Question

When I run this code the selected item is not visible. I’ve already tried to run it in a separate thread with no luck.

import javax.swing.JFrame; import java.awt.Container; import javax.swing.JList; import javax.swing.ListSelectionModel; import javax.swing.JScrollPane; import java.awt.Dimension;  public class ScrollList extends JFrame {     int defaultValue;      ScrollList() {         Container cp = getContentPane();         JList list = createList();         defaultValue = 20;          cp.add(createScrollPane(list));         pack();         setVisible(true);         list.ensureIndexIsVisible(defaultValue);     }      JList createList() {         Integer[] model = new Integer[73];         JList list = new JList(model);          for (int i = 1; i < model.length; i++)             model[i] = i;         list.setSelectedIndex(defaultValue);          return list;     }      JScrollPane createScrollPane(JList list) {         JScrollPane s = new JScrollPane(createList());          s.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);         s.setPreferredSize(new Dimension(100, 200));          return s;     }      public static void main(String[] args) {         new ScrollList();     } } 

Answer 1

I figured it out!!

This is the code:

import javax.swing.JFrame; import java.awt.Container; import javax.swing.JList; import javax.swing.ListSelectionModel; import javax.swing.JScrollPane; import java.awt.Dimension;  public class ScrollList extends JFrame {     final int defaultValue = 20;      ScrollList() {         setDefaultCloseOperation(DISPOSE_ON_CLOSE);         Container cp = getContentPane();         JList list = createList();          cp.add(createScrollPane(list));         pack();         list.ensureIndexIsVisible(list.getSelectedIndex());          setVisible(true);     }      JList createList() {         Integer[] model = new Integer[73];         JList list = new JList(model);          for (int i = 1; i < model.length; i++)             model[i] = i;         list.setSelectedIndex(defaultValue);         return list;     }      JScrollPane createScrollPane(JList list) {         JScrollPane s = new JScrollPane(list); // MAJOR FIX HERE!         s.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);         s.setPreferredSize(new Dimension(100, 200));         return s;     }      public static void main(String[] args) {         new ScrollList();     } } 

Instead of using the list that you passed into the createScrollPane() method, you create a new one.