@discoveryjs/discovery/lib/core/utils/size.js

Frontend framework for rapid data (JSON) analysis, shareable serverless reports and dashboards

import { Observer } from "../observer.js";
const resizeObserverSupported = typeof ResizeObserver === "function";
export class ContentRect extends Observer {
  static supported = resizeObserverSupported;
  el;
  observer;
  constructor() {
    super(null);
    this.el = null;
    this.observer = resizeObserverSupported ? new ResizeObserver((entries) => {
      for (const entry of entries) {
        this.set(entry.contentRect);
      }
    }) : null;
  }
  observe(el) {
    if (this.observer === null) {
      this.el = null;
      return;
    }
    el = el || null;
    if (this.el !== el) {
      if (this.el !== null) {
        this.observer.unobserve(this.el);
      }
      if (el !== null) {
        this.observer.observe(el);
      }
      this.el = el;
    }
  }
  dispose() {
    this.el = null;
    this.observer = null;
  }
}