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Get multiple root directories on JTree to select the leaf - Swing

I have been using JTree to get the multiple root directories of the system, using the example FileTreeModel.java to achieve it. And also trying to get the selected leaf (path) but it throws cast error, please give me some directions on this, have posted the code so far have tried. Thanks.
import java.io.File;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.tree.*;
import java.io.File;
public class FileTreeDemo {
public static void main(String[] args) {
// Figure out where in the filesystem to start displaying
File root;
if (args.length > 0) {
root = new File(args[0]);
//System.out.println(args.length);
}
else root = new File(System.getProperty("user.home"));
//System.out.println(args.length);
// Create a TreeModel object to represent our tree of files
FileTreeModel model = new FileTreeModel(root);
// Create a JTree and tell it to display our model
JTree tree = new JTree();
tree.setModel(model);
tree.setRootVisible(true);
tree.setShowsRootHandles(true);
//tree.setShowsRootHandles(true);
// The JTree can get big, so allow it to scroll.
JScrollPane scrollpane = new JScrollPane(tree);
// Display it all in a window and make the window appear
JFrame frame = new JFrame("FileTreeDemo");
frame.getContentPane().add(scrollpane, "Center");
frame.setSize(400,600);
frame.setVisible(true);
// Add a listener
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) e
.getPath().getLastPathComponent();
System.out.println("You selected " + node);
}
});
}
}
class FileTreeModel implements TreeModel {
protected File root;
public FileTreeModel(File root) { this.root = root; }
public Object getRoot() { return root; }
public boolean isLeaf(Object node) { return ((File)node).isFile(); }
public int getChildCount(Object parent) {
String[] children = ((File)parent).list();
if (children == null) return 0;
return children.length;
}
public Object getChild(Object parent, int index) {
String[] children = ((File)parent).list();
if ((children == null) || (index >= children.length)) return null;
return new File((File) parent, children[index]);
}
public int getIndexOfChild(Object parent, Object child) {
String[] children = ((File)parent).list();
if (children == null) return -1;
String childname = ((File)child).getName();
for(int i = 0; i < children.length; i++) {
if (childname.equals(children[i])) return i;
}
return -1;
}
public void valueForPathChanged(TreePath path, Object newvalue) {}
public void addTreeModelListener(TreeModelListener l) {}
public void removeTreeModelListener(TreeModelListener l) {}
}

In your model you store File's instead of DefaultMutableTreeNode, because of you get ClassCastException here:
DefaultMutableTreeNode node = (DefaultMutableTreeNode)e.getPath().getLastPathComponent();
Change your listener like next:
tree.addTreeSelectionListener(new TreeSelectionListener() {
public void valueChanged(TreeSelectionEvent e) {
File node = (File) e.getPath().getLastPathComponent();
System.out.println("You selected " + node);
}
});

Is the transfer data for transferables from outside the jvm null by default when the TransferHandler canImport method gets called?

I'm working on Drag & Drop support for a JList component and I would like to be able to support files dragged in from my file browser. I however only want to allow files and not folders to be dragged in. Thus I'm trying to check for it in my TransferHandler like this:
#Override
public boolean canImport(TransferSupport support) {
if (support.getComponent().equals(this.resourceFileList)) {
if (!support.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
return false;
} else {
try {
// get file list
Transferable transferable = support.getTransferable();
Object transferData = transferable.getTransferData(DataFlavor.javaFileListFlavor);
// check for folders
boolean containsFiles = false;
List files = (List) transferData;
for (int i = 0; i < files.size(); i++) {
File file = (File) files.get(i);
if (!file.isDirectory()) {
containsFiles = true;
}
}
// return file indicator
return containsFiles;
} catch (IOException | UnsupportedFlavorException e) {
System.out.println("Unable to check for folders due to the following exception:\n" + e);
return false;
}
}
} else {
return false;
}
}
Unfortunately transferData seems to be null here. It is however not when the TransferHandler's importData method gets called. Does anyone have any clue if this is a bug of some sorts or desired behaviour?
I'm on a Mac (OSX 10.8) if it makes a difference and Java version is 1.7.0_21.
Thanks in advance!
EDIT:
Here's a short SSCCE for anyone to test. Just a drag a file into the list and watch the console.
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.File;
import java.io.IOException;
import java.util.List;
import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JScrollPane;
import javax.swing.TransferHandler;
import javax.swing.TransferHandler.TransferSupport;
public class DNDIssue extends TransferHandler {
#Override
public boolean canImport(TransferSupport support) {
if (support.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
try {
Transferable transferable = support.getTransferable();
Object transferData = transferable.getTransferData(DataFlavor.javaFileListFlavor); // <-- this returns null
System.out.println(transferData); // null
} catch (IOException | UnsupportedFlavorException e) {
System.out.println("Unable to check for folders due to the following exception:\n" + e);
} finally {
return false;
}
} else {
return false;
}
}
public static void main(String[] args) {
// create window
JFrame window = new JFrame("DNDIssue");
window.setSize(640, 480);
window.setLocation(100, 100);
// create list with model and set transfer handler
JList<File> list = new JList<File>(new DefaultListModel<File>());
list.setTransferHandler(new DNDIssue());
// add enclosing scroll pane and display window
window.getContentPane().add(new JScrollPane(list));
window.setVisible(true);
}
}

