@atlaskit/editor-plugin-block-controls/dist/es2019/pm-plugins/utils/active-anchor-tracker.js

Block controls plugin for @atlaskit/editor-core

import _defineProperty from "@babel/runtime/helpers/defineProperty";
import { EventEmitter } from 'events';
import { useCallback, useEffect, useState } from 'react';
import { editorExperiment } from '@atlaskit/tmp-editor-statsig/experiments';
export class ActiveAnchorTracker {
  constructor() {
    _defineProperty(this, "lastActiveAnchor", '');
    this.emitter = new EventEmitter();
  }
  getActiveAnchor() {
    return this.lastActiveAnchor;
  }
  subscribe(anchorName, callback) {
    if (this.emitter) {
      this.emitter.on(anchorName, callback);
    }
  }
  unsubscribe(anchorName, callback) {
    if (this.emitter) {
      this.emitter.removeListener(anchorName, callback);
    }
  }
  emit(anchorName) {
    if (this.lastActiveAnchor !== anchorName && this.emitter) {
      this.emitter.emit(this.lastActiveAnchor, false);
      this.emitter.emit(anchorName, true);
      this.lastActiveAnchor = anchorName;
    }
  }
  reset() {
    if (this.emitter) {
      // To prevent any potential memory leaks,
      // we set the event emitter to null and then create a new event emitter.
      this.emitter.removeAllListeners();
      this.emitter = null;
      this.emitter = new EventEmitter();
    }
  }
}

// TODO: ED-26959 - We should use a scoped ActiveAnchorTracker rather than the global static object.
// Move this into the plugin scope once the newApply functions becomes default apply.
export const defaultActiveAnchorTracker = new ActiveAnchorTracker();
export const useActiveAnchorTracker = (anchorName, activeAnchorTracker = defaultActiveAnchorTracker) => {
  const [isActive, setIsActive] = useState(false);
  const onActive = eventIsActive => {
    setIsActive(eventIsActive);
  };
  useEffect(() => {
    if (activeAnchorTracker && anchorName && editorExperiment('advanced_layouts', true)) {
      activeAnchorTracker.subscribe(anchorName, onActive);
      if (activeAnchorTracker.getActiveAnchor() === anchorName) {
        setIsActive(true);
      }
      const unsubscribe = () => {
        activeAnchorTracker.unsubscribe(anchorName, onActive);
      };
      return unsubscribe;
    }
  }, [activeAnchorTracker, anchorName]);
  const setActive = useCallback(() => {
    activeAnchorTracker.emit(anchorName);
  }, [activeAnchorTracker, anchorName]);
  return [isActive, setActive];
};