Java JScrollPane的事件处理程序

Question

I already have a custom control base on JList like this

public class MyClass extends JList<String> {

   private DefaultListModel<String> items = new DefaultListModel<String>();

   public MyClass() {
      setModel(items);
   }

   public String getAAAA() { //code here.. }
   public int getBBB() { //code here... }
}

But I want the Jlist have scrollbar, so I change the super class of my custom control to JScrollPane and add the JList into it. code like this

public class MyClass extends JScrollPanel {

  private JList<String> list = new JList<String>();
  private DefaultListModel<String> items = new DefaultListModel<String>();

  public MyClass() { 
    list.setModel(items);
    this.setViewportView(list);
  }

  public String getAAAA() { //code here.. }
  public int getBBB() { //code here... }
}

Well, if MyClass extends JList, in the JFrame I can addMouseListener to MyClass object and in mouseClicked I compare the MouseEvent getSource is a instance of MyClass and call these method of MyClass.

@Override    
public void mouseClicked(MouseEvent arg0)
{
    Object source = arg0.getSource();
    if (source instanceof MyClass)
    {
        String a = ((MyClass) source).getAAAA();
        int b = ((MyClass) source).getBBB();
    }
 }

But if MyClass extends JScrollPane, I add MouseListener to MyClass object and like above, in mouseClicked I compare the MouseEvent getSource instanceof MyClass and call these method (getAAA(), getBBB()...) but it's not working??

Answer 1

You likely do not want to extend JScrollPane. You can add any Component to a JScrollPane to achieve having scroll bars. JList is a component, so you can add it directly. There shouldn't be much you need to do.

see: http://docs.oracle.com/javase/tutorial/uiswing/components/scrollpane.html