Your SSCCE works fine for me using JDK 1.7.0_21 on Windows 7 64bit.
Could you try following code?
Transferable transferable = support.getTransferable();
System.out.println("----");
String mt = DataFlavor.javaFileListFlavor.getMimeType();
for(DataFlavor df: transferable.getTransferDataFlavors()) {
System.out.println(df.getMimeType());
System.out.println(" "+df.getMimeType().equals(mt));
}
SSCCE 1.0: delete
SSCCE 1.1: Override TransferHandler#importData(...) version
InvalidDnDOperationException: No drop current
java.awt.dnd.InvalidDnDOperationException: No drop current
at sun.awt.dnd.SunDropTargetContextPeer.getTransferData(SunDropTargetContextPeer.java:245)
at sun.awt.datatransfer.TransferableProxy.getTransferData(TransferableProxy.java:73)
at java.awt.dnd.DropTargetContext$TransferableProxy.getTransferData(DropTargetContext.java:376)
at FileTransferHandler.canImport(DNDIssueTest.java:64)
The problem is possibly related to Bug ID 6759788 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6759788
via: http://www.coderanch.com/t/466319/GUI/java/Drag-Drop
SSCCE 1.2: Ignore InvalidDnDOperationException
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.io.*;
import java.util.List;
import javax.swing.*;
import javax.swing.TransferHandler;
import javax.swing.TransferHandler.TransferSupport;
public class DNDIssueTest {
public JComponent makeUI() {
// create list with model and set transfer handler
JList<File> list = new JList<File>(new DefaultListModel<File>());
list.setDropMode(DropMode.INSERT);
list.setTransferHandler(new FileTransferHandler());
return new JScrollPane(list);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override public void run() {
createAndShowGUI();
}
});
}
public static void createAndShowGUI() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new DNDIssueTest().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
class FileTransferHandler extends TransferHandler {
private static final boolean DEBUG = true;
#SuppressWarnings("unchecked")
#Override public boolean importData(TransferSupport support) {
try {
List files = (List)support.getTransferable().getTransferData(DataFlavor.javaFileListFlavor);
System.out.println("importData");
if(!hasDirectory(files) && canImport(support)) {
JList list = (JList)support.getComponent();
DefaultListModel model = (DefaultListModel)list.getModel();
for(Object o: files) {
model.addElement(o);
}
return true;
}
} catch(Exception ex) {
ex.printStackTrace();
}
return false;
}
private boolean hasDirectory(List list) {
System.out.println("hasDirectory check");
for (Object o: list) {
if(o instanceof File) {
File file = (File) o;
if (file.isDirectory()) {
return true;
}
}
}
return false;
}
#Override public boolean canImport(TransferSupport support) {
if(!support.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
return false;
}
if(!DEBUG) return true;
Transferable transferable = support.getTransferable();
try {
Object transferData = transferable.getTransferData(DataFlavor.javaFileListFlavor);
//System.out.println(transferData); // null
System.out.println("canImport");
return !hasDirectory((List)transferData);
} catch (Exception e) {
//e.printStackTrace();
System.out.println("*** Ignore InvalidDnDOperationException ***");
return true;
}
}
}
SSCCE 2.0: DropTargetListener version
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.event.*;
import java.io.*;
import java.util.List;
import javax.swing.*;
public class DNDIssueTest2 {
public JComponent makeUI() {
final DefaultListModel<File> model = new DefaultListModel<>();
JList<File> list = new JList<File>(model);
DropTargetListener dtl = new DropTargetAdapter() {
#Override public void dragOver(DropTargetDragEvent dtde) {
if(dtde.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
Transferable transferable = dtde.getTransferable();
Object transferData = null;
try {
transferData = transferable.getTransferData(DataFlavor.javaFileListFlavor);
} catch(Exception ex) {
dtde.rejectDrag();
return;
}
List<File> files = (List<File>)transferData;
for (int i = 0; i < files.size(); i++) {
File file = (File) files.get(i);
if (file.isDirectory()) {
dtde.rejectDrag();
return;
}
}
dtde.acceptDrag(DnDConstants.ACTION_COPY);
return;
}
dtde.rejectDrag();
}
#Override public void drop(DropTargetDropEvent dtde) {
try {
if(dtde.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
dtde.acceptDrop(DnDConstants.ACTION_COPY);
Transferable transferable = dtde.getTransferable();
List list = (List)transferable.getTransferData(DataFlavor.javaFileListFlavor);
for(Object o: list) {
if(o instanceof File) {
File file = (File) o;
model.addElement(file);
}
}
dtde.dropComplete(true);
return;
}
} catch(UnsupportedFlavorException ufe) {
ufe.printStackTrace();
} catch(IOException ioe) {
ioe.printStackTrace();
}
dtde.rejectDrop();
}
};
new DropTarget(list, DnDConstants.ACTION_COPY, dtl, true);
return new JScrollPane(list);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override public void run() {
createAndShowGUI();
}
});
}
public static void createAndShowGUI() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new DNDIssueTest2().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}

