Java Tutorial/Swing/JList

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A container for pseud code

   <source lang="java">

import java.awt.BorderLayout; import java.awt.Color; import java.awt.Container; import javax.swing.BorderFactory; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.border.Border; public class JListBackground extends JPanel { 

 private static final Color lightBlue = new Color(153, 204, 255);
 public JListBackground() {
   super();
   setBackground(lightBlue);
 }
 public static void addComponentsToPane(Container pane) {
   String[] bruteForceCode = { "int count = 0", 
       "int m = mPattern.length();", 
       "int n = mSource .length();", 
       "outer:", 
       " ++count;", 
       " }", 
       " return count;", 
       "}" 
   };
   JList list = new JList(bruteForceCode);
   Border etch = BorderFactory.createEtchedBorder();
   list.setBorder(BorderFactory.createTitledBorder(etch, "Brute Force Code"));
   JPanel listPanel = new JPanel();
   listPanel.add(list);
   listPanel.setBackground(lightBlue);
   list.setBackground(lightBlue);
   pane.add(listPanel, BorderLayout.CENTER);
   pane.setBackground(lightBlue);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("Brute Force Algorithm");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   addComponentsToPane(frame.getContentPane());
   frame.pack();
   frame.setSize(800, 600);
   frame.setVisible(true);
 }

}</source>





Adding Element-Level Tooltips to List Items

   <source lang="java">

import java.awt.Point; import java.awt.event.MouseEvent; import java.util.Properties; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.ToolTipManager; public class PropertiesList extends JList { 

 public PropertiesList() {
   super(new String[]{ "A", "B", "C", "D", "E", "F", "G", "H" });
   ToolTipManager.sharedInstance().registerComponent(this);
 }
 public String getToolTipText(MouseEvent event) {
   Point p = event.getPoint();
   int location = locationToIndex(p);
   String tip = (String) getModel().getElementAt(location);
   return tip;
 }
 public static void main(String args[]) {
   JFrame frame = new JFrame("Custom Tip Demo");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   PropertiesList list = new PropertiesList();
   
   JScrollPane scrollPane = new JScrollPane(list);
   frame.add(scrollPane);
   frame.setSize(300, 300);
   frame.setVisible(true);
 }

}</source>





Arranging Items in a JList Component

   <source lang="java">

import javax.swing.JList; import javax.swing.JScrollPane; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   JScrollPane scrollingList = new JScrollPane(list);
   // The default layout orientation is JList.VERTICAL
   int orient = list.getLayoutOrientation();
   // Change the layout orientation to left-to-right, top-to-bottom
   list.setLayoutOrientation(JList.HORIZONTAL_WRAP);
 }

}</source>





Bench mark for JList

   <source lang="java">

import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.AbstractListModel; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class JBenchFrame extends JFrame { 

 BorderLayout borderLayout1 = new BorderLayout();
 JList list1 = new JList();
 JButton fillButton = new JButton();
 public static void main(String[] args) {
   JBenchFrame bm = new JBenchFrame();
 }
 public JBenchFrame() {
   this.getContentPane().setLayout(borderLayout1);
   this.setSize(new Dimension(400, 300));
   fillButton.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent e) {
       ListData ld = new ListData();
       long tmStart = System.currentTimeMillis();
       list1.setModel(ld);
       list1.repaint();
       long tmEnd = System.currentTimeMillis();
       System.out.println(tmEnd - tmStart);
     }
   });
   fillButton.setText("Fill");
   this.getContentPane().add(new JScrollPane(list1), BorderLayout.CENTER);
   this.getContentPane().add(fillButton, BorderLayout.SOUTH);
   setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   setVisible(true);
 }

} class ListData extends AbstractListModel { 

 String[] strings = new String[10000];
 public ListData() {
   for (int i = 0; i < 10000; i++) {
     strings[i] = "bob" + i;
   }
 }
 public int getSize() {
   return strings.length;
 }
 public Object getElementAt(int index) {
   return strings[index];
 }

}</source>





Creating JList Components

   <source lang="java">

public JList() JList jlist = new JList(); public JList(Object listData[]) String labels[] = { "A", "B", "C", "D", "E", "F", "G", "H"}; JList jlist = new JList(labels); public JList(Vector listData) Vector vector = aBufferedImage.getSources(); JList jlist = new JList(vector); public JList(ListModel model) ResultSet results = aJDBCStatement.executeQuery("SELECT colName FROM tableName"); DefaultListModel model = new DefaultListModel(); while (result.next()){ 

 model.addElement(result.getString(1));

} JList jlist = new JList(model);</source>



  1. To improve performance, you can set the fixedCellHeight and fixedCellWidth properties.
  2. Setting these properties is one way to avoid having the JList ask each cell for its rendered size.


