import java.applet.*;
import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
/**
* HelloApplet is a simple applet that toggles a message
* when you click on a Draw button.
*/
public class HelloApplet extends JApplet {
/** The flag which controls drawing the message. */
protected boolean requested;
/** init() is an Applet method called by the browser to initialize */
public void init() {
JButton b;
requested = false;
Container cp = (Container)getContentPane();
cp.setLayout(new FlowLayout());
cp.add(b = new JButton("Draw/Don't Draw"));
b.addActionListener(new ActionListener() {
/* Button - toggle the state of the "requested" flag, to draw or
* not to draw.
*/
public void actionPerformed(ActionEvent e) {
String arg = e.getActionCommand();
// Invert the state of the draw request.
requested = !requested;
do_the_work();
}
});
}
/** paint() is an AWT Component method, called when the
* component needs to be painted.
*/
public void do_the_work() {
/* If the Draw button is selected, draw something */
if (requested) {
showStatus("Welcome to Java!");
} else {
showStatus(""); // retract welcome? :-)
}
}
}
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