inserting java code from one class to another

So I have an interesting problem. I have an application that I wanted to have progress bars in each cell of the table. To be safe I wrote a stand alone app that does just what I want but now I'm having problems incorporating it into my pre-existing code. Im getting lost on what I need from each file. I.m posting the app table and the progress bar table code. I need to get these two two mesh or to puot it simply I need the progress bar in the app table. Any help appreciated.
application table
package gui;
import java.awt.BorderLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.AlgorithmParameters;
import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
import javax.swing.ImageIcon;
import javax.swing.JFileChooser;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.table.DefaultTableModel;
public class FileTable extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
private JTable table;
private DefaultTableModel tableModel =
new DefaultTableModel(new String[]
{"File", "Size", "Status" }, 0);
private File dir;
private File temp;
private JPopupMenu popup;
private String key;
private PasswordStorage passwordStorage;
private JFileChooser fileChooser;
private static String salt = "loquetdeliciouslysalty";
private static byte[] IV;
public FileTable() {
// Set Layout Manager
setLayout(new BorderLayout());
// Create Swing Components
table = new JTable();
table.setModel(tableModel);
table.setDropTarget(new TableDnD(table));
table.setShowGrid(false);
table.setFillsViewportHeight(true);
table.getColumnModel().getColumn(0).setPreferredWidth(250);
passwordStorage = new PasswordStorage();
fileChooser = new JFileChooser();
popup = new JPopupMenu();
JMenuItem removeItem = new JMenuItem("Remove");
removeItem.setIcon(new ImageIcon("removeMenu.png"));
popup.add(removeItem);
// Add Components to pane
add(new JScrollPane(table), BorderLayout.CENTER);
table.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
int row = table.rowAtPoint(e.getPoint());
table.getSelectionModel().setSelectionInterval(row, row);
if(e.getButton() == MouseEvent.BUTTON3) {
popup.show(table, e.getX(), e.getY());
}
}
});
removeItem.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
int row = table.getSelectedRow();
if(row > -1) {
tableModel.removeRow(table.getSelectedRow());
}
}
});
}
public boolean isTableEmpty() {
if(tableModel.getRowCount() == 0) {
return true;
}
else {
return false;
}
}
public void addFile(File file) {
tableModel.addRow(
new Object[]{file, file.length() + " kb",Not Processed"});
}
public void removeFile() {
int[] rows = table.getSelectedRows();
for(int i = 0; i < rows.length; i++) {
tableModel.removeRow(rows[i]-i);
}
}
public void clearTable()
{
int rowCount = tableModel.getRowCount();
for(int i = 0; i < rowCount; i++) {
tableModel.removeRow(0);
}
table.removeAll();
}
}
The progress bar table
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.EventQueue;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.swing.JFrame;
import javax.swing.JProgressBar;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingWorker;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.TableCellRenderer;
public class UpdateTable
{
public static void main(String[] args)
{
new UpdateTable();
}
public UpdateTable()
{
EventQueue.invokeLater(new Runnable()
{
#Override
public void run()
{
try
{
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException |
InstantiationException | IllegalAccessException |
UnsupportedLookAndFeelException ex) {
}
UpdatableTableModel model = new UpdatableTableModel();
JTable table = new JTable();
table.setModel(model);
table.getColumn("Status").setCellRenderer(new ProgressCellRender());
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(table));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
FileFinderWorker worker = new FileFinderWorker(model);
worker.execute();
}
});
}
public class ProgressCellRender extends JProgressBar implements TableCellRenderer
{
#Override
public Component getTableCellRendererComponent(JTable
table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
{
int progress = 0;
if (value instanceof Float)
{
progress = Math.round(((Float) value) * 100f);
} else if (value instanceof Integer)
{
progress = (int) value;
}
setValue(progress);
return this;
}
