Drag and drop to rearrange nodes in the JTree

• download example.jar
• download src.zip
• repository

Code

class TreeTransferHandler extends TransferHandler {
  private final DataFlavor nodesFlavor = new DataFlavor(
      List.class, "List of TreeNode");

  @Override public int getSourceActions(JComponent c) {
    return c instanceof JTree
        && TreeUtils.canStartDrag((JTree) c) ? COPY_OR_MOVE : NONE;
  }

  @Override protected Transferable createTransferable(JComponent c) {
    Transferable transferable = null;
    if (c instanceof JTree && ((JTree) c).getSelectionPaths() != null) {
      List<MutableTreeNode> copies = new ArrayList<>();
      Arrays.stream(((JTree) c).getSelectionPaths()).forEach(path -> {
        DefaultMutableTreeNode node =
            (DefaultMutableTreeNode) path.getLastPathComponent();
        DefaultMutableTreeNode clone =
            new DefaultMutableTreeNode(node.getUserObject());
        copies.add(TreeUtils.deepCopy(node, clone));
      });
      transferable = new Transferable() {
        @Override public DataFlavor[] getTransferDataFlavors() {
          return new DataFlavor[] {nodesFlavor};
        }

        @Override public boolean isDataFlavorSupported(
            DataFlavor flavor) {
          return Objects.equals(nodesFlavor, flavor);
        }

        @Override public Object getTransferData(DataFlavor flavor)
            throws UnsupportedFlavorException {
          if (isDataFlavorSupported(flavor)) {
            return copies;
          } else {
            throw new UnsupportedFlavorException(flavor);
          }
        }
      };
    }
    return transferable;
  }

  @Override public boolean canImport(TransferSupport support) {
    DropLocation dl = support.getDropLocation();
    Component c = support.getComponent();
    return support.isDrop()
        && support.isDataFlavorSupported(nodesFlavor)
        && c instanceof JTree
        && dl instanceof JTree.DropLocation
        && TreeUtils.canImportDropLocation(
            (JTree) c, (JTree.DropLocation) dl);
  }

  @Override public boolean importData(TransferSupport support) {
    Component c = support.getComponent();
    DropLocation dl = support.getDropLocation();
    Transferable transferable = support.getTransferable();
    return canImport(support)
        && c instanceof JTree
        && dl instanceof JTree.DropLocation
        && insertNode((JTree) c, (JTree.DropLocation) dl, transferable);
  }

  private boolean insertNode(
      JTree tree, JTree.DropLocation dl, Transferable transferable) {
    TreePath path = dl.getPath();
    Object p = path.getLastPathComponent();
    TreeModel m = tree.getModel();
    List<?> nodes = getTransferData(transferable);
    if (p instanceof MutableTreeNode && m instanceof DefaultTreeModel) {
      MutableTreeNode parent = (MutableTreeNode) p;
      DefaultTreeModel model = (DefaultTreeModel) m;
      int childIndex = dl.getChildIndex();
      AtomicInteger index = new AtomicInteger(
          getDropIndex(parent, childIndex));
      nodes.stream()
          .filter(MutableTreeNode.class::isInstance)
          .map(MutableTreeNode.class::cast)
          .forEach(n -> model.insertNodeInto(
               n, parent, index.getAndIncrement()));
    }
    return !nodes.isEmpty();
  }

  private static int getDropIndex(
      MutableTreeNode parent, int childIndex) {
    // Configure for drop mode.
    int index = childIndex; // DropMode.INSERT
    if (childIndex == -1) { // DropMode.ON
      index = parent.getChildCount();
    }
    return index;
  }

  private List<?> getTransferData(Transferable t) {
    List<?> nodes;
    try {
      nodes = (List<?>) t.getTransferData(nodesFlavor);
    } catch (UnsupportedFlavorException | IOException ex) {
      nodes = Collections.emptyList();
    }
    return nodes;
  }

  @Override protected void exportDone(
      JComponent src, Transferable data, int action) {
    if (src instanceof JTree && (action & MOVE) == MOVE) {
      cleanup((JTree) src);
    }
  }

  private void cleanup(JTree tree) {
    DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
    TreePath[] selectionPaths = tree.getSelectionPaths();
    if (selectionPaths != null) {
      for (TreePath path : selectionPaths) {
        model.removeNodeFromParent(
            (MutableTreeNode) path.getLastPathComponent());
      }
    }
  }
}

