@pmwcs/base/next/utils/apply-passive.js

PMWCS base module

/**
 * @license
 * Copyright 2019 Google Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/**
 * Stores result from applyPassive to avoid redundant processing to detect
 * passive event listener support.
 */
let supportsPassive_;
/**
 * Determine whether the current browser supports passive event listeners, and
 * if so, use them.
 */

export function applyPassive(globalObj, forceRefresh) {
  if (globalObj === undefined) {
    globalObj = window;
  }

  if (forceRefresh === undefined) {
    forceRefresh = false;
  }

  if (supportsPassive_ === undefined || forceRefresh) {
    let isSupported = false;

    try {
      globalObj.document.addEventListener('test', function () {
        return undefined;
      }, {
        get passive() {
          isSupported = true;
          return isSupported;
        }

      });
    } catch (e) {}

    supportsPassive_ = isSupported;
  }

  return supportsPassive_ ? {
    passive: true
  } : false;
}