Refactored keyboard navigation to its own keynav.js. Implemented keyboard navigation on modal dialogs.

2025-12-10 13:57:25 +00:00
parent fbce5b97db
commit 1fe14d5f5f
16 changed files with 631 additions and 330 deletions
@@ -0,0 +1,408 @@
+/**
+ * Keyboard Navigation Module
+ *
+ * Provides reusable arrow key navigation for button groups and grids.
+ *
+ * Concepts:
+ * - Group: A container with focusable elements (buttons, links, items)
+ * - Button row: Left/right arrows navigate between buttons, up/down navigate to adjacent groups
+ * - Grid: A responsive grid of items; arrows follow the visual grid layout
+ *
+ * Data attributes for customization:
+ * - data-nav-group: Marks a navigation group container
+ * - data-nav-primary: Marks the preferred element to focus when entering a group
+ * - data-nav-items: CSS selector for focusable items within the group (default: 'button, a, [tabindex="0"], [tabindex="-1"]:not([disabled])')
+ */
+
+// Direction mapping from key events
+const DIRECTION_MAP = {
+  ArrowLeft: 'left',
+  ArrowRight: 'right',
+  ArrowUp: 'up',
+  ArrowDown: 'down'
+}
+
+/**
+ * Get the direction from a keyboard event.
+ * For text inputs with content, left/right arrows return null to preserve cursor movement.
+ * @param {KeyboardEvent} event
+ * @returns {string|null} 'left', 'right', 'up', 'down', or null
+ */
+export const getDirection = (event) => {
+  const direction = DIRECTION_MAP[event.key]
+  if (!direction) return null
+
+  // For text inputs, preserve left/right for cursor movement when there's content
+  const target = event.target
+  const isTextInput = target.tagName === 'INPUT' || target.tagName === 'TEXTAREA'
+  if (isTextInput && (direction === 'left' || direction === 'right')) {
+    // Only allow navigation when input is empty
+    if (target.value !== '') return null
+  }
+
+  return direction
+}
+
+/**
+ * Get focusable elements within a container
+ * @param {HTMLElement} container
+ * @param {string} selector - CSS selector for items (optional)
+ * @returns {HTMLElement[]}
+ */
+export const getFocusableItems = (container, selector = null) => {
+  if (!container) return []
+  const sel = selector || container.dataset?.navItems || 'button:not([disabled]), a, [tabindex="0"], [tabindex="-1"]:not([disabled])'
+  return Array.from(container.querySelectorAll(sel))
+}
+
+/**
+ * Get grid layout information for a container
+ * @param {HTMLElement} container
+ * @param {string} itemSelector - CSS selector for grid items
+ * @returns {{ items: HTMLElement[], cols: number } | null}
+ */
+export const getGridInfo = (container, itemSelector) => {
+  const items = getFocusableItems(container, itemSelector)
+  if (items.length === 0) return null
+
+  // Calculate columns by checking which items share the same top position
+  const firstTop = items[0].getBoundingClientRect().top
+  let cols = 0
+  for (const item of items) {
+    if (Math.abs(item.getBoundingClientRect().top - firstTop) < 5) cols++
+    else break
+  }
+  return { items, cols: Math.max(1, cols) }
+}
+
+/**
+ * Navigate within a horizontal button row
+ * @param {HTMLElement} container - The container element
+ * @param {HTMLElement} current - Currently focused element
+ * @param {string} direction - 'left', 'right', 'up', or 'down'
+ * @param {Object} options
+ * @param {string} options.itemSelector - CSS selector for buttons
+ * @returns {'moved'|'boundary'|'none'} Result of navigation
+ */
+export const navigateButtonRow = (container, current, direction, options = {}) => {
+  const items = getFocusableItems(container, options.itemSelector)
+  if (items.length === 0) return 'none'
+
+  const currentIndex = items.indexOf(current)
+  if (currentIndex === -1) return 'none'
+
+  if (direction === 'left') {
+    if (currentIndex > 0) {
+      items[currentIndex - 1].focus()
+      return 'moved'
+    }
+    return 'boundary'
+  }
+
+  if (direction === 'right') {
+    if (currentIndex < items.length - 1) {
+      items[currentIndex + 1].focus()
+      return 'moved'
+    }
+    return 'boundary'
+  }
+
+  // Up/down are always boundaries for button rows
+  return 'boundary'
+}
+
+/**
+ * Navigate within a responsive grid
+ * @param {HTMLElement} container - The grid container
+ * @param {HTMLElement} current - Currently focused element
+ * @param {string} direction - 'left', 'right', 'up', or 'down'
+ * @param {Object} options
+ * @param {string} options.itemSelector - CSS selector for grid items
+ * @returns {'moved'|'boundary'|'none'} Result of navigation
+ */
+export const navigateGrid = (container, current, direction, options = {}) => {
+  const grid = getGridInfo(container, options.itemSelector)
+  if (!grid) return 'none'
+
+  const { items, cols } = grid
+  const currentIndex = items.indexOf(current)
+  if (currentIndex === -1) return 'none'
+
+  const row = Math.floor(currentIndex / cols)
+  const col = currentIndex % cols
+  let newIndex = currentIndex
+
+  switch (direction) {
+    case 'left':
+      if (col === 0) return 'boundary'
+      newIndex = currentIndex - 1
+      break
+    case 'right':
+      if (currentIndex >= items.length - 1) return 'boundary'
+      newIndex = currentIndex + 1
+      break
+    case 'up':
+      if (row === 0) return 'boundary'
