View source for Minesweeper in Java

This tutorial gives a brief overview of what to do to get a small, graphical Minesweeper game running on your Overo. If you have not done so, please go through the tutorials [[Eclipse on Gumstix for new users]] and [[HelloWorld in Java]].

This does not explain the game of MineSweeper, rather just lets use utilize the code to see an example of the graphical possibilities using an Overo COM.

*Create a new Project in Eclipse 
:*'''File -> New Project -> Java Project'''
*Create a class '''Main Class'''
:*Copy and paste the following code to that class:
<pre>  
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JOptionPane;

public class MainClass {
  public static void main(String args[]) {
    JFrame f = new JFrame("JColorChooser Sample");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    final JButton button = new JButton("Pick to Change Background");

    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        Color initialBackground = button.getBackground();
        Color background = JColorChooser.showDialog(null,
            "JColorChooser Sample", initialBackground);
        if (background != null) {
          button.setBackground(background);
        }
      }
    };
    button.addActionListener(actionListener);
    f.add(button, BorderLayout.CENTER);
    f.setSize(300, 200);
    f.setVisible(true);
  }

}</pre>
*Create a class '''MineSweeper''' (Capital S!)
:*Copy and paste the following code to that class:
<pre>import java.awt.AWTEvent;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.FlowLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.AWTEventListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

public class MineSweeper extends JPanel implements AWTEventListener, ActionListener {

	  public static enum State {
	    Clicked, Marked, Initial, WrongMarked
	  }

	  public static enum GameState {
	    NotStarted, Playing, Finished
	  }

	  private static final int  MAX_BOMB_COUNT  = 10;
	  private int          ROWS      = 9, COLUMNS = 9, TOTAL = ROWS * COLUMNS;
	  private JPanel        pnlMain      = new JPanel(new GridLayout(ROWS, COLUMNS));
	  private JLabel        lblBombCount  = new JLabel(MAX_BOMB_COUNT + "");
	  private JLabel        lblTimer    = new JLabel("0");
	  private boolean        isColorCheatOn  = false;
	  private JButton        btnReset    = new JButton("Reset");

	  private void startThread() {
	    Thread th = new Thread(new Runnable() {
	      public void run() {
	        while (state == GameState.Playing) {
	          lblTimer.setText((Long.parseLong(lblTimer.getText()) + 1) + "");
	          lblTimer.updateUI();
	          try {
	            Thread.sleep(1000);
	          } catch (InterruptedException e) {
	            e.printStackTrace();
	          }
	        }
	      }
	    });
	    th.start();
	  }

	  private GameState  state  = GameState.NotStarted;

	  public MineSweeper() {
	    setLayout(new BorderLayout());
	    add(pnlMain, BorderLayout.CENTER);
	    createButtons();
	    addControlPanel();
	    Toolkit.getDefaultToolkit().addAWTEventListener(this, AWTEvent.KEY_EVENT_MASK);
	  }

	  private void showAbout() {
	    JOptionPane.showMessageDialog(this, "<html>Author : Justin Cowles Cowperthwaite <br>Version : 1.0</html>", "About", JOptionPane.INFORMATION_MESSAGE);
	  }

	  private void restartGame() {
	    state = GameState.NotStarted;
	    lblTimer.setText("0");
	    pnlMain.removeAll();
	    createButtons();
	    pnlMain.updateUI();
	    lblBombCount.setText("" + MAX_BOMB_COUNT);
	    lblBombCount.updateUI();
	  }

	  private void addControlPanel() {
	    JPanel pnlTimer = new JPanel(new FlowLayout(FlowLayout.RIGHT));

	    pnlTimer.add(lblTimer);