Customizing a JList Look and Feel

Property StringObject TypeList.actionMapActionMapList.backgroundColorList.borderBorderList.cellHeightIntegerList.cellRendererListCellRendererList.focusCellHighlightBorderBorderList.focusInputMapInputMapList.focusInputMap.RightToLeftInputMapList.fontFontList.foregroundColorList.lockToPositionOnScrollBooleanList.rendererUseListColors BooleanList.rendererUseUIBorder BooleanList.selectionBackgroundColorList.selectionForegroundColorList.timeFactorLongListUIString


Detecting Double and Triple Clicks on an Item in a JList Component

   <source lang="java">

import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   list.addMouseListener(new MouseAdapter() {
     public void mouseClicked(MouseEvent evt) {
       JList list = (JList) evt.getSource();
       if (evt.getClickCount() == 2) { // Double-click
         int index = list.locationToIndex(evt.getPoint());
       } else if (evt.getClickCount() == 3) { // Triple-click
         int index = list.locationToIndex(evt.getPoint());
       }
     }
   });
 }

}</source>





Get index of first visible item

   <source lang="java">

import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   int itemIx = list.getFirstVisibleIndex();
   if (itemIx < 0) {
     // List is either not visible or there are no items
   }
 }

}</source>





Get index of last visible item

   <source lang="java">

import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   int itemIx = list.getLastVisibleIndex();
 }

}</source>





JList

The JList component is the basic Swing component for selecting one or more items from a set of choices. Three key elements and their implementations define the JList structure:

  1. A data model for holding the JList data, as defined by the ListModel interface
  2. A cell renderer for drawing the elements of the JList, as described by the ListCellRenderer interface
  3. A selection model for selecting elements of the JList, as described by the ListSelectionModel interface


Listening to JList Events with a ListSelectionListener

If you want to know when elements of a JList have been selected, you need to attach a ListSelectionListener to the JList or the ListSelectionModel.



   <source lang="java">

public interface ListSelectionListener extends EventListener { 

 public void valueChanged(ListSelectionEvent e);

}</source>





ListSelectionModel Modes

By default, every JList component is in multiple-selection mode.

ModeDescriptionListSelectionModel.SINGLE_SELECTIONOne item at a time can be selected.ListSelectionModel.SINGLE_INTERVAL_SELECTIONOne contiguous range of items can be selected.ListSelectionModel.MULTIPLE_INTERVAL_SELECTIONAny set of ranges can be selected. 



   <source lang="java">

import java.awt.BorderLayout; import javax.swing.DefaultListModel; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.ListSelectionModel; public class SelectionModeDemo { 

 public static void main(String args[]) {
   JFrame frame = new JFrame("Sizing Samples");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   DefaultListModel model = new DefaultListModel();
   model.ensureCapacity(100);
   for (int i = 0; i < 100; i++) {
     model.addElement(Integer.toString(i));
   }
   JList jlist2 = new JList(model);
   jlist2.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION );
   
   JScrollPane scrollPane2 = new JScrollPane(jlist2);
   frame.add(scrollPane2, BorderLayout.CENTER);
   frame.setSize(300, 350);
   frame.setVisible(true);
 }

}</source>





Methods are used to find an item

   <source lang="java">

import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   String prefix = "b";
   int start = 0;
   
   int itemIx = list.getNextMatch(prefix, start, javax.swing.text.Position.Bias.Forward);
 }

}</source>





Modifying the Data Model

   <source lang="java">

import java.awt.BorderLayout; import javax.swing.DefaultListModel; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class ModifyModelSample { 

 static String labels[] = { "A", "B", "C", "D", "E", "F", "G" };
 public static void main(String args[]) {
   JFrame frame = new JFrame("Modifying Model");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   // Fill model
   final DefaultListModel model = new DefaultListModel();
   for (int i = 0, n = labels.length; i < n; i++) {
     model.addElement(labels[i]);
   }
   JList jlist = new JList(model);
   JScrollPane scrollPane1 = new JScrollPane(jlist);
   frame.add(scrollPane1, BorderLayout.CENTER);
   frame.setSize(640, 300);
   frame.setVisible(true);
 }

