Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/contextual/js/contextual.toolbar.js

@@ -0,0 +1,72 @@
+/**
+ * @file
+ * Attaches behaviors for the Contextual module's edit toolbar tab.
+ */
+
+(function ($, Drupal, Backbone) {
+
+  "use strict";
+
+  var strings = {
+    tabbingReleased: Drupal.t('Tabbing is no longer constrained by the Contextual module.'),
+    tabbingConstrained: Drupal.t('Tabbing is constrained to a set of @contextualsCount and the edit mode toggle.'),
+    pressEsc: Drupal.t('Press the esc key to exit.')
+  };
+
+  /**
+   * Initializes a contextual link: updates its DOM, sets up model and views.
+   *
+   * @param {HTMLElement} context
+   *   A contextual links DOM element as rendered by the server.
+   */
+  function initContextualToolbar(context) {
+    if (!Drupal.contextual || !Drupal.contextual.collection) {
+      return;
+    }
+
+    var contextualToolbar = Drupal.contextualToolbar;
+    var model = contextualToolbar.model = new contextualToolbar.StateModel({
+      // Checks whether localStorage indicates we should start in edit mode
+      // rather than view mode.
+      // @see Drupal.contextualToolbar.VisualView.persist()
+      isViewing: localStorage.getItem('Drupal.contextualToolbar.isViewing') !== 'false'
+    }, {
+      contextualCollection: Drupal.contextual.collection
+    });
+
+    var viewOptions = {
+      el: $('.toolbar .toolbar-bar .contextual-toolbar-tab'),
+      model: model,
+      strings: strings
+    };
+    new contextualToolbar.VisualView(viewOptions);
+    new contextualToolbar.AuralView(viewOptions);
+  }
+
+  /**
+   * Attaches contextual's edit toolbar tab behavior.
+   *
+   * @type {Drupal~behavior}
+   */
+  Drupal.behaviors.contextualToolbar = {
+    attach: function (context) {
+      if ($('body').once('contextualToolbar-init').length) {
+        initContextualToolbar(context);
+      }
+    }
+  };
+
+  /**
+   * @namespace
+   */
+  Drupal.contextualToolbar = {
+
+    /**
+     * The {@link Drupal.contextualToolbar.StateModel} instance.
+     *
+     * @type {?Drupal.contextualToolbar.StateModel}
+     */
+    model: null
+  };
+
+})(jQuery, Drupal, Backbone);