JTable.getSelectedRow() returning -1 when cell is selected

[lesneskp]

Hello,

I imagine it's my renderer(??), but not sure why -- when I call JTable.getSelectedRow() (or for that matter, getSelectedColumn()), if a full row isn't selected, it will always return -1. But I need the row to be returned correctly even when just a cell is selected. Below is a clip of my cell renderer.

Advice is appreciated! Thanks!


public class CellLabel extends DefaultTableCellRenderer {
public static final Font FIXED_FONT = new Font("courier new", Font.PLAIN, 12);
public static final Font FIXED_FONT_BOLD = new Font("courier new", Font.BOLD, 12);
public static int STANDARD_COURIER_WIDTH = new JLabel().getFontMetrics(FIXED_FONT).charWidth('X');

private boolean mHighlightSelected;

public CellLabel(int horizontalAlignment, Font font, int avgLength, boolean highlight) {
this.setText(""
this.setFont(font);
this.setHorizontalAlignment(horizontalAlignment);
this.mHighlightSelected = highlight;
}

public CellLabel(int horizontalAlignment, Font font, int avgLength) {
this(horizontalAlignment, font, avgLength, true);
}

public Component getTableCellRendererComponent(
JTable jTable,
Object obj,
boolean isSelected,
boolean hasFocus,
int row,
int column) {

Object val = jTable.getModel().getValueAt(row, column);
this.setText((String)val);
if ( isSelected || hasFocus ) {
if ( this.getFont() == FIXED_FONT ) {
this.setFont(this.getFont().deriveFont(Font.BOLD));
}
if ( this.mHighlightSelected ) {
this.setBackground(new Color(204,204,255));
}
} else {
if ( this.getFont() == FIXED_FONT ) {
this.setFont(this.getFont().deriveFont(Font.PLAIN));
}
if ( this.mHighlightSelected ) {
this.setBackground(Color.white);
}
}
return this;
}
}

 

[jnicho02]

Your renderer won't be affecting jtable.getSelectedRow() or jtable.getSelectedColumn(), it only influences the display. Both these methods will return -1 if only a cell is selected.

try getting the Point that the pointer is currently at then calling jtable.columnAtPoint(mousePoint) or jtable.rowAtPoint(mousePoint).

If you're calling the code in a mouseListener the Point can be retrieved from the MouseEvent.getPoint(); Jeremy Nicholson, Director of

http://www.firstlightassociates.co.uk

a UK-based Java and Data Warehousing consultancy

 

[lesneskp]

Thanks. I'd rather not rely on finding points and whatnot, especially anything having to do with the mouse, since the keyboard might have been used instead. Not to mention that the table _should_ be able to give me this information. Many people have suggested that those methods do in fact work when a cell is selected, which is why I guessed that my renderer might be in the way... perhaps it is another part of my code... But in the end, I came up with a hack that seems to work very well:

I found that when a row is not selected (only a cell), I can use a ListSelectionListener (see below) to store the value of the last row number that was selected. It works, but is a complete kludge.

If you have any other input, I am still definitely interested in solving the problem the RIGHT way. Thanks.

table.getSelectionModel().addListSelectionListener(new javax.swing.event.ListSelectionListener() {
public void valueChanged(javax.swing.event.ListSelectionEvent e) {

// grab the row affected, as a temporary hack because when
// just a cell is selected, table.getSelectedRow() is
// returning -1 (not sure why)
// (the only case for which we use this number, both
// getFirstIndex() and getLastIndex() return the
// same value)
//
currentSelectedRow = e.getLastIndex();

}
});