	    JPanel pnl = new JPanel(new FlowLayout(FlowLayout.CENTER));

	    btnReset.setToolTipText("<HTML>Press <B>F2</B> to reset the current game</HTML>");
	    pnl.add(lblBombCount);
	    pnl.add(btnReset);
	    JPanel pnlN = new JPanel(new GridLayout(1, 3));

	    pnlN.add(lblBombCount);
	    pnlN.add(pnl);
	    pnlN.add(pnlTimer);
	    add(pnlN, BorderLayout.NORTH);
	    btnReset.addActionListener(this);
	  }

	  private void createButtons() {
	    List<Point> lstBombsLocation = new ArrayList<Point>();

	    for (int row = 0; row < ROWS; row++) {
	      for (int col = 0; col < COLUMNS; col++) {
	        JButton btn = getButton(lstBombsLocation, TOTAL, new Point(row, col) {
	          @Override
	          public String toString() {
	            return (int) getX() + ", " + (int) getY();
	          }

	          @Override
	          public boolean equals(Object obj) {
	            return ((Point) obj).getX() == getX() && ((Point) obj).getY() == getY();
	          }
	        });
	        pnlMain.add(btn);
	      }
	    }
	    while (lstBombsLocation.size() < MAX_BOMB_COUNT) {
	      updateBomds(lstBombsLocation, pnlMain.getComponents());
	    }
	    for (Component c : pnlMain.getComponents()) {
	      updateBombCount((GameButton) c, pnlMain.getComponents());
	    }
	    // System.out.println("Total Bomb Count: " + lstBombsLocation.size());
	  }

	  private void updateBomds(List<Point> lstBombsLocation, Component[] components) {
	    // int currentPosition = new Double(((location.x) * COLUMNS ) +
	    // location.getY()).intValue();
	    Random r = new Random();
	    for (Component c : components) {
	      Point location = ((GameButton) c).getPosition();
	      int currentPosition = new Double(((location.x) * COLUMNS) + location.getY()).intValue();
	      int bombLocation = r.nextInt(TOTAL);
	      if (bombLocation == currentPosition) {
	        ((GameButton) c).setBomb(true);
	        lstBombsLocation.add(((GameButton) c).getPosition());
	        return;
	      }
	    }
	  }

	  private GameButton getButton(List<Point> lstBombsLocation, int totalLocations, Point location) {
	    GameButton btn = new GameButton(location);
	    btn.setMargin(new Insets(0, 0, 0, 0));
	    btn.setFocusable(false);
	    if (lstBombsLocation.size() < MAX_BOMB_COUNT) {
	      if (isBomb()) {
	        btn.setBomb(true);
	        lstBombsLocation.add(location);
	      }
	    }
	    btn.addMouseListener(new MouseAdapter() {
	      @Override
	      public void mouseClicked(MouseEvent mouseEvent) {
	        if (state != GameState.Playing) {
	          state = GameState.Playing;
	          startThread();
	        }
	        if (((GameButton) mouseEvent.getSource()).isEnabled() == false) {
	          return;
	        }
	        if (mouseEvent.getButton() == MouseEvent.BUTTON1) {
	          if (((GameButton) mouseEvent.getSource()).getState() == State.Marked) {
	            ((GameButton) mouseEvent.getSource()).setState(State.Initial);
	            lblBombCount.setText((Long.parseLong(lblBombCount.getText()) + 1) + "");
	            ((GameButton) mouseEvent.getSource()).updateUI();
	            return;
	          }
	          ((GameButton) mouseEvent.getSource()).setState(State.Clicked);
	          if (((GameButton) mouseEvent.getSource()).isBomb()) {
	            blastBombs();
	            return;
	          } else {
	            if (((GameButton) mouseEvent.getSource()).getBombCount() == 0) {
	              updateSurroundingZeros(((GameButton) mouseEvent.getSource()).getPosition());
	            }
	          }
	          if (!checkGameState()) {
	            ((GameButton) mouseEvent.getSource()).setEnabled(false);
	          }
	        } else if (mouseEvent.getButton() == MouseEvent.BUTTON3) {
	          if (((GameButton) mouseEvent.getSource()).getState() == State.Marked) {
	            ((GameButton) mouseEvent.getSource()).setState(State.Initial);
	            lblBombCount.setText((Long.parseLong(lblBombCount.getText()) + 1) + "");
	          } else {
	            ((GameButton) mouseEvent.getSource()).setState(State.Marked);
	            lblBombCount.setText((Long.parseLong(lblBombCount.getText()) - 1) + "");
	          }
	        }
	        ((GameButton) mouseEvent.getSource()).updateUI();
	      }
	    });
	    return btn;
	  }

