define("core/local/aria/focuslock",["exports","./selectors"],(function(_exports,_selectors){var obj;
/**
   * Tab locking system.
   *
   * This is based on code and examples provided in the ARIA specification.
   * https://www.w3.org/TR/wai-aria-practices/examples/dialog-modal/dialog.html
   *
   * @module     core/local/aria/focuslock
   * @copyright  2019 Andrew Nicols <andrew@nicols.co.uk>
   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
   */Object.defineProperty(_exports,"__esModule",{value:!0}),_exports.untrapFocus=_exports.trapFocus=void 0,_selectors=(obj=_selectors)&&obj.__esModule?obj:{default:obj};const lockRegionStack=[],initialFocusElementStack=[],finalFocusElementStack=[];let lastFocus=null,ignoreFocusChanges=!1,isLocked=!1;const lockHandler=event=>{if(ignoreFocusChanges)return;let lockRegion=getCurrentLockRegion();for(;lockRegion&&!document.contains(lockRegion);)untrapFocus(),lockRegion=getCurrentLockRegion();lockRegion&&(event&&lockRegion.contains(event.target)?lastFocus=event.target:(focusFirstDescendant(),lastFocus==document.activeElement&&focusLastDescendant(),lastFocus=document.activeElement))},keyDownHandler=event=>{if("Tab"===event.key&&getCurrentLockRegion())if(event.shiftKey){const firstFocusable=getCurrentLockRegion().querySelector(_selectors.default.elements.focusable);document.activeElement===firstFocusable&&(lockHandler(),event.preventDefault())}else{const allFocusable=document.querySelectorAll(_selectors.default.elements.focusable);document.activeElement===allFocusable[allFocusable.length-1]&&(lockHandler(),event.preventDefault())}},focusFirstDescendant=()=>{const lockRegion=getCurrentLockRegion(),focusableElements=Array.from(lockRegion.querySelectorAll(_selectors.default.elements.focusable));return focusableElements.unshift(lockRegion),focusableElements.some((focusableElement=>attemptFocus(focusableElement)))},focusLastDescendant=()=>{const lockRegion=getCurrentLockRegion(),focusableElements=Array.from(lockRegion.querySelectorAll(_selectors.default.elements.focusable)).reverse();return focusableElements.push(lockRegion),focusableElements.some((focusableElement=>attemptFocus(focusableElement)))},attemptFocus=focusTarget=>{if(!(focusTarget=>{if(focusTarget.tabIndex>0||0===focusTarget.tabIndex&&null!==focusTarget.getAttribute("tabIndex"))return!0;if(focusTarget.disabled)return!1;switch(focusTarget.nodeName){case"A":return!!focusTarget.href&&"ignore"!=focusTarget.rel;case"INPUT":return"hidden"!=focusTarget.type&&"file"!=focusTarget.type;case"BUTTON":case"SELECT":case"TEXTAREA":return!0;default:return!1}})(focusTarget))return!1;ignoreFocusChanges=!0;try{focusTarget.focus()}catch(e){}return ignoreFocusChanges=!1,document.activeElement===focusTarget},getCurrentLockRegion=()=>lockRegionStack[lockRegionStack.length-1];_exports.trapFocus=newLockRegion=>{if((newLockRegion=>{if(newLockRegion===getCurrentLockRegion())return;lockRegionStack.push(newLockRegion);const currentLockRegion=getCurrentLockRegion(),element=document.createElement("div");element.tabIndex=0,element.style.position="fixed",element.style.top=0,element.style.left=0;const initialNode=element.cloneNode();currentLockRegion.parentNode.insertBefore(initialNode,currentLockRegion),initialFocusElementStack.push(initialNode);const finalNode=element.cloneNode();currentLockRegion.parentNode.insertBefore(finalNode,currentLockRegion.nextSibling),finalFocusElementStack.push(finalNode)})(newLockRegion),isLocked||(document.addEventListener("focus",lockHandler,!0),document.addEventListener("keydown",keyDownHandler,!0)),!focusFirstDescendant()){const currentLockRegion=getCurrentLockRegion(),originalRegionTabIndex=currentLockRegion.tabIndex;currentLockRegion.tabIndex=0,attemptFocus(currentLockRegion),currentLockRegion.tabIndex=originalRegionTabIndex}lastFocus=document.activeElement,isLocked=!0};const untrapFocus=()=>{(()=>{lockRegionStack.pop();const finalNode=finalFocusElementStack.pop();finalNode&&finalNode.remove();const initialNode=initialFocusElementStack.pop();initialNode&&initialNode.remove()})(),lockRegionStack.length||(document.removeEventListener("focus",lockHandler,!0),document.removeEventListener("keydown",keyDownHandler,!0),lastFocus=null,ignoreFocusChanges=!1,isLocked=!1)};_exports.untrapFocus=untrapFocus}));

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