The display i'm trying to acheive is a keypad at the bottom of the applet (from 0 to 9, and a to z) and two text fields above the keypad, one at the top(labelled - input), and one below( labeled - result). any help will be appreciated. (ps. nevermind about the calculations as i havent finished that yet - its just the display i cant do) thanks in advance
the code i've got so far is:
- Code: Select all
import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;
public class RecogniseNumber3 extends java.applet.Applet
implements ActionListener
{
final int IDLE = 0;
final int BUILDING_REAL = 1;
final int BUILDING_INT = 2;
final int INVALID = 3;
int state;//current user holds state
Panel ip;//contains user buttons
TextField input;//displays current number
TextField result;//displays result of number check
StringBuffer currentinput;//input characters stored here
char currentchar;
public void init()
{
setLayout(new BorderLayout());
input = new TextField(24);
input.setEditable(false);//read only
add("North", input);
result = new TextField(24);
result.setEditable(false);//read only
add("Center", result);
ip = new Panel();
ip.setLayout(new GridLayout(4,3,5,5));
Button b;
for (char input='a'; input < 'z' + 1; input++)
{
b = new Button ("" + input);
b.addActionListener(this);
ip.add(b);
}//end for
for (char input='0'; input < '9' + 1; input++ )
{
b = new Button ("" + input);
b.addActionListener(this);
ip.add(b);
}//end for
b = new Button(".");
b.addActionListener(this);
ip.add(b);
b = new Button("Finish");
b.addActionListener(this);
ip.add(b);
add("South", ip);
currentinput = new StringBuffer();
state = IDLE;//initial state
}//end init
public void handleChar()
{
switch(state)
{
case IDLE:
result.setText("");//clear result of any display
input.setText("");//clear any previous display
if (currentchar == '.')//decimal point so must be real
{
state = BUILDING_REAL;
currentinput.append(currentchar);
//add to the input string
input.setText(currentinput.toString());
//refresh output window
break;
}
else//must be a digit
{
state = BUILDING_INT;
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}
case BUILDING_REAL:
if (currentchar == '.')//cant have two
{
state = INVALID;
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}
else
{
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}
case BUILDING_INT:
if (currentchar == '.')
{
state = BUILDING_REAL;
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}
else
{
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}
case INVALID:
currentinput.append(currentchar);
input.setText(currentinput.toString());
break;
}//end switch
}//end handleChar
public void finish()
{
switch(state)
{
case BUILDING_REAL:
result.setText("Valid");
state = IDLE;
currentinput = new StringBuffer();
//discard old string bufffer
break;
case BUILDING_INT:
result.setText("The number is an integer");
state = IDLE;
currentinput = new StringBuffer();
break;
case INVALID:
result.setText("Invalid");
state = IDLE;
currentinput = new StringBuffer();
}//end switch
}//end finish
public void actionPerformed(ActionEvent event)
{
String command = event.getActionCommand();
if (event.getSource() instanceof Button)
{
if (command.equals("Finish"))
{
finish();
}
else
{
currentchar = command.charAt(0);
handleChar();
}
}
}
}
