JTable - Getting a cell into Edit mode on pressing Tab

Question

This is possibly has a trivial solution, but I am at the end of my tether so I hope somebody can help out.

I use a JTable which has a custom renderer and a custom ed

Answer 1

Here's a code snippet that I put together for a project that I was working on. The code has been tested and verified for a table that has non-editable cells in the first and last column. The class restricts tabbing to only the editable cells of the table. It also supports shift-tabbing to tab in reverse.

public class JTableCellTabbing {
/**
 * 
 * Creates a new {@code JTableCellTabbing} object.
 *
 *
 */
private JTableCellTabbing() {        
}

/**
 * 
 * Set Action Map for tabbing and shift-tabbing for the JTable
 *
 *
 * @param theTable - Jtable with NRows and MCols of cells
 * @param startRow - valid start row for tabbing [ 0 - (numRows-1) ]
 * @param numRows - Number of rows for tabbing
 * @param startCol - valid start col for tabbing [ 0 - (numCols-1) ]
 * @param numCols -  Number of columns for tabbing
 */
@SuppressWarnings("serial")
static public void setTabMapping(final JTable theTable, final int startRow, final int numRows, final int startCol, final int numCols) {
    if (theTable == null) {
        throw new IllegalArgumentException("theTable is null");
    }

    // Calculate last row and column for tabbing
    final int endRow = startRow + (numRows - 1);
    final int endCol = startCol + (numCols - 1);

    // Check for valid range
    if ((startRow > endRow) || (startCol > endCol)) {
        throw new IllegalArgumentException("Table Size incorrect");            
    }

    // Get Input and Action Map to set tabbing order on the JTable
    InputMap im = theTable.getInputMap(JTable.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);
    ActionMap am = theTable.getActionMap();

    // Get Tab Keystroke
    KeyStroke tabKey = KeyStroke.getKeyStroke(KeyEvent.VK_TAB, 0);                    
    am.put(im.get(tabKey), new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent e) {
            int row = theTable.getSelectedRow();
            int col = theTable.getSelectedColumn();

            col++;

            // Move to next row and left column
            if (col > endCol) {
                col = startCol;
                row++;
            }

            // Move to top row
            if (row > endRow ) {
                row = startRow;
            }

            // Move cell selection
            theTable.changeSelection(row, col, false, false);
        }            
    });

    // Get Shift tab Keystroke
    KeyStroke shiftTab = 
        KeyStroke.getKeyStroke(KeyEvent.VK_TAB, java.awt.event.InputEvent.SHIFT_DOWN_MASK);                    
    am.put(im.get(shiftTab), new AbstractAction() {

        @Override
        public void actionPerformed(ActionEvent e) {
            int row = theTable.getSelectedRow();
            int col = theTable.getSelectedColumn();

            col--;

            // Move to top right cell
            if (col < startCol) {
                col = endCol;
                row--;
            }

            // Move to bottom row
            if (row < startRow ) {
                row = endRow;
            }

            // Move cell selection
            theTable.changeSelection(row, col, false, false);
        }            
    });                    
}

}

And here's how the class is used for your table:

JTable myTable = new JTable();
// Set up table attributes....
JTableCellTabbing.setTabMapping(myTable, 0, NUM_ROWS, 1, (NUM_COLS-1));