Debounce function for Lens Studio. Also provides setTimeout and clearTimeout functions.

snap-debounce.js

/*

  Debouncing functions is used for delaying a function call until a certain amount of time has passed. 
  In the example below, it's used to hide a slider after 3 seconds if the user isn't interacting with it.

*/

/**
 * Polyfill for browser function setTimeout
 * @param {function} callback - function to trigger after timeout is completed 
 * @param {number} delay - time in milliseconds to delay the callback
 * @returns {DelayedCallbackEvent} - event can be cancelled with `clearTimeout(event)`
 */
function setTimeout(callback, delay) {
  var e = script.createEvent('DelayedCallbackEvent')
  e.reset(delay * .001)
  e.bind(callback)
  return e
}

/**
 * Polyfill for browser function clearTimeout
 * @param {DelayedCallbackEvent} event - The event returned from setTimeout
 */
function clearTimeout(event) {
  event.enabled = false
}

/**
 * Debounce function generator for delaying a function call
 * @param {function} callback - function to debounce
 * @param {number} delay - time to delay, in milliseconds
 * @returns {function} - debounced function
 */
function debounce(callback, delay) {
  if(!delay) throw Error('missing delay from debounce')
  var timeoutEvent
  return function () {
    // Clear any existing timeout
    if (timeoutEvent) {
      clearTimeout(timeoutEvent)
    }

    // Set a new timeout to call the callback function after a delay
    timeoutEvent = setTimeout(callback, delay)
  }
}

/*

  EXAMPLE
  Slider controller

*/

//@input Component.AudioComponent audio
/** @type {AudioComponent} */
var audio = script.audio

//@input Component.ScriptComponent sliderScript
/** @type {ScriptComponent} */
var sliderScript = script.sliderScript
var slider = sliderScript.api

slider.addCallback('onSliderValueChanged', function (v) {
  audio.volume = v
  // prevent hiding while using the slider
  debouncedHide()
})

var st = sliderScript.getSceneObject().getComponent('ScreenTransform')

function show() {
  print('show slider')
  // show your slider!
}

function hide() {
  print('hide slider')
  // hide your slider!
}

var debouncedHide = debounce(hide, 3000)

script.createEvent('TapEvent').bind(function () {
  // tapping the screen will show the slider
  show()
  // slider will hide if user hasn't tapped the screen or used the slider within 3 seconds
  debouncedHide()
})