pinafore/src/routes/_utils/throttleTimer.js

21 wiersze
524 B
JavaScript

// Sometimes we want to queue multiple requestAnimationFrames but only run the last one.
// It's tedious to do this using cancelAnimationFrame, so this is a utility to throttle
// a timer such that it only runs the last callback when it fires.
export const throttleTimer = timer => {
let queuedCallback
const flush = () => {
const callback = queuedCallback
queuedCallback = null
callback()
}
return callback => {
if (!queuedCallback) {
timer(flush)
}
queuedCallback = callback
}
}