►The Racket Graphical Interface Toolkit
▼3 Windowing Classes
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get-items
on-demand
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interface

menu-item-container<%> : interface?

A menu-item-container<%> object is a menu%, popup-menu%, or menu-bar%.

method

(send a-menu-item-container get-items)

 → (listof (is-a?/c menu-item<%>))
Returns a list of the items in the menu, popup menu, or menu bar. The order of the items in the returned list corresponds to the order as the user sees them in the menu or menu bar.

method

(send a-menu-item-container on-demand) → void?

Specification: Called when the user clicks on the container as a menu bar (before the user sees any menu items, except with Unity’s global menu bar as noted below), just before the container as a popup menu is popped up, or just before inspecting the menu bar containing the item for a shortcut key binding.

If the container is not a menu bar or a popup menu, this method is normally called via the on-demand method of the container’s owning menu bar or popup menu, because the default implementation of the method chains to the on-demand method of its items. However, the method can be overridden in a container such that it does not call the on-demand method of its items.

On Unix with the Unity window manager using the global menu bar (which is the default on Ubuntu), racket/gui/base receives no notification when the user clicks the menu bar. To approximate on-demand triggered by user clicks of the menu bar, on-demand is called for a menu bar whenever its frame% object loses the keyboard focus. Beware that if keyboard focus was lost because a menu was clicked, then items added to the clicked menu during an on-demand invocation may not appear for the user.

Default implementation: Calls the demand-callback procedure that was provided when the object was created, then calls the on-demand method of the contained items.

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