Java Swing How to - Add icon to Table Column Header

• Back to JTable  ↑

Question

We would like to know how to add icon to Table Column Header.

Answer

/*  w  w w  .ja va 2 s .com*/

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Polygon;

import javax.swing.Icon;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.UIManager;
import javax.swing.border.Border;
import javax.swing.table.TableCellRenderer;
import javax.swing.table.TableColumn;
import javax.swing.table.TableColumnModel;

public class Main {
    public static void main(String args[]) {
        Object rows[][] = { { "one", "ichi - \u4E00" },
                { "two", "ni - \u4E8C" }, { "three", "san - \u4E09" },
                { "four", "shi - \u56DB" }, { "five", "go - \u4E94" },
                { "six", "roku - \u516D" }, { "seven", "shichi - \u4E03" },
                { "eight", "hachi - \u516B" }, { "nine", "kyu - \u4E5D" },
                { "ten", "ju - \u5341" } };
        JFrame frame = new JFrame("Label Header");
        String headers[] = { "English", "Japanese" };
        JTable table = new JTable(rows, headers);
        JScrollPane scrollPane = new JScrollPane(table);

        Icon redIcon = new DiamondIcon(Color.red);
        Icon blueIcon = new DiamondIcon(Color.blue);

        Border headerBorder = UIManager.getBorder("TableHeader.cellBorder");

        JLabel blueLabel = new JLabel(headers[0], blueIcon, JLabel.CENTER);
        blueLabel.setBorder(headerBorder);
        JLabel redLabel = new JLabel(headers[1], redIcon, JLabel.CENTER);
        redLabel.setBorder(headerBorder);

        TableCellRenderer renderer = new JComponentTableCellRenderer();

        TableColumnModel columnModel = table.getColumnModel();

        TableColumn column0 = columnModel.getColumn(0);
        TableColumn column1 = columnModel.getColumn(1);

        column0.setHeaderRenderer(renderer);
        column0.setHeaderValue(blueLabel);

        column1.setHeaderRenderer(renderer);
        column1.setHeaderValue(redLabel);

        frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
        frame.setSize(300, 150);
        frame.setVisible(true);
    }
}

class DiamondIcon implements Icon {
    private Color color;

    private boolean selected;

    private int width;

    private int height;

    private Polygon poly;

    private static final int DEFAULT_WIDTH = 10;

    private static final int DEFAULT_HEIGHT = 10;

    public DiamondIcon(Color color) {
        this(color, true, DEFAULT_WIDTH, DEFAULT_HEIGHT);
    }

    public DiamondIcon(Color color, boolean selected) {
        this(color, selected, DEFAULT_WIDTH, DEFAULT_HEIGHT);
    }

    public DiamondIcon(Color color, boolean selected, int width, int height) {
        this.color = color;
        this.selected = selected;
        this.width = width;
        this.height = height;
        initPolygon();
    }

    private void initPolygon() {
        poly = new Polygon();
        int halfWidth = width / 2;
        int halfHeight = height / 2;
        poly.addPoint(0, halfHeight);
        poly.addPoint(halfWidth, 0);
        poly.addPoint(width, halfHeight);
        poly.addPoint(halfWidth, height);
    }

    public int getIconHeight() {
        return height;
    }

    public int getIconWidth() {
        return width;
    }

    public void paintIcon(Component c, Graphics g, int x, int y) {
        g.setColor(color);
        g.translate(x, y);
        if (selected) {
            g.fillPolygon(poly);
        } else {
            g.drawPolygon(poly);
        }
        g.translate(-x, -y);
    }
}

class JComponentTableCellRenderer implements TableCellRenderer {
    public Component getTableCellRendererComponent(JTable table, Object value,
            boolean isSelected, boolean hasFocus, int row, int column) {
        return (JComponent) value;
    }
}

• Back to JTable  ↑