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visibilityChangeListener

Waits until the tab is focused, executing a callback function when it happens.

目前为 2023-11-20 提交的版本。查看 最新版本。

此脚本不应直接安装，它是一个供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.cn-greasyfork.org/scripts/480373/1283459/visibilityChangeListener.js 

// ==UserScript==
// @name         visibilityChangeListener
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Waits until the tab is focused, executing a callback function when it happens.
// @author       IgnaV
// @grant        none
// ==/UserScript==

const visibilityChangeListener = (onFocus, onBlur, minTime = 0) => {
    let lastExecutionFocusTime = 0;
    let lastExecutionBlurTime = 0;

    document.addEventListener('visibilitychange', function () {
        const currentTime = Date.now();

        if (document.visibilityState === 'visible') {
            if (currentTime - lastExecutionFocusTime >= minTime) {
                onFocus?.();
                lastExecutionFocusTime = currentTime;
            }
        } else if (currentTime - lastExecutionBlurTime >= minTime) {
            onBlur?.();
            lastExecutionBlurTime = currentTime;
        }
    });
};