Game

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


public class Game extends JFrame implements WindowListener
{
  private static int DEFAULT_FPS = 80;

  private gamePanel wp;
  private JTextField jtfBox;   // displays no.of boxes used
  private JTextField jtfTime;  // displays time spent in game

  private int pWidth, pHeight;   // diemensions of the panel


  public Game(long period)
  { super("The Worm Chase");

    makeGUI();

    pack();   // first one (the GUI doesn't include the JPanel yet)
    setResizable(false);   // sizes may change when non-resizable
    calcSizes();
    setResizable(true);

    Container c = getContentPane();
    wp = new gamePanel(this, period, pWidth, pHeight);
    c.add(wp, "Center");
    pack();  // second, after JPanel added

    addWindowListener( this );

    addComponentListener( new ComponentAdapter() {
      public void componentMoved(ComponentEvent e)
      /* Called by the Component listener when the JFrame is
         moved. Put it back in its original position. */
      {  setLocation(0,0);  }
    });

    setResizable(false);
    setVisible(true);
  }  // end of WormChase() constructor


  private void makeGUI()
  // Create the GUI, minus the JPanel drawing area
  {
    Container c = getContentPane();    // default BorderLayout used

    JPanel ctrls = new JPanel();   // a row of textfields
    ctrls.setLayout( new BoxLayout(ctrls, BoxLayout.X_AXIS));

    jtfBox = new JTextField("Boxes used: 0");
    jtfBox.setEditable(false);
    ctrls.add(jtfBox);

    jtfTime = new JTextField("Time Spent: 0 secs");
    jtfTime.setEditable(false);
    ctrls.add(jtfTime);

    c.add(ctrls, "South");
  }  // end of makeGUI()


  public void setBoxNumber(int no)
  {  jtfBox.setText("Boxes used: " + no);  }

  public void setTimeSpent(int t)
  {  jtfTime.setText("Time Spent: " + t + " secs");  }


  private void calcSizes()
  /* Calculate the size of the drawing panel to fill the screen, but
     leaving room for the JFrame's title bar and insets, the OS's insets
     (e.g. taskbar) and the textfields under the JPanel.
  */
  {
    GraphicsConfiguration gc = getGraphicsConfiguration();
    Rectangle screenRect = gc.getBounds();
    // System.out.println("Screen size: " + screenRect);

    Toolkit tk = Toolkit.getDefaultToolkit();
    Insets desktopInsets = tk.getScreenInsets(gc);
    // System.out.println("OS Insets: " + desktopInsets);

    Insets frameInsets = getInsets();     // only works after a pack() call
    // System.out.println("JFrame Insets: " + frameInsets);

    Dimension tfDim = jtfBox.getPreferredSize();   // size of text field
    // System.out.println("Box TF Size: " + tfDim );
    // System.out.println("Time TF Size: " + jtfTime.getPreferredSize() );


    pWidth = screenRect.width - (desktopInsets.left + desktopInsets.right)
                              - (frameInsets.left + frameInsets.right);

    pHeight = screenRect.height - (desktopInsets.top + desktopInsets.bottom)
                                - (frameInsets.top + frameInsets.bottom)
                                - tfDim.height;

    // System.out.println("pWidth: " + pWidth + "; pHeight: " + pHeight);
  }  // end of calcSizes()


  // ----------------- window listener methods -------------

  public void windowActivated(WindowEvent e)
  { wp.resumeGame();  }

  public void windowDeactivated(WindowEvent e)
  {  wp.pauseGame();  }


  public void windowDeiconified(WindowEvent e)
  {  wp.resumeGame();  }

  public void windowIconified(WindowEvent e)
  {  wp.pauseGame(); }

  public void windowClosing(WindowEvent e)
  {  wp.stopGame();  }

  public void windowClosed(WindowEvent e) {}
  public void windowOpened(WindowEvent e) {}


  // ----------------------------------------------------

  public static void main(String args[])
  {
    int fps = DEFAULT_FPS;
    if (args.length != 0)
      fps = Integer.parseInt(args[0]);

    long period = (long) 1000.0/fps;
    System.out.println("fps: " + fps + "; period: " + period + " ms");

    new Game(period*1000000L);    // ms --> nanosecs
  }

} // end of WormChase class