net.pacbell.jfai.toh.domain
Class Disk

java.lang.Object
  java.util.Observable
      net.pacbell.jfai.toh.domain.Disk

All Implemented Interfaces:

Comparable

public class Disk
extends Observable
implements Comparable

Disks are stacked to form a tower.

Constructor Summary

Disk(int size, Pin pin)
Create an instance with the given size and located at the given Pin.

Method Summary

void	changePinTo(Pin aPin) Move the receiver from the current pin to the given pin.
int	compareTo(Object o) Interface Comparable: Compare the receiver with the argument.
boolean	equals(Object obj)
Pin	getPin() Gets the pin.
int	getSize() Gets the size.
int	hashCode()
void	moveTo(Pin target) Remove the receiver from the top of the current pin and add it to the top of the specified pin.
void	remove() Remove the receiver from the puzzle.
void	setSize(int size) Sets the size.
String	toString()

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Disk

public Disk(int size,
            Pin pin)

Create an instance with the given size and located at the given Pin.

Parameters:

size - Relative radius

pin - A pin

Method Detail

changePinTo

public void changePinTo(Pin aPin)

Move the receiver from the current pin to the given pin.

Note: this does not notify observers.

Parameters:

aPin - A pin

compareTo

public int compareTo(Object o)

Interface Comparable: Compare the receiver with the argument. If the argument is not a Disk, a ClassCastException is thrown. Otherwise, the size of the two Disks are compared (disks are sorted in descending size order): this.size < o.size: result is 1 this.size = o.size: result is 0 this.size > o.size: result is -1

Specified by:

compareTo in interface Comparable

Parameters:

o - The object to compare.

Returns:

The result of the comparison - see description.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

See Also:

Object.equals(java.lang.Object)

getPin

public Pin getPin()

Gets the pin.

Returns:

the pin

getSize

public int getSize()

Gets the size.

Returns:

An integer between 1 and the total number of disks of the puzzle. The smallest disk has size 1.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

See Also:

Object.hashCode()

moveTo

public void moveTo(Pin target)
            throws InvalidMoveException

Remove the receiver from the top of the current pin and add it to the top of the specified pin. An exception is thrown if this is an invalid move. Notify observers.

Parameters:

target - A pin

Throws:

InvalidMoveException - if an invalid move is attempted

remove

public void remove()

Remove the receiver from the puzzle. Note: this does not notify observers.

setSize

public void setSize(int size)

Sets the size.

Parameters:

size - An integer between 1 and the total number of disks of the puzzle. The smallest disk has size 1.

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()