//: c13:Separation.java
// Separating GUI logic and business objects.
// <applet code=Separation
// width=250 height=150> </applet>
import javax.swing.*;
import java.awt.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.applet.*;
import com.bruceeckel.swing.*;
class BusinessLogic {
private int modifier;
public BusinessLogic(int mod) {
modifier = mod;
}
public void setModifier(int mod) {
modifier = mod;
}
public int getModifier() {
return modifier;
}
// Some business operations:
public int calculation1(int arg) {
return arg * modifier;
}
public int calculation2(int arg) {
return arg + modifier;
}
}
public class Separation extends JApplet {
JTextField
t = new JTextField(15),
mod = new JTextField(15);
BusinessLogic bl = new BusinessLogic(2);
JButton
calc1 = new JButton("Calculation 1"),
calc2 = new JButton("Calculation 2");
static int getValue(JTextField tf) {
try {
return Integer.parseInt(tf.getText());
} catch(NumberFormatException e) {
return 0;
}
}
class Calc1L implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText(Integer.toString(
bl.calculation1(getValue(t))));
}
}
class Calc2L implements ActionListener {
public void actionPerformed(ActionEvent e) {
t.setText(Integer.toString(
bl.calculation2(getValue(t))));
}
}
// If you want something to happen whenever
// a JTextField changes, add this listener:
class ModL implements DocumentListener {
public void changedUpdate(DocumentEvent e) {}
public void insertUpdate(DocumentEvent e) {
bl.setModifier(getValue(mod));
}
public void removeUpdate(DocumentEvent e) {
bl.setModifier(getValue(mod));
}
}
public void init() {
Container cp = getContentPane();
cp.setLayout(new FlowLayout());
cp.add(t);
calc1.addActionListener(new Calc1L());
calc2.addActionListener(new Calc2L());
JPanel p1 = new JPanel();
p1.add(calc1);
p1.add(calc2);
cp.add(p1);
mod.getDocument().
addDocumentListener(new ModL());
JPanel p2 = new JPanel();
p2.add(new JLabel("Modifier:"));
p2.add(mod);
cp.add(p2);
}
public static void main(String[] args) {
Console.run(new Separation(), 250, 100);
}
} ///:~