}</source>





public Point indexToLocation(int index): returning a Point as the origin of the provided index

   <source lang="java">

import java.awt.BorderLayout; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class JListLocationToIndexSample { 

 public static void main(String args[]) {
   String labels[] = { "A", "B", "C", "D", "E", "F", "G", "H" };
   JFrame frame = new JFrame("Selecting JList");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   JList jlist = new JList(labels);
   JScrollPane scrollPane1 = new JScrollPane(jlist);
   frame.add(scrollPane1, BorderLayout.CENTER);
   System.out.println(jlist.indexToLocation(5));
   frame.setSize(350, 200);
   frame.setVisible(true);
 }

}</source>





Selection event for double-clicking an item in the list

public int locationToIndex(Point location) in JList: map screen coordinates to list elements



   <source lang="java">

import java.awt.BorderLayout; import java.awt.event.MouseAdapter; import java.awt.event.MouseEvent; import java.awt.event.MouseListener; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class JListLocationToIndexSample { 

 public static void main(String args[]) {
   String labels[] = { "A", "B", "C", "D", "E", "F", "G", "H" };
   JFrame frame = new JFrame("Selecting JList");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   JList jlist = new JList(labels);
   JScrollPane scrollPane1 = new JScrollPane(jlist);
   frame.add(scrollPane1, BorderLayout.CENTER);
   MouseListener mouseListener = new MouseAdapter() {
     public void mouseClicked(MouseEvent mouseEvent) {
       JList theList = (JList) mouseEvent.getSource();
       if (mouseEvent.getClickCount() == 2) {
         int index = theList.locationToIndex(mouseEvent.getPoint());
         if (index >= 0) {
           Object o = theList.getModel().getElementAt(index);
           System.out.println("Double-clicked on: " + o.toString());
         }
       }
     }
   };
   jlist.addMouseListener(mouseListener);
   frame.setSize(350, 200);
   frame.setVisible(true);
 }

}</source>





Selection Methods

The class JList supports a list of set and get methods to deal with various selection attributes:



   <source lang="java">

void setSelectedIndex(int index) 

 void setSelectedIndices(int[] indices)   
 void setSelectedValue(Object object, boolean shouldScroll)</source>



Set selected index

You can set an initial selection (s) by using the setSelectedIndex and setSelectedIndices methods (the indexing is zero-based, so index 0 refers to the first option in the JList).



   <source lang="java">

public void setSelectedIndex (int index) public void setSelectedIndices (int[] indices)</source>





Setting a Tool Tip for an Item in a JList Component

   <source lang="java">

import java.awt.event.MouseEvent; import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items) {
     // This method is called as the cursor moves within the list.
     public String getToolTipText(MouseEvent evt) {
       // Get item index
       int index = locationToIndex(evt.getPoint());
       // Get item
       Object item = getModel().getElementAt(index);
       // Return the tool tip text
       return "tool tip for " + item;
     }
   };
 }

}</source>





Setting the number of visible rows with setVisibleRowCount()

   <source lang="java">

import java.awt.BorderLayout; import javax.swing.DefaultListModel; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class SizingSamples { 

 public static void main(String args[]) {
   String labels[] = { "A", "B", "C", "D", "E", "F" ,"G","H","I","J"};
   JFrame frame = new JFrame("Sizing Samples");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   JList jlist1 = new JList(labels);
   jlist1.setVisibleRowCount(4);
   DefaultListModel model = new DefaultListModel();
   model.ensureCapacity(100);
   for (int i = 0; i < 100; i++) {
       model.addElement(Integer.toString(i));
   }
   JScrollPane scrollPane1 = new JScrollPane(jlist1);
   frame.add(scrollPane1, BorderLayout.NORTH);
   JList jlist2 = new JList(model);
   jlist2.setVisibleRowCount(4);
   jlist2.setFixedCellHeight(12);
   jlist2.setFixedCellWidth(200);
   JScrollPane scrollPane2 = new JScrollPane(jlist2);
   frame.add(scrollPane2, BorderLayout.CENTER);
   JList jlist3 = new JList(labels);
   jlist3.setVisibleRowCount(4);
   frame.add(jlist3, BorderLayout.SOUTH);
   frame.setSize(300, 350);
   frame.setVisible(true);
 }

