Visual C++ Programming: Concepts and Projects

1. Visual C++ Programming: Concepts and Projects Chapter 13B: Object-Oriented Programming (Tutorial)

2. Tutorial: Maze Program • Problem analysis • Create a program in which a mouse navigates a maze looking for the hidden cheese • The maze consists of a two-dimensional array of cells • The Mouse is an object created from a Mouse class definition • Each cell in the maze is an object created from a Cell class definition Programming with Visual C++

3. Problem Analysis Programming with Visual C++

4. The Mouse Class Definition • Class variables • Various icons of mouse facing different directions • private data members • Row and column locations of the mouse in the maze (row and col) • Icon • private methods • Default constructor – Mouse() Programming with Visual C++

5. The Mouse Class Definition (continued) • publicmethods • Initializing constructor – Mouse(int, int) • Accessor methods • getRow() • getCol() • getIcon() • Mutator methods • setRow() • setCol() Programming with Visual C++

6. The Mouse Class Definition (continued) • publicmethods • Utility methods • goRight() • goLeft() • goUp() • goDown() Programming with Visual C++

7. The Mouse Class Definition (continued) Programming with Visual C++

8. The Mouse Class Definition (continued) Programming with Visual C++

9. The Mouse Class Definition (continued) Programming with Visual C++

10. Programming with Visual C++

11. The Cell Class Definition • private data members • row: int – row location of Cell in maze • col: int – column location of Cell in maze • access: bool – indicates whether Mouse can enter this Cell • hasCheese: bool – indicates whether cheese is in this Cell • private methods • Default constructor – Cell() Programming with Visual C++

12. The Cell Class Definition (continued) • publicmethods • Initializing constructor – Cell(int, int) • Accessor methods • getRow() • getCol() • getAccess() • getCheese() • Mutator methods • setAccess() • setCheese() Programming with Visual C++

13. The Cell Class Definition (continued) Programming with Visual C++

14. Programming with Visual C++

15. The Cell Class Definition (continued) • An initializing constructor is used to assign each Cell a row and column location as well as a Boolean access value Programming with Visual C++

16. Design • A maze consists of rows and columns • Rows run horizontally • Columns run vertically • Each cell has a row and column location Programming with Visual C++

17. Design (continued) Programming with Visual C++

18. Design (continued) Programming with Visual C++

19. Design (continued) Programming with Visual C++

20. Design (continued) • The interface contains two buttons (used to start and stop the animation) • A Timer control is used to perform Mouse movement • The Mouse moves from one Cell to another • Previous cells are colored brown • When the mouse reaches the cell with the cheese, a MessageBox pops up Programming with Visual C++

21. Design (continued) Programming with Visual C++

22. Design (continued) • The size of Cells and the number of rows and columns of Cells in the maze are constants Programming with Visual C++

23. Design (continued) Programming with Visual C++

24. Design (continued) • The maze is a two-dimensional array of Cells • Use the Array template as a foundation for this Programming with Visual C++

25. Design (continued) • Instance variables include the mouse, maze, and a variable to indicate which direction the mouse is moving Programming with Visual C++

26. Design (continued) • Creating the maze requires the instantiation of 320 Cell objects (20 in each row) Programming with Visual C++

27. Design (continued) • The Form1_Load() event will construct the interface, complete with maze, mouse, and cheese Programming with Visual C++

28. Design (continued) • Drawing the maze (nested loops for rows and columns) Programming with Visual C++

29. Design (continued) • Drawing and positioning the Mouse Programming with Visual C++

30. Design (continued) • Keep the mouse in the maze by checking for edges Programming with Visual C++

31. Development • Interface construction (only two buttons) • Timer control used to control movement • Form1_Load() will draw the maze initially • The maze and mouse are redrawn in each Timer_Tick()event Programming with Visual C++

32. Development (continued) Programming with Visual C++

33. Development (continued) • The Mouse and Cell class definition header files must both be included at the top of the client (Form1.h) Programming with Visual C++

34. Development (continued) • Instance variables, constants, and object handles Programming with Visual C++

35. Development (continued) • Form1_Load()constructs the maze Programming with Visual C++

36. Development (continued) • The start button creates the mouse and cheese Programming with Visual C++

37. Development (continued) • The mouse and cheese icons are displayed in Rectangles Programming with Visual C++

38. Development (continued) • The maze cells are drawn in drawMaze() Programming with Visual C++

39. Development (continued) • At each interval of the Timer, its Tick() event: • Redraws the maze • Draws the mouse at its new location • The animation can be halted with btnStop_Click() Programming with Visual C++

40. Development (continued) • The Timer1_Tick() event: • Creates a Rectangle based on the cell in which the mouse currently resides (oldRect) Programming with Visual C++

41. Development (continued) • If mouse is not at edge, then move in current direction Programming with Visual C++

42. Development (continued) • If mouse moves into cell with cheese, congratulations! • If mouse was at an edge, then choose new direction Programming with Visual C++

43. Development (continued) • Check for edges by checking row and column Programming with Visual C++

44. Testing • When btnStart is clicked: • Maze appears (16 rows x 20 columns of cells) • Mouse and cheese appear • Mouse moves across the maze from left to right • When mouse reaches the edge, it turns and follows the edges around • Reposition the cheese so that the mouse finds it in its path Programming with Visual C++

45. On Your Own • Stronger mutators • Do not allow negative values • Private instance methods • verifyRow()and verifyCol() for Mouse class • New UML class diagram • Add verifyRow() and verifyCol() to Mouse UML diagram Programming with Visual C++