}
public class RowData
{
private File file;
private String type;
private long length;
private float status;
public RowData(File file, String type)
{
this.file = file;
this.type = type;
this.length = file.length();
this.status = 0f;
}
public File getFile()
{
return file;
}
public long getLength()
{
return length;
}
public float getStatus()
{
return status;
}
public String getType()
{
return type;
}
public void setStatus(float status)
{
this.status = status;
}
}
public class UpdatableTableModel extends AbstractTableModel
{
private List<RowData> rows;
private Map<File, RowData> mapLookup;
public UpdatableTableModel()
{
rows = new ArrayList<>(25);
mapLookup = new HashMap<>(25);
}
#Override
public int getRowCount()
{
return rows.size();
}
#Override
public int getColumnCount()
{
return 4;
}
#Override
public String getColumnName(int column)
{
String name = "??";
switch (column) {
case 0:
name = "File";
break;
case 1:
name = "File Type";
break;
case 2:
name = "Size";
break;
case 3:
name = "Status";
break;
}
return name;
}
#Override
public Object getValueAt(int rowIndex, int columnIndex)
{
RowData rowData = rows.get(rowIndex);
Object value = null;
switch (columnIndex)
{
case 0:
value = rowData.getFile();
break;
case 1:
value = rowData.getType();
break;
case 2:
value = rowData.getLength();
break;
case 3:
value = rowData.getStatus();
break;
}
return value;
}
#Override//new value //row to change //column to change
public void setValueAt(Object aValue, int rowIndex, int columnIndex)
{
RowData rowData = rows.get(rowIndex);
switch (columnIndex)
{
case 3:
if (aValue instanceof Float)
{
rowData.setStatus((float) aValue);
}
break;
}
}
public void addFile(File file)
{
RowData rowData = new RowData(file, "A File");
mapLookup.put(file, rowData);
rows.add(rowData);
fireTableRowsInserted(rows.size() - 1, rows.size() - 1);
}
protected void updateStatus(File file, int progress)
{
RowData rowData = mapLookup.get(file);
if (rowData != null) {
int row = rows.indexOf(rowData);
float p = (float) progress / 100f;
setValueAt(p, row, 3);
fireTableCellUpdated(row, 3);
}
}
}
public class FileFinderWorker extends SwingWorker<List<File>, File>
{
private UpdatableTableModel model;
public FileFinderWorker(UpdatableTableModel model)
{
this.model = model;
}
#Override
protected void process(List<File> chunks) //data chunks
{
for (File file : chunks)
{
model.addFile(file);
}
}
#Override
protected List<File> doInBackground() throws Exception
{
String usrHome = "user.home"; // takes the entire home dir
// user.dir will use working directory
// (wherever you save your Java shit)
File files[] = new
File(System.getProperty(usrHome)).listFiles();//grabbing all files from directory.
List<File> lstFiles = new ArrayList<>(Arrays.asList(files));
for (File file : lstFiles)
{
publish(file);
}
return lstFiles;
}
#Override
protected void done()
{
try {
List<File> files = get();
for (File file : files)
{
new FileReaderWorker(model, file).execute();
}
} catch (Exception exp) {
exp.printStackTrace();
}
}
}
public class FileReaderWorker extends SwingWorker<File, File>
{
private File currentFile;
private UpdatableTableModel model;
public FileReaderWorker(UpdatableTableModel model, File file)
{
this.currentFile = file;
this.model = model;
addPropertyChangeListener(new PropertyChangeListener()
{
#Override
public void propertyChange(PropertyChangeEvent evt)
{
if (evt.getPropertyName().equals("progress"))
{
FileReaderWorker.this.model.updateStatus(currentFile, (int) evt.getNewValue());
}
}
});
}
#Override
protected File doInBackground() throws Exception
{
if (currentFile.isFile())
{
setProgress(0);
long fileLength = currentFile.length();
BufferedReader reader = null;
char[] cbuf = new char[1024];//change this if everything loads too fast
try {
reader = new BufferedReader(new FileReader(currentFile));
int bytesRead = -1;
int totalBytesRead = 0;
while ((bytesRead = reader.read(cbuf)) != -1) {
totalBytesRead += bytesRead;
int progress = (int) Math.round(((double) totalBytesRead / (double) fileLength) *
100d);
setProgress(progress);
Thread.sleep(25);
}
setProgress(100);
} catch (Exception e) {
e.printStackTrace();
setProgress(100);
} finally {
try {
reader.close();
} catch (Exception e) {
}
}
} else {
setProgress(100);
}
return currentFile;
}
}
}
progress bar needs to get into application

