In this section, we illustrate three problems that utilize event-driven programming. The first is the design of a simple GUI interface. The second is a Java applet, and the third involves the design of an interactive game using the Model-View-Controller (MVC) design pattern. | Programming Languages 2nd edition Tucker and Noonan Chapter 16 Event-Driven Programming Of all men’s miseries the bitterest is this, to know so much and to have control over nothing. Herodotus (484-432 BC) Contents Event-Driven Control Event Handling Three Examples Other Applications Designing a Java Applet Can convert previous application An applet runs inside a web browser Differences Extend JApplet Lacks a main method Method init replaces constructor import .*; import .*; import .*; public class SkelApplet extends JApplet { // Global "state" of the interaction private int lastX = 0; private int lastY = 0; . public void init( ) { JPanel panel = new JPanel( ); . // Create a button and add it to the Panel. JButton clearButton = new JButton("Clear"); (); (); (clearButton); ( new ClearButtonHandler()); . getContentPane( ).add(panel); } Tic-Tac-Toe State of the board Whose turn: X or O Whether game is over private int player = -1; // Current player: EX, or OH private int[ ] board = new int[9]; public abstract class CellIcon implements Icon { private Color color = ; private int size; public CellIcon(int size) { = size; } public int size( ) { return size; } public Color getColor( ) { return color; } public void setColor(Color c) { color = c; } public int getIconWidth( ) { return size; } public int getIconHeight( ) { return size; } } private int[ ][ ] lines = { {0, 1, 2}, {3, 4, 5}, {6, 7, 8}, //across {0, 3, 6}, {1, 4, 7}, {2, 5, 8}, //down {0, 4, 8}, {2, 4, 6} //diagonal }; public boolean won( ) { for (int i = 0; i < ; i++) if (board[lines[i][0]] == player && board[lines[i][1]] == player && board[lines[i][2]] == player) return true; return false; } // won public class CellXIcon extends CellIcon { public CellXIcon(int size) { super(size); } public void . | Programming Languages 2nd edition Tucker and Noonan Chapter 16 Event-Driven Programming Of all men’s miseries the bitterest is this, to know so much and to have control over nothing. Herodotus (484-432 BC) Contents Event-Driven Control Event Handling Three Examples Other Applications Designing a Java Applet Can convert previous application An applet runs inside a web browser Differences Extend JApplet Lacks a main method Method init replaces constructor import .*; import .*; import .*; public class SkelApplet extends JApplet { // Global "state" of the interaction private int lastX = 0; private int lastY = 0; . public void init( ) { JPanel panel = new JPanel( ); . // Create a button and add it to the Panel. JButton clearButton = new JButton("Clear"); (); (); (clearButton); ( new ClearButtonHandler()); . .
