COPYRIGHT:

Copyright (C) 1993 by Christian Schlichtherle.

For distribution conditions please read the
GNU General Public License version 2.

INSTALLATION:

For installation just copy all the *.pl files into your favorite XPCE
directory. The only condition is that the files are in the search path of the
use_module/1 predicate.

USE:

For use, start XPCE, load the program via
?- [rubikpce].
and then start it via
?- rubikpce.

As this is the first version, the interface to the program is quite simple:
At the bottom of the appearing window there is a dialog box with a collection
of buttons. The buttons function like a record player. This is their meaning:

Disorder:
	This will load and start a cube disordering sequence.
	Only possible when no other sequence is running (paused sequences
	will be discarded).
Order:
	This will load and start a cube adjusting sequence.
	Only possible when no other sequence is running (paused sequences
	will be discarded).
Quit:
	Guess what.
Step:
	This will show a single move. The sequence will pause after the move
	has completed.
Play:
	This will continue to play a paused sequence.
Pause:
	This will pause a running sequence.
Stop:
	This will stop and discard the current loaded sequence.

The fancy thing about the program is the ability to do moves to the cube:
Just move the mouse to a field on any view, hold down the left mouse button,
drag the field to any position you want and release the mouse button.
If the move is impossible, the cube "snaps" back to the last possible position.

BUGS:

- There is a harmless bug in the mouse drag animation, but you will hardly
  ever notice it.
    If you dare, try some unusual mouse drags and look whats happening when
  you release the mouse button. Then compare this behaviour to what is
  happening when you release the mouse button on a normal drag. Gotcha!
    If you dare even more, look at the source code for a detailed comment about
  the bug.
    Since the bug is harmless and only arouses on very unusual mouse drags
  and fixing it would require to rewrite the whole mouse drag code I decided
  not to fix it!

TODO:

- Add a kind of "edit" mode where the user can construct a disordered cube
  and the program shows the user how to adjust it.
  As this was the reason for programming the core 'rubik.pl' module, the
  graphical interface should really be capable of doing this.
- Use constraints to center the devices on which the cube is displayed within
  the visible area of their windows. But how can this be done?
- Use only one timer object for every instance of the program. Hopefully this
  will save some CPU time when using more than one instance of the program.
- print/1 does not use the portray/1 clauses defined in the core module,
  but it really should.
- There should be a class for the frame in which the cube is displayed.
- Use a file selector to allow the user to load some nice pattern-generating
  movelists (there is already a collection of movelists hidden as comments).
- Produce better documentation.
- Construct a smarter communication with the user by outputting text like
  "Oh how lovely - you adjusted the first plane!" or
  "Let me show you how to do these kind of things!" or
  "Oh damn, you stupid guy sucked it again!".
  Wouldn't this be cute?! ;-)