You should look into AOP aspectJ.
Using this you could do the task

Change mouse cursor on hover over node in JTree

I'm creating a JTree and adding some nodes doing something like this:
DefaultMutableTreeNode top = new DefaultMutableTreeNode("The Java Series");
tree = new JTree(top);
...
DefaultMutableTreeNode node = new DefaultMutableTreeNode("<html>"+code+" "+description+"</html>");
top.add(node);
...
Now I added a "addMouseMotionListener" to the node which is ok. My problem is that the mouse cursor changes whenever I hover over any part of the node. What I really want is to only change mouse cursor when hovering over the HTML hyperlink text part of the node
""+code+""
and NOT the description.
So is there a way to make the mouse cursor change only when hovering in certain parts of the node?
Thanks in advance.

OK, it took me a while, but what I described in my comment seems to work. There may be other/better ways and I would love to read about it, but so far this is all I have found.
The idea is that:
I use a JEditorPane as a TreeCellRenderer
I listen for mouse move (and also, as a bonus for mouse click)
For each event I recreate the renderer for the hovered cell
I translate the event to the component coordinates
I use viewToModel to find if I am hovering an anchor element
I change the cursor accordingly.
Here is the code and as a bonus, you also get working hyperlinks!
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.Desktop;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import javax.swing.JEditorPane;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.text.AttributeSet;
import javax.swing.text.Element;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLDocument;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeCellRenderer;
import javax.swing.tree.TreeModel;
import javax.swing.tree.TreeNode;
import javax.swing.tree.TreePath;
public class TestTreeHyperlinks {
private final class HyperlinkMouseListener extends MouseAdapter {
private final JTree tree;
private HyperlinkMouseListener(JTree tree) {
this.tree = tree;
}
#Override
public void mouseExited(MouseEvent e) {
tree.setCursor(Cursor.getDefaultCursor());
}
#Override
public void mouseClicked(MouseEvent e) {
Element h = getHyperlinkElement(e);
if (h != null) {
Object attribute = h.getAttributes().getAttribute(HTML.Tag.A);
if (attribute instanceof AttributeSet) {
AttributeSet set = (AttributeSet) attribute;
String href = (String) set.getAttribute(HTML.Attribute.HREF);
if (href != null) {
try {
Desktop.getDesktop().browse(new URI(href));
} catch (IOException e1) {
e1.printStackTrace();
} catch (URISyntaxException e1) {
e1.printStackTrace();
}
}
}
}
}
#Override
public void mouseMoved(MouseEvent event) {
boolean isHyperlink = isHyperlink(event);
if (isHyperlink) {
tree.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
} else {
tree.setCursor(Cursor.getDefaultCursor());
}
}
private boolean isHyperlink(MouseEvent event) {
return getHyperlinkElement(event) != null;
}
private Element getHyperlinkElement(MouseEvent event) {
Point p = event.getPoint();
int selRow = tree.getRowForLocation(p.x, p.y);
TreeCellRenderer r = tree.getCellRenderer();
