JTable + AbstractTableModel

[Alex Kravets]

Hi,
I have a table that has one of its 7 columns editable. All the data that comes to the JTable is of type String. Now, what I needed was to make editable column aligned right. I read that in AbstractTableModel I can implement method: public Class getColumnClass(int column){} by changing it to:
public Class getColumnClass(int c){
return (c == 1) ? Number.class : String.class;
}
When I did this, my column did align right, but now I can select it, but cannot edit it as before. Does anybody have any ideas on why this would happen?
thanks,
Alex

[Stevie Kaligis]

Originally posted by Alex Kravets:
I have a table that has one of its 7 columns editable. All the data that comes to the JTable is of type String....I read that in AbstractTableModel I can implement method: public Class getColumnClass(int column){} by changing it to:
public Class getColumnClass(int c){
return (c == 1) ? Number.class : String.class;
}

Hi Alex,
The class of the column is used by the table to know what values are possible to include in the column, if all the data are type String, why you need to make a Number.class as a possible option ?
try change the getColumnClass method into :
public Class getColumnClass(int c){
return getValueAt(0,c).getClass();
}
regard's
stevie

[This message has been edited by Stevie Kaligis (edited November 04, 2001).]

[Alex Kravets]

the thing is that my data comes from the database and is formatted into a string, which is fed into JTable. All the data in the JTable is in String format, so it's left-aligned by default. I need to make it right-aligned. That's why I thought I would make the column display integers this way it's going to align right by default. It works, but I cannot modify the data in the cell of the column.
thanks,
Alex

[Stevie Kaligis]

Ah...That's what I tought,
have you tried using Wraper Class, for example :
use type Integer for that column (let say for column 1), and you hold the data on obArrayData[][],
modify setValueAt method :

public void setValueAt(Object value, int row, int col) {
  if (col != 1) {
    obArrayData[row][col] = value; //original value
  }
  else {
    obArrayData[row][col] = new Integer(value); //see note
  }
}

note :
you must make sure that the data for that column is a String of number ("1", "2", "3", etc...) not ("12F", etc...).
you can create another method (ex : getNumberString, that return String object) to check the string for that column, then you modify the code at setValueAt method to :
obArrayData[row][col] = new Integer(getNumberString(value.toString()));

[eric moon]

Ouch! That's a lot of kludging to get a simple result. All you really need to do is set your own renderer for the column in question. You can even put it in an anonymous inner class. Here's how I did it:

TableColumn tableColumn = getColumnModel().getColumn(0);
        
        tableColumn.setCellRenderer(new TableCellRenderer()  {
                /**
                 *  Returns the component used for drawing the cell.  This method is
                 *  used to configure the renderer appropriately before drawing.
                 *
                 * @paramtablethe <code>JTable</code> that is asking the
                 *renderer to draw; can be <code>null</code>
                 * @paramvaluethe value of the cell to be rendered.  It is
                 *up to the specific renderer to interpret
                 *and draw the value.  For example, if
                 *<code>value</code>
                 *is the string "true", it could be rendered as a
                 *string or it could be rendered as a check
                 *box that is checked.  <code>null</code> is a
                 *valid value
                 * @paramisSelectedtrue if the cell is to be rendered with the
                 *selection highlighted; otherwise false
                 * @paramhasFocusif true, render cell appropriately.  For
                 *example, put a special border on the cell, if
                 *the cell can be edited, render in the color used
                 *to indicate editing
                 * @paramrow        the row index of the cell being drawn.  When
                 *drawing the header, the value of
                 *<code>row</code> is -1
                 * @paramcolumn        the column index of the cell being drawn
                 */
                public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
                    if (column == 0) {
                        JLabel numberLabel = new JLabel(value.toString());
                        numberLabel.setHorizontalAlignment(JLabel.TRAILING);
                        return numberLabel;
                    }
                    return getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
                }
            });

Worked like a charm for me!
e

[This message has been edited by eric moon (edited November 06, 2001).]