Graphics.UI.GLUT.Menu

GLUT supports simple cascading pop-up menus. They are designed to let a user select various modes within a program. The functionality is simple and minimalistic and is meant to be that way. Do not mistake GLUT's pop-up menu facility with an attempt to create a full-featured user interface.

Documentation

data Menu

A menu is simply a list of menu items, possibly with an associated font.

Constructors

Menu [MenuItem]

MenuWithFont BitmapFont [MenuItem]

data MenuItem

A single item within a menu can either be a plain menu entry or a sub-menu entry, allowing for arbitrarily deep nested menus.

Constructors

MenuEntry String MenuCallback

A plain menu entry with an associated callback, which is triggered when the user selects the entry

SubMenu String Menu

A sub-menu, which is cascaded when the user selects the entry, allowing sub-menu entries to be selected

type MenuCallback = IO ()

attachMenu :: MonadIO m => MouseButton -> Menu -> m ()

Create a new pop-up menu for the current window, attaching it to the given mouse button. A previously attached menu (if any), is detached before and won't receive callbacks anymore.

It is illegal to call attachMenu while any (sub-)menu is in use, i.e. popped up.

X Implementation Notes: If available, GLUT for X will take advantage of overlay planes for implementing pop-up menus. The use of overlay planes can eliminate display callbacks when pop-up menus are deactivated. The SERVER_OVERLAY_VISUALS convention is used to determine if overlay visuals are available.

numMenuItems :: GettableStateVar Int

Contains the number of menu items in the current menu.