- /**
- * Add public methods to the TabbingManager class.
- */
- $.extend(TabbingManager.prototype, /** @lends Drupal~TabbingManager# */{
-
- /**
- * Constrain tabbing to the specified set of elements only.
- *
- * Makes elements outside of the specified set of elements unreachable via
- * the tab key.
- *
- * @param {jQuery} elements
- * The set of elements to which tabbing should be constrained. Can also
- * be a jQuery-compatible selector string.
- *
- * @return {Drupal~TabbingContext}
- * The TabbingContext instance.
- *
- * @fires event:drupalTabbingConstrained
- */
- constrain(elements) {
- // Deactivate all tabbingContexts to prepare for the new constraint. A
- // tabbingContext instance will only be reactivated if the stack is
- // unwound to it in the _unwindStack() method.
- const il = this.stack.length;
- for (let i = 0; i < il; i++) {
- this.stack[i].deactivate();
- }
-
- // The "active tabbing set" are the elements tabbing should be constrained
- // to.
- const $elements = $(elements).find(':tabbable').addBack(':tabbable');
-
- const tabbingContext = new TabbingContext({
- // The level is the current height of the stack before this new
- // tabbingContext is pushed on top of the stack.
- level: this.stack.length,
- $tabbableElements: $elements,
- });
-
- this.stack.push(tabbingContext);
-
- // Activates the tabbingContext; this will manipulate the DOM to constrain
- // tabbing.
- tabbingContext.activate();
-
- // Allow modules to respond to the constrain event.
- $(document).trigger('drupalTabbingConstrained', tabbingContext);
-
- return tabbingContext;
- },
-
- /**
- * Restores a former tabbingContext when an active one is released.
- *
- * The TabbingManager stack of tabbingContext instances will be unwound
- * from the top-most released tabbingContext down to the first non-released
- * tabbingContext instance. This non-released instance is then activated.
- */
- release() {
- // Unwind as far as possible: find the topmost non-released
- // tabbingContext.
- let toActivate = this.stack.length - 1;
- while (toActivate >= 0 && this.stack[toActivate].released) {
- toActivate--;
- }
-
- // Delete all tabbingContexts after the to be activated one. They have
- // already been deactivated, so their effect on the DOM has been reversed.
- this.stack.splice(toActivate + 1);
-
- // Get topmost tabbingContext, if one exists, and activate it.
- if (toActivate >= 0) {
- this.stack[toActivate].activate();
- }
- },
-
- /**
- * Makes all elements outside of the tabbingContext's set untabbable.
- *
- * Elements made untabbable have their original tabindex and autofocus
- * values stored so that they might be restored later when this
- * tabbingContext is deactivated.
- *
- * @param {Drupal~TabbingContext} tabbingContext
- * The TabbingContext instance that has been activated.
- */
- activate(tabbingContext) {
- const $set = tabbingContext.$tabbableElements;
- const level = tabbingContext.level;
- // Determine which elements are reachable via tabbing by default.
- const $disabledSet = $(':tabbable')
- // Exclude elements of the active tabbing set.
- .not($set);
- // Set the disabled set on the tabbingContext.
- tabbingContext.$disabledElements = $disabledSet;
- // Record the tabindex for each element, so we can restore it later.
- const il = $disabledSet.length;
- for (let i = 0; i < il; i++) {
- this.recordTabindex($disabledSet.eq(i), level);
- }
- // Make all tabbable elements outside of the active tabbing set
- // unreachable.
- $disabledSet
- .prop('tabindex', -1)
- .prop('autofocus', false);
-
- // Set focus on an element in the tabbingContext's set of tabbable
- // elements. First, check if there is an element with an autofocus
- // attribute. Select the last one from the DOM order.
- let $hasFocus = $set.filter('[autofocus]').eq(-1);
- // If no element in the tabbable set has an autofocus attribute, select
- // the first element in the set.
- if ($hasFocus.length === 0) {
- $hasFocus = $set.eq(0);
- }
- $hasFocus.trigger('focus');
- },
-
- /**
- * Restores that tabbable state of a tabbingContext's disabled elements.
- *
- * Elements that were made untabbable have their original tabindex and
- * autofocus values restored.
- *
- * @param {Drupal~TabbingContext} tabbingContext
- * The TabbingContext instance that has been deactivated.
- */
- deactivate(tabbingContext) {
- const $set = tabbingContext.$disabledElements;
- const level = tabbingContext.level;
- const il = $set.length;
- for (let i = 0; i < il; i++) {
- this.restoreTabindex($set.eq(i), level);
- }
- },
-
- /**
- * Records the tabindex and autofocus values of an untabbable element.
- *
- * @param {jQuery} $el
- * The set of elements that have been disabled.
- * @param {number} level
- * The stack level for which the tabindex attribute should be recorded.
- */
- recordTabindex($el, level) {
- const tabInfo = $el.data('drupalOriginalTabIndices') || {};
- tabInfo[level] = {
- tabindex: $el[0].getAttribute('tabindex'),
- autofocus: $el[0].hasAttribute('autofocus'),
- };
- $el.data('drupalOriginalTabIndices', tabInfo);
- },
-
- /**
- * Restores the tabindex and autofocus values of a reactivated element.
- *
- * @param {jQuery} $el
- * The element that is being reactivated.
- * @param {number} level
- * The stack level for which the tabindex attribute should be restored.
- */
- restoreTabindex($el, level) {
- const tabInfo = $el.data('drupalOriginalTabIndices');
- if (tabInfo && tabInfo[level]) {
- const data = tabInfo[level];
- if (data.tabindex) {
- $el[0].setAttribute('tabindex', data.tabindex);
- }
- // If the element did not have a tabindex at this stack level then
- // remove it.
- else {
- $el[0].removeAttribute('tabindex');
- }
- if (data.autofocus) {
- $el[0].setAttribute('autofocus', 'autofocus');
- }
-
- // Clean up $.data.
- if (level === 0) {
- // Remove all data.
- $el.removeData('drupalOriginalTabIndices');
- }
- else {
- // Remove the data for this stack level and higher.
- let levelToDelete = level;
- while (tabInfo.hasOwnProperty(levelToDelete)) {
- delete tabInfo[levelToDelete];
- levelToDelete++;
- }
- $el.data('drupalOriginalTabIndices', tabInfo);
- }
- }
- },
- });
-