}</source>





Sharing the Data Model for a JComboBox and JList

   <source lang="java">

import java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.DefaultComboBoxModel; import javax.swing.JButton; import javax.swing.JComboBox; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JPanel; import javax.swing.JScrollPane; public class SharedDataBetweenComboBoxAndListSample { 

 public static void main(String args[]) {
   final String labels[] = { "A", "B", "C", "D", "E", "F", "G" };
   final DefaultComboBoxModel model = new DefaultComboBoxModel(labels);
   JFrame frame = new JFrame("Shared Data");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   JPanel panel = new JPanel();
   JComboBox comboBox1 = new JComboBox(model);
   comboBox1.setEditable(true);
   panel.add(comboBox1);
   frame.add(panel, BorderLayout.NORTH);
   JList jlist = new JList(model);
   JScrollPane scrollPane = new JScrollPane(jlist);
   frame.add(scrollPane, BorderLayout.CENTER);

   JButton button = new JButton("Add");
   frame.add(button, BorderLayout.SOUTH);
   ActionListener actionListener = new ActionListener() {
     public void actionPerformed(ActionEvent actionEvent) {
       model.addElement("New Added");
     }
   };
   button.addActionListener(actionListener);
   frame.setSize(300, 200);
   frame.setVisible(true);
 }

}</source>





Storing value in Vector and adding them into JList

   <source lang="java">

import java.util.Vector; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class StoringvalueinVectorandaddingthemintoJList { 

 public static void main(String[] a) {
   JFrame frame = new JFrame();
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   Vector months = new Vector();
   JList list = new JList(months);
   months.addElement("January");
   months.addElement("December");
   frame.add(new JScrollPane(list));
   frame.setSize(300, 200);
   frame.setVisible(true);
 }

}</source>





These methods can be used to find the range of visible items

   <source lang="java">

import javax.swing.JList; public class Main { 

 public static void main(String[] argv) throws Exception {
   String[] items = { "A", "B", "C", "D" };
   JList list = new JList(items);
   // Get number of visible items
   int visibleSize = list.getVisibleRowCount();
 }

}</source>





To make multiple list selections, you can use the anchor and lead indices of the selection items.

   <source lang="java">

void setAnchorSelectionIndex(int index) 

 void setLeadSelectionIndex(int index)</source>



To programmatically move the list to the top

The firstVisibleIndex and lastVisibleIndex properties allow you to find out which choices are currently visible. To request that a specific element be made visible, use the public void ensureIndexIsVisible(int index) method.



   <source lang="java">

import java.awt.BorderLayout; import javax.swing.DefaultListModel; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class SizingSamples { 

 public static void main(String args[]) {
   JFrame frame = new JFrame("Sizing Samples");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   DefaultListModel model = new DefaultListModel();
   model.ensureCapacity(100);
   for (int i = 0; i < 100; i++) {
       model.addElement(Integer.toString(i));
   }
   JList jlist2 = new JList(model);
   
   
   JScrollPane scrollPane2 = new JScrollPane(jlist2);
   frame.add(scrollPane2, BorderLayout.CENTER);
   frame.setSize(300, 350);
   frame.setVisible(true);
   
   jlist2.ensureIndexIsVisible(50);
 }

}</source>





Use drag and drop to reorder a list

   <source lang="java">

import java.awt.datatransfer.DataFlavor; import java.awt.datatransfer.StringSelection; import java.awt.datatransfer.Transferable; import java.awt.dnd.DnDConstants; import java.awt.dnd.DragGestureEvent; import java.awt.dnd.DragGestureListener; import java.awt.dnd.DragGestureRecognizer; import java.awt.dnd.DragSource; import java.awt.dnd.DragSourceDragEvent; import java.awt.dnd.DragSourceDropEvent; import java.awt.dnd.DragSourceEvent; import java.awt.dnd.DragSourceListener; import javax.swing.DefaultListModel; import javax.swing.DropMode; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.TransferHandler; public class DragDropList extends JList { 