References

• JTree - drag and drop inside one tree - Java 1.6 (Swing / AWT / SWT forum at Coderanch)
• java - Drag and Drop nodes in JTree - Stack Overflow
• Drag and drop to rearrange nodes in the JTree(Japanese)

Create a new JFrame when the JTabbedPane tab is dropped outside the frame

• download example.jar
• download src.zip
• repository

Code

class TabDragSourceListener implements DragSourceListener {
  @Override public void dragEnter(DragSourceDragEvent e) {
    e.getDragSourceContext().setCursor(DragSource.DefaultMoveDrop);
  }

  @Override public void dragExit(DragSourceEvent e) {
    e.getDragSourceContext().setCursor(DragSource.DefaultMoveNoDrop);
  }

  @Override public void dragDropEnd(DragSourceDropEvent e) {
    Component c = e.getDragSourceContext().getComponent();
    JRootPane root = ((JComponent) c).getRootPane();
    Class<GhostGlassPane> clz = GhostGlassPane.class;
    Optional.ofNullable(root.getGlassPane())
        .filter(clz::isInstance).map(clz::cast)
        .ifPresent(p -> p.setVisible(false));
    boolean dropSuccess = e.getDropSuccess();
    Window w = SwingUtilities.getWindowAncestor(c);
    boolean outOfFrame = !w.getBounds().contains(e.getLocation());
    if (dropSuccess && outOfFrame && c instanceof DnDTabbedPane) {
      DnDTabbedPane src = (DnDTabbedPane) c;
      int index = src.dragTabIndex;
      final Component cmp = src.getComponentAt(index);
      final Component tab = src.getTabComponentAt(index);
      final String title = src.getTitleAt(index);
      final Icon icon = src.getIconAt(index);
      final String tip = src.getToolTipTextAt(index);
      src.remove(index);
      DnDTabbedPane tabs = new DnDTabbedPane();
      tabs.setTabLayoutPolicy(JTabbedPane.SCROLL_TAB_LAYOUT);
      tabs.addTab(title, icon, cmp, tip);
      tabs.setTabComponentAt(0, tab);
      JFrame frame = new JFrame();
      frame.getContentPane().add(tabs);
      frame.setSize(320, 240);
      frame.setLocation(e.getLocation());
      frame.setVisible(true);
    }
  }

  @Override public void dropActionChanged(DragSourceDragEvent e) {
    /* not needed */
  }

  @Override public void dragOver(DragSourceDragEvent e) {
    /* not needed */
  }
}

References

• Create a new JFrame when the JTabbedPane tab is dropped outside the frame(Japanese)

Create a custom drag ghost image

• download example.jar
• download src.zip
• repository

Code

class ListItemTransferHandler extends TransferHandler {
  @Override public int getSourceActions(JComponent c) {
    System.out.println("getSourceActions");
    if (!(c instanceof JList)) {
      return TransferHandler.NONE;
    }
    JList<?> source = (JList<?>) c;
    Point pt;
    if (compact) {
      int w = source.getFixedCellWidth();
      int h = source.getFixedCellHeight() - 20; // TODO: 20 ???
      setDragImage(createCompactDragImage(source, w, h));
      pt = new Point(w / 2, h);
    } else {
      setDragImage(createDragImage(source));
      pt = c.getMousePosition();
    }
    if (pt != null) {
      setDragImageOffset(pt);
    }
    return TransferHandler.MOVE; // TransferHandler.COPY_OR_MOVE;
  }

  private static BufferedImage createDragImage(JList source) {
    int w = source.getWidth();
    int h = source.getHeight();
    BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
    Graphics g = bi.getGraphics();
    DefaultListCellRenderer renderer =
      (DefaultListCellRenderer) source.getCellRenderer();
    for (int i : source.getSelectedIndices()) {
      Component c = renderer.getListCellRendererComponent(
          source, source.getModel().getElementAt(i), i, false, false);
      Rectangle rect = source.getCellBounds(i, i);
      SwingUtilities.paintComponent(g, c, source, rect);
    }
    g.dispose();
    return bi;
  }