+      newIndex = currentIndex - cols
+      break
+    case 'down':
+      if (currentIndex + cols >= items.length) return 'boundary'
+      newIndex = currentIndex + cols
+      break
+    default:
+      return 'none'
+  }
+
+  if (newIndex !== currentIndex) {
+    items[newIndex].focus()
+    return 'moved'
+  }
+  return 'none'
+}
+
+/**
+ * Focus the preferred element in a group (primary or first focusable)
+ * @param {HTMLElement} container
+ * @param {Object} options
+ * @param {string} options.primarySelector - CSS selector for primary element
+ * @param {string} options.itemSelector - CSS selector for items
+ * @returns {HTMLElement|null} The focused element, or null if none found
+ */
+export const focusPreferred = (container, options = {}) => {
+  if (!container) return null
+
+  // First try data-nav-primary
+  const primary = container.querySelector('[data-nav-primary]') ||
+                  (options.primarySelector && container.querySelector(options.primarySelector))
+  if (primary) {
+    primary.focus()
+    return primary
+  }
+
+  // Fall back to first focusable
+  const items = getFocusableItems(container, options.itemSelector)
+  if (items.length > 0) {
+    items[0].focus()
+    return items[0]
+  }
+
+  return null
+}
+
+/**
+ * Focus a specific item by index in a group
+ * @param {HTMLElement} container
+ * @param {number} index - Index of item to focus (negative counts from end)
+ * @param {Object} options
+ * @param {string} options.itemSelector - CSS selector for items
+ * @returns {HTMLElement|null} The focused element, or null if not found
+ */
+export const focusAtIndex = (container, index, options = {}) => {
+  if (!container) return null
+
+  const items = getFocusableItems(container, options.itemSelector)
+  if (items.length === 0) return null
+
+  // Support negative indices
+  const resolvedIndex = index < 0 ? items.length + index : index
+  if (resolvedIndex >= 0 && resolvedIndex < items.length) {
+    items[resolvedIndex].focus()
+    return items[resolvedIndex]
+  }
+
+  return null
+}
+
+/**
+ * Create a keydown handler for button row navigation
+ * @param {Object} options
+ * @param {() => HTMLElement} options.getContainer - Function returning the container element
+ * @param {string} options.itemSelector - CSS selector for buttons
+ * @param {(direction: string) => void} options.onBoundary - Called when navigation hits a boundary
+ * @param {() => boolean} options.isDisabled - Function returning whether navigation is disabled
+ * @returns {(event: KeyboardEvent) => void}
+ */
+export const createButtonRowHandler = (options) => {
+  const { getContainer, itemSelector, onBoundary, isDisabled } = options
+
+  return (event) => {
+    if (isDisabled?.()) return
+
+    const direction = getDirection(event)
+    if (!direction) return
+
+    event.preventDefault()
+    const container = getContainer()
+
+    if (direction === 'up' || direction === 'down') {
+      // Vertical navigation always exits button rows
+      onBoundary?.(direction)
+      return
+    }
+
+    const result = navigateButtonRow(container, event.target, direction, { itemSelector })
+    if (result === 'boundary') {
+      onBoundary?.(direction)
+    }
+  }
+}
+
+/**
+ * Create a keydown handler for grid navigation
+ * @param {Object} options
+ * @param {() => HTMLElement} options.getContainer - Function returning the container element
+ * @param {string} options.itemSelector - CSS selector for grid items
+ * @param {(direction: string) => void} options.onBoundary - Called when navigation hits a boundary
+ * @param {() => boolean} options.isDisabled - Function returning whether navigation is disabled
+ * @returns {(event: KeyboardEvent) => void}
+ */
+export const createGridHandler = (options) => {
+  const { getContainer, itemSelector, onBoundary, isDisabled } = options
+
+  return (event) => {
+    if (isDisabled?.()) return
+
+    const direction = getDirection(event)
+    if (!direction) return
+
+    event.preventDefault()
+    const container = getContainer()
+    const result = navigateGrid(container, event.target, direction, { itemSelector })
+
+    if (result === 'boundary') {
+      onBoundary?.(direction)
+    }
+  }
+}
+
+/**
+ * Handle escape key to navigate out of a component
+ * @param {KeyboardEvent} event
+ * @param {(direction: string) => void} onNavigateOut - Callback with direction
+ * @param {() => boolean} isDisabled - Function returning whether navigation is disabled
+ */
+export const handleEscape = (event, onNavigateOut, isDisabled) => {
+  if (isDisabled?.()) return false
+  if (event.key !== 'Escape') return false
+
+  event.preventDefault()
+  onNavigateOut?.('up')
+  return true
+}
+
+/**
+ * Handle delete/backspace key for item deletion
+ * @param {KeyboardEvent} event
+ * @param {() => void} onDelete - Callback to perform deletion
+ * @returns {boolean} Whether the key was handled
+ */
+export const handleDeleteKey = (event, onDelete) => {
+  const isMac = navigator.userAgent.includes('Mac OS')
+  if (event.key === 'Delete' || (isMac && event.key === 'Backspace')) {
+    event.preventDefault()
+    onDelete?.()
+    return true
+  }
+  return false
+}
+
+/**
+ * Focus the most appropriate button in a dialog/modal.
