Java™ Application Development on Linux - Dator

16.7 Getting Down to Cases: Designing a GUI for BudgetPro367do here because it can’t be any other type of event—or we wouldn’t have beencalled. All we’re doing with it is checking to see if the user just selected or deselectedsomething. The only action we take is to enable or disable the viewbutton.Deep inside the cdaction object is a line that does the real action thatwe’re after with our selection. It says:61 int row = list.getSelectedRow();This shows that a JTable (list) has a method, getSelectedRow(), whichwill return the row number of the row that the user has selected (that is,clicked on). This is all part of the action listener (defined on lines 54–75 ofBudgetPro) for the View Subaccount button.54 private ActionListener cdAction = new ActionListener()55 {56 public void57 actionPerformed(ActionEvent e)58 {59 // this is the action for VIEW subdirectory;60 // a "cd" into the subaccount.61 int row = list.getSelectedRow();62 // System.out.println("Row="+row); // DEBUG; TODO: REMOVE63 if (row > -1) { // only if a row was selected64 String subname = (String) model.getValueAt(row, 0);// name column65 Account next = current.getSub(subname);66 if (next != null) {67 current = next;68 // System.out.println("cd to:"+current.getName());69 setStatus();70 // notify the table, too71 model.fireTableDataChanged();72 } // TODO: else infodialog or Beep.73 }74 }75 } ;With the row number in hand, the actionPerformed() method canthen use the row number to look up the account name. Since the account nameis in the first column (numbered 0) of our table, we call getValueAt(row, 0)to get that name. Then we give the name to the current account to look up thesubaccount (line 65).