  private BufferedImage createCompactDragImage(JList source, int w, int h) {
    BufferedImage br = null;
    if (w > 0 && h > 0) {
      br = source.getGraphicsConfiguration().createCompatibleImage(
          w, h, Transparency.TRANSLUCENT);
    } else {
      return null;
    }
    int[] selectedIndices = source.getSelectedIndices();
    int length = selectedIndices.length;
    Graphics g = br.getGraphics();
    DefaultListCellRenderer renderer =
      (DefaultListCellRenderer) source.getCellRenderer();
    int idx = selectedIndices[0];
    Object valueAt = source.getModel().getElementAt(idx);
    Component c = renderer.getListCellRendererComponent(
        source, valueAt, idx, false, false);
    Rectangle rect = source.getCellBounds(idx, idx);
    SwingUtilities.paintComponent(g, c, source, 0, 0, rect.width, rect.height);
    if (length > 1) {
      LABEL.setText(String.valueOf(length));
      Dimension d = LABEL.getPreferredSize();
      SwingUtilities.paintComponent(
          g, LABEL, source, (w - d.width) / 2, (h - d.height) / 2, d.width, d.height);
    }
    g.dispose();
    br.coerceData(true);
    return br;
  }
// ...

References

• Create a custom drag ghost image(Japanese)

Draggable and sortable JPanels

• download example.jar
• download src.zip
• repository

Code

class RearrangingHandler extends MouseAdapter {
  private static final Rectangle R1 = new Rectangle();
  private static final Rectangle R2 = new Rectangle();
  private final Rectangle prevRect = new Rectangle();
  private final int gestureMotionThreshold = DragSource.getDragThreshold();
  private final JWindow window = new JWindow();
  private final Point startPt = new Point();
  private int index = -1;
  private Component draggingComponent;
  private Component gap;
  private final Point dragOffset = new Point();

  public RearrangingHandler() {
    super();
    window.setBackground(new Color(0x0, true));
  }

  @Override public void mousePressed(MouseEvent e) {
    if (((JComponent) e.getComponent()).getComponentCount() <= 1) {
      startPt.setLocation(0, 0);
    } else {
      startPt.setLocation(e.getPoint());
    }
  }

  private void startDragging(JComponent parent, Point pt) {
    Component c = parent.getComponentAt(pt);
    index = parent.getComponentZOrder(c);
    if (Objects.equals(c, parent) || index < 0) {
      return;
    }
    draggingComponent = c;
    Dimension d = draggingComponent.getSize();

    Point dp = draggingComponent.getLocation();
    dragOffset.setLocation(pt.x - dp.x, pt.y - dp.y);

    gap = Box.createRigidArea(d);
    swapComponentLocation(parent, c, gap, index);

    window.add(draggingComponent);
    // window.setSize(d);
    window.pack();

    updateWindowLocation(pt, parent);
    window.setVisible(true);
  }

  private void updateWindowLocation(Point pt, JComponent parent) {
    if (window.isVisible() && Objects.nonNull(draggingComponent)) {
      Point p = new Point(pt.x - dragOffset.x, pt.y - dragOffset.y);
      SwingUtilities.convertPointToScreen(p, parent);
      window.setLocation(p);
    }
  }

  private int getTargetIndex(Rectangle r, Point pt, int i) {
    int ht2 = (int) (.5 + r.height * .5);
    R1.setBounds(r.x, r.y, r.width, ht2);
    R2.setBounds(r.x, r.y + ht2, r.width, ht2);
    if (R1.contains(pt)) {
      prevRect.setBounds(R1);
      return i - 1 > 0 ? i : 0;
    } else if (R2.contains(pt)) {
      prevRect.setBounds(R2);
      return i;
    }
    return -1;
  }

  private static void swapComponentLocation(
      Container parent, Component remove, Component add, int idx) {
    parent.remove(remove);
    parent.add(add, idx);
    parent.revalidate();
    parent.repaint();
  }

  @Override public void mouseDragged(MouseEvent e) {
    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();
    if (Objects.isNull(draggingComponent)) {
      if (startPt.distance(pt) > gestureMotionThreshold) {
        startDragging(parent, pt);
      }
      return;
    }
    updateWindowLocation(pt, parent);

    if (prevRect.contains(pt)) {
      return;
    }
    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      Rectangle r = c.getBounds();
      if (Objects.equals(c, gap) && r.contains(pt)) {
        return;
      }
      int tgt = getTargetIndex(r, pt, i);
      if (tgt >= 0) {
        swapComponentLocation(parent, gap, gap, tgt);
        return;
      }
    }
    // System.out.println("outer");
    parent.remove(gap);
    parent.revalidate();
  }

