import javax.microedition.io.*;
import java.io.*;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class MainScreen extends List implements CommandListener
{
	private static Displayable instance ;
	synchronized public static Displayable getInstance()
	{
		if(instance == null)
			instance = new MainScreen() ;
		return instance ;
	} 
	private MainScreen()
	{
		super("菜單",Choice.IMPLICIT) ;
		append("瀏覽數據",null) ;
		append("增加數據",null) ;
		addCommand(new Command("離開",Command.EXIT,1)) ;
		setCommandListener(this) ;
	}
	public void commandAction(Command c,Displayable s)
	{
		if(c == List.SELECT_COMMAND)
		{
			String cmd = getString(getSelectedIndex()) ;
			if(cmd.equals("瀏覽數據"))
			{
				String url = Navigator.midlet.getAppProperty("midletuserdataurl") ;
				GetUserDataThread t = new GetUserDataThread(url) ;
				t.start() ;
			}else if(cmd.equals("增加數據"))
			{
				Navigator.flow(cmd) ;
			}
		}else
		{
			String cmd = c.getLabel() ;
			Navigator.flow(cmd) ;
		}
	}
}