PREFAB-INTRO(2) PREFAB-INTRO(2)
NAME
Prefab: intro - Interactive TV tookit
SYNOPSIS
include "draw.m";
include "prefab.m";
prefab := load Prefab Prefab->PATH;
DESCRIPTION
The Prefab module contains components for building graphics
objects suitable for Interactive Television (ITV) applica-
tions using infrared remote controls. Using the Draw
module's operations for simple text and images (see draw-
intro(2)), the toolkit can group individual items, treat
those groups as units, and then activate the items on com-
mand. The other user interface toolkit, tk(2), provides
facilities for keyboard- and mouse-driven applications.
The objects on the screen are of type Compound, each of
which occupies a unique window on the display and contains
objects of type Element. An Element may be a single object
or a list of further Elements, to build hierarchically
structured components.
Prefab defines Environ and Style types that specify the
appearance of objects: their colours, fonts, backgrounds,
and so on. A Style gives font and colour information, while
an Environ identifies the Screen upon which the items will
be displayed and the Style in which they will be drawn.
Applications should allocate Elements and Compounds only
through the appropriate member functions, as described in
the corresponding sections of the manual. Items created
with regular Limbo definitions will not work properly.
Moreover, except where indicated, applications should not
modify the data members directly. Although the type defini-
tions make data members visible, the members should usually
be treated as read-only data.
SOURCE
/interp/prefab.c
/prefab/*.c
SEE ALSO
draw-intro(2), ir(2)
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