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

core/modules/contextual/js/views/VisualView.js

@@ -0,0 +1,76 @@
+/**
+ * @file
+ * A Backbone View that provides the visual view of a contextual link.
+ */
+
+(function (Drupal, Backbone, Modernizr) {
+
+  "use strict";
+
+  Drupal.contextual.VisualView = Backbone.View.extend(/** @lends Drupal.contextual.VisualView# */{
+
+    /**
+     * @return {object}
+     */
+    events: function () {
+      // Prevents delay and simulated mouse events.
+      var touchEndToClick = function (event) {
+        event.preventDefault();
+        event.target.click();
+      };
+      var mapping = {
+        'click .trigger': function () { this.model.toggleOpen(); },
+        'touchend .trigger': touchEndToClick,
+        'click .contextual-links a': function () { this.model.close().blur(); },
+        'touchend .contextual-links a': touchEndToClick
+      };
+      // We only want mouse hover events on non-touch.
+      if (!Modernizr.touch) {
+        mapping.mouseenter = function () { this.model.focus(); };
+      }
+      return mapping;
+    },
+
+    /**
+     * Renders the visual view of a contextual link. Listens to mouse & touch.
+     *
+     * @constructs
+     *
+     * @augments Backbone.View
+     */
+    initialize: function () {
+      this.listenTo(this.model, 'change', this.render);
+    },
+
+    /**
+     * @inheritdoc
+     *
+     * @return {Drupal.contextual.VisualView}
+     */
+    render: function () {
+      var isOpen = this.model.get('isOpen');
+      // The trigger should be visible when:
+      //  - the mouse hovered over the region,
+      //  - the trigger is locked,
+      //  - and for as long as the contextual menu is open.
+      var isVisible = this.model.get('isLocked') || this.model.get('regionIsHovered') || isOpen;
+
+      this.$el
+        // The open state determines if the links are visible.
+        .toggleClass('open', isOpen)
+        // Update the visibility of the trigger.
+        .find('.trigger').toggleClass('visually-hidden', !isVisible);
+
+      // Nested contextual region handling: hide any nested contextual triggers.
+      if ('isOpen' in this.model.changed) {
+        this.$el.closest('.contextual-region')
+          .find('.contextual .trigger:not(:first)')
+          .toggle(!isOpen);
+      }
+
+      return this;
+    }
+
+  });
+
+})(Drupal, Backbone, Modernizr);