CS111 PS10 Task 2 Gubble Contract

Instances of the Gubble class represent whimsical creatures that are relatives of buggles and that inhabit an instance of the GubbleWorld class. Conceptually, every gubble has four abstract state variables:

position: A point specifying the location of the gubble in the gubbleworld grid.
direction: The direction that the gubble is facing.
color: The color of the gubble.
world: The instance of GubbleWorld in which the gubble lives.

Constructor Methods

public Gubble (GubbleWorld gw, Point pos, Direction dir, Color col);
Creates and returns a new gubble with color col that lives in gubbleworld gw and is initially at position pos facing direction dir.

Instance Methods

public Point getPosition ();
Returns the current position of this gubble in the gubbleworld grid.
public Direction getDirection ();
Returns the direction in which this gubble is facing.
public Color getColor ();
Returns the color of this gubble.
public void left ();
Turns this gubble left by 90 degrees.
public void right ();
Turns this gubble right by 90 degrees.
public void forward ();
Moves this gubble forward one step (in its current direction). Complains if the gubble is facing a wall.

public boolean isBlockedFront ();
Returns true if there is an obstruction (a wall or another gubble) immediately in front of this gubble; otherwise returns false.
public boolean isInLeftCorner ();
Returns true if there is an obstruction (a wall or another gubble) immediately in front of and to the left of this gubble, but there is no obstruction immediately to the right; otherwise returns false.
public boolean isInRightCorner ();
Returns true if there is an obstruction (a wall or another gubble) immediately in front of and to the right of this gubble, but there is no obstruction immediately to the left; otherwise returns false.
public boolean isSurrounded ();
Returns true if there is an obstruction (a wall or another gubble) immediately in front of, to the right of, and to the left of this gubble; otherwise returns false.
public Gubble copy ();
Returns a new gubble that has the same state (color, direction, position, world) as this buggle. Changes to the resulting gubble should have no effect on the original gubble and vice versa.
public void draw (Graphics g, Rectangle r);
Draws a pictorial representation of this gubble in the given rectangle using the given graphics context. The representation must show the current direction and color of the gubble. Here is a picture of a red gubble facing north:
In a square, the head of a gubble is a filled circle that is 25% of its body length, and its abdomen is a filled circle that is 75% of its body length. It also has four legs that project outward from the center of its abdomen.
public String toString ();
Returns a string representation of this gubble.