You can not select more than 25 topics
			Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
		
		
		
		
			
				
					193 lines
				
				5.3 KiB
			
		
		
			
		
	
	
					193 lines
				
				5.3 KiB
			| 
								 
											4 years ago
										 
									 | 
							
								
							 | 
						||
| 
								 | 
							
								/*
							 | 
						||
| 
								 | 
							
								* Licensed to the Apache Software Foundation (ASF) under one
							 | 
						||
| 
								 | 
							
								* or more contributor license agreements.  See the NOTICE file
							 | 
						||
| 
								 | 
							
								* distributed with this work for additional information
							 | 
						||
| 
								 | 
							
								* regarding copyright ownership.  The ASF licenses this file
							 | 
						||
| 
								 | 
							
								* to you under the Apache License, Version 2.0 (the
							 | 
						||
| 
								 | 
							
								* "License"); you may not use this file except in compliance
							 | 
						||
| 
								 | 
							
								* with the License.  You may obtain a copy of the License at
							 | 
						||
| 
								 | 
							
								*
							 | 
						||
| 
								 | 
							
								*   http://www.apache.org/licenses/LICENSE-2.0
							 | 
						||
| 
								 | 
							
								*
							 | 
						||
| 
								 | 
							
								* Unless required by applicable law or agreed to in writing,
							 | 
						||
| 
								 | 
							
								* software distributed under the License is distributed on an
							 | 
						||
| 
								 | 
							
								* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
							 | 
						||
| 
								 | 
							
								* KIND, either express or implied.  See the License for the
							 | 
						||
| 
								 | 
							
								* specific language governing permissions and limitations
							 | 
						||
| 
								 | 
							
								* under the License.
							 | 
						||
| 
								 | 
							
								*/
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								/*
							 | 
						||
| 
								 | 
							
								* Licensed to the Apache Software Foundation (ASF) under one
							 | 
						||
| 
								 | 
							
								* or more contributor license agreements.  See the NOTICE file
							 | 
						||
| 
								 | 
							
								* distributed with this work for additional information
							 | 
						||
| 
								 | 
							
								* regarding copyright ownership.  The ASF licenses this file
							 | 
						||
| 
								 | 
							
								* to you under the Apache License, Version 2.0 (the
							 | 
						||
| 
								 | 
							
								* "License"); you may not use this file except in compliance
							 | 
						||
| 
								 | 
							
								* with the License.  You may obtain a copy of the License at
							 | 
						||
| 
								 | 
							
								*
							 | 
						||
| 
								 | 
							
								*   http://www.apache.org/licenses/LICENSE-2.0
							 | 
						||
| 
								 | 
							
								*
							 | 
						||
| 
								 | 
							
								* Unless required by applicable law or agreed to in writing,
							 | 
						||
| 
								 | 
							
								* software distributed under the License is distributed on an
							 | 
						||
| 
								 | 
							
								* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
							 | 
						||
| 
								 | 
							
								* KIND, either express or implied.  See the License for the
							 | 
						||
| 
								 | 
							
								* specific language governing permissions and limitations
							 | 
						||
| 
								 | 
							
								* under the License.
							 | 
						||
| 
								 | 
							
								*/
							 | 
						||
| 
								 | 
							
								var ORIGIN_METHOD = '\0__throttleOriginMethod';
							 | 
						||
| 
								 | 
							
								var RATE = '\0__throttleRate';
							 | 
						||
| 
								 | 
							
								var THROTTLE_TYPE = '\0__throttleType';
							 | 
						||
| 
								 | 
							
								/**
							 | 
						||
| 
								 | 
							
								 * @public
							 | 
						||
| 
								 | 
							
								 * @param {(Function)} fn
							 | 
						||
| 
								 | 
							
								 * @param {number} [delay=0] Unit: ms.
							 | 
						||
| 
								 | 
							
								 * @param {boolean} [debounce=false]
							 | 
						||
| 
								 | 
							
								 *        true: If call interval less than `delay`, only the last call works.
							 | 
						||
| 
								 | 
							
								 *        false: If call interval less than `delay, call works on fixed rate.
							 | 
						||
| 
								 | 
							