 DefaultListModel model;
 public DragDropList() {
   super(new DefaultListModel());
   model = (DefaultListModel) getModel();
   setDragEnabled(true);
   setDropMode(DropMode.INSERT);
   setTransferHandler(new MyListDropHandler(this));
   new MyDragListener(this);
   
   model.addElement("a");
   model.addElement("b");
   model.addElement("c");
 }
 public static void main(String[] a){
   JFrame f = new JFrame();
   f.add(new JScrollPane(new DragDropList()));
   f.setSize(300,300);
   f.setVisible(true);
 }

} class MyDragListener implements DragSourceListener, DragGestureListener { 

 DragDropList list;
 DragSource ds = new DragSource();
 public MyDragListener(DragDropList list) {
   this.list = list;
   DragGestureRecognizer dgr = ds.createDefaultDragGestureRecognizer(list,
       DnDConstants.ACTION_MOVE, this);
 }
 public void dragGestureRecognized(DragGestureEvent dge) {
   StringSelection transferable = new StringSelection(Integer.toString(list.getSelectedIndex()));
   ds.startDrag(dge, DragSource.DefaultCopyDrop, transferable, this);
 }
 public void dragEnter(DragSourceDragEvent dsde) {
 }
 public void dragExit(DragSourceEvent dse) {
 }
 public void dragOver(DragSourceDragEvent dsde) {
 }
 public void dragDropEnd(DragSourceDropEvent dsde) {
   if (dsde.getDropSuccess()) {
     System.out.println("Succeeded");
   } else {
     System.out.println("Failed");
   }
 }
 public void dropActionChanged(DragSourceDragEvent dsde) {
 }

} class MyListDropHandler extends TransferHandler { 

 DragDropList list;
 public MyListDropHandler(DragDropList list) {
   this.list = list;
 }
 public boolean canImport(TransferHandler.TransferSupport support) {
   if (!support.isDataFlavorSupported(DataFlavor.stringFlavor)) {
     return false;
   }
   JList.DropLocation dl = (JList.DropLocation) support.getDropLocation();
   if (dl.getIndex() == -1) {
     return false;
   } else {
     return true;
   }
 }
 public boolean importData(TransferHandler.TransferSupport support) {
   if (!canImport(support)) {
     return false;
   }
   Transferable transferable = support.getTransferable();
   String indexString;
   try {
     indexString = (String) transferable.getTransferData(DataFlavor.stringFlavor);
   } catch (Exception e) {
     return false;
   }
   int index = Integer.parseInt(indexString);
   JList.DropLocation dl = (JList.DropLocation) support.getDropLocation();
   int dropTargetIndex = dl.getIndex();
   System.out.println(dropTargetIndex + " : ");
   System.out.println("inserted");
   return true;
 }

}</source>





Using a Custom Data Model

   <source lang="java">

import java.awt.BorderLayout; import java.util.ArrayList; import java.util.Collection; import javax.swing.AbstractListModel; import javax.swing.ruboBoxModel; import javax.swing.JComboBox; import javax.swing.JFrame; class ArrayListComboBoxModel extends AbstractListModel implements ComboBoxModel { 

 private Object selectedItem;
 private ArrayList anArrayList;
 public ArrayListComboBoxModel(ArrayList arrayList) {
   anArrayList = arrayList;
 }
 public Object getSelectedItem() {
   return selectedItem;
 }
 public void setSelectedItem(Object newValue) {
   selectedItem = newValue;
 }
 public int getSize() {
   return anArrayList.size();
 }
 public Object getElementAt(int i) {
   return anArrayList.get(i);
 }

} public class ArrayListComboBoxModelDemo { 

 public static void main(String args[]) {
   JFrame frame = new JFrame("ArrayListComboBoxModel");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   ArrayList<Object> arrayList = new ArrayList<Object>();
   arrayList.add("A");
   arrayList.add("B");
   arrayList.add("C");
   ArrayListComboBoxModel model = new ArrayListComboBoxModel(arrayList);
   JComboBox comboBox = new JComboBox(model);
   frame.add(comboBox, BorderLayout.NORTH);
   frame.setSize(300, 225);
   frame.setVisible(true);
 }

