Chess

This application is a chess, written in java. It's free to use and share it. Commercial use is restricted.

Note: This is a technical README! If you want to learn the chess rules, have a look at this: https://en.wikipedia.org/wiki/Rules_of_chess

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The Main() class app.java

```Java public static void main(String[] args) {

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

settings = new Settings(playerDatas);

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

}

It just creates an instance of Settings.java. This is the first GUI class where the users have to input their names and chose a maximal game time. No more variables or instanzes are created or saved in this class. Settings.java handles the start of a new game.

<h2>Settings.java</h2>
```Java
// -------------------------------------------------------------
// LAOYUT (GRID IN GRID IN BORDER IN FRAME)
// -------------------------------------------------------------

JFrame firstBorderLayoutFrame = new JFrame();
BorderLayout firstBorderLayout = new BorderLayout();

JPanel secondGridLayoutPanel = new JPanel();
GridLayout secondGridLayout = new GridLayout(2, 1);
Border secondGridLayoutPanelBorder = BorderFactory.createEmptyBorder(130,
		170, 130, 170);

JPanel thirdGridLayoutPanelTop = new JPanel();
JPanel thirdGridLayoutPanelBottom = new JPanel();
GridLayout thirdGridLayoutTop = new GridLayout(1, 3);
GridLayout thirdGridLayoutBottom = new GridLayout(2, 1);

JPanel fourthPanelTopFirst = new JPanel();
JPanel fourthPanelTopSecond = new JPanel();
JPanel fourthPanelTopThird = new JPanel();
JPanel fourthPanelBottomTop = new JPanel();
JPanel fourthPanelBottomBottom = new JPanel();
GridLayout finalGridLayout = new GridLayout(2, 1);
Border fourthPanelTopBorder = BorderFactory.createEmptyBorder(75, 50, 100,
		50);
Border fourthPanelBottomBorder = BorderFactory.createEmptyBorder(10, 100,
		10, 100);

The layout looks quite difficult, but is very easy once you've seen it. There are two JTextFields (not shown here), where the users can input their names. Further there is a JSlider which represents the timer. As you chose 0 as time, you will have an endless game (at least until someone got checked).

ChessBoard.java

```Java // ------------------------------------------------------------- // LAOYUT (GRID IN BORDER IN FRAME) // ------------------------------------------------------------- private static JFrame firstBorderLayoutFrame = new JFrame(); private BorderLayout firstBorderLayout = new BorderLayout();

private JPanel secondGridLayoutPanelNorth = new JPanel(); private GridLayout secondGridLayoutNorth = new GridLayout(1, 3); Border secondGridLayoutNorthBorder = BorderFactory.createEmptyBorder(40, 75, 40, 75);

private JPanel secondGridLayoutPanelWest = new JPanel(); private GridLayout secondGridLayoutWest = new GridLayout(1, 1); Border secondGridLayoutWestBorder = BorderFactory.createEmptyBorder(20, 20, 20, 20);

private JPanel secondGridLayoutPanelSouth = new JPanel(); private GridLayout secondGridLayoutSouth = new GridLayout(3, 1); Border secondGridLayoutSouthBorder = BorderFactory.createEmptyBorder(20, 340, 20, 340);

private JPanel secondGridLayoutPanelEast = new JPanel(); private GridLayout secondGridLayoutEast = new GridLayout(1, 1); Border secondGridLayoutEastBorder = BorderFactory.createEmptyBorder(20, 20, 20, 20);

private JPanel secondGridLayoutPanelCenter = new JPanel(); private GridLayout secondGridLayoutCenter = new GridLayout(8, 8); Border secondGridLayoutCenterBorder = BorderFactory.createEmptyBorder(0, 180, 0, 180);

Here we display the two names of the players in the top right and left corners and the timer right in the middle. In a square there are 8x8 buttons, each with an event handler. By clicking on them, you select a coordinate and move a figure in a two dimensional array. Of course this only happens if the move was validated first. On the bottom of the window we have three  buttons: A button for the castlings, a button to suggest a draw and one to surrender.
<br>The code for the event handler looks like the following:
```Java
@Override
public void mouseClicked(MouseEvent e) {

	// -------------------------------------------------------------
	// EVENT TO HAPPEN IF LEFT CLICK
	// -------------------------------------------------------------

	if (SwingUtilities.isLeftMouseButton(e)) {

		// -------------------------------------------------------------
		// PRINTS SOME INFO FOR THE PROGRAMMER
		// UPDATES PLAYERDATAS
		// REMOVES OLD BORDERS
		// CREATES NEW BORDER
		// -------------------------------------------------------------

		System.out.println(button.getName());

		game.getPlayerDatas().setFromSelectedJButton(
				button.getName());

		game.clearBoard();

		button.setBorder(new LineBorder(Color.RED, 2));

	} else {

		// -------------------------------------------------------------
		// EVENT TO HAPPEN IF RIGHT CLICK
		// -------------------------------------------------------------

		if (SwingUtilities.isRightMouseButton(e)) {

			// -------------------------------------------------------------
			// UPDATES PLAYERDATAS
			// REMOVES OLD BORDERS
			// CREATES NEW BORDER
			// -------------------------------------------------------------

			game.getPlayerDatas().setToSelectedJButton(
					button.getName());
				game.clearBoard();
				button.setBorder(new LineBorder(Color.RED, 2));
			}

		}

}

Figure.move

As soon as fromSelectedJButton:int[] and toSelectedJButton:int[] are set, the move gets validated by calling the move() method. Note: An Exception.NullPointerException could be thrown if PlayerDatas or Figure[][] are set to null! ```Java /** * move() - Actualizes data with current game informations, then checks if * the step is valid * * @param currentX * The current x-coordinate (which the player selected) * @param currentY * The current y-coordinate (which the player selected) * @param toX * The selected aim x-coordinate * @param toY * The selected aim y-coordinate * @param playerDatas * Required the PlayerDatas to check color * @param figures * Require actual figures positions * @throws Exception * Throws null pointer exception for DataBase | Figure[][] == * null * @return Returns true if the move is valid */ public abstract Boolean move(int currentX, int currentY, int toX, int toY, PlayerDatas playerDatas, Figure[][] figures) throws Exception; ```

Package figures.check

This package contains the classes which validate moves. By calling each classes check() method, they return true if the move is valid, or false if not. Basically they check for the right color, the right range, the right direction and the right aim. Also it is checked if nothing is in between the figure and the aim. If the king is checked and you do not change this with your move, the move() method returns false too.
If this method returns false, the move will be undone!

KingCheck.java

```Java // ------------------------------------------------------------- // DETECTS THE KING // -------------------------------------------------------------

for (int y = 0; y < 8; y = y + 1) {

for (int x = 0; x < 8; x = x + 1) {

	if (String.valueOf(getFigure(x, y)).contains(
			"Figures.Figures.King")
			&& getFigure(x, y).getColor() == getColorToCheck()) {

		setxCoordinate(x);
		setyCoordinate(y);

		x = 8;
		y = 8;

	}

}

}

This class is there to check if the king of current player is checked. First of all it has to detect, where the king stands. This happens in a doubled "for" loop. Next it searches in every direction away from the king for an enemies figure. He is not checked if: The end of the game board is reached or a figure of the own color stands in between the other.

<br><br><strong>This is just a short introduction! For more informations have a look into the Java Documentation.</strong>

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All rights preserverd @ bbortt!
Contact me: timon.borter@post.ch

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