Question

I am using a JInternalFrame in that i have added JTable. Now i want to show background image in JTable. so i have added following code in the JScrollPane's customize code.

jScrollPane1 = new javax.swing.JScrollPane(ViewBalanceReportTable) {{
    setOpaque(false);
    getViewport().setOpaque(false);
}
@Override
protected void paintComponent(Graphics g) {
    final int imageWidth = image.getIconWidth();
    final int imageHeight = image.getIconHeight();
    final Dimension d = getSize();
    final int x = (d.width - imageWidth)/2;
    final int y = (d.height - imageHeight)/2;
    g.drawImage(image.getImage(), x, y, null, null);
    super.paintComponent(g);
}

}

but still it is not showing the background image can any one help me on this

Answer 1

Basically, you need to make sure that EVERYTHING that sits on top of the frame is transparent (opaque == false).

The table is a special case, it doesn’t tend to respect the opaque setting, because that would be easy. Instead, we can trick it by also using a transparent color.

You are AWLAYS better of replacing the content pane if you want to paint to any kind of frame. This will allow you to paint within the content area and not in areas used by things like the frame’s border or menus.

public class TableWithBackground {

    public static void main(String[] args) {
        new TableWithBackground();
    }

    public TableWithBackground() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JDesktopPane desktopPane = new JDesktopPane();
                BackgroundInternalFrame backgroundInternalFrame = new BackgroundInternalFrame();
                desktopPane.add(backgroundInternalFrame);
                try {
                    backgroundInternalFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class BackgroundInternalFrame extends JInternalFrame {

        public BackgroundInternalFrame() {
            super("Hello", true, true, true, true);

            setSize(100, 100);
            setLocation(10, 10);
            setVisible(true);

            setContentPane(new TransparentContentPane());

            JTable table = new JTable();
            table.setModel(new javax.swing.table.DefaultTableModel(
                    new Object[][]{
                        {null, null, null, null},
                        {null, null, null, null},
                        {null, null, null, null},
                        {null, null, null, null}
                    },
                    new String[]{
                        "Title 1", "Title 2", "Title 3", "Title 4"
                    }));

            JScrollPane scrollPane = new JScrollPane(table);
            setLayout(new BorderLayout());
            add(scrollPane);

            scrollPane.setOpaque(false);
            scrollPane.getViewport().setOpaque(false);
            table.setOpaque(false);
            table.setBackground(new Color(255, 255, 255, 0));
        }
    }

    public class TransparentContentPane extends JPanel {

        public TransparentContentPane() {
            setOpaque(false);
        }

        @Override
        protected void paintComponent(Graphics g) {
            Graphics2D g2d = (Graphics2D) g.create();
            g2d.setColor(getBackground());
            g2d.fillRect(0, 0, getWidth(), getHeight());
            g2d.setColor(Color.RED);
            g2d.drawLine(0, 0, getWidth(), getHeight());
            super.paintComponent(g2d); //To change body of generated methods, choose Tools | Templates.
            g2d.dispose();
        }
    }
}

Image Table

Possibly a “simpler” solution would be to render the image directly onto the background the table. This means that the image becomes apart of the table and will scroll with it.

This is a little tricky, as JTable#paintComponent not only fills the background, but also renders the tables content.

public class TableBackground {

    private BufferedImage background;

    public static void main(String[] args) {
        new TableBackground();
    }

    public TableBackground() {
        try {
            background = ImageIO.read(new File("C:/Users/swhitehead/Documents/My Dropbox/issue362.jpg"));
        } catch (IOException ex) {
            ex.printStackTrace();
        }

        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JDesktopPane desktopPane = new JDesktopPane();
                JInternalFrame ittyFrame = new JInternalFrame("Hello", true, true, true, true);
                ittyFrame.setSize(100, 100);
                ittyFrame.setLocation(0, 0);
                ittyFrame.setVisible(true);
                desktopPane.add(ittyFrame);
                try {
                    ittyFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                Object[][] data = new Object[50][4];
                for (int row = 0; row < 50; row++) {
                    for (int col = 0; col < 4; col++) {
                        data[row][col] = col + "." + row;
                    }
                }

