Building Dynamic UI Layouts in JavaFX - JavaFX 8: A Definitive Guide to Building Desktop, Mobile, and Embedded Java Clients - page 216

int y = cellY + directionY;
while (x >=0 && x < BOARD_SIZE && y >=0 && y < BOARD_SIZE) {
bind(board[x][y]);
x += directionX;
y += directionY;
}
}
@Override
protected boolean computeValue() {
Owner turnVal = turn.get();
int x = cellX + directionX;
int y = cellY + directionY;
boolean first = true;
while (x >=0 && x < BOARD_SIZE && y >=0 && y < BOARD_SIZE && board[x][y].get() != Owner.NONE) {
if (board[x][y].get() == turnVal) {
return !first;
}
first = false;
x += directionX;
y += directionY;
}
return false;
}
};
}

The last step in highlighting legal moves is to wire the legalMove model function up to the squares. This involves
binding the style property of the ReversiSquare class to the legalMove method (changes in bold).

public ReversiSquare( final int x, final int y ) {
styleProperty().bind(Bindings.when(model.legalMove(x, y))
.then("-fx-background-color: derive(dodgerblue, -60%)")
.otherwise("-fx-background-color: burlywood"));
Light.Distant light = new Light.Distant();

■ the derive function used is a JavaFX-specific Css function that lets you create a new color based on an
existing one. the second parameter is brightness, which can range from -100% (black) to 100% white.

Tip

Also, don't forget to add in the static model variable on which this code depends:

private static ReversiModel model = ReversiModel.getInstance();

And also to update the ReversiSquare construction in the tiles() method to pass in the x and y board coordinates:

ReversiSquare square = new ReversiSquare(i, j);

Now on running the application, it correctly highlights the same four moves for black that were described in the
“Board Layout and Basic Rules” section, as shown in Figure 5-15 .