dom.js

/**
 * Copyright 2020 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


export function findClosestLink(ev) {
  // can't use closest() when shadow DOM is involved
  const path = ev.composedPath();
  path.reverse();
  for (const cand of path) {
    if (cand.localName === 'a' && cand.href) {
      return cand;
    }
  }
  return null;
}

export function urlFromClickEvent(ev) {
  if (ev.ctrlKey || ev.metaKey || ev.which > 1) {
    return null;  // ignore event while buttons are pressed
  }

  const path = ev.composedPath();
  path.reverse();
  for (const cand of path) {
    if (cand.localName === 'a' && cand.href) {
      return new URL(cand.href);
    }
  }
  return null;
}