A better pattern extra methods in the CapitalizeApplet class and does
not expose CapitalizeApplet's private fields.
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class CapitalizeApplet extends Applet {
private TextField input;
private TextField output;
public void init () {
// Construct the TextFields
this.input = new TextField(40);
this.output = new TextField(40);
this.output.setEditable(false);
Button b = new Button("Capitalize");
// add the button to the layout
this.add(input);
this.add(b);
this.add(output);
// specify that action events sent by the
// button or the input TextField should be handled
// by the same CapitalizerAction object
CapitalizerAction ca = new CapitalizerAction(this);
b.addActionListener(ca);
this.input.addActionListener(ca);
// notice that ActionEvents produced by output are ignored.
}
public void capitalize() {
String s = input.getText();
output.setText(s.toUpperCase());
}
}
class CapitalizerAction implements ActionListener {
private CapitalizeApplet target;
public CapitalizerAction(CapitalizeApplet target) {
this.target = target;
}
public void actionPerformed(ActionEvent ae) {
target.capitalize();
}
}