Java Swing How to - Create Sorted List Model for JList

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Question

We would like to know how to create Sorted List Model for JList.

Answer

/* w  ww  .  jav a2 s . c  o  m*/
/*
Definitive Guide to Swing for Java 2, Second Edition
By John Zukowski        
ISBN: 1-893115-78-X
Publisher: APress
*/

import java.awt.Point;
import java.awt.event.MouseEvent;
import java.util.Arrays;
import java.util.Collection;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.Properties;
import java.util.SortedSet;
import java.util.TreeSet;

import javax.swing.AbstractListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ToolTipManager;

public class Main{

  public static void main(String args[]) {
      JFrame frame = new JFrame("Custom Tip Demo");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      Properties props = System.getProperties();
      PropertiesList list = new PropertiesList(props);
      JScrollPane scrollPane = new JScrollPane(list);
      frame.getContentPane().add(scrollPane);
      frame.setSize(300, 300);
      frame.setVisible(true);
  }
}

class PropertiesList extends JList {

    SortedListModel model;

    Properties tipProps;

    public PropertiesList(Properties props) {
        model = new SortedListModel();
        setModel(model);
        ToolTipManager.sharedInstance().registerComponent(this);

        tipProps = props;
        addProperties(props);
    }

    private void addProperties(Properties props) {
        // Load
        Enumeration e = props.propertyNames();
        while (e.hasMoreElements()) {
            model.add(e.nextElement());
        }
    }

    public String getToolTipText(MouseEvent event) {
        Point p = event.getPoint();
        int location = locationToIndex(p);
        String key = (String) model.getElementAt(location);
        String tip = tipProps.getProperty(key);
        return tip;
    }

}

class SortedListModel extends AbstractListModel {

    SortedSet model;

    public SortedListModel() {
        model = new TreeSet();
    }

    public int getSize() {
        return model.size();
    }

    public Object getElementAt(int index) {
        return model.toArray()[index];
    }

    public void add(Object element) {
        if (model.add(element)) {
            fireContentsChanged(this, 0, getSize());
        }
    }

    public void addAll(Object elements[]) {
        Collection c = Arrays.asList(elements);
        model.addAll(c);
        fireContentsChanged(this, 0, getSize());
    }

    public void clear() {
        model.clear();
        fireContentsChanged(this, 0, getSize());
    }

    public boolean contains(Object element) {
        return model.contains(element);
    }

    public Object firstElement() {
        return model.first();
    }

    public Iterator iterator() {
        return model.iterator();
    }

    public Object lastElement() {
        return model.last();
    }

    public boolean removeElement(Object element) {
        boolean removed = model.remove(element);
        if (removed) {
            fireContentsChanged(this, 0, getSize());
        }
        return removed;
    }
}

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