PositionObserver

The tool that can easily replace most of your scroll and resize event listeners. Simple design and easy to use.

Installation

Usage

import PositionObserver from '@thednp/position-observer';

const target = document.getElementById('myElement');
const observer = new PositionObserver((entries, currentObserver) => {
  const entry = currentObserver.getEntry(target);

  if (entry.target === target) console.log('this is myTarget!');
  else console.log('this is NOT myTarget!')
});

observer.observe(target);

Example

In this example these tooltips will stick to their trigger button while you scroll up and down or resize the window. First is handled by via the PositionObserver callback, while the second is handled by both scroll and resize event handlers. Both callbacks are wrapped in a requestAnimationFrame wrapper and both event listeners are set as passive, just to make sure we have a fair comparison.

Click one of the buttons below and start scrolling and or resize the window for a couple of seconds. After 500 updates, an average and a maximum execution time in microseconds will be calculated and displayed.

Average
Maximum
Average
Maximum