multialert.java

Alert和Timer编程范例

/* MultiAlert.java
 *
 * This example tests an alert router by using several timers to create alerts at different time intervals.
 *
 */
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.util.*;
import com.j2medeveloper.util.*;

public class MultiAlert extends MIDlet {

    Display      display;
    Command      exitCommand = new Command( "Exit", Command.EXIT,
                                                             1 );
    Timer        timer1 = new Timer();
    Timer        timer2 = new Timer();
    Timer        timer3 = new Timer();
    MainForm     form = new MainForm();
    AlertRouter  router;

    public MultiAlert() {
        display = Display.getDisplay( this );
        router = new AlertRouter( display );

        timer1.schedule( new AlertTrigger( "Alert 1",
                             "This is alert #1" ), 5000, 10000 );
        timer2.schedule( new AlertTrigger( "Alert 2",
                              "This is alert #2" ), 5000, 7000 );
        timer3.schedule( new AlertTrigger( "Alert 3",
                              "This is alert #3" ), 5000, 9000 );
    }

    protected void destroyApp( boolean unconditional ) {
        timer1.cancel();
        timer2.cancel();
        timer3.cancel();
    }

    protected void startApp() {
        display.setCurrent( form );
    }

    protected void pauseApp() {
    }

    public void exit(){
        destroyApp( true );
        notifyDestroyed();
    }

    class AlertTrigger extends TimerTask {

        public AlertTrigger( String title, String message )
        {
            this.title = title;
            this.message = message;
        }

          public void run(){
            Alert alert = new Alert( title, message, null, null );
            alert.setTimeout( Alert.FOREVER );
            router.showAlert( alert );
       }

        private String title;
        private String message;
    }

    class MainForm extends Form implements CommandListener {
        public MainForm(){
            super( "MultiAlert Demo" );
            addCommand( exitCommand );
            setCommandListener( this );
        }

        public void commandAction( Command c, Displayable d ){
            exit();
        }
    }
}