shift73k/assets_old/node_modules/lodash.debounce/index.js

377 lines
10 KiB
JavaScript

/**
* lodash (Custom Build) <https://lodash.com/>
* Build: `lodash modularize exports="npm" -o ./`
* Copyright jQuery Foundation and other contributors <https://jquery.org/>
* Released under MIT license <https://lodash.com/license>
* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
* Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
*/
/** Used as the `TypeError` message for "Functions" methods. */
var FUNC_ERROR_TEXT = 'Expected a function';
/** Used as references for various `Number` constants. */
var NAN = 0 / 0;
/** `Object#toString` result references. */
var symbolTag = '[object Symbol]';
/** Used to match leading and trailing whitespace. */
var reTrim = /^\s+|\s+$/g;
/** Used to detect bad signed hexadecimal string values. */
var reIsBadHex = /^[-+]0x[0-9a-f]+$/i;
/** Used to detect binary string values. */
var reIsBinary = /^0b[01]+$/i;
/** Used to detect octal string values. */
var reIsOctal = /^0o[0-7]+$/i;
/** Built-in method references without a dependency on `root`. */
var freeParseInt = parseInt;
/** Detect free variable `global` from Node.js. */
var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;
/** Detect free variable `self`. */
var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
/** Used as a reference to the global object. */
var root = freeGlobal || freeSelf || Function('return this')();
/** Used for built-in method references. */
var objectProto = Object.prototype;
/**
* Used to resolve the
* [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
* of values.
*/
var objectToString = objectProto.toString;
/* Built-in method references for those with the same name as other `lodash` methods. */
var nativeMax = Math.max,
nativeMin = Math.min;
/**
* Gets the timestamp of the number of milliseconds that have elapsed since
* the Unix epoch (1 January 1970 00:00:00 UTC).
*
* @static
* @memberOf _
* @since 2.4.0
* @category Date
* @returns {number} Returns the timestamp.
* @example
*
* _.defer(function(stamp) {
* console.log(_.now() - stamp);
* }, _.now());
* // => Logs the number of milliseconds it took for the deferred invocation.
*/
var now = function() {
return root.Date.now();
};
/**
* Creates a debounced function that delays invoking `func` until after `wait`
* milliseconds have elapsed since the last time the debounced function was
* invoked. The debounced function comes with a `cancel` method to cancel
* delayed `func` invocations and a `flush` method to immediately invoke them.
* Provide `options` to indicate whether `func` should be invoked on the
* leading and/or trailing edge of the `wait` timeout. The `func` is invoked
* with the last arguments provided to the debounced function. Subsequent
* calls to the debounced function return the result of the last `func`
* invocation.
*
* **Note:** If `leading` and `trailing` options are `true`, `func` is
* invoked on the trailing edge of the timeout only if the debounced function
* is invoked more than once during the `wait` timeout.
*
* If `wait` is `0` and `leading` is `false`, `func` invocation is deferred
* until to the next tick, similar to `setTimeout` with a timeout of `0`.
*
* See [David Corbacho's article](https://css-tricks.com/debouncing-throttling-explained-examples/)
* for details over the differences between `_.debounce` and `_.throttle`.
*
* @static
* @memberOf _
* @since 0.1.0
* @category Function
* @param {Function} func The function to debounce.
* @param {number} [wait=0] The number of milliseconds to delay.
* @param {Object} [options={}] The options object.
* @param {boolean} [options.leading=false]
* Specify invoking on the leading edge of the timeout.
* @param {number} [options.maxWait]
* The maximum time `func` is allowed to be delayed before it's invoked.
* @param {boolean} [options.trailing=true]
* Specify invoking on the trailing edge of the timeout.
* @returns {Function} Returns the new debounced function.
* @example
*
* // Avoid costly calculations while the window size is in flux.
* jQuery(window).on('resize', _.debounce(calculateLayout, 150));
*
* // Invoke `sendMail` when clicked, debouncing subsequent calls.
* jQuery(element).on('click', _.debounce(sendMail, 300, {
* 'leading': true,
* 'trailing': false
* }));
*
* // Ensure `batchLog` is invoked once after 1 second of debounced calls.
* var debounced = _.debounce(batchLog, 250, { 'maxWait': 1000 });
* var source = new EventSource('/stream');
* jQuery(source).on('message', debounced);
*
* // Cancel the trailing debounced invocation.