if (selRow != -1 && r != null) {
TreePath path = tree.getPathForRow(selRow);
Object lastPath = path.getLastPathComponent();
Component rComponent = r.getTreeCellRendererComponent(tree, lastPath, tree.isRowSelected(selRow), tree.isExpanded(selRow),
tree.getModel().isLeaf(lastPath), selRow, true);
if (rComponent instanceof JEditorPane) {
Rectangle pathBounds = tree.getPathBounds(path);
JEditorPane editor = (JEditorPane) rComponent;
editor.setBounds(tree.getRowBounds(selRow));
p.translate(-pathBounds.x, -pathBounds.y);
int pos = editor.getUI().viewToModel(editor, p);
if (pos >= 0 && editor.getDocument() instanceof HTMLDocument) {
HTMLDocument hdoc = (HTMLDocument) editor.getDocument();
Element elem = hdoc.getCharacterElement(pos);
if (elem.getAttributes().getAttribute(HTML.Tag.A) != null) {
return elem;
}
}
}
}
return null;
}
}
#SuppressWarnings("serial")
public class MyTreeCellRenderer extends DefaultTreeCellRenderer implements TreeCellRenderer {
private JEditorPane editorPane;
public MyTreeCellRenderer() {
editorPane = new JEditorPane("text/html", null);
}
#Override
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row,
boolean hasFocus) {
Component c = super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus);
if (c instanceof JLabel) {
JLabel label = (JLabel) c;
editorPane.setText(label.getText());
editorPane.setToolTipText(label.getToolTipText());
editorPane.setOpaque(label.isOpaque());
editorPane.setBackground(label.getBackground());
editorPane.setBorder(label.getBorder());
}
return editorPane;
}
}
protected void initUI() {
final JTree tree = new JTree(getTreeModel());
tree.setCellRenderer(new MyTreeCellRenderer());
HyperlinkMouseListener listener = new HyperlinkMouseListener(tree);
tree.addMouseListener(listener);
tree.addMouseMotionListener(listener);
JFrame f = new JFrame(TestTreeHyperlinks.class.getSimpleName());
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new JScrollPane(tree), BorderLayout.CENTER);
f.pack();
f.setSize(f.getWidth() + 100, f.getHeight() + 100);
f.setVisible(true);
}
private TreeModel getTreeModel() {
return new DefaultTreeModel(
getNodes(new DefaultMutableTreeNode("<html>Root Google</html>"), 5));
}
private TreeNode getNodes(DefaultMutableTreeNode parent, int i) {
if (i > 0) {
for (int j = 0; j < 5; j++) {
DefaultMutableTreeNode newChild = new DefaultMutableTreeNode(
"<html>Node "
+ (j + 1)
+ " a link to stackoverflow</html> and some more text not in an hyperlink");
getNodes(newChild, i - 1);
parent.add(newChild);
}
}
return parent;
}
public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException,
UnsupportedLookAndFeelException {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new TestTreeHyperlinks().initUI();
}
});
}
}

This code works:
tree_object.addMouseMotionListener(new MouseMotionListener() {
#Override
public void mouseDragged(MouseEvent e) {
}
#Override
public void mouseMoved(MouseEvent e) {
TreePath tp = ((JTree)e.getSource()).getPathForLocation(e.getX(), e.getY());
if(tp != null)
{
((JTree)e.getSource()).setCursor(new Cursor(Cursor.HAND_CURSOR));
}
else
{
((JTree)e.getSource()).setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
}
}
});

