JTable: calculate result from 2 cells and put it in another cell
hi,
I have implemented this method in my JTable variant:
publicvoid tableChanged(TableModelEvent e){
int column = e.getColumn();
DefaultTableModel model = (DefaultTableModel)e.getSource();
if (model.getRowCount() > 0 && column > 0)
{
double pos = (Double)model.getValueAt(1, column);
double neg = (Double)model.getValueAt(2, column);
double res = pos - neg;
((Vector)model.getDataVector().elementAt(3)).setElementAt((Double)res, column);
}
else
super.tableChanged(e);
}
it is pretty obvious what it tries to do.
However, the result in the 3rd row is updated only when I click with my mouse on that row (any cell of that row). Why?
Is there a better way to implement what I am trying to do?
[1183 byte] By [
xpantaa] at [2007-11-27 9:21:58]
# 2
> Is there a better way to implement what I am trying to do?
Your solution is close, but you should never update the data vector directly. All changes to the data should be done through the TableModel. The TableModel will then fire the appropriate event to make sure the table repaints itself. So basically use the setValueAt(...) method as suggest above.
# 3
To be honest, I had tried the .setValueAt() method but I got the feeling that setValueAt() triggers tableChanged() and so I got a StackOverFlowError like the following:
Exception in thread "AWT-EventQueue-0" java.lang.StackOverflowError
at java.lang.Double.<init>(Unknown Source)
at java.lang.Double.valueOf(Unknown Source)
at com.client.EfedreiesJTable.tableChanged(EfedreiesJTable.java:55)
at javax.swing.table.AbstractTableModel.fireTableChanged(Unknown Source)
at javax.swing.table.AbstractTableModel.fireTableCellUpdated(Unknown Source)
at javax.swing.table.DefaultTableModel.setValueAt(Unknown Source)
at com.client.EfedreiesJTable.tableChanged(EfedreiesJTable.java:55)
(... and so on...)
That is why I tried to insert directly to the Data Vector...
