[과제] Windows Event를 이용한 신호등 예제

import java.awt.*;

import java.awt.event.*;

public class EventHomeWork extends Frame implements ItemListener{

Panel p1, p2, p3;

CheckboxGroup g1;

Checkbox rdoThree, rdoFour;

Checkbox chkRed, chkYellow, chkLeft, chkGreen;

Button btnRed, btnYellow, btnLeft, btnGreen;

public EventHomeWork() {

addWindowListener(new WinClosing(this));

p1 = new Panel();

p2 = new Panel();

p3 = new Panel();

chkRed = new Checkbox("빨강");

chkYellow = new Checkbox("노랑");

chkLeft = new Checkbox("좌회전");

chkGreen = new Checkbox("초록");

g1 = new CheckboxGroup();

rdoThree = new Checkbox("3등식", g1, false);

rdoFour = new Checkbox("4등식", g1, true);

btnRed = new Button("빨강");

btnYellow = new Button("노랑");

btnLeft = new Button("<-");

btnGreen = new Button("초록");

p1.add(rdoThree);

p1.add(rdoFour);

p2.add(chkRed);

p2.add(chkYellow);

p2.add(chkGreen);

p2.add(chkLeft);

p3.setLayout(new GridLayout(1, 4));

p3.add(btnRed);

p3.add(btnYellow);

p3.add(btnGreen);

p3.add(btnLeft);

add("North",p1);

add("Center",p2);

add("South",p3);

rdoThree.addItemListener(this);

rdoFour.addItemListener(this);

chkRed.addItemListener(this);

chkYellow.addItemListener(this);

chkGreen.addItemListener(this);

chkLeft.addItemListener(this);

}

@Override

public void itemStateChanged(ItemEvent e) {

Checkbox cb = (Checkbox)e.getSource();

switch(cb.getLabel()){

case "3등식" :

chkLeft.setVisible(false);

break;

case "4등식" : 

chkLeft.setVisible(true);

break;

case "빨강" :

if(cb.getState() == true){

btnRed.setBackground(Color.red);

}else{

btnRed.setBackground(new Color(234,234,234));

}

break;

case "초록" :

if(cb.getState() == true){

btnGreen.setBackground(Color.green);

}else{

btnGreen.setBackground(new Color(234,234,234));

}

break;

case "노랑" :

if(cb.getState() == true){

btnYellow.setBackground(Color.yellow);

}else{

btnYellow.setBackground(new Color(234,234,234));

}

break;

case "좌회전" :

if(cb.getState() == true){

btnLeft.setBackground(Color.orange);

}else{

btnLeft.setBackground(new Color(234,234,234));

}

break;

}

}

public static void main(String[] args) {

EventHomeWork test = new EventHomeWork();

test.setSize(300,400);

test.setVisible(true);

}