MVC+ SWING and a ListSelectionListener - swing

Question

What I am trying to do is get the selected value from my SWING View JList to my controller class, so I can use that data in my controller.
For simplicity I manually added 2 elements to my JList("Item 1", "Item 2", (so I have something to pass)I seem to have a problem accessing it. My View has a JList with a ListSelectionListener which I pass to my controller via my main:
public class AppMain {
private AppView appView = null;
public static void main(String[] args) {
AppView appView = new AppView();
Controller controller = new Controller(appView);
}
public AppView getView() {
return appView;
}
}
My view is:
import javax.swing.event.ListSelectionListener;
public class AppView extends javax.swing.JFrame {
public AppView() {
initComponents();
this.setVisible(true);
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
ValueList = new javax.swing.JList();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
ValueList.setModel(new javax.swing.AbstractListModel() {
String[] strings = { "Item 1", "Item 2", " " };
public int getSize() { return strings.length; }
public Object getElementAt(int i) { return strings[i]; }
});
jScrollPane1.setViewportView(ValueList);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(75, 75, 75)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(63, Short.MAX_VALUE))
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(45, 45, 45)
.addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 52, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap(27, Short.MAX_VALUE))
);
pack();
}// </editor-fold>
// Variables declaration - do not modify
private javax.swing.JList ValueList;
private javax.swing.JScrollPane jScrollPane1;
// End of variables declaration
public void ListSelectionListener(ListSelectionListener selectionListener) {
ValueList.addListSelectionListener(selectionListener);
}
}
And a Controller:
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;
public class Controller implements ListSelectionListener{
AppView gui;
public Controller(AppView v)
{
gui = v;
gui.ListSelectionListener(this);
}
#Override
public void valueChanged(ListSelectionEvent e) {
this.gui.ListSelectionListener(this);
System.out.println("FOO");
}
}
No I want TO get the selectedValue in the Controller. I can't seem to grasp it. Also This prints Foo 3 times and I also cannot find out why.
Thanks in advance

Answer 1

As shown in How to Write a List Selection Listener more than one ListSelectionEvent may be generated as the user selects fist one entry and then another. Try checking when the selection is stable.
if (!e.getValueIsAdjusting()) {
// examine result
ListSelectionModel lsm = (ListSelectionModel)e.getSource();
int minIndex = lsm.getMinSelectionIndex();
int maxIndex = lsm.getMaxSelectionIndex();
…
}