import java.awt.Event;
import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.*;

public class SkemaFrame extends JFrame implements ActionListener {
  private static final int N_LEKTIONER_PR_DAG = 8;
  private static final String[] LESSON_TYPES = { "Fri", "SWK", "SWD", "ITO",
      "Studie" };
  private static final String[] DAY_NAMES = { "mandag", "tirsdag", "onsdag",
      "torsdag", "fredag" };
  private JMenuItem printMI;
  private JComboBox[][] lektioner;

  public SkemaFrame(String title) {
    super( title );

    setJMenuBar( createMenuBar() );

    buildSkema();

    setDefaultCloseOperation( EXIT_ON_CLOSE );

    pack();
    setVisible( true );
  }

  private void buildSkema() {
    getContentPane().setLayout(
        new GridLayout( 1 + N_LEKTIONER_PR_DAG, 1 + DAY_NAMES.length ) );

    getContentPane().add( new JLabel() );
    for (int i = 0; i < DAY_NAMES.length; i++) {
      JLabel dayName = new JLabel( DAY_NAMES[i] );
      dayName.setHorizontalAlignment( SwingConstants.CENTER );
      getContentPane().add( dayName );
    }

    lektioner = new JComboBox[DAY_NAMES.length][N_LEKTIONER_PR_DAG];

    for (int lesson = 0; lesson < N_LEKTIONER_PR_DAG; lesson++) {
      JLabel lektionsNummer = new JLabel( (lesson + 1) + ". " );
      lektionsNummer.setHorizontalAlignment( SwingConstants.RIGHT );
      getContentPane().add( lektionsNummer );

      for (int day = 0; day < DAY_NAMES.length; day++) {
        lektioner[day][lesson] = new JComboBox( LESSON_TYPES );
        getContentPane().add( lektioner[day][lesson] );
      }
    }
  }

  private JMenuBar createMenuBar() {
    JMenuBar bar = new JMenuBar();

    JMenu fileMenu = new JMenu( "File" );
    {
      printMI = new JMenuItem( "Print" );
      printMI.setAccelerator( KeyStroke.getKeyStroke( 'P', Event.CTRL_MASK ) );
      printMI.addActionListener( this );
      fileMenu.add( printMI );
    }
    bar.add( fileMenu );

    return bar;
  }

  private static final int COLUMN_WIDTH = 10;

  public void actionPerformed( ActionEvent e ) {
    Object source = e.getSource();

    System.out.print( "          " );
    for (int i = 0; i < DAY_NAMES.length; i++)
      System.out.print( tekstFormat( DAY_NAMES[i], COLUMN_WIDTH, CENTER ) );
    System.out.println();

    if (source == printMI) {
      for (int lesson = 0; lesson < N_LEKTIONER_PR_DAG; lesson++) {
        System.out.print( tekstFormat( (lesson + 1) + ". ", COLUMN_WIDTH, RIGHT ) );
        for (int day = 0; day < DAY_NAMES.length; day++)
          System.out.print(
		    tekstFormat( " " + lektioner[day][lesson].getSelectedItem(), COLUMN_WIDTH, LEFT ) );
        System.out.println();
      }
    }
  }

  // konstanter for positioner
  private static final int LEFT = 0;
  private static final int CENTER = 1;
  private static final int RIGHT = 2;

  private String tekstFormat( Object obj, int width, int position ) {
    String txt = obj.toString();

    switch (position) {
      case LEFT:
        while (txt.length() < width)
          txt = txt + " ";
        break;

      case CENTER:
        while (txt.length() < width)
          // modulus er blot et trick til at få det at skifte hver gang
          if (txt.length() % 2 == 0)
            txt = txt + " ";
          else
            txt = " " + txt;
        break;

      case RIGHT:
        while (txt.length() < width)
          txt = " " + txt;
        break;
    }

    return txt;
  }
}