Function addFluidObserver

packages/shared/src/fluids.ts:156–170

(target: any, observer: FluidObserver)

): typeof observer

function addFluidObserver(target: any, observer: FluidObserver) {
  if (target[$get]) {
    let observers: Set<FluidObserver> = target[$observers]
    if (!observers) {
      setHidden(target, $observers, (observers = new Set()))
    }
    if (!observers.has(observer)) {
      observers.add(observer)
      if (target.observerAdded) {
        target.observerAdded(observers.size, observer)
      }
    }
  }
  return observer
}

/** Stop observing a `fluids`-compatible object. */
function removeFluidObserver<E extends FluidEvent>(