class NQueensPanel extends SolutionPanel<NQueens> {

    public static final String LOGO_PATH = "/org/optaplanner/examples/nqueens/swingui/nqueensLogo.png";
    private static final String QUEEN_IMAGE_PATH = "/org/optaplanner/examples/nqueens/swingui/queenImage.png";

    private ImageIcon queenImageIcon;

    public NQueensPanel() {
        setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
        setBackground(Color.BLACK);
        queenImageIcon = new ImageIcon(getClass().getResource(QUEEN_IMAGE_PATH));
    }

    @Override
    public void resetPanel(NQueens nQueens) {<FILL_FUNCTION_BODY>}

    private class QueenAction extends AbstractAction {

        private Queen queen;

        public QueenAction(Queen queen) {
            super(null, queenImageIcon);
            this.queen = queen;
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            JPanel messagePanel = new JPanel(new BorderLayout());
            messagePanel.add(new JLabel("Move to row: "), BorderLayout.WEST);
            List<Row> rowList = getSolution().getRowList();
            // Add 1 to array size to add null, which makes the entity unassigned
            JComboBox rowListField = new JComboBox(
                    rowList.toArray(new Object[rowList.size() + 1]));
            LabeledComboBoxRenderer.applyToComboBox(rowListField);
            rowListField.setSelectedItem(queen.getRow());
            messagePanel.add(rowListField, BorderLayout.CENTER);
            int result = JOptionPane.showConfirmDialog(NQueensPanel.this.getRootPane(), messagePanel,
                    "Queen in column " + queen.getColumn().getIndex(),
                    JOptionPane.OK_CANCEL_OPTION);
            if (result == JOptionPane.OK_OPTION) {
                Row toRow = (Row) rowListField.getSelectedItem();
                doProblemChange((workingSolution, problemChangeDirector) -> problemChangeDirector.changeVariable(queen, "row",
                        q -> q.setRow(toRow)));
                solverAndPersistenceFrame.resetScreen();
            }
        }

    }

}

        removeAll();
        repaint(); // When GridLayout doesn't fill up all the space
        int n = nQueens.getN();
        if (n > 100) {
            JLabel tooBigToShowLabel = new JLabel("The dataset is too big to show.");
            tooBigToShowLabel.setForeground(Color.WHITE);
            add(tooBigToShowLabel);
            return;
        }
        List<Queen> queenList = nQueens.getQueenList();
        setLayout(new GridLayout(n, n));
        for (int row = 0; row < n; row++) {
            for (int column = 0; column < n; column++) {
                Queen queen = queenList.get(column);
                if (queen.getColumn().getIndex() != column) {
                    throw new IllegalStateException("The queenList is not in the expected order.");
                }
                String toolTip = "<html>Row " + row + "<br/>Column " + column + "</html>";
                if (queen.getRow() != null && queen.getRow().getIndex() == row) {
                    JButton button = new JButton(new QueenAction(queen));
                    button.setMinimumSize(new Dimension(20, 20));
                    button.setPreferredSize(new Dimension(20, 20));
                    button.setToolTipText(toolTip);
                    add(button);
                } else {
                    JPanel panel = new JPanel();
                    panel.setBorder(BorderFactory.createCompoundBorder(
                            BorderFactory.createLineBorder(TangoColorFactory.ALUMINIUM_6),
                            BorderFactory.createEmptyBorder(5, 5, 5, 5)));
                    Color background = (((row + column) % 2) == 0) ? Color.WHITE : TangoColorFactory.ALUMINIUM_3;
                    panel.setBackground(background);
                    panel.setToolTipText(toolTip);
                    add(panel);
                }
            }
        }
    
<methods>public non-sealed void <init>() ,public java.awt.Color determinePlanningEntityColor(java.lang.Object, java.lang.Object) ,public java.lang.String determinePlanningEntityTooltip(java.lang.Object) ,public void doProblemChange(ProblemChange<org.optaplanner.examples.nqueens.domain.NQueens>) ,public void doProblemChange(ProblemChange<org.optaplanner.examples.nqueens.domain.NQueens>, boolean) ,public java.awt.Dimension getPreferredScrollableViewportSize() ,public int getScrollableBlockIncrement(java.awt.Rectangle, int, int) ,public boolean getScrollableTracksViewportHeight() ,public boolean getScrollableTracksViewportWidth() ,public int getScrollableUnitIncrement(java.awt.Rectangle, int, int) ,public org.optaplanner.examples.nqueens.domain.NQueens getSolution() ,public SolutionBusiness<org.optaplanner.examples.nqueens.domain.NQueens,?> getSolutionBusiness() ,public SolverAndPersistenceFrame<org.optaplanner.examples.nqueens.domain.NQueens> getSolverAndPersistenceFrame() ,public java.lang.String getUsageExplanationPath() ,public boolean isIndictmentHeatMapEnabled() ,public boolean isUseIndictmentColor() ,public boolean isWrapInScrollPane() ,public abstract void resetPanel(org.optaplanner.examples.nqueens.domain.NQueens) ,public void setSolutionBusiness(SolutionBusiness<org.optaplanner.examples.nqueens.domain.NQueens,?>) ,public void setSolverAndPersistenceFrame(SolverAndPersistenceFrame<org.optaplanner.examples.nqueens.domain.NQueens>) ,public void setUseIndictmentColor(boolean) ,public void updatePanel(org.optaplanner.examples.nqueens.domain.NQueens) <variables>protected static final java.awt.Color[][] INDICTMENT_COLORS,public static final java.awt.Dimension PREFERRED_SCROLLABLE_VIEWPORT_SIZE,protected static final java.lang.String USAGE_EXPLANATION_PATH,protected double[] indictmentMinimumLevelNumbers,protected final transient Logger logger,protected org.optaplanner.swing.impl.TangoColorFactory normalColorFactory,protected SolutionBusiness<org.optaplanner.examples.nqueens.domain.NQueens,?> solutionBusiness,protected SolverAndPersistenceFrame<org.optaplanner.examples.nqueens.domain.NQueens> solverAndPersistenceFrame,protected boolean useIndictmentColor