edu.kit.iti.formal.lights

Class Lights

java.lang.Object

edu.kit.iti.formal.lights.Lights

public class Lights
extends Object

This class can be used to solve "Light Up" puzzles.

It is meant as a framework for the programming assignment "Light Up" available at the homepage of the lecture.

Please consider checking for updates every now and then since there might still be errors in these classes.

Features

• "Lights" boards can be created from description strings.
• Description strings can be created from boards.
• You can query and ...
• ...set single fields of the boards.
• You can visualise the board either on the console (toConsole()) ...
• ... or as a dialog window (showWindow()).
• You can create a Set of CNF-clauses for certain problems (Clause.exactlySetN)

Version:

2015.1

Author:

Mattias Ulbrich

Field Summary

Fields

Modifier and Type	Field and Description
static Object	BLOCK this immutable object stands for an unconstrained block
static Object	LIGHT this immutable object stands for a light

Constructor Summary

Constructors

Constructor and Description
Lights(int dimension) create a new empty Lights-board.
Lights(String desc) convert a board description into a Lights object.

Method Summary

Modifier and Type	Method and Description
void	clear(int row, int col) set a field on the board to empty.
Lights	clone() create a new object of this class which gets a copy the fields array.
boolean	equals(Object obj) compare this Lights board to another object.
int	getBlockConstraint(int row, int col) Get the value of a constraint of a field.
int	getDimension() get the width/height of this board.
Object	getField(int row, int col) return the (immutable) object that is used to describe a field on the board.
int	getLitNeighbours(int row, int col) Get the number of neighbouring fields that contain a light.
boolean	isBlock(int row, int col) check if a field on the board has been set to a block.
boolean	isConstrainedBlock(int row, int col) check if a field on the board has been set to a constrained block.
boolean	isEmpty(int row, int col) check if a field on the board is empty, i.e. neither a light nor a block is placed on it.
boolean	isLight(int row, int col) check if a field on the board has been set to a light.
boolean	isLit(int row, int col) check if a field in the board is lit a by a light placed on the board.
void	setBlock(int row, int col) set a field on the board to an unconstrained block.
void	setBlockConstraint(int row, int col, int constraint) set a field on the board to a constrained block.
void	setEmpty(int row, int col) set a field on the board to "Empty".
void	setLight(int row, int col) set a field on the board to "Light".
void	showWindow() open a modal dialog window that displays the current field.
void	toConsole() print the board to the console, i.e.
String	toString() generate a describing String from this board.

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LIGHT

public static final Object LIGHT

this immutable object stands for a light

BLOCK

public static final Object BLOCK

this immutable object stands for an unconstrained block

Constructor Detail

Lights

public Lights(String desc)
       throws LightsFormatException

convert a board description into a Lights object. The description must be well formulated otherwise an exception will be raised.

The string must begin with a positive number - the dimension of the board followed by a colon. The following characters describe the board:

'a'-'z'	1-26 empty fields in succession.
'0'-'4'	a constrained block
'L'	a light
'B'	a block
' ', '\t', '\n', '\r'	spaces are ignored

Parameters:

desc - a board description as string

Throws:

LightsFormatException - if the string is not formated according to the specifications.

See Also:

toString()

Lights

public Lights(int dimension)

create a new empty Lights-board.

Parameters:

dimension - the height and width of the board, positive.

Throws:

IllegalArgumentException - if dimension is not positive.

Method Detail

toString

public String toString()

generate a describing String from this board.

see Lights(String) for the format of the string.

Overrides:

toString in class Object

Returns:

a string completely describing the board

getField

public Object getField(int row,
                       int col)

return the (immutable) object that is used to describe a field on the board.

The returned object can either be

• null if it is empty
• LIGHT if it is a light
• BLOCK if it is an unconstrained block
• an instance of Integer with value 0 .. 4 if it is a contrained block

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

see above.

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

LIGHT, BLOCK

getDimension

public int getDimension()

get the width/height of this board.

Returns:

a positive integer

isEmpty

public boolean isEmpty(int row,
                       int col)

check if a field on the board is empty, i.e. neither a light nor a block is placed on it.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

true iff the field is indeed empty

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

clear(int, int)

isLight

public boolean isLight(int row,
                       int col)

check if a field on the board has been set to a light.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

true iff the field is indeed a light.

