@atlaskit/editor-plugin-interactivity/dist/es2019/collector/interaction-observer.js

Interactivity plugin for @atlaskit/editor-core

import { REPORTING_THRESHOLD_MS } from './bucket-boundaries';
/** `performance.interactionCount` is Chromium-only and absent from the DOM typings. */
const interactionCount = () => performance.interactionCount;

/** `durationThreshold` is absent from the DOM typings for `PerformanceObserverInit`. */

/**
 * Reports the interactions the browser observes to `onEntries`.
 *
 * `drain` and `stop` are safe to call before `start` and after each other, so a session
 * that never started collecting needs no special handling.
 */
export class InteractionObserver {
  /**
   * Whether the browser reports both things a session needs: `interactionId`, which groups
   * entries into interactions, and `performance.interactionCount`, which counts the ones
   * below the reporting threshold. Both are Chromium-only, and without the count
   * `totalCount` would be indistinguishable from `observedCount`.
   */
  static isSupported() {
    if (typeof window === 'undefined' || typeof PerformanceObserver === 'undefined') {
      return false;
    }
    if (!('PerformanceEventTiming' in window) || !('interactionId' in PerformanceEventTiming.prototype)) {
      return false;
    }
    if (!PerformanceObserver.supportedEntryTypes.includes('event')) {
      return false;
    }
    return typeof interactionCount() === 'number';
  }

  /**
   * Total interactions on the page since page load, including those below the reporting
   * threshold that no observer ever sees. A property of the page, not of an observer.
   */
  static readPageInteractionCount() {
    var _interactionCount;
    return (_interactionCount = interactionCount()) !== null && _interactionCount !== void 0 ? _interactionCount : 0;
  }
  constructor(onEntries) {
    this.onEntries = onEntries;
  }

  /**
   * Starts reporting interactions from this point on. Does nothing when already started, so
   * a second call cannot leave an observer running with nobody to disconnect it.
   *
   * `buffered` is `false`: the entries the browser collected earlier are interactions with
   * the page while the editor was still loading, and they belong to no session of ours.
   */
  start() {
    if (this.observer) {
      return;
    }
    this.observer = new PerformanceObserver(list => {
      // Delay by a microtask to work around a Safari bug where the callback is
      // invoked synchronously rather than in a separate task.
      // See: https://github.com/GoogleChrome/web-vitals/issues/277
      Promise.resolve().then(() => {
        this.onEntries(list.getEntries());
      });
    });
    const init = {
      type: 'event',
      buffered: false,
      // 16 ms is also the smallest value the spec honours; lower values are clamped.
      durationThreshold: REPORTING_THRESHOLD_MS
    };
    this.observer.observe(init);
  }

  /**
   * Synchronously reports the entries the browser has produced but not yet dispatched to
   * the callback. A snapshot taken because the page is going away has to include them,
   * because there is no later chance to.
   */
  drain() {
    var _this$observer;
    const entries = (_this$observer = this.observer) === null || _this$observer === void 0 ? void 0 : _this$observer.takeRecords();
    if (entries) {
      this.onEntries(entries);
    }
  }
  stop() {
    var _this$observer2;
    (_this$observer2 = this.observer) === null || _this$observer2 === void 0 ? void 0 : _this$observer2.disconnect();
    this.observer = undefined;
  }
}