The Java Developers Almanac 1.4


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Home > List of Packages > javax.swing.table  [62 examples] > Events  [4 examples]

e964. Listening for Selection Events in a JTable Component

To listen for selection changes, you need to add a listener to both the JTable's table model and to the table column model.

A selection change event has a first and last property that specifies the range of affected rows (or columns). For example, if the 5th row is selected and the user selects the 7th row, the first property is 4 and the last is property 6. There is not enough information in the event to determine exactly which cells have changed. See e942 Getting the Selected Cells in a JTable Component for an example of how to determine the selected cells.

Changing the selection programmatically (see e941 Programmatically Making Selections in a JTable Component) causes selection change events to be fired.

    SelectionListener listener = new SelectionListener(table);
    table.getSelectionModel().addListSelectionListener(listener);
    table.getColumnModel().getSelectionModel()
        .addListSelectionListener(listener);
    
    public class SelectionListener implements ListSelectionListener {
        JTable table;
    
        // It is necessary to keep the table since it is not possible
        // to determine the table from the event's source
        SelectionListener(JTable table) {
            this.table = table;
        }
        public void valueChanged(ListSelectionEvent e) {
            // If cell selection is enabled, both row and column change events are fired
            if (e.getSource() == table.getSelectionModel()
                  && table.getRowSelectionAllowed()) {
                // Column selection changed
                int first = e.getFirstIndex();
                int last = e.getLastIndex();
            } else if (e.getSource() == table.getColumnModel().getSelectionModel()
                   && table.getColumnSelectionAllowed() ){
                // Row selection changed
                int first = e.getFirstIndex();
                int last = e.getLastIndex();
            }
    
            if (e.getValueIsAdjusting()) {
                // The mouse button has not yet been released
            }
        }
    }

 Related Examples
e965. Listening for Changes to the Rows and Columns of a JTable Component
e966. Listening for Column-Related Changes in a JTable Component
e967. Listening for Clicks on a Column Header in a JTable Component

See also: Cells    Column Heads    Columns    Editing    Layout    Rows    Scrolling    Selection    Sorting    Table Model    Tool Tips   


© 2002 Addison-Wesley.