                JTable table = new BackgroundImageTable();
                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                table.setModel(new javax.swing.table.DefaultTableModel(
                                data,
                                new String[]{
                                    "Title 1", "Title 2", "Title 3", "Title 4"
                                }));

                table.setForeground(Color.WHITE);
                JScrollPane scrollPane = new JScrollPane(table);
                ittyFrame.setLayout(new BorderLayout());
                ittyFrame.add(scrollPane);

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class BackgroundInternalFrame extends JInternalFrame {

        public BackgroundInternalFrame() {
            super("Hello", true, true, true, true);

            setSize(100, 100);
            setLocation(10, 10);
            setVisible(true);

            setContentPane(new TransparentContentPane());

            JTable table = new JTable();
            table.setModel(new javax.swing.table.DefaultTableModel(
                            new Object[][]{
                                {null, null, null, null},
                                {null, null, null, null},
                                {null, null, null, null},
                                {null, null, null, null}
                            },
                            new String[]{
                                "Title 1", "Title 2", "Title 3", "Title 4"
                            }));

            JScrollPane scrollPane = new JScrollPane(table);
            setLayout(new BorderLayout());
            add(scrollPane);

            scrollPane.setOpaque(false);
            scrollPane.getViewport().setOpaque(false);
            table.setOpaque(false);
            table.setBackground(new Color(255, 255, 255, 0));
        }
    }
}

Sticky Viewport

Your other option is to create a custom viewport. This allows you to render the content behind a verity of other components. This will run into the same issue’s you had before. The table and it’s background must be set to transparent.

It also means, that with some clever work, you either have the image “stick” or “follow” the content, depending on what you need.

public class TableBackground {

    private BufferedImage background;

    public static void main(String[] args) {
        new TableBackground();
    }

    public TableBackground() {
        try {
            background = ImageIO.read(new File("C:/Users/swhitehead/Documents/My Dropbox/issue362.jpg"));
        } catch (IOException ex) {
            ex.printStackTrace();
        }

        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JDesktopPane desktopPane = new JDesktopPane();
                JInternalFrame ittyFrame = new JInternalFrame("Hello", true, true, true, true);
                ittyFrame.setSize(100, 100);
                ittyFrame.setLocation(0, 0);
                ittyFrame.setVisible(true);
                desktopPane.add(ittyFrame);
                try {
                    ittyFrame.setMaximum(true);
                } catch (PropertyVetoException ex) {
                    ex.printStackTrace();
                }

                Object[][] data = new Object[50][4];
                for (int row = 0; row < 50; row++) {
                    for (int col = 0; col < 4; col++) {
                        data[row][col] = col + "." + row;
                    }
                }

                JTable table = new JTable();
                table.setForeground(Color.WHITE);
                table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
                table.setModel(new javax.swing.table.DefaultTableModel(
                                data,
                                new String[]{
                                    "Title 1", "Title 2", "Title 3", "Title 4"
                                }));

                JScrollPane scrollPane = new JScrollPane();
                table.setOpaque(false);
                table.setBackground(new Color(255, 255, 255, 0));
                scrollPane.setViewport(new ImageViewport());
                scrollPane.setViewportView(table);
                ittyFrame.setLayout(new BorderLayout());
                ittyFrame.add(scrollPane);

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(desktopPane);
                frame.setSize(200, 200);
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class ImageViewport extends JViewport {

        public ImageViewport() {
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            if (background != null) {
                Rectangle bounds = getViewRect();
                int x = Math.max(0, (bounds.width - background.getWidth()) / 2);
                int y = Math.max(0, (bounds.height - background.getHeight()) / 2);
                g.drawImage(background, x, y, this);
            }
        }
    }
}

A lot of it will come down to your actual requirements