+ * Priority: .btn-primary > .btn-secondary > any button
+ * @param {HTMLElement} container - The dialog/modal container element
+ * @returns {HTMLElement|null} The focused element, or null if none found
+ */
+export const focusDialogButton = (container) => {
+  if (!container) return null
+
+  // Priority order for button selection
+  const selectors = [
+    '.btn-primary:not([disabled])',
+    '.btn-secondary:not([disabled])',
+    'button:not([disabled])'
+  ]
+
+  for (const selector of selectors) {
+    const btn = container.querySelector(selector)
+    if (btn) {
+      btn.focus()
+      return btn
+    }
+  }
+
+  return null
+}
+
+/**
+ * Focus the most appropriate element in a dialog/modal.
+ * For dialogs with input fields (rename/edit forms): focuses first input and selects text
+ * For other dialogs: focuses primary button (or fallback)
+ * @param {HTMLElement} container - The dialog/modal container element
+ * @returns {HTMLElement|null} The focused element, or null if none found
+ */
+export const focusDialogDefault = (container) => {
+  if (!container) return null
+
+  // Check for input fields first (form dialogs like rename)
+  const input = container.querySelector('input:not([disabled]):not([type="hidden"]), textarea:not([disabled])')
+  if (input) {
+    input.focus()
+    // Select text for better UX in rename dialogs
+    if (typeof input.select === 'function') {
+      input.select()
+    }
+    return input
+  }
+
+  // Fall back to button focus for non-form dialogs
+  return focusDialogButton(container)
+}
+
+/**
+ * Standard keydown handler for button rows with left/right navigation.
+ * Can be used directly on buttons or on a container with event delegation.
+ * Automatically finds the .button-row or .modal-actions container.
+ * @param {KeyboardEvent} event - The keydown event
+ * @param {Object} options
+ * @param {(direction: string) => void} options.onBoundary - Called when navigation hits a boundary (up/down or edge)
+ */
+export const handleButtonKeydown = (event, options = {}) => {
+  const direction = getDirection(event)
+  if (!direction) return
+
+  // Find the button row container
+  const target = event.target
+  if (target.tagName !== 'BUTTON' && target.tagName !== 'A') return
+
+  const container = target.closest('.button-row, .modal-actions')
+  if (!container) return
+
+  if (direction === 'left' || direction === 'right') {
+    event.preventDefault()
+    const result = navigateButtonRow(container, target, direction, { itemSelector: 'button, a' })
+    if (result === 'boundary') {
+      options.onBoundary?.(direction)
+    }
+  } else if (direction === 'up' || direction === 'down') {
+    // Vertical navigation exits button rows
+    options.onBoundary?.(direction)
+  }
+}
+
+/**
+ * Install keyboard navigation on a container element.
+ * Handles arrow key navigation for buttons within .button-row or .modal-actions.
+ * Uses event delegation so no need to add handlers to individual buttons.
+ * @param {HTMLElement} container - The container element to enable navigation on
+ * @param {Object} options
+ * @param {(direction: string) => void} options.onBoundary - Called when navigation hits a boundary
+ * @returns {() => void} Cleanup function to remove the event listener
+ */
+export const installKeyboardNav = (container, options = {}) => {
+  if (!container) return () => {}
+
+  const handler = (event) => handleButtonKeydown(event, options)
+  container.addEventListener('keydown', handler)
+
+  return () => container.removeEventListener('keydown', handler)
+}