@turbox3d/shared/lib/debounce.js

turbox shared internal utility

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.debounce = debounce;
var now = Date.now;
function debounce(func) {
  var wait = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 300;
  var lastArgs;
  var lastThis;
  var maxWait;
  var result;
  var timerId;
  var lastCallTime;
  var lastInvokeTime = 0;
  var leading = false;
  var maxing = false;
  var trailing = true;
  if (typeof func !== 'function') {
    throw new TypeError('Expected a function');
  }
  function invokeFunc(time) {
    var args = lastArgs;
    var thisArg = lastThis;
    // eslint-disable-next-line no-multi-assign
    lastArgs = lastThis = undefined;
    lastInvokeTime = time;
    result = func.apply(thisArg, args);
    return result;
  }
  function shouldInvoke(time) {
    var timeSinceLastCall = time - lastCallTime;
    var timeSinceLastInvoke = time - lastInvokeTime;
    // Either this is the first call, activity has stopped and we're at the
    // trailing edge, the system time has gone backwards and we're treating
    // it as the trailing edge, or we've hit the `maxWait` limit.
    return lastCallTime === undefined || timeSinceLastCall >= wait || timeSinceLastCall < 0 || maxing && timeSinceLastInvoke >= maxWait;
  }
  function remainingWait(time) {
    var timeSinceLastCall = time - lastCallTime;
    var timeSinceLastInvoke = time - lastInvokeTime;
    var timeWaiting = wait - timeSinceLastCall;
    return maxing ? Math.min(timeWaiting, maxWait - timeSinceLastInvoke) : timeWaiting;
  }
  function trailingEdge(time) {
    timerId = undefined;
    // Only invoke if we have `lastArgs` which means `func` has been
    // debounced at least once.
    if (trailing && lastArgs) {
      return invokeFunc(time);
    }
    // eslint-disable-next-line no-multi-assign
    lastArgs = lastThis = undefined;
    return result;
  }
  function timerExpired() {
    var time = now();
    if (shouldInvoke(time)) {
      return trailingEdge(time);
    }
    // Restart the timer.
    timerId = setTimeout(timerExpired, remainingWait(time));
  }
  function leadingEdge(time) {
    // Reset any `maxWait` timer.
    lastInvokeTime = time;
    // Start the timer for the trailing edge.
    timerId = setTimeout(timerExpired, wait);
    // Invoke the leading edge.
    return leading ? invokeFunc(time) : result;
  }
  function cancel() {
    if (timerId !== undefined) {
      clearTimeout(timerId);
    }
    lastInvokeTime = 0;
    // eslint-disable-next-line no-multi-assign
    lastArgs = lastCallTime = lastThis = timerId = undefined;
  }
  function flush() {
    return timerId === undefined ? result : trailingEdge(now());
  }
  function debounced() {
    var time = now();
    var isInvoking = shouldInvoke(time);
    // eslint-disable-next-line prefer-rest-params
    lastArgs = arguments;
    // eslint-disable-next-line @typescript-eslint/no-this-alias
    lastThis = this;
    lastCallTime = time;
    if (isInvoking) {
      if (timerId === undefined) {
        return leadingEdge(lastCallTime);
      }
      if (maxing) {
        // Handle invocations in a tight loop.
        clearTimeout(timerId);
        timerId = setTimeout(timerExpired, wait);
        return invokeFunc(lastCallTime);
      }
    }
    if (timerId === undefined) {
      timerId = setTimeout(timerExpired, wait);
    }
    return result;
  }
  debounced.cancel = cancel;
  debounced.flush = flush;
  return debounced;
}