/*!
* VisualEditor TabIndexScope class.
*
* @copyright See AUTHORS.txt
*/
/**
* TabIndex Scope container constructor
*
* @class
* @constructor
*
* @param {Object} [config] Configuration options
* @param {jQuery} [config.root] Initial root element to scope tabIndex within
* @param {boolean} [config.skipAriaDisabled] Whether to skip elements that are just aria-disabled from the order
*/
ve.ui.TabIndexScope = function VeUiTabIndexScope( config ) {
config = ve.extendObject( {
root: false,
skipAriaDisabled: true,
skipAriaHidden: true
}, config );
this.skipAriaDisabled = config.skipAriaDisabled;
this.skipAriaHidden = config.skipAriaHidden;
this.onRootKeyDownBound = this.onRootKeyDown.bind( this );
if ( config.root ) {
this.setTabRoot( config.root );
}
};
/* Setup */
OO.initClass( ve.ui.TabIndexScope );
/* Methods */
/**
* Set the current root element for tabbing
*
* @param {jQuery} $root root element to scope tabIndex within
*/
ve.ui.TabIndexScope.prototype.setTabRoot = function ( $root ) {
if ( this.$root ) {
this.$root.off( 'keydown', this.onRootKeyDownBound );
}
this.$root = $( $root ).on( 'keydown', this.onRootKeyDownBound );
};
/**
* Build a list of elements in the current root, in tab order
*
* This mimics browser behavior: fetch focusable elements, sort by [tabIndex, DOM order]
*
* @return {HTMLElement[]} list of elements in the order they should be tabbed through
*/
ve.ui.TabIndexScope.prototype.getElementsInRoot = function () {
const elements = this.$root.find( '*' )
.filter( ( index, element ) => {
if ( element.tabIndex === -1 ) {
// tabIndex -1 is focusable, but shouldn't appear to keyboard-navigation
return false;
}
if ( this.skipAriaDisabled && element.getAttribute( 'aria-disabled' ) === 'true' ) {
return false;
}
if ( this.skipAriaHidden && $( element ).closest( '[aria-hidden="true"]', this.$root[ 0 ] ).length ) {
return false;
}
if ( element.isContentEditable && element.contentEditable !== 'true' ) {
// Skip nodes within contentEditable nodes (but not the root contentEditable nodes),
// which would be focusable if they weren't editable, e.g. links.
// This matches browser behavior.
return false;
}
return OO.ui.isFocusableElement( $( element ) );
} )
.map( ( index, element ) => ( { element: element, index: index } ) )
.get();
elements.sort( ( a, b ) => {
if ( a.element.tabIndex < b.element.tabIndex ) {
return -1;
}
if ( a.element.tabIndex > b.element.tabIndex ) {
return 1;
}
return a.index - b.index;
} );
return elements.map( ( data ) => data.element );
};
/**
* Handle keydown events on elements
*
* @private
* @param {jQuery.Event} e
*/
ve.ui.TabIndexScope.prototype.onRootKeyDown = function ( e ) {
if ( e.which !== OO.ui.Keys.TAB ) {
return;
}
const elements = this.getElementsInRoot();
let index = elements.indexOf( e.target );
if ( index === -1 ) {
return;
}
index += e.shiftKey ? -1 : 1;
if ( ( index < 0 || index >= elements.length ) ) {
return;
}
e.preventDefault();
elements[ index ].focus();
};
/**
* Teardown tabbable elements manager
*/
ve.ui.TabIndexScope.prototype.teardown = function () {
this.setRoot( [] );
};