ResizeObserver: it's like document.onresize for elements | Articles | web.dev

Before ResizeObserver, you had to attach a listener to the document's resize event to get notified of any change of the viewport's dimensions. In the event handler, you would then have to figure out which elements have been affected by that change and call a specific routine to react appropriately. If you needed the new dimensions of an element after a resize, you had to call getBoundingClientRect

[yosuke_furukawa]

Resize Observerのスペックあるのかー