|
|
Web Configuration:
<applet code="ChoiceRemove.class"
codebase="applet" width=300 height=150>
</applet>
Source Code:
/* ChoiceRemove.java
*
* This example creates a choice and a row of buttons that
* control the insertion and removal of items from the
* choice.
*/
import java.awt.*;
import java.awt.event.*;
public class ChoiceRemove extends java.applet.Applet implements
ActionListener{
Choice choice = new Choice();
Button removeBtn = new Button ("Remove");
Button removeAllBtn = new Button ("Remove All");
Button insertBtn = new Button ("Insert");
int lastItemCount = 0;
public void init () {
//Initialize the choice with ten
items
for (int i = 0; i <10; i++){
choice.addItem("Item" + (lastItemCount++));
}
// Listen for events.
removeBtn.addActionListener(this);
removeAllBtn.addActionListener(this);
insertBtn.addActionListener(this);
Panel p = new Panel(new
GridLayout(1,0));
p.add(removeBtn);
p.add(removeAllBtn);
p.add(insertBtn);
setLayout( new BorderLayout());
add(p, BorderLayout.NORTH);
add(choice, BorderLayout.CENTER);
}
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
if (cmd.equals("Remove All")){
choice.removeAll();
} else {
int target =
choice.getSelectedIndex();
if (cmd.equals("Remove")){
if (target >= 0){
choice.remove(target);
}
} else {
if (target >= 0){
choice.insert("item" +
(lastItemCount++),target);
choice.select(target);
} else {
choice.add("Item" +(lastItemCount++));
}
}
}
removeBtn.setEnabled(choice.getItemCount() > 0);
removeAllBtn.setEnabled(choice.getItemCount() >0);
}
}
|