Source: modules/toolbar/js/models/ToolbarModel.es6.js

/**
 * @file
 * A Backbone Model for the toolbar.
 */

(function (Backbone, Drupal) {
  /**
   * Backbone model for the toolbar.
   *
   * @constructor
   *
   * @augments Backbone.Model
   */
  Drupal.toolbar.ToolbarModel = Backbone.Model.extend(
    /** @lends Drupal.toolbar.ToolbarModel# */ {
      /**
       * @type {object}
       *
       * @prop activeTab
       * @prop activeTray
       * @prop isOriented
       * @prop isFixed
       * @prop areSubtreesLoaded
       * @prop isViewportOverflowConstrained
       * @prop orientation
       * @prop locked
       * @prop isTrayToggleVisible
       * @prop height
       * @prop offsets
       */
      defaults: /** @lends Drupal.toolbar.ToolbarModel# */ {
        /**
         * The active toolbar tab. All other tabs should be inactive under
         * normal circumstances. It will remain active across page loads. The
         * active item is stored as an ID selector e.g. '#toolbar-item--1'.
         *
         * @type {string}
         */
        activeTab: null,

        /**
         * Represents whether a tray is open or not. Stored as an ID selector e.g.
         * '#toolbar-item--1-tray'.
         *
         * @type {string}
         */
        activeTray: null,

        /**
         * Indicates whether the toolbar is displayed in an oriented fashion,
         * either horizontal or vertical.
         *
         * @type {bool}
         */
        isOriented: false,

        /**
         * Indicates whether the toolbar is positioned absolute (false) or fixed
         * (true).
         *
         * @type {bool}
         */
        isFixed: false,

        /**
         * Menu subtrees are loaded through an AJAX request only when the Toolbar
         * is set to a vertical orientation.
         *
         * @type {bool}
         */
        areSubtreesLoaded: false,

        /**
         * If the viewport overflow becomes constrained, isFixed must be true so
         * that elements in the trays aren't lost off-screen and impossible to
         * get to.
         *
         * @type {bool}
         */
        isViewportOverflowConstrained: false,

        /**
         * The orientation of the active tray.
         *
         * @type {string}
         */
        orientation: 'horizontal',

        /**
         * A tray is locked if a user toggled it to vertical. Otherwise a tray
         * will switch between vertical and horizontal orientation based on the
         * configured breakpoints. The locked state will be maintained across page
         * loads.
         *
         * @type {bool}
         */
        locked: false,

        /**
         * Indicates whether the tray orientation toggle is visible.
         *
         * @type {bool}
         */
        isTrayToggleVisible: true,

        /**
         * The height of the toolbar.
         *
         * @type {number}
         */
        height: null,

        /**
         * The current viewport offsets determined by {@link Drupal.displace}. The
         * offsets suggest how a module might position is components relative to
         * the viewport.
         *
         * @type {object}
         *
         * @prop {number} top
         * @prop {number} right
         * @prop {number} bottom
         * @prop {number} left
         */
        offsets: {
          top: 0,
          right: 0,
          bottom: 0,
          left: 0,
        },
      },

      /**
       * {@inheritdoc}
       *
       * @param {object} attributes
       *   Attributes for the toolbar.
       * @param {object} options
       *   Options for the toolbar.
       *
       * @return {string|undefined}
       *   Returns an error message if validation failed.
       */
      validate(attributes, options) {
        // Prevent the orientation being set to horizontal if it is locked, unless
        // override has not been passed as an option.
        if (
          attributes.orientation === 'horizontal' &&
          this.get('locked') &&
          !options.override
        ) {
          return Drupal.t(
            'The toolbar cannot be set to a horizontal orientation when it is locked.',
          );
        }
      },
    },
  );
})(Backbone, Drupal);