The TADS Alternate Library
Version 2.0
Special Display Attributes
Copyright 2000 by Kevin Forchione.
This is part of the TADS Alternate Library Authors Manual.
Introduction and Table of Contents
Special Display Attributes
Alt implements the so-called
inform-style room display. TADS authors can take advantage of the following
object description properties:
·
initial
·
describe
·
whenOpen & whenClosed
·
whenOn & whenOff
Additionally, Alt will alter
the normal room display to reflect the following order:
·
room.initial
·
room.nrmLkAround
o
room.describe or room.ldesc
o
room.contents_fixeditems.heredesc
o
room.contents.describe
room.contents_containers.whenOpen & whenClosed
o
room.contents_switchItems.whenOn & whenOff
o
room.contents_doorway.whenOpen & whenClosed
o
room.contents_actors.actorDesc
o
room.contents.initial
o
room.contents.listCont()
o
room.contents.listContCont()
·
room.firstseen
Why Use Special Display Attributes?
The
initial, describe, whenOpen, whenClosed, whenOn, and whenOff are useful to
create certain effects in a game display. For instance:
Wonderful World of Containers
This is
Room 11, east of the foyer. You notice a typical piece of scenery which turns
out to be a surface: a mantelpiece.
A bearded
psychiatrist has you under observation.
A portable
television set has two sub-objects attached: a power button and a screen.
A pretty
typical shut cupboard is bolted to one wall.
A macrame
hangs from the ceiling, shut tight. Inside you can make out a music box.
You can
also see a green ball, a red cone, a blue pyramid, a plain shopping bag (which
can only hold 2 things), and a glass box with a lid, a steel box with a lid, a
toothed bag, and a bolted key here.
Ordinarily
TADS would display the room.sdesc, followed by the room.ldesc, actor.actorDesc,
and then a listing of the room contents. The above display demonstrates the use
of initial and describe to separate out certain objects from the room contents
as being of special note, and provides more information than would normally be
available with obj.sdesc.
initial String or method
For
objects: The description of an object not yet picked up, used when a room is
described.
For
rooms: Called when the room is arrived in. Displays before room.sdesc.
Warning:
If the object is a doorway, or a container, or is switchItem, then use one of
the when-properties rather than initial.
No
return value expected from method.
describe String or method
For
objects: Called when the object is to be described in a room description,
regardless of whether the object has been moved or not.
For
rooms: not yet incorporated.
No
return value expected from method.
whenOpen String or method
For
objects: Called when the container or doorway is open.
No
return value expected from method.
whenClosed: String or method
For
objects: Called when the container or doorway is closed.
No
return value expected from method.
whenOn: String or method
For
objects: Called when the switchItem is active.
No
return value expected from method.
whenOff: String or method
For
objects: Called when the switchItem is not active.
No
return value expected from method.