ListIt.java Source code

Introduction

Here is the source code for ListIt.java

Source

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ComboBoxModel;
import javax.swing.DefaultListModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
import javax.swing.ListSelectionModel;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;

public class ListIt {

    final String partsList[][] = { { "Item 1", "10", "99c" }, { "Item 2", "12", "$18.99" },
            { "Item 3", "1", "$10.00" } };

    class PartsListModel extends DefaultListModel implements ComboBoxModel {

        Object currentValue;

        public PartsListModel() {
            for (int i = 0, n = partsList.length; i < n; i++) {
                addElement(partsList[i]);
            }
        }

        // ComboBoxModel methods
        public Object getSelectedItem() {
            return currentValue;
        }

        public void setSelectedItem(Object anObject) {
            currentValue = anObject;
            fireContentsChanged(this, -1, -1);
        }
    }

    class MyLabelRenderer extends JLabel implements ListCellRenderer {
        public MyLabelRenderer() {
            setOpaque(true);
        }

        public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected,
                boolean cellHasFocus) {
            if (value != null) {
                String values[] = (String[]) value;
                String setting = values[0] + " / " + values[1] + " / " + values[2];
                setText(setting);
            }
            setBackground(isSelected ? Color.BLUE : Color.WHITE);
            setForeground(isSelected ? Color.WHITE : Color.BLUE);
            return this;
        }
    }

    public ListIt() {
        JFrame f = new JFrame();
        final PartsListModel pcm = new PartsListModel();
        ListCellRenderer lcr = new MyLabelRenderer();
        JList jl = new JList(pcm);
        jl.setCellRenderer(lcr);
        ListSelectionModel lsm = jl.getSelectionModel();
        lsm.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        jl.addListSelectionListener(new ListSelectionListener() {
            public void valueChanged(ListSelectionEvent e) {
                if (!e.getValueIsAdjusting()) {
                    String element[] = (String[]) pcm.getElementAt(e.getFirstIndex());
                    System.out.println(element[0] + " : " + element[1] + " : " + element[2]);
                }
            }
        });
        JScrollPane jsp = new JScrollPane(jl);
        JComboBox jc = new JComboBox(pcm);
        jc.setRenderer(lcr);
        JButton jb = new JButton("Add Merchandise");
        jb.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                pcm.addElement(partsList[(int) (Math.random() * partsList.length)]);
            }
        });
        Container c = f.getContentPane();
        c.add(jsp, BorderLayout.NORTH);
        c.add(jc, BorderLayout.CENTER);
        c.add(jb, BorderLayout.SOUTH);
        f.setSize(250, 250);
        f.show();
    }

    public static void main(String args[]) {
        new ListIt();
    }
}