Alerts in J2Me

				
//**************************************
// Name: Alerts in J2Me
// Description:Just an example of how the new alert feature in MIDP 2 works
// By: Bmaq007
//
// Side Effects:Nothing
//
//This code is copyrighted and has// limited warranties.Please see http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=4349&lngWId=2//for details.//**************************************

import java.io.*;
import java.util.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
// A simple MIDlet for testing various alerts.
public class AlertTest extends MIDlet
 implements CommandListener {
// An abstract class for our alert tests.
public abstract class AlertRunner {
protected static final int ONE_SECOND = 1000;
protected static final int FIVE_SECONDS = 5000;
public AlertRunner( String title ){
_title = title;
}
public abstract Alert doAlert();
public String getTitle(){ return _title; }
public String toString(){ return getTitle(); }
private String _title;
}
// An alert test for a simple timed alert.
public class TimedAlert extends AlertRunner {
public TimedAlert( String title ){
super( title );
}
public Alert doAlert(){
Alert a = new Alert( getTitle() );
a.setString( "Times out after 5 seconds..." );
a.setTimeout( FIVE_SECONDS );
showAlert( a );
return a;
}
}
// An alert test for a simple modal alert.
public class ModalAlert extends AlertRunner {
public ModalAlert( String title ){
super( title );
}
public Alert doAlert(){
Alert a = new Alert( getTitle() );
a.setString( "Waits to be dismissed" );
a.setTimeout( Alert.FOREVER );
showAlert( a );
return a;
}
}
// An alert test that displays an alert with
// a gauge whose value is increased every second.
// The alert can be dismissed only after the gauge
// reaches its maximum value.
public class ProgressAlert extends AlertRunner
 implements CommandListener, Runnable {
private static final int MAX = 10;
public ProgressAlert( String title ){
super( title );
}
public Alert doAlert(){
_gauge = new Gauge( null, false, MAX, 0 );
_gauge.setValue( 0 );
_done = false;
_alert = new Alert( getTitle() );
_alert.setString( "Counts to " + MAX +
" and then lets you dismiss it" );
_alert.setCommandListener( this );
_alert.setIndicator( _gauge );
// Set a _very_ long timeout
_alert.setTimeout( ONE_SECOND * 3600 );
showAlert( _alert );
new Thread( this ).start();
return _alert;
}
public void commandAction( Command c,
Displayable d ){
if( _done || _gauge.getValue() >= MAX ){
showList();
}
}
private void done(){
_alert.addCommand(
 new Command( "Done", Command.OK, 1 ) );
_done = true;
}
// A thread that bumps the value of the counter
// every second.
public void run(){
int val = _gauge.getValue();
Thread thread = Thread.currentThread();
try {
while( val < MAX ){
thread.sleep( ONE_SECOND );
_gauge.setValue( ++val );
}
}
catch( InterruptedException e ){
}
done();
}
private Alert_alert;
private int _counter;
private boolean _done;
private Gauge_gauge;
}
// An alert test that displays a continuously
// running gauge before automatically timing out.
public class BusyAlert extends AlertRunner {
public BusyAlert( String title ){
super( title );
}
public Alert doAlert(){
_gauge = new Gauge( null, false,
Gauge.INDEFINITE,
Gauge.CONTINUOUS_RUNNING );
_alert = new Alert( getTitle() );
_alert.setString( "Runs for 5 seconds and " +
"times out automatically" );
_alert.setIndicator( _gauge );
_alert.setTimeout( FIVE_SECONDS );
showAlert( _alert );
return _alert;
}
private Alert_alert;
private Gauge_gauge;
}
// Standard MIDlet code. Displays a list of
// available alert tests and runs the test once
// it's been chosen.
private Display display;
public static final Command exitCommand =
 new Command( "Exit",
 Command.EXIT, 1 ); 
public AlertTest(){
}
public void commandAction( Command c,
Displayable d ){
if( c == exitCommand ){
exitMIDlet();
} else if( c == List.SELECT_COMMAND ){
int index = _alertList.getSelectedIndex();
_alertRunners[ index ].doAlert();
}
}
protected void destroyApp( boolean unconditional )
throws MIDletStateChangeException {
exitMIDlet();
}
public void exitMIDlet(){
notifyDestroyed();
}
public Display getDisplay(){ return display; }
protected void initMIDlet(){
// The list of alert tests....
_alertRunners = new AlertRunner[] {
new TimedAlert( "Timed alert" ),
new ModalAlert( "Modal alert" ),
new ProgressAlert( "Progress alert" ),
new BusyAlert( "Busy alert" )
};
_alertList = new List( "Alert Testing",
List.IMPLICIT );
_alertList.setCommandListener( this );
for( int i = 0; i < _alertRunners.length; ++i ){
_alertList.append(
 _alertRunners[i].toString(), null );
}
showList();
}
protected void pauseApp(){
}
private void showAlert( Alert a ){
getDisplay().setCurrent( a, _alertList );
}
private void showList(){
getDisplay().setCurrent( _alertList );
}
protected void startApp()
throws MIDletStateChangeException {
if( display == null ){ 
display = Display.getDisplay( this );
initMIDlet();
}
}
private List _alertList;
private AlertRunner[] _alertRunners;
}