Question

I have one JTable with vertical scroll bar on it,when i added new row the scroll bar will move to the new row. The problem is scrollbar is visible in the frame but i can’t scroll it.

this is way i created jtable

           table = new javax.swing.JTable(){
        public boolean isCellEditable(int rowIndex, int colIndex) {
            return false;   //Disallow the editing of any cell
        }
    };

    model = (DefaultTableModel) table.getModel();

    table.setRowHeight(20);

    selectionModel = table.getSelectionModel();
    selectionModel.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);

    // Create a couple of columns
    model.addColumn("ServerIP");
    model.addColumn("Port");
    model.addColumn("Number of Request");
    JTableHeader header = table.getTableHeader();
    Color c = new Color(163, 250, 250);
    header.setBackground(c);
        pane = new JScrollPane(table);
       pane.setViewportView(table);
        pane.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS); 

        table.setFocusable(false);


     //when added new row here i call scrollbar


  scrollToNewRow(table, rowCount, 1);
  rowCount++;




private static void scrollToNewRow(JTable table, int row, int col) {
    if (!(table.getParent() instanceof JViewport)) {
        return;
    }
    JViewport viewport = (JViewport)table.getParent();

    // This rectangle is relative to the table where the
    // northwest corner of cell (0,0) is always (0,0).
    Rectangle rect = table.getCellRect(0, 0, true);

    // The location of the viewport relative to the table
    Point pt = viewport.getViewPosition();

    // Translate the cell location so that it is relative
    // to the view, assuming the northwest corner of the
    // view is (0,0)
    rect.setLocation(rect.x-pt.x, rect.y-pt.y);

    // Scroll the area into view
    viewport.scrollRectToVisible(rect);
}

private static JScrollPane getScrollPane(Component c) {
    while ((c = c.getParent()) != null)
        if (c instanceof JScrollPane)
            return (JScrollPane) c;
    return null;
}

Answer 1

You’re always calling getCellRect for the cell at (0, 0). Try replacing:

Rectangle rect = table.getCellRect(0, 0, true);

with :

Rectangle rect = table.getCellRect(row, col, true);