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| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 | 'use client'; import { useEffect, useRef, useCallback } from 'react'; /** * Focusable element selectors */ const FOCUSABLE_SELECTORS = [ 'button:not([disabled])', '[href]', 'input:not([disabled])', 'select:not([disabled])', 'textarea:not([disabled])', '[tabindex]:not([tabindex="-1"])', ].join(', '); export interface UseFocusTrapOptions { /** Whether focus trapping is active */ isActive: boolean; /** Whether to auto-focus the first element when activated */ autoFocus?: boolean; /** Whether to restore focus to the previously focused element when deactivated */ restoreFocus?: boolean; /** Optional callback when Escape key is pressed */ onEscape?: () => void; } export interface UseFocusTrapReturn<T extends HTMLElement> { /** Ref to attach to the container element */ containerRef: React.RefObject<T | null>; /** Get all focusable elements in the container */ getFocusableElements: () => HTMLElement[]; /** Focus the first focusable element */ focusFirst: () => void; /** Focus the last focusable element */ focusLast: () => void; } /** * useFocusTrap Hook * * Traps keyboard focus within a container element. * Essential for modal dialogs, dropdown menus, and other overlay components * to ensure proper accessibility. * * Features: * - Traps Tab/Shift+Tab focus within container * - Auto-focuses first element when activated * - Restores focus to previous element when deactivated * - Optional Escape key handler * - Returns utilities for manual focus management * * @example * ```tsx * function Modal({ isOpen, onClose, children }) { * const { containerRef } = useFocusTrap<HTMLDivElement>({ * isActive: isOpen, * onEscape: onClose, * }); * * if (!isOpen) return null; * * return ( * <div ref={containerRef} role="dialog" aria-modal="true"> * {children} * <button onClick={onClose}>Close</button> * </div> * ); * } * ``` * * @example * ```tsx * // With manual focus control * function Dropdown({ isOpen, items }) { * const { containerRef, focusFirst, focusLast } = useFocusTrap<HTMLUListElement>({ * isActive: isOpen, * autoFocus: false, // We'll manage focus manually * }); * * useEffect(() => { * if (isOpen) { * focusFirst(); * } * }, [isOpen, focusFirst]); * * return ( * <ul ref={containerRef} role="menu"> * {items.map(item => <li key={item.id}>{item.label}</li>)} * </ul> * ); * } * ``` */ export function useFocusTrap<T extends HTMLElement = HTMLDivElement>({ isActive, autoFocus = true, restoreFocus = true, onEscape, }: UseFocusTrapOptions): UseFocusTrapReturn<T> { const containerRef = useRef<T>(null); const previousActiveElement = useRef<HTMLElement | null>(null); /** * Get all focusable elements within the container */ const getFocusableElements = useCallback((): HTMLElement[] => { if (!containerRef.current) return []; return Array.from( containerRef.current.querySelectorAll<HTMLElement>(FOCUSABLE_SELECTORS) ); }, []); /** * Focus the first focusable element */ const focusFirst = useCallback(() => { const elements = getFocusableElements(); if (elements.length > 0) { elements[0].focus(); } }, [getFocusableElements]); /** * Focus the last focusable element */ const focusLast = useCallback(() => { const elements = getFocusableElements(); if (elements.length > 0) { elements[elements.length - 1].focus(); } }, [getFocusableElements]); useEffect(() => { if (!isActive || !containerRef.current) return; // Store previously focused element if (restoreFocus) { previousActiveElement.current = document.activeElement as HTMLElement; } // Auto-focus first element if (autoFocus) { // Small delay to ensure the container is in the DOM const timer = setTimeout(() => { focusFirst(); }, 0); // Cleanup timer if effect is cancelled const cleanup = () => clearTimeout(timer); return cleanup; } }, [isActive, autoFocus, restoreFocus, focusFirst]); useEffect(() => { if (!isActive || !containerRef.current) return; const container = containerRef.current; /** * Handle Tab key to trap focus */ const handleKeyDown = (event: KeyboardEvent) => { // Handle Escape key if (event.key === 'Escape' && onEscape) { event.preventDefault(); onEscape(); return; } // Only handle Tab key if (event.key !== 'Tab') return; const focusableElements = getFocusableElements(); if (focusableElements.length === 0) return; const firstElement = focusableElements[0]; const lastElement = focusableElements[focusableElements.length - 1]; const activeElement = document.activeElement; // Shift+Tab from first element -> focus last element if (event.shiftKey && activeElement === firstElement) { event.preventDefault(); lastElement.focus(); } // Tab from last element -> focus first element else if (!event.shiftKey && activeElement === lastElement) { event.preventDefault(); firstElement.focus(); } }; container.addEventListener('keydown', handleKeyDown); return () => { container.removeEventListener('keydown', handleKeyDown); }; }, [isActive, onEscape, getFocusableElements]); // Restore focus when deactivated useEffect(() => { if (!isActive && restoreFocus && previousActiveElement.current) { previousActiveElement.current.focus(); previousActiveElement.current = null; } }, [isActive, restoreFocus]); return { containerRef, getFocusableElements, focusFirst, focusLast, }; } export default useFocusTrap; |