Subclass of TreeNode DnD issue

I have a class structure as follows:
DefaultMutableTreeNode
|_
BCStructure
|_
| Module
|_
| Section
|_
Page
Module, Section, and Page are what I actually use in my JTree. If you run the sample code below, the drag and drop works. Notice it is using DefaultMutableTreeNodes. If however, I place the code in my real applicaiont which uses the subclasses of DefualtMutableTreeNode, it does not work.
While stepping through the code, I have noticed two areas of interest. The first is this:
class TreeTransferHandler extends TransferHandler {
DataFlavor nodesFlavor;
DataFlavor[] flavors = new DataFlavor[1];
DefaultMutableTreeNode[] nodesToRemove;
public TreeTransferHandler() {
try {
String mimeType = DataFlavor.javaJVMLocalObjectMimeType
+ ";class=\""
+ javax.swing.tree.DefaultMutableTreeNode[].class.getName()
+ "\"";
nodesFlavor = new DataFlavor(mimeType);
flavors[0] = nodesFlavor;
} catch (ClassNotFoundException e) {
System.out.println("ClassNotFound: " + e.getMessage());
}
}
This is where it sets the DataFlavor. It is setting it to a DefualtMutableTreeNode array which I assume is correct since DefaultMutableTreeNode is the super class of my nodes. But this was one area where I thought the problem could lie.
The other point is while debugging this code, I get as far as:
public DataFlavor[] getTransferDataFlavors() {
return flavors;
}
before the drag and drop fails. I assume that it returns a DataFlavor that is not liked to well. This is why I think there is something wrong with the DataFlavor. Is there something more I need to do/modify in order for this to work with subclasses? Any ideas or suggestions?
Thanks!
Complete sample code:
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.util.*;
import java.util.List;
import javax.swing.*;
import javax.swing.tree.*;
public class TreeDragAndDrop {
private JScrollPane getContent() {
JTree tree = new JTree();
tree.setDragEnabled(true);
tree.setDropMode(DropMode.ON_OR_INSERT);
tree.setTransferHandler(new TreeTransferHandler());
tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.CONTIGUOUS_TREE_SELECTION);
expandTree(tree);
return new JScrollPane(tree);
}
private void expandTree(JTree tree) {
DefaultMutableTreeNode root =
(DefaultMutableTreeNode)tree.getModel().getRoot();
Enumeration e = root.breadthFirstEnumeration();
while(e.hasMoreElements()) {
DefaultMutableTreeNode node =
(DefaultMutableTreeNode)e.nextElement();
if(node.isLeaf()) continue;
int row = tree.getRowForPath(new TreePath(node.getPath()));
tree.expandRow(row);
}
}
public static void main(String[] args) {
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(new TreeDragAndDrop().getContent());
f.setSize(400,400);
f.setLocation(200,200);
f.setVisible(true);
}
}
class TreeTransferHandler extends TransferHandler {
DataFlavor nodesFlavor;
DataFlavor[] flavors = new DataFlavor[1];
DefaultMutableTreeNode[] nodesToRemove;
public TreeTransferHandler() {
try {
String mimeType = DataFlavor.javaJVMLocalObjectMimeType +
";class=\"" +
javax.swing.tree.DefaultMutableTreeNode[].class.getName() +
"\"";
nodesFlavor = new DataFlavor(mimeType);
flavors[0] = nodesFlavor;
} catch(ClassNotFoundException e) {
System.out.println("ClassNotFound: " + e.getMessage());
}
}
public boolean canImport(TransferHandler.TransferSupport support) {
if(!support.isDrop()) {
return false;
}
support.setShowDropLocation(true);
if(!support.isDataFlavorSupported(nodesFlavor)) {
return false;
}
// Do not allow a drop on the drag source selections.
JTree.DropLocation dl =
(JTree.DropLocation)support.getDropLocation();
JTree tree = (JTree)support.getComponent();
int dropRow = tree.getRowForPath(dl.getPath());
int[] selRows = tree.getSelectionRows();
for(int i = 0; i 0 &&
target.getLevel() 0 && selRows.length == 1)
return false;
// first may have children.
for(int i = 1; i selRows.length-1) {
// Not all children of first are selected.
return false;
}
}
}
return true;
}
protected Transferable createTransferable(JComponent c) {
JTree tree = (JTree)c;
TreePath[] paths = tree.getSelectionPaths();
if(paths != null) {
// Make up a node array of copies for transfer and
// another for/of the nodes that will be removed in
// exportDone after a successful drop.
List copies =
new ArrayList();
List toRemove =
new ArrayList();
DefaultMutableTreeNode node =
(DefaultMutableTreeNode)paths[0].getLastPathComponent();
DefaultMutableTreeNode copy = copy(node);
copies.add(copy);
toRemove.add(node);
for(int i = 1; i node.getLevel()) { // child node
copy.add(copy(next));
// node already contains child
} else { // sibling
copies.add(copy(next));
toRemove.add(next);
}
}
DefaultMutableTreeNode[] nodes =
copies.toArray(new DefaultMutableTreeNode[copies.size()]);
nodesToRemove =
toRemove.toArray(new DefaultMutableTreeNode[toRemove.size()]);
return new NodesTransferable(nodes);
}
return null;
}
/** Defensive copy used in createTransferable. */
private DefaultMutableTreeNode copy(TreeNode node) {
return new DefaultMutableTreeNode(node);
}
protected void exportDone(JComponent source, Transferable data, int action) {
if((action & MOVE) == MOVE) {
JTree tree = (JTree)source;
DefaultTreeModel model = (DefaultTreeModel)tree.getModel();
// Remove nodes saved in nodesToRemove in createTransferable.
for(int i = 0; i

