amis-rpc-design/node_modules/throttle-debounce/umd/index.js
2023-10-07 19:42:30 +08:00

184 lines
7.6 KiB
JavaScript

(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
typeof define === 'function' && define.amd ? define(['exports'], factory) :
(global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory(global.throttleDebounce = {}));
})(this, (function (exports) { 'use strict';
/* eslint-disable no-undefined,no-param-reassign,no-shadow */
/**
* Throttle execution of a function. Especially useful for rate limiting
* execution of handlers on events like resize and scroll.
*
* @param {number} delay - A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher)
* are most useful.
* @param {Function} callback - A function to be executed after delay milliseconds. The `this` context and all arguments are passed through,
* as-is, to `callback` when the throttled-function is executed.
* @param {object} [options] - An object to configure options.
* @param {boolean} [options.noTrailing] - Optional, defaults to false. If noTrailing is true, callback will only execute every `delay` milliseconds
* while the throttled-function is being called. If noTrailing is false or unspecified, callback will be executed
* one final time after the last throttled-function call. (After the throttled-function has not been called for
* `delay` milliseconds, the internal counter is reset).
* @param {boolean} [options.noLeading] - Optional, defaults to false. If noLeading is false, the first throttled-function call will execute callback
* immediately. If noLeading is true, the first the callback execution will be skipped. It should be noted that
* callback will never executed if both noLeading = true and noTrailing = true.
* @param {boolean} [options.debounceMode] - If `debounceMode` is true (at begin), schedule `clear` to execute after `delay` ms. If `debounceMode` is
* false (at end), schedule `callback` to execute after `delay` ms.
*
* @returns {Function} A new, throttled, function.
*/
function throttle (delay, callback, options) {
var _ref = options || {},
_ref$noTrailing = _ref.noTrailing,
noTrailing = _ref$noTrailing === void 0 ? false : _ref$noTrailing,
_ref$noLeading = _ref.noLeading,
noLeading = _ref$noLeading === void 0 ? false : _ref$noLeading,
_ref$debounceMode = _ref.debounceMode,
debounceMode = _ref$debounceMode === void 0 ? undefined : _ref$debounceMode;
/*
* After wrapper has stopped being called, this timeout ensures that
* `callback` is executed at the proper times in `throttle` and `end`
* debounce modes.
*/
var timeoutID;
var cancelled = false; // Keep track of the last time `callback` was executed.
var lastExec = 0; // Function to clear existing timeout
function clearExistingTimeout() {
if (timeoutID) {
clearTimeout(timeoutID);
}
} // Function to cancel next exec
function cancel(options) {
var _ref2 = options || {},
_ref2$upcomingOnly = _ref2.upcomingOnly,
upcomingOnly = _ref2$upcomingOnly === void 0 ? false : _ref2$upcomingOnly;
clearExistingTimeout();
cancelled = !upcomingOnly;
}
/*
* The `wrapper` function encapsulates all of the throttling / debouncing
* functionality and when executed will limit the rate at which `callback`
* is executed.
*/
function wrapper() {
for (var _len = arguments.length, arguments_ = new Array(_len), _key = 0; _key < _len; _key++) {
arguments_[_key] = arguments[_key];
}
var self = this;
var elapsed = Date.now() - lastExec;
if (cancelled) {
return;
} // Execute `callback` and update the `lastExec` timestamp.
function exec() {
lastExec = Date.now();
callback.apply(self, arguments_);
}
/*
* If `debounceMode` is true (at begin) this is used to clear the flag
* to allow future `callback` executions.
*/
function clear() {
timeoutID = undefined;
}
if (!noLeading && debounceMode && !timeoutID) {
/*
* Since `wrapper` is being called for the first time and
* `debounceMode` is true (at begin), execute `callback`
* and noLeading != true.
*/
exec();
}
clearExistingTimeout();
if (debounceMode === undefined && elapsed > delay) {
if (noLeading) {
/*
* In throttle mode with noLeading, if `delay` time has
* been exceeded, update `lastExec` and schedule `callback`
* to execute after `delay` ms.
*/
lastExec = Date.now();
if (!noTrailing) {
timeoutID = setTimeout(debounceMode ? clear : exec, delay);
}
} else {
/*
* In throttle mode without noLeading, if `delay` time has been exceeded, execute
* `callback`.
*/
exec();
}
} else if (noTrailing !== true) {
/*
* In trailing throttle mode, since `delay` time has not been
* exceeded, schedule `callback` to execute `delay` ms after most
* recent execution.
*
* If `debounceMode` is true (at begin), schedule `clear` to execute
* after `delay` ms.
*
* If `debounceMode` is false (at end), schedule `callback` to
* execute after `delay` ms.
*/
timeoutID = setTimeout(debounceMode ? clear : exec, debounceMode === undefined ? delay - elapsed : delay);
}
}
wrapper.cancel = cancel; // Return the wrapper function.
return wrapper;
}
/* eslint-disable no-undefined */
/**
* Debounce execution of a function. Debouncing, unlike throttling,
* guarantees that a function is only executed a single time, either at the
* very beginning of a series of calls, or at the very end.
*
* @param {number} delay - A zero-or-greater delay in milliseconds. For event callbacks, values around 100 or 250 (or even higher) are most useful.
* @param {Function} callback - A function to be executed after delay milliseconds. The `this` context and all arguments are passed through, as-is,
* to `callback` when the debounced-function is executed.
* @param {object} [options] - An object to configure options.
* @param {boolean} [options.atBegin] - Optional, defaults to false. If atBegin is false or unspecified, callback will only be executed `delay` milliseconds
* after the last debounced-function call. If atBegin is true, callback will be executed only at the first debounced-function call.
* (After the throttled-function has not been called for `delay` milliseconds, the internal counter is reset).
*
* @returns {Function} A new, debounced function.
*/
function debounce (delay, callback, options) {
var _ref = options || {},
_ref$atBegin = _ref.atBegin,
atBegin = _ref$atBegin === void 0 ? false : _ref$atBegin;
return throttle(delay, callback, {
debounceMode: atBegin !== false
});
}
exports.debounce = debounce;
exports.throttle = throttle;
Object.defineProperty(exports, '__esModule', { value: true });
}));
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