Observe element size changes and callback before and after layout reflow has occured.
ReflowObserver wraps around ResizeObserver. It provides the same basic interface with a few subtle differences, listed below.
ResizeObserver takes a callback as it's only argument.ReflowObserver requires two callbacks: beforeReflow and afterReflow.
ResizeObserver passes an Array of ResizeObserverEntry objects to it's callback.ReflowObserver passes a DOMHiResTimeStamp object to both of it's callbacks.
Returns an array of all nodes that are being observed by this ReflowObserver instance.
import{ReflowObserver}from'./ReflowObserver.js';constobserver=newReflowObserver(functionbeforeReflow(timestamp){console.log(timestamp,'about to reflow',this);},functionafterReflow(timestamp){console.log(timestamp,'reflow complete',this);});observer.observe(document.body);A well commented example implementation is contained in this repository. Find it at ./example.html.