  @Override public void mouseReleased(MouseEvent e) {
    startPt.setLocation(0, 0);
    dragOffset.setLocation(0, 0);
    prevRect.setBounds(0, 0, 0, 0);
    window.setVisible(false);

    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();
    Component cmp = draggingComponent;
    draggingComponent = null;

    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      if (Objects.equals(c, gap)) {
        swapComponentLocation(parent, gap, cmp, i);
        return;
      }
      int tgt = getTargetIndex(c.getBounds(), pt, i);
      if (tgt >= 0) {
        swapComponentLocation(parent, gap, cmp, tgt);
        return;
      }
    }
    if (parent.getParent().getBounds().contains(pt)) {
      swapComponentLocation(parent, gap, cmp, parent.getComponentCount());
    } else {
      swapComponentLocation(parent, gap, cmp, index);
    }
  }
}

References

• Draggable and sortable JPanels(Japanese)
• Rearrange JToolBar icons(Japanese)
• swing - Java, drag and drop to change the order of panels - Stack Overflow

Rearrange JToolBar icon by drag and drop

• download example.jar
• download src.zip
• repository

Code

class DragHandler extends MouseAdapter {
  private final JWindow window = new JWindow();
  private Component draggingComponent = null;
  private int index = -1;
  private Component gap = Box.createHorizontalStrut(24);
  private Point startPt = null;
  private int gestureMotionThreshold = DragSource.getDragThreshold();
  public DragHandler() {
    window.setBackground(new Color(0x0, true));
  }

  @Override public void mousePressed(MouseEvent e) {
    JComponent parent = (JComponent) e.getComponent();
    if (parent.getComponentCount() <= 1) {
      startPt = null;
      return;
    }
    startPt = e.getPoint();
  }

  @Override public void mouseDragged(MouseEvent e) {
    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();
    if (startPt != null && startPt.distance(pt) > gestureMotionThreshold) {
      startPt = null;
      Component c = parent.getComponentAt(pt);
      index = parent.getComponentZOrder(c);
      if (c == parent || index < 0) {
        return;
      }
      draggingComponent = c;

      parent.remove(draggingComponent);
      parent.add(gap, index);
      parent.revalidate();
      parent.repaint();

      window.add(draggingComponent);
      window.pack();

      Dimension d = draggingComponent.getPreferredSize();
      Point p = new Point(pt.x - d.width / 2, pt.y - d.height / 2);
      SwingUtilities.convertPointToScreen(p, parent);
      window.setLocation(p);
      window.setVisible(true);

      return;
    }
    if (!window.isVisible() || draggingComponent == null) {
      return;
    }

    Dimension d = draggingComponent.getPreferredSize();
    Point p = new Point(pt.x - d.width / 2, pt.y - d.height / 2);
    SwingUtilities.convertPointToScreen(p, parent);
    window.setLocation(p);

    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      Rectangle r = c.getBounds();
      Rectangle r1 = new Rectangle(r.x, r.y, r.width / 2, r.height);
      Rectangle r2 = new Rectangle(r.x + r.width / 2, r.y, r.width / 2, r.height);
      if (r1.contains(pt)) {
        if (c == gap) {
          return;
        }
        int n = i - 1 >= 0 ? i : 0;
        parent.remove(gap);
        parent.add(gap, n);
        parent.revalidate();
        parent.repaint();
        return;
      } else if (r2.contains(pt)) {
        if (c == gap) {
          return;
        }
        parent.remove(gap);
        parent.add(gap, i);
        parent.revalidate();
        parent.repaint();
        return;
      }
    }
    parent.remove(gap);
    parent.revalidate();
    parent.repaint();
  }

  @Override public void mouseReleased(MouseEvent e) {
    startPt = null;
    if (!window.isVisible() || draggingComponent == null) {
      return;
    }
    Point pt = e.getPoint();
    JComponent parent = (JComponent) e.getComponent();

