@awsui/components-react/internal/hooks/focus-visible/index.js

AWS UI is a collection of [React](https://reactjs.org/) components that help create intuitive, responsive, and accessible user experiences for web applications. It is developed by Amazon Web Services (AWS). This work is available under the terms of the [A

import { useEffect, useState } from 'react';
import { KeyCode } from '../../keycode';
import { unstable_batchedUpdates } from 'react-dom';
var ControlTracker = (function () {
    function ControlTracker(root) {
        var _this = this;
        this.root = root;
        this.listeners = new Set();
        this.isKeyboard = false;
        this.handleMousedown = function () {
            _this.isKeyboard = false;
            _this.notify();
        };
        this.handleKeydown = function (event) {
            var isSpecialKey = [KeyCode.shift, KeyCode.alt, KeyCode.control, KeyCode.meta].indexOf(event.keyCode) > -1;
            if (!isSpecialKey) {
                _this.isKeyboard = true;
                _this.notify();
            }
        };
    }
    ControlTracker.prototype.addDocumentListeners = function () {
        this.root.addEventListener('mousedown', this.handleMousedown);
        this.root.addEventListener('keydown', this.handleKeydown);
    };
    ControlTracker.prototype.removeDocumentListeners = function () {
        this.root.removeEventListener('mousedown', this.handleMousedown);
        this.root.removeEventListener('keydown', this.handleKeydown);
    };
    ControlTracker.prototype.notify = function () {
        var _this = this;
        unstable_batchedUpdates(function () {
            _this.listeners.forEach(function (listener) { return listener(_this.isKeyboard); });
        });
    };
    ControlTracker.prototype.subscribe = function (callback) {
        var _this = this;
        if (this.listeners.size === 0) {
            this.addDocumentListeners();
        }
        this.listeners.add(callback);
        callback(this.isKeyboard);
        return function () {
            _this.listeners["delete"](callback);
            if (_this.listeners.size === 0) {
                _this.removeDocumentListeners();
            }
        };
    };
    return ControlTracker;
}());
var tracker = typeof document !== 'undefined' && new ControlTracker(document);
export default function useFocusVisible() {
    var _a = useState(false), visible = _a[0], setVisible = _a[1];
    useEffect(function () {
        if (tracker) {
            return tracker.subscribe(function (isKeyboard) { return setVisible(isKeyboard); });
        }
    }, []);
    return visible ? { 'data-awsui-focus-visible': visible } : {};
}