}</source>





Using DefaultListModel to control the Data in a JList

   <source lang="java">

import java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.DefaultListModel; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class ModifyModelSampleModelAction { 

 static String labels[] = { "A", "B", "C", "D", "E", "F", "G" };
 public static void main(String args[]) {
   JFrame frame = new JFrame("Modifying Model");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   // Fill model
   final DefaultListModel model = new DefaultListModel();
   for (int i = 0, n = labels.length; i < n; i++) {
     model.addElement(labels[i]);
   }
   JList jlist = new JList(model);
   JScrollPane scrollPane1 = new JScrollPane(jlist);
   frame.add(scrollPane1, BorderLayout.CENTER);
   JButton jb = new JButton("add F");
   jb.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent actionEvent) {
       model.add(0, "First");
       model.clear();
       model.addElement("Last");
       model.addElement("Last");
       model.addElement("Last");
       model.addElement("Last");
       
       int size = model.getSize();
       model.insertElementAt("Middle", size / 2);
       model.set(0, "New First");
       model.setElementAt("New Last", size - 1);
       model.remove(0);
       // model.removeAllElements();
   //    model.removeElement("Last");
 //      model.removeElementAt(size / 2);

// model.removeRange(0, size / 2); 

     }
   });
   frame.add(jb, BorderLayout.SOUTH);
   frame.setSize(640, 300);
   frame.setVisible(true);
 }

}</source>





Using JList

   <source lang="java">

import java.awt.FlowLayout; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; public class JListTest { 

 public static void main(String[] args) {
   JFrame.setDefaultLookAndFeelDecorated(true);
   JFrame frame = new JFrame("JList Test");
   frame.setLayout(new FlowLayout());
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   String[] selections = { "green", "red", "orange", "dark blue" };
   JList list = new JList(selections);
   list.setSelectedIndex(1);
   System.out.println(list.getSelectedValue());
   frame.add(new JScrollPane(list));
   frame.pack();
   frame.setVisible(true);
 }

}</source>





Using ListDataListener to listen to ListModel Events

To find out when the contents of the list model change, you can register a ListDataListener with the model.

ListDataEvent Type Constants

Type ConstantMethodCONTENTS_CHANGEDcontentsChanged()INTERVAL_ADDEDintervalAdded()INTERVAL_REMOVEDintervalRemoved() 



   <source lang="java">

import java.awt.BorderLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.DefaultListModel; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.event.ListDataEvent; import javax.swing.event.ListDataListener; public class ModifyModelSampleListDataListener { 

 static String labels[] = { "A", "B", "C", "D", "E", "F", "G" };
 public static void main(String args[]) {
   JFrame frame = new JFrame("Modifying Model");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   // Fill model
   final DefaultListModel model = new DefaultListModel();
   for (int i = 0, n = labels.length; i < n; i++) {
     model.addElement(labels[i]);
   }
   JList jlist = new JList(model);
   JScrollPane scrollPane1 = new JScrollPane(jlist);
   frame.add(scrollPane1, BorderLayout.CENTER);
   
   ListDataListener listDataListener = new ListDataListener() {
     public void contentsChanged(ListDataEvent listDataEvent) {
       appendEvent(listDataEvent);
     }
     public void intervalAdded(ListDataEvent listDataEvent) {
       appendEvent(listDataEvent);
     }
     public void intervalRemoved(ListDataEvent listDataEvent) {
       appendEvent(listDataEvent);
     }
     private void appendEvent(ListDataEvent listDataEvent) {
       switch (listDataEvent.getType()) {
       case ListDataEvent.CONTENTS_CHANGED:
         System.out.println("Type: Contents Changed");
         break;
       case ListDataEvent.INTERVAL_ADDED:
         System.out.println("Type: Interval Added");
         break;
       case ListDataEvent.INTERVAL_REMOVED:
         System.out.println("Type: Interval Removed");
         break;
       }
       System.out.println(", Index0: " + listDataEvent.getIndex0());
       System.out.println(", Index1: " + listDataEvent.getIndex1());
       DefaultListModel theModel = (DefaultListModel) listDataEvent.getSource();
       System.out.println(theModel);
     }
   };
   model.addListDataListener(listDataListener);
   
   JButton jb = new JButton("add F");
   jb.addActionListener(new ActionListener() {
     public void actionPerformed(ActionEvent actionEvent) {
       model.add(0, "First");
     }
   });
   
   frame.add(jb,BorderLayout.SOUTH);    
   
   frame.setSize(640, 300);
   frame.setVisible(true);
 }

}</source>


Источник — «http://jexp.ru/index.php?title=Java_Tutorial/Swing/JList&oldid=3982»