	  private boolean checkGameState() {
	    boolean isWin = false;
	    for (Component c : pnlMain.getComponents()) {
	      GameButton b = (GameButton) c;
	      if (b.getState() != State.Clicked) {
	        if (b.isBomb()) {
	          isWin = true;
	        } else {
	          return false;
	        }
	      }
	    }
	    if (isWin) {
	      state = GameState.Finished;
	      for (Component c : pnlMain.getComponents()) {
	        GameButton b = (GameButton) c;
	        if (b.isBomb()) {
	          b.setState(State.Marked);
	        }
	        b.setEnabled(false);

	      }
	      JOptionPane.showMessageDialog(this, "You win the game :D", "Congrats", JOptionPane.INFORMATION_MESSAGE, null);
	    }
	    return isWin;
	  }

	  private void updateSurroundingZeros(Point currentPoint) {
	    Point[] points = getSurroundings(currentPoint);

	    for (Point p : points) {
	      GameButton b = getButtonAt(pnlMain.getComponents(), p);
	      if (b != null && b.getBombCount() == 0 && b.getState() != State.Clicked && b.getState() != State.Marked && b.isBomb() == false) {
	        b.setState(State.Clicked);
	        updateSurroundingZeros(b.getPosition());
	        b.updateUI();
	      }
	      if (b != null && b.getBombCount() > 0 && b.getState() != State.Clicked && b.getState() != State.Marked && b.isBomb() == false) {
	        b.setEnabled(false);
	        b.setState(State.Clicked);
	        b.updateUI();
	      }
	    }
	  }

	  private void blastBombs() {
	    int blastCount = 0;
	    for (Component c : pnlMain.getComponents()) {
	      ((GameButton) c).setEnabled(false);
	      ((GameButton) c).transferFocus();
	      if (((GameButton) c).isBomb() && ((GameButton) c).getState() != State.Marked) {
	        ((GameButton) c).setState(State.Clicked);
	        ((GameButton) c).updateUI();
	        blastCount++;
	      }
	      if (((GameButton) c).isBomb() == false && ((GameButton) c).getState() == State.Marked) {
	        ((GameButton) c).setState(State.WrongMarked);
	      }
	    }
	    lblBombCount.setText("" + blastCount);
	    lblBombCount.updateUI();
	    state = GameState.Finished;
	    JOptionPane.showMessageDialog(this, "You loose the game :(", "Game Over", JOptionPane.ERROR_MESSAGE, null);
	    for (Component c : pnlMain.getComponents()) {
	      GameButton b = (GameButton) c;
	      b.setEnabled(false);
	    }
	  }

	  private boolean isBomb() {
	    Random r = new Random();
	    return r.nextInt(ROWS) == 1;
	  }

	  public static void main(String[] args) {
	    JFrame fr = new JFrame("MineSweeper");
	    fr.setLayout(new BorderLayout());
	    fr.add(new MineSweeper());
	    fr.setResizable(false);
	    fr.setSize(250, 350);
	    fr.setLocationRelativeTo(null);
	    fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
	    fr.setVisible(true);
	  }

	  class GameButton extends JButton {
	    private boolean  isBomb    = false;
	    private Point  position  = null;
	    private int    bombCount  = 0;
	    private State  state    = State.Initial;

	    public void setState(State state) {
	      this.state = state;
	      if (getBombCount() == 0 && !isBomb) {
	        setEnabled(false);
	      }
	    }

	    public State getState() {
	      return state;
	    }

	    public int getBombCount() {
	      return bombCount;
	    }

	    public void setBombCount(int bombCount) {
	      this.bombCount = bombCount;
	    }

	    public GameButton(Point position) {
	      setPosition(position);
	      setText(position.toString());
	    }

