Java/Swing Components/Dual List

Dual Lists Demo

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.SortedSet;
import java.util.TreeSet;
import javax.swing.AbstractListModel;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.ListCellRenderer;
import javax.swing.ListModel;
public class MainClass {
  public static void main(String args[]) {
    JFrame frame = new JFrame("Dual List Box Tester");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    DualListBox dual = new DualListBox();
    dual.addSourceElements(new String[] { "One", "Two", "Three" });
    frame.add(dual, BorderLayout.CENTER);
    frame.setSize(400, 300);
    frame.setVisible(true);
  }
}
class DualListBox extends JPanel {
  private static final Insets EMPTY_INSETS = new Insets(0, 0, 0, 0);
  private static final String ADD_BUTTON_LABEL = "Add >>";
  private static final String REMOVE_BUTTON_LABEL = "<< Remove";
  private static final String DEFAULT_SOURCE_CHOICE_LABEL = "Available Choices";
  private static final String DEFAULT_DEST_CHOICE_LABEL = "Your Choices";
  private JLabel sourceLabel;
  private JList sourceList;
  private SortedListModel sourceListModel;
  private JList destList;
  private SortedListModel destListModel;
  private JLabel destLabel;
  private JButton addButton;
  private JButton removeButton;
  public DualListBox() {
    initScreen();
  }
  public String getSourceChoicesTitle() {
    return sourceLabel.getText();
  }
  public void setSourceChoicesTitle(String newValue) {
    sourceLabel.setText(newValue);
  }
  public String getDestinationChoicesTitle() {
    return destLabel.getText();
  }
  public void setDestinationChoicesTitle(String newValue) {
    destLabel.setText(newValue);
  }
  public void clearSourceListModel() {
    sourceListModel.clear();
  }
  public void clearDestinationListModel() {
    destListModel.clear();
  }
  public void addSourceElements(ListModel newValue) {
    fillListModel(sourceListModel, newValue);
  }
  public void setSourceElements(ListModel newValue) {
    clearSourceListModel();
    addSourceElements(newValue);
  }
  public void addDestinationElements(ListModel newValue) {
    fillListModel(destListModel, newValue);
  }
  private void fillListModel(SortedListModel model, ListModel newValues) {
    int size = newValues.getSize();
    for (int i = 0; i < size; i++) {
      model.add(newValues.getElementAt(i));
    }
  }
  public void addSourceElements(Object newValue[]) {
    fillListModel(sourceListModel, newValue);
  }
  public void setSourceElements(Object newValue[]) {
    clearSourceListModel();
    addSourceElements(newValue);
  }
  public void addDestinationElements(Object newValue[]) {
    fillListModel(destListModel, newValue);
  }
  private void fillListModel(SortedListModel model, Object newValues[]) {
    model.addAll(newValues);
  }
  public Iterator sourceIterator() {
    return sourceListModel.iterator();
  }
  public Iterator destinationIterator() {
    return destListModel.iterator();
  }
  public void setSourceCellRenderer(ListCellRenderer newValue) {
    sourceList.setCellRenderer(newValue);
  }
  public ListCellRenderer getSourceCellRenderer() {
    return sourceList.getCellRenderer();
  }
  public void setDestinationCellRenderer(ListCellRenderer newValue) {
    destList.setCellRenderer(newValue);
  }
  public ListCellRenderer getDestinationCellRenderer() {
    return destList.getCellRenderer();
  }
  public void setVisibleRowCount(int newValue) {
    sourceList.setVisibleRowCount(newValue);
    destList.setVisibleRowCount(newValue);
  }
  public int getVisibleRowCount() {
    return sourceList.getVisibleRowCount();
  }
  public void setSelectionBackground(Color newValue) {
    sourceList.setSelectionBackground(newValue);
    destList.setSelectionBackground(newValue);
  }
  public Color getSelectionBackground() {
    return sourceList.getSelectionBackground();
  }
  public void setSelectionForeground(Color newValue) {
    sourceList.setSelectionForeground(newValue);
    destList.setSelectionForeground(newValue);
  }
  public Color getSelectionForeground() {
    return sourceList.getSelectionForeground();
  }
  private void clearSourceSelected() {
    Object selected[] = sourceList.getSelectedValues();
    for (int i = selected.length - 1; i >= 0; --i) {
      sourceListModel.removeElement(selected[i]);
    }
    sourceList.getSelectionModel().clearSelection();
  }
  private void clearDestinationSelected() {
    Object selected[] = destList.getSelectedValues();
    for (int i = selected.length - 1; i >= 0; --i) {
      destListModel.removeElement(selected[i]);
    }
    destList.getSelectionModel().clearSelection();
  }
  private void initScreen() {
    setBorder(BorderFactory.createEtchedBorder());
    setLayout(new GridBagLayout());
    sourceLabel = new JLabel(DEFAULT_SOURCE_CHOICE_LABEL);
    sourceListModel = new SortedListModel();
    sourceList = new JList(sourceListModel);
    add(sourceLabel, new GridBagConstraints(0, 0, 1, 1, 0, 0, GridBagConstraints.CENTER,
        GridBagConstraints.NONE, EMPTY_INSETS, 0, 0));
    add(new JScrollPane(sourceList), new GridBagConstraints(0, 1, 1, 5, .5, 1,
        GridBagConstraints.CENTER, GridBagConstraints.BOTH, EMPTY_INSETS, 0, 0));
    addButton = new JButton(ADD_BUTTON_LABEL);
    add(addButton, new GridBagConstraints(1, 2, 1, 2, 0, .25, GridBagConstraints.CENTER,
        GridBagConstraints.NONE, EMPTY_INSETS, 0, 0));
    addButton.addActionListener(new AddListener());
    removeButton = new JButton(REMOVE_BUTTON_LABEL);
    add(removeButton, new GridBagConstraints(1, 4, 1, 2, 0, .25, GridBagConstraints.CENTER,
        GridBagConstraints.NONE, new Insets(0, 5, 0, 5), 0, 0));
    removeButton.addActionListener(new RemoveListener());
    destLabel = new JLabel(DEFAULT_DEST_CHOICE_LABEL);
    destListModel = new SortedListModel();
    destList = new JList(destListModel);
    add(destLabel, new GridBagConstraints(2, 0, 1, 1, 0, 0, GridBagConstraints.CENTER,
        GridBagConstraints.NONE, EMPTY_INSETS, 0, 0));
    add(new JScrollPane(destList), new GridBagConstraints(2, 1, 1, 5, .5, 1.0,
        GridBagConstraints.CENTER, GridBagConstraints.BOTH, EMPTY_INSETS, 0, 0));
  }
  private class AddListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      Object selected[] = sourceList.getSelectedValues();
      addDestinationElements(selected);
      clearSourceSelected();
    }
  }
  private class RemoveListener implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      Object selected[] = destList.getSelectedValues();
      addSourceElements(selected);
      clearDestinationSelected();
    }
  }
}
class SortedListModel extends AbstractListModel {
  SortedSet<Object> model;
  public SortedListModel() {
    model = new TreeSet<Object>();
  }
  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<Object> 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;
  }
}