41 lines
1.1 KiB
JavaScript
41 lines
1.1 KiB
JavaScript
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/**
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* @param {Function} func
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* @param {number} wait
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* @param {boolean} immediate
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* @return {*}
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*/
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export function debounce(func, wait, immediate) {
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let timeout, args, context, timestamp, result
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const later = function () {
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// 据上一次触发时间间隔
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const last = +new Date() - timestamp
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// 上次被包装函数被调用时间间隔 last 小于设定时间间隔 wait
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if (last < wait && last > 0) {
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timeout = setTimeout(later, wait - last)
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} else {
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timeout = null
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// 如果设定为immediate===true，因为开始边界已经调用过了此处无需调用
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if (!immediate) {
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result = func.apply(context, args)
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if (!timeout) context = args = null
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}
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}
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}
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return function (...args) {
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context = this
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timestamp = +new Date()
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const callNow = immediate && !timeout
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// 如果延时不存在，重新设定延时
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if (!timeout) timeout = setTimeout(later, wait)
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if (callNow) {
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result = func.apply(context, args)
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context = args = null
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}
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return result
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}
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}
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