Function getNodeForCharacterOffset

code/composition/public/app.js:6445–6466

* Get object describing the nodes which contain characters at offset. * * @param {DOMElement|DOMTextNode} root * @param {number} offset * @return {?object}

(root, offset)

 * @return {?object}
 */
function getNodeForCharacterOffset(root, offset) {
  var node = getLeafNode(root);
  var nodeStart = 0;
  var nodeEnd = 0;

  while (node) {
    if (node.nodeType === TEXT_NODE) {
      nodeEnd = nodeStart + node.textContent.length;

      if (nodeStart <= offset && nodeEnd >= offset) {
        return {
          node: node,
          offset: offset - nodeStart
        };
      }

      nodeStart = nodeEnd;
    }

    node = getLeafNode(getSiblingNode(node));
  }
}

/**
 * @param {DOMElement} outerNode