# Menus

The menusys.t module (which requires the menucon.t module) provides a way of displaying menus from which the player can make choices. It is identical to the adv3 module of the same name. If your game doesn't need any menus you can excluse menusys.t from your build, but you will need to include it if your game includes hints.

Menus consist of MenuItems, MenuTopicItems, and MenuLongTopicItems.

MenuItems are the menu (and sub-menu) items that the player will select. Their title attribute is what will be shown in the menu, and the heading attribute is shown as the heading while the menu itself is active; by default, the heading simply uses the title.

MenuTopicItems are for lists of topic strings that the player will be shown, like hints. title is what will be shown in the menu; menuContents is a list of either strings to be displayed, one at a time, or objects which each must return a string via a "menuContents" method.

MenuLongTopicItems are for longer discourses. title is what will be shown in the menu; menuContents is either a (single-quoted or doube-quoted) string to be displayed or a routine to be called.

advLite.h contains templates for MenuItem and MenuLongTopicItem, for your convenience.

A simple example menu:

       FirstMenu: MenuItem 'Test menu';
       + MenuItem 'Pets';
       ++ MenuItem 'Chinchillas';
       +++ MenuTopicItem 'About them'
           menuContents = ['Furry', 'South American', 'Curious', 'Note: Not a coat'];
       +++ MenuTopicItem 'Benefits'
            menuContents = ['Non-allergenic', 'Cute', 'Require little space'];
       +++ MenuTopicItem 'Downsides'
             menuContents = ['Require dust baths', 'Startle easily'];
       ++ MenuItem 'Cats';
       +++ MenuLongTopicItem 'Pure evil'
          menuContents = 'Cats are, quite simply, pure evil. I would provide
                          ample evidence were there room for it in this
                          simple example.';
       +++ MenuTopicItem 'Benefits'
         menuContents = ['They, uh, well...', 'Okay, I can\'t think of any.'];

To display the menu in the first place, call its display() method. For example, to display the menu in the above example you would use the statement FirstMenu.display().

Note that some interpreters (e.g. text-only interpreters) cannot cope with a menu that shows more than nine items at a time, so you may want to arrange your menus accordingly (for example, by dividing them up between sub-menus if the player might need to choose between more than nine items).

You might typically use a menu to give your players information about your game at the beginning (in response to an ABOUT command, say), and maybe to show some options at the end (in response to an AMUSING command, say). To construct an ABOUT menu you would typically use a MenuItem for the top-level aboutMenu, with a number of MenuLongTopicItems to describe various aspects of your game; if you have a lot to say you might need to use another level of MenuItems to divide your information into sub-menus, e.g.:

       aboutMenu: MenuItem 'About';
       + MenuItem 'About Adventure';

       ++ MenuLongTopicItem 'About the Game'
           menuContents = 'This charming piece is something I cribbed off an obscure
    	     work by Crowther and Woods. '
       ;

       ++ MenuLongTopicItem 'Special Commands'
           'Under no circumstances should you use the commands
    		 PLUGH and XYZZY without a special license. '
       ;

       + MenuItem 'Playing TADS games';

       ++ MenuLongTopicItem 'Standard Commands'
           menuContents = "Common IF commands include EXAMINE, TAKE..."
       ;

       ++ MenuLongTopicItem 'Conversational Commands'
          "TADS games use a modified version of the ASK/TELL system..."
       ;

You could then call aboutMenu.display(); in the versionInfo.showAbout() method. The above examples also illustrate how menu definitions can be abbreviated through the use of the relevant templates.

adv3Lite Library Manual
Table of Contents | Optional Modules > Menus
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