| /** |
| * -------------------------------------------------------------------------- |
| * Bootstrap (v5.2.1): util/focustrap.js |
| * Licensed under MIT (https://github.com/twbs/bootstrap/blob/main/LICENSE) |
| * -------------------------------------------------------------------------- |
| */ |
| |
| import EventHandler from '../dom/event-handler' |
| import SelectorEngine from '../dom/selector-engine' |
| import Config from './config' |
| |
| /** |
| * Constants |
| */ |
| |
| const NAME = 'focustrap' |
| const DATA_KEY = 'bs.focustrap' |
| const EVENT_KEY = `.${DATA_KEY}` |
| const EVENT_FOCUSIN = `focusin${EVENT_KEY}` |
| const EVENT_KEYDOWN_TAB = `keydown.tab${EVENT_KEY}` |
| |
| const TAB_KEY = 'Tab' |
| const TAB_NAV_FORWARD = 'forward' |
| const TAB_NAV_BACKWARD = 'backward' |
| |
| const Default = { |
| autofocus: true, |
| trapElement: null // The element to trap focus inside of |
| } |
| |
| const DefaultType = { |
| autofocus: 'boolean', |
| trapElement: 'element' |
| } |
| |
| /** |
| * Class definition |
| */ |
| |
| class FocusTrap extends Config { |
| constructor(config) { |
| super() |
| this._config = this._getConfig(config) |
| this._isActive = false |
| this._lastTabNavDirection = null |
| } |
| |
| // Getters |
| static get Default() { |
| return Default |
| } |
| |
| static get DefaultType() { |
| return DefaultType |
| } |
| |
| static get NAME() { |
| return NAME |
| } |
| |
| // Public |
| activate() { |
| if (this._isActive) { |
| return |
| } |
| |
| if (this._config.autofocus) { |
| this._config.trapElement.focus() |
| } |
| |
| EventHandler.off(document, EVENT_KEY) // guard against infinite focus loop |
| EventHandler.on(document, EVENT_FOCUSIN, event => this._handleFocusin(event)) |
| EventHandler.on(document, EVENT_KEYDOWN_TAB, event => this._handleKeydown(event)) |
| |
| this._isActive = true |
| } |
| |
| deactivate() { |
| if (!this._isActive) { |
| return |
| } |
| |
| this._isActive = false |
| EventHandler.off(document, EVENT_KEY) |
| } |
| |
| // Private |
| _handleFocusin(event) { |
| const { trapElement } = this._config |
| |
| if (event.target === document || event.target === trapElement || trapElement.contains(event.target)) { |
| return |
| } |
| |
| const elements = SelectorEngine.focusableChildren(trapElement) |
| |
| if (elements.length === 0) { |
| trapElement.focus() |
| } else if (this._lastTabNavDirection === TAB_NAV_BACKWARD) { |
| elements[elements.length - 1].focus() |
| } else { |
| elements[0].focus() |
| } |
| } |
| |
| _handleKeydown(event) { |
| if (event.key !== TAB_KEY) { |
| return |
| } |
| |
| this._lastTabNavDirection = event.shiftKey ? TAB_NAV_BACKWARD : TAB_NAV_FORWARD |
| } |
| } |
| |
| export default FocusTrap |