Introduction

This assignment will give you practice in developing a larger, multi-class application and in constructing a more complex graphical interface involving mouse selections.

The Game of Life

The "Game of Life" (not to be confused with the Parker Brothers edition) is a well-known mathematical simulation that can mimic some very complex behavior. The games tries to mimic the life cycle of cells.

The rules for the game are really very simple:

• The game is played on a rectangular board.
• The board is made up of squares.
• Each square can be either empty or occupied (contains a cell).
• To start the game, the user selects which squares are initially occupied. This is the zeroith (start) generation.
• For each generation, the next generation is computed. The transition from one generation to another is called a turn.
• In each turn the next generation is computed as follows:
• If an empty square is surrounded by exactly 3 neighbors, a new cell is born (that square becomes occupied).
• A cell dies of overcrowding if it is surrounded by 4 or more neighbors (that square becomes empty).
• A cell dies of loneliness if it has zero or one neighbors (that square becomes empty).
• If a cell has 2 neighbors it remains as it is (square stays either empty or occupied)

Neighbors are defined as any adjacent square left, right, up, down or diagonally. The diagram below depicts all the neighbors of a center cell.

+---+---+---+

| 1 | 2 | 3 |

+---+---+---+

| 4 | 5 | 6 | So a cell at 5, would need to check its neighbors at 1,2,3,4,6,7,8,9.

+---+---+---+

| 7 | 8 | 9 |

+---+---+---+

If a cell is at a border, then treat all locations off-board as empty.

Here are a few sample illustrations to help demonstrate the rules. A C means the square is occupied by a cell.

+---+---+---+

| C |   |   |

+---+---+---+

|   | C |   | This center cell would die (become an empty square) in the next generation

+---+---+---+ since it only has 1 neighbor.

|   |   |   |

+---+---+---+

+---+---+---+

|   |   |   |

+---+---+---+

| C | C | C |  This center cell would die (become an empty square) in the next generation

+---+---+---+  since it has 4 neighbors.

| C |   | C |

+---+---+---+

+---+---+---+

| C |   |   |

+---+---+---+

|   |   |   | This center cell would be born (become an occupied square) in the next

+---+---+---+ generation since it has exactly 3 neighbors.

| C |   | C |

+---+---+---+

Program Requirements

User Interface

Your program should run as a GUI application in a JFrame. You should have a JPanel-derived class containing 3 buttons (Run/Stop, Step, and Clear), a JLabel, a text entry field and a drawing area.

• Run/Stop: Run the game animated. Calculate and show each generation automatically based upon the time delay. When the game is running, pressing Stop halts the game. Essentially, this one button should either show "Run" or "Stop". When the game isn't running animated, then the button should show "Run" so that the user can start it. When the game is running, it should show "Stop" so that the use can halt it.
• Step: Advance the game one turn, calculate and show the next generation. This operates the simulation in single step mode. This button has no effect in animate mode.
• Clear: Clear all the cells, Make all squares unoccupied. When the game is animating, this button has no effect until the animation is stopped. (You cannot clear the cells while an animation is in progress)

You should display the current generation number (turn number) in a JLabel.

You should allow the user to enter a delay to use for the animate mode. The default delay if no other entry has been made is 100ms.

In the drawing area, you should display the grid representing the squares that hold the cells. The default grid size should be 20 x 20.

When starting the game, the user should be allowed to click with the mouse inside each cell to make that cell occupied or empty. Clicking on an empty cell makes it occupied. Clicking on an occupied cell makes it empty. Once the user presses the Step or Run button, mouse clicks in the grid area are ignored until the clear button is pressed.

When a square is occupied it should be filled in with the color of your choice. All the squares should be the same color. (For the ambitious: newly born cells in each generation can be colored with a different color from the older cells in a generation).

Some special start cell sequences

Here are some interesting starting sequences. You can also use these to test your application.

The glider. The glider is cool because it repeats itself every few generations and seems to move across the screen. It will move down and right every 4 generations.

Turn-in Procedures

After you have finished your program, turn the files in via Webwork You will be submitting multiple files. Please make sure they are named as shown below: