This example creates a list of items (Item1 to Item4) and calls the prepare method whenever an item is selected. The testItem# methods, where # s a number between 1 and 4, call the prepare method and set the name of the menu.
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
public class EventEx1 extends MIDlet implements CommandListener {
// display manager
Display display = null;
// a menu with items
List menu = null; // main menu
// textbox
TextBox input = null;
// command
static final Command backCommand = new Command("Back", Command.BACK, 0);
static final Command mainMenuCommand = new Command("Main", Command.SCREEN, 1);
static final Command exitCommand = new Command("Exit", Command.STOP, 2);
String currentMenu = null;
// constructor.
public EventEx1() {
}
/**
* Start the MIDlet by creating a list of items and associating the
* exit command with it.
*/
public void startApp() throws MIDletStateChangeException {
display = Display.getDisplay(this);
menu = new List("Menu Items", Choice.IMPLICIT);
menu.append("Item1", null);
menu.append("Item2", null);
menu.append("Item3", null);
menu.append("Item4", null);
menu.addCommand(exitCommand);
menu.setCommandListener(this);
mainMenu();
}
public void pauseApp() {
display = null;
menu = null;
input = null;
}
public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
// main menu
void mainMenu() {
display.setCurrent(menu);
currentMenu = "Main";
}
/**
* a generic method that will be called when selected any of
* the items on the list.
*/
public void prepare() {
input = new TextBox("Enter some text: ", "", 5, TextField.ANY);
input.addCommand(backCommand);
input.setCommandListener(this);
input.setString("");
display.setCurrent(input);
}
/**
* Test item1.
*/
public void testItem1() {
prepare();
currentMenu = "item1";
}
/**
* Test item2.
*/
public void testItem2() {
prepare();
currentMenu = "item2";
}
/**
* Test item3.
*/
public void testItem3() {
prepare();
currentMenu = "item3";
}
/**
* Test item4.
*/
public void testItem4() {
prepare();
currentMenu = "item4";
}
/**
* Handle events.
*/
public void commandAction(Command c, Displayable d) {
String label = c.getLabel();
if (label.equals("Exit")) {
destroyApp(true);
} else if (label.equals("Back")) {
if(currentMenu.equals("item1") || currentMenu.equals("item2") ||
currentMenu.equals("item3") || currentMenu.equals("item4")) {
// go back to menu
mainMenu();
}
} else {
List down = (List)display.getCurrent();
switch(down.getSelectedIndex()) {
case 0: testItem1();break;
case 1: testItem2();break;
case 2: testItem3();break;
case 3: testItem4();break;
}
}
}
}
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