buttons on an <input type="number">. Anonymous divs do not seem to
	  // expose properties, triggering a "Permission denied error" if any of its
	  // properties are accessed. The only seemingly possible way to avoid erroring
	  // is to access a property that typically works for non-anonymous divs and
	  // catch any error that may otherwise arise. See
	  // https://bugzilla.mozilla.org/show_bug.cgi?id=208427

	  try {
	    /* eslint-disable no-unused-expressions */
	    anchorNode.nodeType;
	    focusNode.nodeType;
	    /* eslint-enable no-unused-expressions */
	  } catch (e) {
	    return null;
	  }

	  return getModernOffsetsFromPoints(outerNode, anchorNode, anchorOffset, focusNode, focusOffset);
	}
	/**
	 * Returns {start, end} where `start` is the character/codepoint index of
	 * (anchorNode, anchorOffset) within the textContent of `outerNode`, and