Setting cellSpan in JTable

Question

You most likely are familular with tame's swing examples at http://www2.gol.com/users/tame/swing/examples/SwingExamples.html which have proven most helpful.
In JTable Examples 4 in the Multi-Span Example it is easy to find how tame combines multiple cells into one. The cells are selected after the table is created and then an Action Listener on a button calls cellAtt.combine.
But what if one wants to combine cells based on the data they are using to build the table. So when the tablemodel is being built, that is before we have cellAtt and before we render the table, how can we combine cells.
I tried to capture the number of rows I wanted to span when I built my tablemodel and then when I render cells (getTableCellRendererComponent) if cellAtt instanceof CellSpan I call cellAtt.combine. But this doesn't work.
Sorry no code as it is just to long to make sense here and I am really looking for the theory behind this rather than exatly what code is needed.

Answer 1

JScrollPane scrollPane = new JScrollPane( table );
//scrollPane.add(table); // this is wrongYou never add a component directly to the scrollpane. You either
a) create the scroll pane with the component as a parameter (as you did correctly)
b) set the view of the viewport with your component
JTable table = this.tv.getTable();
AssignmentsTableModel atm = (AssignmentsTableModel)table.getModel();
atm.fireTableDataChanged();
scrollToVisible(table, row, 0); This code makes no sense.
a) The variable row doesn't have a value.
b) Why would clicking on the table header cause you to invoke "fireTableDataChanged"? You haven't changed any of the data.
viewport.scrollRectToVisible(rect);I always invoke the scrollRectToVisible(... ) method on the component added to the scrollpane (ie. the table).
For more help create a [url http://sscce.org]SSCCE, that demonstrates the incorrect behaviour.