LayoutManager代わりに、セルの優先サイズを尊重 するを使用することを選択できます。GridLayout各セルに同量の使用可能なスペースを提供しますが、これは希望どおりではないようです。
たとえば、GridBagLayout
public class TestChessBoard {
public static void main(String[] args) {
new TestChessBoard();
}
public TestChessBoard() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new ChessBoardPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ChessBoardPane extends JPanel {
public ChessBoardPane() {
int index = 0;
setLayout(new GridBagLayout());
GridBagConstraints gbc = new GridBagConstraints();
for (int row = 0; row < 8; row++) {
for (int col = 0; col < 8; col++) {
Color color = index % 2 == 0 ? Color.BLACK : Color.WHITE;
gbc.gridx = col;
gbc.gridy = row;
add(new Cell(color), gbc);
index++;
}
index++;
}
}
}
public class Cell extends JButton {
public Cell(Color background) {
setContentAreaFilled(false);
setBorderPainted(false);
setBackground(background);
setOpaque(true);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(25, 25);
}
}
}
比例例で更新
ここで、比例レイアウトを実行したい場合（使用可能なスペースに関係なく、グリッドの各セルが他のセルに比例したままになるように）、物事は...楽しくなり始めます...
public class TestChessBoard {
public static void main(String[] args) {
new TestChessBoard();
}
public TestChessBoard() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestChessBoard.ChessBoardPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class ChessBoardPane extends JPanel {
public ChessBoardPane() {
int index = 0;
setLayout(new ChessBoardLayoutManager());
for (int row = 0; row < 8; row++) {
for (int col = 0; col < 8; col++) {
Color color = index % 2 == 0 ? Color.BLACK : Color.WHITE;
add(new TestChessBoard.Cell(color), new Point(col, row));
index++;
}
index++;
}
}
}
public class Cell extends JButton {
public Cell(Color background) {
setContentAreaFilled(false);
setBorderPainted(false);
setBackground(background);
setOpaque(true);
}
@Override
public Dimension getPreferredSize() {
return new Dimension(25, 25);
}
}
public class ChessBoardLayoutManager implements LayoutManager2 {
private Map<Point, Component> mapComps;
public ChessBoardLayoutManager() {
mapComps = new HashMap<>(25);
}
@Override
public void addLayoutComponent(Component comp, Object constraints) {
if (constraints instanceof Point) {
mapComps.put((Point) constraints, comp);
} else {
throw new IllegalArgumentException("ChessBoard constraints must be a Point");
}
}
@Override
public Dimension maximumLayoutSize(Container target) {
return preferredLayoutSize(target);
}
@Override
public float getLayoutAlignmentX(Container target) {
return 0.5f;
}
@Override
public float getLayoutAlignmentY(Container target) {
return 0.5f;
}
@Override
public void invalidateLayout(Container target) {
}
@Override
public void addLayoutComponent(String name, Component comp) {
}
@Override
public void removeLayoutComponent(Component comp) {
Point[] keys = mapComps.keySet().toArray(new Point[mapComps.size()]);
for (Point p : keys) {
if (mapComps.get(p).equals(comp)) {
mapComps.remove(p);
break;
}
}
}
@Override
public Dimension preferredLayoutSize(Container parent) {
return new CellGrid(mapComps).getPreferredSize();
}
@Override
public Dimension minimumLayoutSize(Container parent) {
return preferredLayoutSize(parent);
}
@Override
public void layoutContainer(Container parent) {
int width = parent.getWidth();
int height = parent.getHeight();
int gridSize = Math.min(width, height);
CellGrid grid = new CellGrid(mapComps);
int rowCount = grid.getRowCount();
int columnCount = grid.getColumnCount();
int cellSize = gridSize / Math.max(rowCount, columnCount);
int xOffset = (width - (cellSize * columnCount)) / 2;
int yOffset = (height - (cellSize * rowCount)) / 2;
Map<Integer, List<CellGrid.Cell>> cellRows = grid.getCellRows();
for (Integer row : cellRows.keySet()) {
List<CellGrid.Cell> rows = cellRows.get(row);
for (CellGrid.Cell cell : rows) {
Point p = cell.getPoint();
Component comp = cell.getComponent();
int x = xOffset + (p.x * cellSize);
int y = yOffset + (p.y * cellSize);
comp.setLocation(x, y);
comp.setSize(cellSize, cellSize);
}
}
}
public class CellGrid {
private Dimension prefSize;
private int cellWidth;
private int cellHeight;
private Map<Integer, List<Cell>> mapRows;
private Map<Integer, List<Cell>> mapCols;
public CellGrid(Map<Point, Component> mapComps) {
mapRows = new HashMap<>(25);
mapCols = new HashMap<>(25);
for (Point p : mapComps.keySet()) {
int row = p.y;
int col = p.x;
List<Cell> rows = mapRows.get(row);
List<Cell> cols = mapCols.get(col);
if (rows == null) {
rows = new ArrayList<>(25);
mapRows.put(row, rows);
}
if (cols == null) {
cols = new ArrayList<>(25);
mapCols.put(col, cols);
}
Cell cell = new Cell(p, mapComps.get(p));
rows.add(cell);
cols.add(cell);
}
int rowCount = mapRows.size();
int colCount = mapCols.size();
cellWidth = 0;
cellHeight = 0;
for (List<Cell> comps : mapRows.values()) {
for (Cell cell : comps) {
Component comp = cell.getComponent();
cellWidth = Math.max(cellWidth, comp.getPreferredSize().width);
cellHeight = Math.max(cellHeight, comp.getPreferredSize().height);
}
}
int cellSize = Math.max(cellHeight, cellWidth);
prefSize = new Dimension(cellSize * colCount, cellSize * rowCount);
System.out.println(prefSize);
}
public int getRowCount() {
return getCellRows().size();
}
public int getColumnCount() {
return getCellColumns().size();
}
public Map<Integer, List<Cell>> getCellColumns() {
return mapCols;
}
public Map<Integer, List<Cell>> getCellRows() {
return mapRows;
}
public Dimension getPreferredSize() {
return prefSize;
}
public int getCellHeight() {
return cellHeight;
}
public int getCellWidth() {
return cellWidth;
}
public class Cell {
private Point point;
private Component component;
public Cell(Point p, Component comp) {
this.point = p;
this.component = comp;
}
public Point getPoint() {
return point;
}
public Component getComponent() {
return component;
}
}
}
}
}