.. highlightlang:: us

.. index:: OnCommandUI
.. index:: UI

.. _oncommandui:

OnCommandUI
===========

.. us.tag  OnCommandUI ENGLISH Menu New300

:ref:`OnCommandUI` is used here as a placeholder for a function
that is called when a user clicks a button on the user toolbar or selects
a function from a menu.

.. function::  svUI = OnCommandUI()

.. us.return

**Return Value**

*svUI*.

.. us.return

**Return Value**

*svUI* is a string vector with one or more
elements from the following list:

.. list-table::
   :header-rows: 1

   * - Value
     - Meaning
   * - ``""``
     - The menu item is enabled.
   * - ``"@g"`` or ``"@grayed"``
     - The menu item is disabled.
   * - ``"@h"`` or ``"@hide"``
     - The menu item is hidden.
   * - ``"@c"`` or ``"@checked"``
     - Places a check mark next to or removes a check mark from a menu item.
   * - ``"text"``
     - ``"text"`` is the text that is displayed as the menu item.

.. us.comment

**Comment**

The function name is identical to the :ref:`OnCommand` function name
plus the added **UI**. The function is called by the framework.

.. us.example

**Example**

The following "UI" function checks if the **OnXY_Fit** is loaded.
If the function is not loaded the menu item will not be displayed.

::

   def OnXY_FitUI()
   {
       if (!IsFunctionLoaded("OnXY_Fit")) {
           return "@hide";
       }
       return "";
   }

.. seealso::
   :ref:`overview-menus`,
   :ref:`OnCommand`

:sub:`id-1012446`