JTable cell listener?

Question

I am using a JTable. I need to get a notification whenever a cell selection change. I tried to use the ListSelectionListener but I only get notification when the row selection change. If I select a new column on the same row, I don't get notify. I need to know when the cell is selected, not when the cell is changed. Is there a listener that I can use to do this ?

Answer 1

The easiest way to do this is to call setCellSelectionEnabled(true), and pass a reference to your table to the listener. When the listener is invoked, call getSelectedRow() and getSelectedColumn() on the original table.

The alternative is to set a row selection listener on the table, a column selection listener on the ColumnModel, and then figure out their intersection.

Answer 2

One way to receive notification on column selection changes - as already answered by @parsifal(in the comments - is to grab the TableColumnModel's internal selectionModel and register a listener:

table.getColumnModel().getSelectionModel().addListSelectionListener(selectionListener);

Another way is to register a TableColumnModelListener with the columnModel:

table.getColumnModel().addColumnModelListener(columnModelListener);

The first is "shorter" in terms of code: just one method to implement vs. several - most empty except the columnSelectionChanged.

The second is more robust against dynamic changes: with the first there is no possibility to guard against changes of the selectionModel property of the columnModel ... because it is not a property. Or in other words: in the (concededly rare) case that application code swaps out the selectionModel the listener is listening to the Void. Installing a columnModelListener is immune against such a change, as the columnModel passes on the events from its selectionModel whichever it would be.