--- /dev/null
+/**
+ * @file
+ * A Backbone View that provides the aural view of the edit mode toggle.
+ */
+
+(function ($, Drupal, Backbone, _) {
+
+ 'use strict';
+
+ Drupal.contextualToolbar.AuralView = Backbone.View.extend(/** @lends Drupal.contextualToolbar.AuralView# */{
+
+ /**
+ * Tracks whether the tabbing constraint announcement has been read once.
+ *
+ * @type {bool}
+ */
+ announcedOnce: false,
+
+ /**
+ * Renders the aural view of the edit mode toggle (screen reader support).
+ *
+ * @constructs
+ *
+ * @augments Backbone.View
+ *
+ * @param {object} options
+ * Options for the view.
+ */
+ initialize: function (options) {
+ this.options = options;
+
+ this.listenTo(this.model, 'change', this.render);
+ this.listenTo(this.model, 'change:isViewing', this.manageTabbing);
+
+ $(document).on('keyup', _.bind(this.onKeypress, this));
+ },
+
+ /**
+ * @inheritdoc
+ *
+ * @return {Drupal.contextualToolbar.AuralView}
+ * The current contextual toolbar aural view.
+ */
+ render: function () {
+ // Render the state.
+ this.$el.find('button').attr('aria-pressed', !this.model.get('isViewing'));
+
+ return this;
+ },
+
+ /**
+ * Limits tabbing to the contextual links and edit mode toolbar tab.
+ */
+ manageTabbing: function () {
+ var tabbingContext = this.model.get('tabbingContext');
+ // Always release an existing tabbing context.
+ if (tabbingContext) {
+ tabbingContext.release();
+ Drupal.announce(this.options.strings.tabbingReleased);
+ }
+ // Create a new tabbing context when edit mode is enabled.
+ if (!this.model.get('isViewing')) {
+ tabbingContext = Drupal.tabbingManager.constrain($('.contextual-toolbar-tab, .contextual'));
+ this.model.set('tabbingContext', tabbingContext);
+ this.announceTabbingConstraint();
+ this.announcedOnce = true;
+ }
+ },
+
+ /**
+ * Announces the current tabbing constraint.
+ */
+ announceTabbingConstraint: function () {
+ var strings = this.options.strings;
+ Drupal.announce(Drupal.formatString(strings.tabbingConstrained, {
+ '@contextualsCount': Drupal.formatPlural(Drupal.contextual.collection.length, '@count contextual link', '@count contextual links')
+ }));
+ Drupal.announce(strings.pressEsc);
+ },
+
+ /**
+ * Responds to esc and tab key press events.
+ *
+ * @param {jQuery.Event} event
+ * The keypress event.
+ */
+ onKeypress: function (event) {
+ // The first tab key press is tracked so that an annoucement about tabbing
+ // constraints can be raised if edit mode is enabled when the page is
+ // loaded.
+ if (!this.announcedOnce && event.keyCode === 9 && !this.model.get('isViewing')) {
+ this.announceTabbingConstraint();
+ // Set announce to true so that this conditional block won't run again.
+ this.announcedOnce = true;
+ }
+ // Respond to the ESC key. Exit out of edit mode.
+ if (event.keyCode === 27) {
+ this.model.set('isViewing', true);
+ }
+ }
+
+ });
+
+})(jQuery, Drupal, Backbone, _);