	    public Point getPosition() {
	      return position;
	    }

	    public void setPosition(Point position) {
	      this.position = position;
	    }

	    public boolean isBomb() {
	      return isBomb;
	    }

	    public void setBomb(boolean isBomb) {
	      this.isBomb = isBomb;
	    }

	    @Override
	    public String getText() {
	      if (state == State.Initial) {
	        return "";
	      }
	      if (state == State.Marked) {
	        return "\u00B6";
	      }
	      if (state == State.Clicked) {
	        if (isBomb) {
	          return "<html><font size='16'><b>*</b></font></html>";
	        } else {
	          if (getBombCount() > 0)
	            return getBombCount() + "";
	          else
	            return "";
	        }
	      }
	      if (state == State.WrongMarked) {
	        return "X";
	      }
	      return super.getText();
	    }

	    @Override
	    public Color getBackground() {
	      if (isColorCheatOn && isBomb) {
	        return Color.MAGENTA;
	      }
	      if (state == State.Clicked) {
	        if (isBomb) {
	          return Color.RED;
	        }
	        if (getBombCount() > 0) {
	          return Color.GREEN;
	        }
	      }
	      if (isEnabled()) {
	        return Color.YELLOW.brighter();
	      } else {
	        return super.getBackground();
	      }
	    }
	  }

	  private Point[] getSurroundings(Point cPoint) {
	    int cX = (int) cPoint.getX();
	    int cY = (int) cPoint.getY();
	    Point[] points = { new Point(cX - 1, cY - 1), new Point(cX - 1, cY), new Point(cX - 1, cY + 1), new Point(cX, cY - 1), new Point(cX, cY + 1), 
                                         new Point(cX + 1, cY - 1), new Point(cX + 1, cY), new Point(cX + 1, cY + 1) };
	    return points;
	  }

	  private void updateBombCount(GameButton btn, Component[] components) {
	    Point[] points = getSurroundings(btn.getPosition());

	    for (Point p : points) {
	      GameButton b = getButtonAt(components, p);
	      if (b != null && b.isBomb()) {
	        btn.setBombCount(btn.getBombCount() + 1);
	      }
	    }
	    btn.setText(btn.getBombCount() + "");
	  }

	  private GameButton getButtonAt(Component[] components, Point position) {
	    for (Component btn : components) {
	      if ((((GameButton) btn).getPosition().equals(position))) {
	        return (GameButton) btn;
	      }
	    }
	    return null;
	  }

	  public void eventDispatched(AWTEvent event) {
	    if (KeyEvent.class.isInstance(event) && ((KeyEvent) (event)).getID() == KeyEvent.KEY_RELEASED) {
	      if (((KeyEvent) (event)).getKeyCode() == KeyEvent.VK_F1) {
	        showAbout();
	      }
	      if (((KeyEvent) (event)).getKeyCode() == KeyEvent.VK_F2) {
	        restartGame();
	      }
	      if (((KeyEvent) (event)).getKeyCode() == KeyEvent.VK_F3) {
	        isColorCheatOn = !isColorCheatOn;
	        if (state == GameState.Playing) {
	          pnlMain.updateUI();
	        }
	      }

	      if (((KeyEvent) (event)).getKeyCode() == KeyEvent.VK_F12) {
	        for (Component c : pnlMain.getComponents()) {
	          GameButton b = (GameButton) c;
	          if (b.isBomb() == false) {
	            b.setState(State.Clicked);
	          } else {
	            b.setState(State.Marked);
	          }
	          b.setEnabled(false);
	        }
	        checkGameState();
	      }
	    }
	  }

	  public void actionPerformed(ActionEvent actionEvent) {
	    if (actionEvent.getSource() == btnReset) {
	      restartGame();
	    }
	  }
	}</pre>

Go back to [[HelloWorld in Java]] and follow the instructions for Exporting and Running a Java Program on the Over COM. When you are done, you should be able to play a 9x10 colorful game of MineSweeper on the monitor connected to your Overo COM expansion board.