								 * @return {(Function)} throttled fn.
							 | 
						||
| 
								 | 
							
								 */
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								function throttle(fn, delay, debounce) {
							 | 
						||
| 
								 | 
							
								  var currCall;
							 | 
						||
| 
								 | 
							
								  var lastCall = 0;
							 | 
						||
| 
								 | 
							
								  var lastExec = 0;
							 | 
						||
| 
								 | 
							
								  var timer = null;
							 | 
						||
| 
								 | 
							
								  var diff;
							 | 
						||
| 
								 | 
							
								  var scope;
							 | 
						||
| 
								 | 
							
								  var args;
							 | 
						||
| 
								 | 
							
								  var debounceNextCall;
							 | 
						||
| 
								 | 
							
								  delay = delay || 0;
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  function exec() {
							 | 
						||
| 
								 | 
							
								    lastExec = new Date().getTime();
							 | 
						||
| 
								 | 
							
								    timer = null;
							 | 
						||
| 
								 | 
							
								    fn.apply(scope, args || []);
							 | 
						||
| 
								 | 
							
								  }
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  var cb = function () {
							 | 
						||
| 
								 | 
							
								    currCall = new Date().getTime();
							 | 
						||
| 
								 | 
							
								    scope = this;
							 | 
						||
| 
								 | 
							
								    args = arguments;
							 | 
						||
| 
								 | 
							
								    var thisDelay = debounceNextCall || delay;
							 | 
						||
| 
								 | 
							
								    var thisDebounce = debounceNextCall || debounce;
							 | 
						||
| 
								 | 
							
								    debounceNextCall = null;
							 | 
						||
| 
								 | 
							
								    diff = currCall - (thisDebounce ? lastCall : lastExec) - thisDelay;
							 | 
						||
| 
								 | 
							
								    clearTimeout(timer); // Here we should make sure that: the `exec` SHOULD NOT be called later
							 | 
						||
| 
								 | 
							
								    // than a new call of `cb`, that is, preserving the command order. Consider
							 | 
						||
| 
								 | 
							
								    // calculating "scale rate" when roaming as an example. When a call of `cb`
							 | 
						||
| 
								 | 
							
								    // happens, either the `exec` is called dierectly, or the call is delayed.
							 | 
						||
| 
								 | 
							
								    // But the delayed call should never be later than next call of `cb`. Under
							 | 
						||
| 
								 | 
							
								    // this assurance, we can simply update view state each time `dispatchAction`
							 | 
						||
| 
								 | 
							
								    // triggered by user roaming, but not need to add extra code to avoid the
							 | 
						||
| 
								 | 
							
								    // state being "rolled-back".
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								    if (thisDebounce) {
							 | 
						||
| 
								 | 
							
								      timer = setTimeout(exec, thisDelay);
							 | 
						||
| 
								 | 
							
								    } else {
							 | 
						||
| 
								 | 
							
								      if (diff >= 0) {
							 | 
						||
| 
								 | 
							
								        exec();
							 | 
						||
| 
								 | 
							
								      } else {
							 | 
						||
| 
								 | 
							
								        timer = setTimeout(exec, -diff);
							 | 
						||
| 
								 | 
							
								      }
							 | 
						||
| 
								 | 
							
								    }
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								    lastCall = currCall;
							 | 
						||
| 
								 | 
							
								  };
							 | 
						||
| 
								 | 
							
								  /**
							 | 
						||
| 
								 | 
							
								   * Clear throttle.
							 | 
						||
| 
								 | 
							
								   * @public
							 | 
						||
| 
								 | 
							
								   */
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  cb.clear = function () {
							 | 
						||
| 
								 | 
							
								    if (timer) {
							 | 
						||
| 
								 | 
							
								      clearTimeout(timer);
							 | 
						||
| 
								 | 
							
								      timer = null;
							 | 
						||
| 
								 | 
							
								    }
							 | 
						||
| 
								 | 
							
								  };
							 | 
						||
| 
								 | 
							
								  /**
							 | 
						||
| 
								 | 
							
								   * Enable debounce once.
							 | 
						||
| 
								 | 
							
								   */
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  cb.debounceNextCall = function (debounceDelay) {
							 | 
						||
| 
								 | 
							
								    debounceNextCall = debounceDelay;
							 | 
						||
| 
								 | 
							
								  };
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  return cb;
							 | 
						||
| 
								 | 
							
								}
							 | 
						||
| 
								 | 
							
								/**
							 | 
						||
| 
								 | 
							
								 * Create throttle method or update throttle rate.
							 | 
						||
| 
								 | 
							