If you think the problem is that you subclass the DefaultMutableTreeNode, try making your DataFlavor to be an array of Object, or even better, an ArrayList:
DataFlavor.javaJVMLocalObjectMimeType + ";class=java.util.ArrayList"
This way you can return your copies list along with your transferable. Maybe it will avoid the problem.
here's a rough scetch of how to do this with lists:
import javax.swing.*;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.Transferable;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.IOException;
import java.util.*;
import java.util.List;
/**
* Author: Denis Tulskiy
* Date: 1/5/11
*/
public class Test extends JFrame {
class NodeA extends DefaultMutableTreeNode {
NodeA(Object userObject) {
super(userObject);
}
}
class NodeB extends DefaultMutableTreeNode {
NodeB(Object userObject) {
super(userObject);
}
}
class NodeC extends DefaultMutableTreeNode {
NodeC(Object userObject) {
super(userObject);
}
}
private static class MyTransferHandler extends TransferHandler {
#Override
public int getSourceActions(JComponent c) {
return MOVE;
}
#Override
protected Transferable createTransferable(JComponent c) {
JTree tree = (JTree) c;
ArrayList<TreeNode> nodes = new ArrayList<TreeNode>();
for (TreePath path : tree.getSelectionPaths()) {
DefaultMutableTreeNode component = (DefaultMutableTreeNode) path.getLastPathComponent();
nodes.add(component);
}
return new NodesTransferable(nodes);
}
#Override
public boolean canImport(TransferSupport support) {
return support.isDataFlavorSupported(NodesTransferable.getDataFlavor());
}
#Override
public boolean importData(TransferSupport support) {
if (!canImport(support)) {
return false;
}
JTree tree = (JTree) support.getComponent();
List<DefaultMutableTreeNode> data = null;
try {
data = (List<DefaultMutableTreeNode>) support.getTransferable().getTransferData(NodesTransferable.getDataFlavor());
} catch (UnsupportedFlavorException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
if (data != null) {
Point dropPoint = support.getDropLocation().getDropPoint();
TreePath path = tree.getPathForLocation(dropPoint.x, dropPoint.y);
DefaultMutableTreeNode parent = (DefaultMutableTreeNode) path.getLastPathComponent();
for (DefaultMutableTreeNode node : data) {
node.removeFromParent();
parent.add(node);
}
DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
model.reload();
}
return true;
}
}
static class NodesTransferable implements Transferable {
private static DataFlavor dataFlavor;
public static DataFlavor getDataFlavor() {
if (dataFlavor == null) {
try {
dataFlavor = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType + ";class=java.util.ArrayList");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
return dataFlavor;
}
private java.util.List<TreeNode> nodes;
NodesTransferable(List<TreeNode> nodes) {
this.nodes = nodes;
}
#Override
public DataFlavor[] getTransferDataFlavors() {
return new DataFlavor[]{getDataFlavor()};
}
#Override
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.match(dataFlavor);
}
#Override
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
return nodes;
}
}
public Test() {
JTree tree = new JTree();
tree.setDragEnabled(true);
tree.setDropMode(DropMode.ON_OR_INSERT);
DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
NodeA child = new NodeA("nodea");
root.add(child);
child.add(new NodeB("nodeb"));
child.add(new NodeC("nodec"));
tree.setModel(new DefaultTreeModel(root));
tree.setTransferHandler(new MyTransferHandler());
setLayout(new BorderLayout());
add(tree, BorderLayout.CENTER);
setSize(300, 400);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
public static void main(String[] args) {
new Test().setVisible(true);
}
}