SYNOPSIS
xpce prolog-option ...DESCRIPTION
XPCE is a language independant library for GUI (Graphical User Interfaces). This manual page discusses XPCE/Prolog: the combination of a Prolog environment and XPCE.XPCE is an object-oriented engine that can have methods defined in various languages. XPCE has about 150 predefined classes that deal mainly with GUI's. The object engine of XPE is made available to Prolog using the following predicates:
Predicates:
- new(?Ref, +Term)
-
Create an XPCE object from
Term
and bind the object to the reference
Ref.
The functor-name of
Term
describes the class from which to create an instance. The arguments of
Term
are used as initialisation arguments for the new object. If the object
was created successfully and
Ref
is a variable,
Ref
will be unified with the term @<RefNumber>. If
Ref
is a term of the form @<Atom>, this term will serve as a reference for
the new object.
For example ?- new(@p, picture('Hello World'). Creates a graphical window object with title "Hello World".
- send(+Ref, +Selector, +Args...)
-
Ref
is a reference to an existing XPCE object.
Selector
is the name of a (send-)method defined on (the class of) this object and
Args
are terms that describe arguments to be passed to the method.
send/[2-12] will convert the arguments to XPCE data objects, resolve the procedure (C-function, Prolog predicate) implementing the method and run the implementation. If the execution is successful, send succeeds, otherwise send fails.
For example ?- send(@p, open, point(400,100)). opens the picture created above at position 400,100 on the display.
- get(+Ref, +Selector, +Args ..., -Value)
-
Ref
is a reference to an existing XPCE object.
Selector
is the name of a (get-)method defined on (the class of) this object and
Args
are terms to provide additional arguments.
get/[3-13] works similar as
send/[2-12]
but returns a value rather than succeeding/failing (boolean operation).
For example get(@p, height, H). Unifies H with the height of the graphical window.
- free(+Ref)
- If Ref is a reference to an XPCE object, invoke send(Ref, free). to the object. Otherwise succeed silently.
COPYING
XPCE is distributed under the General Public Licence version 2, also known as the GPL-2 licence. The license terms are in the file COPYING or on the GNU website at http://www.gnu.org.In a nutshell, you can modify and use XPCE as long as you clearly indicate changes, don't change copyright messages and distribute the complete source of your work with every binary copy or make the source in some other form available for free to your users
Especially if you do not wish to distribute the source of your work you may wish to consider optaining a commercial license. Please visit the SWI-Prolog home-page for details.
COPYRIGHT
Copyright (c) 1985-2001 University of Amsterdam.AUTHOR
Jan Wielemaker and Anjo Anjewierden