Просмотр исходного текста страницы Java Tutorial/Swing/JList

==  A container for pseud code ==






   
  <!-- start source 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>
    
   
  <!-- end source code -->
   




==  Adding Element-Level Tooltips to List Items ==






   
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    <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>
    
   
  <!-- end source code -->
   




==  Arranging Items in a JList Component ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Bench mark for JList ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Creating JList Components ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   

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



==  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 ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Get index of first visible item ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Get index of last visible item ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  JList ==




<p>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:</p>
<OL><LI>A data model for holding the JList data, as defined by the ListModel interface</LI><LI>A cell renderer for drawing the elements of the JList, as described by the ListCellRenderer interface</LI><LI>A selection model for selecting elements of the JList, as described by the ListSelectionModel interface</LI></OL>



==  Listening to JList Events with a ListSelectionListener ==




<p>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.</p>

   
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    <source lang="java">
public interface ListSelectionListener extends EventListener {
  public void valueChanged(ListSelectionEvent e);
}</source>
    
   
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==  ListSelectionModel Modes ==




<p>By default, every JList component is in multiple-selection mode.</p>
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.

   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Methods are used to find an item ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Modifying the Data Model ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




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






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Selection event for double-clicking an item in the list ==




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

   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Selection Methods ==




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

   
  <!-- start source code -->
   
    <source lang="java">
void setSelectedIndex(int index)   
  void setSelectedIndices(int[] indices)   
  void setSelectedValue(Object object, boolean shouldScroll)</source>
    
   
  <!-- end source code -->
   




==  Set selected index ==




<p>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).</p>

   
  <!-- start source code -->
   
    <source lang="java">
public void setSelectedIndex (int index)
public void setSelectedIndices (int[] indices)</source>
    
   
  <!-- end source code -->
   




==  Setting a Tool Tip for an Item in a JList Component ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Setting the number of visible rows with setVisibleRowCount() ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Sharing the Data Model for a JComboBox and JList ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Storing value in Vector and adding them into JList ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




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






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




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






   
  <!-- start source code -->
   
    <source lang="java">
void setAnchorSelectionIndex(int index)   
  void setLeadSelectionIndex(int index)</source>
    
   
  <!-- end source code -->
   




==  To programmatically move the list to the top ==




<p>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.</p>

   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Use drag and drop to reorder a list ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Using a Custom Data Model ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Using DefaultListModel to control the Data in a JList ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Using JList ==






   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->
   




==  Using ListDataListener to listen to ListModel Events ==




<p>To find out when the contents of the list model change, 
you can register a ListDataListener with the model.</p>
<p>ListDataEvent Type Constants</p>
Type ConstantMethodCONTENTS_CHANGEDcontentsChanged()INTERVAL_ADDEDintervalAdded()INTERVAL_REMOVEDintervalRemoved()

   
  <!-- start source code -->
   
    <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>
    
   
  <!-- end source code -->