* jQuery(window).on('popstate', debounced.cancel);
*/
function debounce(func, wait, options) {
var lastArgs,
lastThis,
maxWait,
result,
timerId,
lastCallTime,
lastInvokeTime = 0,
leading = false,
maxing = false,
trailing = true;
if (typeof func != 'function') {
throw new TypeError(FUNC_ERROR_TEXT);
}
wait = toNumber(wait) || 0;
if (isObject(options)) {
leading = !!options.leading;
maxing = 'maxWait' in options;
maxWait = maxing ? nativeMax(toNumber(options.maxWait) || 0, wait) : maxWait;
trailing = 'trailing' in options ? !!options.trailing : trailing;
}
function invokeFunc(time) {
var args = lastArgs,
thisArg = lastThis;
lastArgs = lastThis = undefined;
lastInvokeTime = time;
result = func.apply(thisArg, args);
return result;
}
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 remainingWait(time) {
var timeSinceLastCall = time - lastCallTime,
timeSinceLastInvoke = time - lastInvokeTime,
result = wait - timeSinceLastCall;
return maxing ? nativeMin(result, maxWait - timeSinceLastInvoke) : result;
}
function shouldInvoke(time) {
var timeSinceLastCall = time - lastCallTime,
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 timerExpired() {
var time = now();
if (shouldInvoke(time)) {
return trailingEdge(time);
}
// Restart the timer.
timerId = setTimeout(timerExpired, remainingWait(time));
}
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);
}
lastArgs = lastThis = undefined;
return result;
}
function cancel() {
if (timerId !== undefined) {
clearTimeout(timerId);
}
lastInvokeTime = 0;
lastArgs = lastCallTime = lastThis = timerId = undefined;
}
function flush() {
return timerId === undefined ? result : trailingEdge(now());
}
function debounced() {
var time = now(),
isInvoking = shouldInvoke(time);
lastArgs = arguments;
lastThis = this;
lastCallTime = time;
if (isInvoking) {
if (timerId === undefined) {
return leadingEdge(lastCallTime);
}
if (maxing) {
// Handle invocations in a tight loop.
timerId = setTimeout(timerExpired, wait);
return invokeFunc(lastCallTime);
}
}
if (timerId === undefined) {
timerId = setTimeout(timerExpired, wait);
}
return result;
}
debounced.cancel = cancel;
debounced.flush = flush;
return debounced;
}
/**
* Checks if `value` is the
* [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
* of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @since 0.1.0
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject([1, 2, 3]);
* // => true
*
* _.isObject(_.noop);
* // => true
*
* _.isObject(null);
* // => false
*/
function isObject(value) {
var type = typeof value;
return !!value && (type == 'object' || type == 'function');
}
/**
* Checks if `value` is object-like. A value is object-like if it's not `null`
* and has a `typeof` result of "object".
*
* @static
* @memberOf _
* @since 4.0.0
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
* @example
*
* _.isObjectLike({});
* // => true
*
* _.isObjectLike([1, 2, 3]);
* // => true
*
* _.isObjectLike(_.noop);
* // => false
*
* _.isObjectLike(null);
* // => false
*/
function isObjectLike(value) {
return !!value && typeof value == 'object';
}
/**
* Checks if `value` is classified as a `Symbol` primitive or object.
*
* @static
* @memberOf _
* @since 4.0.0
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a symbol, else `false`.
* @example
*
* _.isSymbol(Symbol.iterator);
* // => true
*
* _.isSymbol('abc');
* // => false
*/
function isSymbol(value) {
return typeof value == 'symbol' ||
(isObjectLike(value) && objectToString.call(value) == symbolTag);
}
/**
* Converts `value` to a number.
*
* @static
* @memberOf _
* @since 4.0.0
* @category Lang
* @param {*} value The value to process.
* @returns {number} Returns the number.
* @example
*
* _.toNumber(3.2);
* // => 3.2
*
* _.toNumber(Number.MIN_VALUE);
* // => 5e-324
*
* _.toNumber(Infinity);
* // => Infinity
*
* _.toNumber('3.2');
* // => 3.2
*/
function toNumber(value) {
if (typeof value == 'number') {
return value;
}
if (isSymbol(value)) {
return NAN;
}
if (isObject(value)) {
var other = typeof value.valueOf == 'function' ? value.valueOf() : value;
value = isObject(other) ? (other + '') : other;
}
if (typeof value != 'string') {
return value === 0 ? value : +value;
}
value = value.replace(reTrim, '');
var isBinary = reIsBinary.test(value);
return (isBinary || reIsOctal.test(value))
? freeParseInt(value.slice(2), isBinary ? 2 : 8)
: (reIsBadHex.test(value) ? NAN : +value);
}
module.exports = debounce;