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

setLight(int, int)

isBlock

public boolean isBlock(int row,
                       int col)

check if a field on the board has been set to a block. This can be either a constrained or an unconstrained block.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

true iff the field is indeed a block.

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

setBlock(int, int)

isConstrainedBlock

public boolean isConstrainedBlock(int row,
                                  int col)

check if a field on the board has been set to a constrained block. This returns false for unconstrained blocks

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

true iff the field is indeed a constrained block.

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

getBlockConstraint

public int getBlockConstraint(int row,
                              int col)

Get the value of a constraint of a field.

This value is between 0 and 4. Please make sure the indexed field contains indeed a constrained block. Otherwise a IllegalArgumentException will be thrown.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

the value of the constraint of the indexed field (0..4)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

IllegalArgumentException - if the field is not a constrained block

See Also:

setBlockConstraint(int, int, int)

getLitNeighbours

public int getLitNeighbours(int row,
                            int col)

Get the number of neighbouring fields that contain a light.

In a valid solution this value needs to be the same as the result of getBlockConstraint(int, int)(row,col) if this does not yield an exception.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

the number of fields which are neighbours (horizontally or vertically) on which a light is placed

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

isLit

public boolean isLit(int row,
                     int col)

check if a field in the board is lit a by a light placed on the board. This can be on the same field or on a field horizontally or vertically visible from this field. Light does not go through blocks.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Returns:

true iff the indexed field is lit by a light placed somewhere on the board.

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

isLight(int, int)

clear

public void clear(int row,
                  int col)

set a field on the board to empty.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

See Also:

setLight(int, int), setBlock(int, int), setBlockConstraint(int, int, int)

setLight

public void setLight(int row,
                     int col)

set a field on the board to "Light". This can only be done if the field is empty or has been set to "Light" previously. This restriction is a precaution to not accidently change the structure of a field.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

IllegalArgumentException - if the indexed field is neither empty nor a light.

See Also:

isLight(int, int)

setEmpty

public void setEmpty(int row,
                     int col)

set a field on the board to "Empty". This can only be done if the field is empty or has been set to "Light" previously. This restriction is a precaution to not accidently change the structure of a field.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

IllegalArgumentException - if the indexed field is neither empty nor a light.

See Also:

isLight(int, int)

setBlock

public void setBlock(int row,
                     int col)

set a field on the board to an unconstrained block. This can only be done if the field is empty or has perviously been set to an unconstrained block. This restriction is a precaution to not accidently change the structure of a field.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

IllegalArgumentException - if the indexed field is neither empty nor an unconstrained block.

See Also:

isBlock(int, int)

setBlockConstraint

public void setBlockConstraint(int row,
                               int col,
                               int constraint)

set a field on the board to a constrained block. This can only be done if the field is empty or has previously been set to a constrained block. This restriction is a precaution to not accidently change the structure of a field. Please note that you can change the value of the constraint without exception.

Parameters:

row - the index of the row of the field (0 .. dimension-1)

col - the index of the column of the field (0 .. dimension-1)

constraint - the value to set to the field (0..4)

Throws:

IndexOutOfBoundsException - if row or col are not within the bounds.

IllegalArgumentException - if the indexed field is neither empty nor a constrained block or if the constraint is not within the valid range.

See Also:

getBlockConstraint(int, int), isConstrainedBlock(int, int)

showWindow

public void showWindow()

open a modal dialog window that displays the current field. The thread continues after the window has been closed.

Pleas note: You need to terminate your program via System.exit(int) if you use this method. This is due to some AWT thread.

See Also:

JDialog, LightsComponent

toConsole

public void toConsole()

print the board to the console, i.e. System.out each field is represented by a character with the following meanings:

• ' ' (space) for an empty field
• 'B' for an unconstrained block
• '0'-'4' for a constrained block
• 'L' for a light

clone

public Lights clone()

create a new object of this class which gets a copy the fields array. The entries in the array are not deep copied since they are immutable.

Overrides:

clone in class Object

Returns:

a new (identical) Lights object

equals

public boolean equals(Object obj)

compare this Lights board to another object.

They are considered equal if and only if obj is an instance of Lights and the field has the same dimension and contains the same object in the same order.

Overrides:

equals in class Object

Parameters:

obj - an arbitrary object or null

Returns:

true iff the board is equal to the board described by obj