Java AWT Tutorials

In this example we are going to handle Choice Box. To control the Choice Box we are using three type of package. One is java.awt.* second is java.applet.* and third is java.awt.event.*; .The java.awt.* is used for GUI interface. AWT classes are contain in this package. The java.applet.* package is used to create an applet and java.awt.event.*; defined within the java.awt.*; package is a subclass of EventObject. It is a super class of all AWT-based event.

The Choice class is used to create a pop-up list of items from which the user may choose. A choice control is a form of menu. Each item in a list is a string that appears as a left-justified label in the order it is add to the choice object.To add a selection to the list, call add().

void add(string name);

In our example first we implement two interface:

ItemListener(): Each listener implement the ItemLinstner.

itemStateChange(): When a option is selected or an event is occur this interface is called.

To deterrmine which item is currently selected,you may call : String getSelectedItem(); It returns a string containing the name of the item. or int getSelectedIndex(); It return the index of the item.

To obtain the number of item in the list call:

int getItemCount();

In our example we create two choice menu one is country and other is city.

Example

//Choice
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/*
<applet code="ChoiceDemo" width=300 height=200>
</applet>
*/
public class ChoiceDemo extends Applet implements ItemListener {
Choice country,city;
String msg="";
public void init(){
country = new Choice();
city = new Choice();
country.add("India");
country.add("Rusia");
country.add("Pakistan");
country.add("Srilanka");
city.add("unnao");
city.add("Lucknow"); 
city.add("Lahour"); 
city.add("Kuvait");
city.select("Caindy");
add(country);
add(city);
country.addItemListener(this);
city.addItemListener(this);
}
public void itemStateChanged(ItemEvent ie){
repaint();
}
public void paint(Graphics g){
msg="Your country name is:";
msg+=country.getSelectedItem();
g.drawString(msg,6,120);
msg="your city name is:";
msg += city.getSelectedItem();
g.drawString(msg,6,140);
}
}