forked from enviPath/enviPy
42 lines
944 B
JavaScript
42 lines
944 B
JavaScript
// It's actually "debounce"
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'use strict';
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var callable = require('es5-ext/object/valid-callable')
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, nextTick = require('next-tick')
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, validTimeout = require('./valid-timeout')
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, apply = Function.prototype.apply;
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module.exports = function (fn/*, timeout*/) {
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var scheduled, run, context, args, delay, timeout = arguments[1], handle;
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callable(fn);
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if (timeout == null) {
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delay = nextTick;
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} else {
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timeout = validTimeout(timeout);
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delay = setTimeout;
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}
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run = function () {
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if (!scheduled) return; // IE8 tends to not clear immediate timeouts properly
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scheduled = false;
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handle = null;
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apply.call(fn, context, args);
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context = null;
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args = null;
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};
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return function () {
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if (scheduled) {
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if (handle == null) {
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// 'nextTick' based, no room for debounce
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return;
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}
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clearTimeout(handle);
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}
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scheduled = true;
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context = this;
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args = arguments;
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handle = delay(run, timeout);
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};
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};
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