								 *
							 | 
						||
| 
								 | 
							
								 * @example
							 | 
						||
| 
								 | 
							
								 * ComponentView.prototype.render = function () {
							 | 
						||
| 
								 | 
							
								 *     ...
							 | 
						||
| 
								 | 
							
								 *     throttle.createOrUpdate(
							 | 
						||
| 
								 | 
							
								 *         this,
							 | 
						||
| 
								 | 
							
								 *         '_dispatchAction',
							 | 
						||
| 
								 | 
							
								 *         this.model.get('throttle'),
							 | 
						||
| 
								 | 
							
								 *         'fixRate'
							 | 
						||
| 
								 | 
							
								 *     );
							 | 
						||
| 
								 | 
							
								 * };
							 | 
						||
| 
								 | 
							
								 * ComponentView.prototype.remove = function () {
							 | 
						||
| 
								 | 
							
								 *     throttle.clear(this, '_dispatchAction');
							 | 
						||
| 
								 | 
							
								 * };
							 | 
						||
| 
								 | 
							
								 * ComponentView.prototype.dispose = function () {
							 | 
						||
| 
								 | 
							
								 *     throttle.clear(this, '_dispatchAction');
							 | 
						||
| 
								 | 
							
								 * };
							 | 
						||
| 
								 | 
							
								 *
							 | 
						||
| 
								 | 
							
								 * @public
							 | 
						||
| 
								 | 
							
								 * @param {Object} obj
							 | 
						||
| 
								 | 
							
								 * @param {string} fnAttr
							 | 
						||
| 
								 | 
							
								 * @param {number} [rate]
							 | 
						||
| 
								 | 
							
								 * @param {string} [throttleType='fixRate'] 'fixRate' or 'debounce'
							 | 
						||
| 
								 | 
							
								 * @return {Function} throttled function.
							 | 
						||
| 
								 | 
							
								 */
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								function createOrUpdate(obj, fnAttr, rate, throttleType) {
							 | 
						||
| 
								 | 
							
								  var fn = obj[fnAttr];
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  if (!fn) {
							 | 
						||
| 
								 | 
							
								    return;
							 | 
						||
| 
								 | 
							
								  }
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  var originFn = fn[ORIGIN_METHOD] || fn;
							 | 
						||
| 
								 | 
							
								  var lastThrottleType = fn[THROTTLE_TYPE];
							 | 
						||
| 
								 | 
							
								  var lastRate = fn[RATE];
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  if (lastRate !== rate || lastThrottleType !== throttleType) {
							 | 
						||
| 
								 | 
							
								    if (rate == null || !throttleType) {
							 | 
						||
| 
								 | 
							
								      return obj[fnAttr] = originFn;
							 | 
						||
| 
								 | 
							
								    }
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								    fn = obj[fnAttr] = throttle(originFn, rate, throttleType === 'debounce');
							 | 
						||
| 
								 | 
							
								    fn[ORIGIN_METHOD] = originFn;
							 | 
						||
| 
								 | 
							
								    fn[THROTTLE_TYPE] = throttleType;
							 | 
						||
| 
								 | 
							
								    fn[RATE] = rate;
							 | 
						||
| 
								 | 
							
								  }
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  return fn;
							 | 
						||
| 
								 | 
							
								}
							 | 
						||
| 
								 | 
							
								/**
							 | 
						||
| 
								 | 
							
								 * Clear throttle. Example see throttle.createOrUpdate.
							 | 
						||
| 
								 | 
							
								 *
							 | 
						||
| 
								 | 
							
								 * @public
							 | 
						||
| 
								 | 
							
								 * @param {Object} obj
							 | 
						||
| 
								 | 
							
								 * @param {string} fnAttr
							 | 
						||
| 
								 | 
							
								 */
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								function clear(obj, fnAttr) {
							 | 
						||
| 
								 | 
							
								  var fn = obj[fnAttr];
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								  if (fn && fn[ORIGIN_METHOD]) {
							 | 
						||
| 
								 | 
							
								    obj[fnAttr] = fn[ORIGIN_METHOD];
							 | 
						||
| 
								 | 
							
								  }
							 | 
						||
| 
								 | 
							
								}
							 | 
						||
| 
								 | 
							
								
							 | 
						||
| 
								 | 
							
								exports.throttle = throttle;
							 | 
						||
| 
								 | 
							
								exports.createOrUpdate = createOrUpdate;
							 | 
						||
| 
								 | 
							
								exports.clear = clear;
							 |