How can I create a JTable with a row header?
This question seems simple and I could find a lot of tips with Google searches. Nevertheless, everything I have found were tips of how make a column which mimics the real header. Although this is good, it comes with the problem of that the look and feel can not be applied very well.
try this. The code was taken from here and there, but it works reasonably well.
It is a JTable with a redimensionable rowHeader (drag mouse between header rows to resize, as usual with columns)
It ask for an image path to show the repaint while resizing (works well)
$ java JTableRowHeader /path/to/image.gif
This is the code
import javax.swing.; import javax.swing.event.MouseInputAdapter; import javax.swing.table.DefaultTableCellRenderer; import javax.swing.table.JTableHeader; import javax.swing.table.TableColumn; import java.awt.; import java.awt.event.MouseEvent; import java.io.File; import java.util.Vector;/** * JTable redimensionable * User: alberto * Date: 23/01/13 * Time: 1:04 */ public class JTableRowHeader {
private static final String COL_IMAGE = "Image"; private static final int MIN_ROW_HEIGHT = 12; public static void main(String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE); String filename = args[0]; if (new File(filename).exists()) { System.out.println("Provide the path of an image"); } final JTable table = new JTable(new Object[][]{ {filename, filename, 5.5} , {filename, null, 7} , {"nothing", null, 12}} , new Object[]{"File", COL_IMAGE, "Number"}); JScrollPane scrollPane = new JScrollPane(table); JPanel panel = new JPanel(new BorderLayout()); panel.add(scrollPane, BorderLayout.CENTER); TableColumn column = table.getColumn(COL_IMAGE); column.setCellRenderer(new DefaultTableCellRenderer() { @Override public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) { if (value != null) { ImageIcon image = new ImageIcon(value.toString()); setIcon(image); } else { setIcon(null); } setHorizontalAlignment(JLabel.CENTER); return this; } }); table.setRowHeight(0, 200); scrollPane.setRowHeaderView(buildRowHeader(table)); frame.getContentPane().add(panel); frame.setPreferredSize(new Dimension(400, 400)); frame.pack(); frame.setVisible(true); } private static JList buildRowHeader(final JTable table) { final Vector<String> headers = new Vector<String>(); for (int i = 0; i < table.getRowCount(); i++) { headers.add(String.valueOf((char) (i + 65)).toUpperCase()); } ListModel lm = new AbstractListModel() { public int getSize() { return headers.size(); } public Object getElementAt(int index) { return headers.get(index); } }; final JList rowHeader = new JList(lm); rowHeader.setOpaque(false); rowHeader.setFixedCellWidth(50); MouseInputAdapter mouseAdapter = new MouseInputAdapter() { Cursor oldCursor; Cursor RESIZE_CURSOR = Cursor.getPredefinedCursor(Cursor.S_RESIZE_CURSOR); int index = -1; int oldY = -1; @Override public void mousePressed(MouseEvent e) { super.mousePressed(e); } @Override public void mouseMoved(MouseEvent e) { super.mouseMoved(e); int previ = getLocationToIndex(new Point(e.getX(), e.getY() - 3)); int nexti = getLocationToIndex(new Point(e.getX(), e.getY() + 3)); if (previ != -1 && previ != nexti) { if (!isResizeCursor()) { oldCursor = rowHeader.getCursor(); rowHeader.setCursor(RESIZE_CURSOR); index = previ; } } else if (isResizeCursor()) { rowHeader.setCursor(oldCursor); } } private int getLocationToIndex(Point point) { int i = rowHeader.locationToIndex(point); if (!rowHeader.getCellBounds(i, i).contains(point)) { i = -1; } return i; } @Override public void mouseReleased(MouseEvent e) { super.mouseReleased(e); if (isResizeCursor()) { rowHeader.setCursor(oldCursor); index = -1; oldY = -1; } } @Override public void mouseDragged(MouseEvent e) { super.mouseDragged(e); if (isResizeCursor() && index != -1) { int y = e.getY(); if (oldY != -1) { int inc = y - oldY; int oldRowHeight = table.getRowHeight(index); if (oldRowHeight > 12 || inc > 0) { int rowHeight = Math.max(MIN_ROW_HEIGHT, oldRowHeight + inc); table.setRowHeight(index, rowHeight); if (rowHeader.getModel().getSize() > index + 1) { int rowHeight1 = table.getRowHeight(index + 1) - inc; rowHeight1 = Math.max(12, rowHeight1); table.setRowHeight(index + 1, rowHeight1); } } } oldY = y; } } private boolean isResizeCursor() { return rowHeader.getCursor() == RESIZE_CURSOR; } }; rowHeader.addMouseListener(mouseAdapter); rowHeader.addMouseMotionListener(mouseAdapter); rowHeader.addMouseWheelListener(mouseAdapter); rowHeader.setCellRenderer(new RowHeaderRenderer(table)); rowHeader.setBackground(table.getBackground()); rowHeader.setForeground(table.getForeground()); return rowHeader; } static class RowHeaderRenderer extends JLabel implements ListCellRenderer { private JTable table; RowHeaderRenderer(JTable table) { this.table = table; JTableHeader header = this.table.getTableHeader(); setOpaque(true); setBorder(UIManager.getBorder("TableHeader.cellBorder")); setHorizontalAlignment(CENTER); setForeground(header.getForeground()); setBackground(header.getBackground()); setFont(header.getFont()); setDoubleBuffered(true); } public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) { setText((value == null) ? "" : value.toString()); setPreferredSize(null); setPreferredSize(new Dimension((int) getPreferredSize().getWidth(), table.getRowHeight(index))); //trick to force repaint on JList (set updateLayoutStateNeeded = true) on BasicListUI list.firePropertyChange("cellRenderer", 0, 1); return this; } }
}
comment lines about image path if you don't care about that.
Here is the result:
to resolve my problem I simply return as my renderer to the row header a header already with the title I want. Let me explain, I create a table, with the header, get the header and return it as my renderer.
Thanks! Leandro