CS111 TuggleWorld Contract

An instance of the TuggleWorld class represents a text-based world that may be inhabited by tuggles and their bagels. Conceptually, each TuggleWorld has the following abstract state variables:

• rows: The number of rows in the grid.
• cols: The number of columns in the grid.
• numTuggles: The number of tuggles that live in the grid.
• tuggles: A collection of the numTuggles tuggles that live in the grid. These can be referenced by an index in the range [1 .. numTuggles].
• gridState: A representation of the colors and bagels in each grid cell. Cell locations are specified by coordinates (x,y), where x is in the range [1..cols] and y is in the range [1..rows].

Unlike BuggleWorld, TuggleWorld is not an applet. Instances of TuggleWorld are constructed directly by the programmer.

Constructor Method

public TuggleWorld (int r, int c, int numTuggles)
Constructs an instance of TuggleWorld with r rows, c columns, and numTuggles tuggles. Complains if r ≤ 0, c ≤ 0, or numTuggles < 0.

Public Instance Methods

public int numTuggles ()
Return the number of tuggles in this world.

public Tuggle getTuggle (int i)
Return the ith tuggle in this world, where i is an index between 1 and numTuggles(), inclusive.

public String toString ()
Return a string representation of this world's grid. The contents of cells are separated horizontally by the characters

+-+

+
|
+

+-+-+-+-+
| | | | |
+-+-+-+-+
| | | | |
+-+-+-+-+
| | | | |
+-+-+-+-+

+-+
|X|
+-+

• If the cell contains one or more tuggles, X does not show the cell color or bagel (if any) but only shows the heading of the highest-indexed tuggle in the cell as follows:

  Direction	Character
  EAST	'>'
  NORTH	'^'
  WEST	'<'
  SOUTH	'V'

• If the cell contains no tuggles, X shows the color and bagel (if any) as follows:

  Color	Character If No Bagel	Character If Bagel
  black	'k'	'K'
  blue	'b'	'B'
  cyan	'c'	'C'
  green	'g'	'G'
  magenta	'm'	'M'
  red	'r'	'R'
  white	' ' (a space char)	'O'
  yellow	'y'	'Y'
  any other color	'?'	'$'

Protected Instance Methods (These instance methods can be used only within the TuggleWorld and Tuggle classes.)

protected int getRows ()
Return the number of rows in this world's grid.

protected int getCols ()
Return the number of columns in this world's grid.

protected boolean contains (Point p)
Return true if p is a legal grid position in this world and false otherwise.

protected Color getColorAt (int x, int y)
Return the color at grid location (x,y). Complains if this location is not in the grid.

protected void setColorAt (int x, int y, Color c)
Change the color at grid location (x,y) to be c. Complains if this location is not in the grid.

protected boolean getBagelAt (int x, int y)
Return true if there is a bagel at grid location (x,y) and false otherwise. Complains if this location is not in the grid.

protected void setBagelAt (int x, int y, boolean b)
Change the bagel state of grid location (x,y) to be b. Complains if this location is not in the grid.

protected Tuggle getTuggleAt (int x, int y)
If there is at least one tuggle at (x,y), return the tuggle with the highest index; otherwise returns null.