visual c++ programming: concepts and projects

Visual C++ Programming: Concepts and Projects

Chapter 13B: Object-Oriented Programming

(Tutorial)

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

2Programming with Visual C++

Problem Analysis


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()


The Mouse Class Definition (continued)

• public methods– Initializing constructor – Mouse(int, int)– Accessor methods

• getRow()• getCol()• getIcon()

– Mutator methods• setRow()• setCol()



• public methods– Utility methods

• goRight()• goLeft()• goUp()• goDown()


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()


The Cell Class Definition (continued)

• public methods– Initializing constructor – Cell(int, int)– Accessor methods

• getRow()• getCol()• getAccess()• getCheese()

– Mutator methods• setAccess()• setCheese()



• An initializing constructor is used to assign each Cell a row and column location as well as a Boolean access value


Design

• A maze consists of rows and columns– Rows run horizontally– Columns run vertically

• Each cell has a row and column location


Design (continued)


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


Design (continued)


Design (continued)

• The size of Cells and the number of rows and columns of Cells in the maze are constants


Design (continued)


Design (continued)

• The maze is a two-dimensional array of Cells• Use the Array template as a foundation for

this


Design (continued)

• Instance variables include the mouse, maze, and a variable to indicate which direction the mouse is moving


Design (continued)

• Creating the maze requires the instantiation of 320 Cell objects (20 in each row)


Design (continued)

• The Form1_Load() event will construct the interface, complete with maze, mouse, and cheese


Design (continued)

• Drawing the maze (nested loops for rows and columns)


Design (continued)

• Drawing and positioning the Mouse


Design (continued)

• Keep the mouse in the maze by checking for edges


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


Development (continued)



• The Mouse and Cell class definition header files must both be included at the top of the client (Form1.h)



• Instance variables, constants, and object handles



• Form1_Load() constructs the maze



• The start button creates the mouse and cheese



• The mouse and cheese icons are displayed in Rectangles



• The maze cells are drawn in drawMaze()



• 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()



• The Timer1_Tick() event:– Creates a Rectangle based on the cell in which the

mouse currently resides (oldRect)


Development (continued)• If mouse is not at edge, then move in current

direction



• If mouse moves into cell with cheese, congratulations!• If mouse was at an edge, then choose new direction



• Check for edges by checking row and column


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


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


visual c++ programming: concepts and projects

Documents

visual c programming

visual c programming

visual c designa maze

visual c problem analysis

mouse movementthe mouse

verticallyeach cell

int column location

int row location of