AccessTrackingCellRenderer.java

package elw.dp.ui;

import javax.swing.*;
import javax.swing.table.TableCellRenderer;
import java.awt.*;

public class AccessTrackingCellRenderer implements TableCellRenderer {
    private final TableCellRenderer wrapped;
    private final RendererFactory factory;

    private static final Color W_COLOR = new Color(0xFF, 0xDD, 0xDD);
    private static final Color R_COLOR = new Color(0xEE, 0xDD, 0xFF);
    private static final Color N_COLOR = Color.white;

    public AccessTrackingCellRenderer(TableCellRenderer wrapped, RendererFactory factory) {
        this.wrapped = wrapped;
        this.factory = factory;
    }

    public Component getTableCellRendererComponent(JTable table, Object obj,
                                                   boolean isSelected, boolean hasFocus,
                                                   int row, int column) {
        Component cell = wrapped.getTableCellRendererComponent(table, obj, isSelected, hasFocus, row, column);

        final int accCol = factory.lookupAccessColumn(table);
        if (accCol < 0 || isSelected) {
            return cell;
        }

        final String acc = (String) table.getModel().getValueAt(row, accCol);
        if (acc.indexOf("w") >= 0) {
            cell.setBackground(darker(W_COLOR, row));
        } else if (acc.indexOf("r") >= 0) {
            cell.setBackground(darker(R_COLOR, row));
        } else {
            cell.setBackground(darker(N_COLOR, row));
        }

        return cell;
    }

    private Color darker(Color what, int row) {
        if (row % 2 == 0) {
            return what;
        }
        return new Color(
                Math.max((int) (what.getRed() * 0.95), 0),
                Math.max((int) (what.getGreen() * 0.95), 0),
                Math.max((int) (what.getBlue() * 0.95), 0)
        );
    }
}