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-rw-r--r--vendor/twbs/bootstrap/js/src/util/focustrap.js105
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diff --git a/vendor/twbs/bootstrap/js/src/util/focustrap.js b/vendor/twbs/bootstrap/js/src/util/focustrap.js
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+/**
+ * --------------------------------------------------------------------------
+ * Bootstrap (v5.1.3): 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 { typeCheckConfig } from './index'
+
+const Default = {
+ trapElement: null, // The element to trap focus inside of
+ autofocus: true
+}
+
+const DefaultType = {
+ trapElement: 'element',
+ autofocus: 'boolean'
+}
+
+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'
+
+class FocusTrap {
+ constructor(config) {
+ this._config = this._getConfig(config)
+ this._isActive = false
+ this._lastTabNavDirection = null
+ }
+
+ activate() {
+ const { trapElement, autofocus } = this._config
+
+ if (this._isActive) {
+ return
+ }
+
+ if (autofocus) {
+ 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 { target } = event
+ const { trapElement } = this._config
+
+ if (target === document || target === trapElement || trapElement.contains(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
+ }
+
+ _getConfig(config) {
+ config = {
+ ...Default,
+ ...(typeof config === 'object' ? config : {})
+ }
+ typeCheckConfig(NAME, config, DefaultType)
+ return config
+ }
+}
+
+export default FocusTrap