Help command : Command « J2ME « Java Tutorial

1. Java Tutorial
2. J2ME
3. Command

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.TextBox;
import javax.microedition.midlet.MIDlet;

public class J2MEOnlineHelp extends MIDlet implements CommandListener {
  private Display display;

  private Command back = new Command("Back", Command.BACK, 2);

  private Command exit = new Command("Exit", Command.EXIT, 1);

  private Command help = new Command("Help", Command.HELP, 3);

  private Form form = new Form("Online Help Example");

  private TextBox helpMesg;

  public J2MEOnlineHelp() {
    display = Display.getDisplay(this);
    helpMesg = new TextBox("Online Help","Press Back to return .",81, 0);
    helpMesg.addCommand(back);
    form.addCommand(exit);
    form.addCommand(help);
    form.setCommandListener(this);
    helpMesg.setCommandListener(this);
  }

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

  public void pauseApp() {
  }

  public void destroyApp(boolean unconditional) {
  }

  public void commandAction(Command command, Displayable displayable) {
    if (command == back) {
      display.setCurrent(form);
    } else if (command == exit) {
      destroyApp(false);
      notifyDestroyed();
    } else if (command == help) {
      display.setCurrent(helpMesg);
    }
  }
}

31.17.Command
	31.17.1.	Add Command to MIDlet
	31.17.2.	Start the MIDlet by creating a list of items and associating the exit command with it
	31.17.3.	A MIDlet with simple text and a few commands.
	31.17.4.	Get command label and type
	31.17.5.	Exit Command
	31.17.6.	Help command