    Component cmp = draggingComponent;
    draggingComponent = null;
    window.setVisible(false);

    for (int i = 0; i < parent.getComponentCount(); i++) {
      Component c = parent.getComponent(i);
      Rectangle r = c.getBounds();
      Rectangle r1 = new Rectangle(r.x, r.y, r.width / 2, r.height);
      Rectangle r2 = new Rectangle(r.x + r.width / 2, r.y, r.width / 2, r.height);
      if (r1.contains(pt)) {
        int n = i - 1 >= 0 ? i : 0;
        parent.remove(gap);
        parent.add(cmp, n);
        parent.revalidate();
        parent.repaint();
        return;
      } else if (r2.contains(pt)) {
        parent.remove(gap);
        parent.add(cmp, i);
        parent.revalidate();
        parent.repaint();
        return;
      }
    }
    if (parent.getBounds().contains(pt)) {
      parent.remove(gap);
      parent.add(cmp);
    } else {
      parent.remove(gap);
      parent.add(cmp, index);
    }
    parent.revalidate();
    parent.repaint();
  }
}

References

• Rearrange JToolBar icon by drag and drop(Japanese)

Sharing tabs between 2 JFrames

• download example.jar
• download src.zip
• repository

Code

class DropLocationLayerUI extends LayerUI<DnDTabbedPane> {
  private static final int LINEWIDTH = 3;
  private final Rectangle lineRect = new Rectangle();
  @Override public void paint(Graphics g, JComponent c) {
    super.paint(g, c);
    if (c instanceof JLayer) {
      JLayer layer = (JLayer) c;
      DnDTabbedPane tabbedPane = (DnDTabbedPane) layer.getView();
      DnDTabbedPane.DropLocation loc = tabbedPane.getDropLocation();
      if (loc != null && loc.isDroppable() && loc.getIndex() >= 0) {
        Graphics2D g2 = (Graphics2D) g.create();
        g2.setComposite(
            AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f));
        g2.setColor(Color.RED);
        initLineRect(tabbedPane, loc);
        g2.fill(lineRect);
        g2.dispose();
      }
    }
  }

  private void initLineRect(JTabbedPane tabbedPane, DnDTabbedPane.DropLocation loc) {
    int index = loc.getIndex();
    int a = index == 0 ? 0 : 1;
    Rectangle r = tabbedPane.getBoundsAt(a * (index - 1));
    if (tabbedPane.getTabPlacement() == JTabbedPane.TOP
        || tabbedPane.getTabPlacement() == JTabbedPane.BOTTOM) {
      lineRect.setBounds(
        r.x - LINE_WIDTH / 2 + r.width * a, r.y, LINE_WIDTH, r.height);
    } else {
      lineRect.setBounds(
        r.x, r.y - LINE_WIDTH / 2 + r.height * a, r.width, LINE_WIDTH);
    }
  }
}

// ...
private final JLabel label = new JLabel() {
  @Override public boolean contains(int x, int y) {
    return false;
  }
};
private final JWindow dialog = new JWindow();
public TabTransferHandler() {
  dialog.add(label);
  // dialog.setAlwaysOnTop(true); // Web Start
  dialog.setOpacity(.5f);
  // com.sun.awt.AWTUtilities.setWindowOpacity(dialog, .5f); // JDK 1.6.0
  DragSource.getDefaultDragSource().addDragSourceMotionListener(
      new DragSourceMotionListener() {
    @Override public void dragMouseMoved(DragSourceDragEvent dsde) {
      Point pt = dsde.getLocation();
      pt.translate(5, 5); // offset
      dialog.setLocation(pt);
    }
  });
// ...

References

• Sharing tabs between 2 JFrames(Japanese)
• Free the pixel: GHOST drag and drop, over multiple windows

JTable group directories first sorting

• download example.jar
• download src.zip
• repository

Code

// > dir /O:GN
// > ls --group-directories-first
class FileGroupComparator extends DefaultFileComparator {
  private static final long serialVersionUID = 1L;
  private final JTable table;
  public FileGroupComparator(JTable table, int column) {
    super(column);
    this.table = table;
  }

  @Override public int compare(File a, File b) {
    int flag = 1;
    List<? extends TableRowSorter.SortKey> keys =
        table.getRowSorter().getSortKeys();
    if (!keys.isEmpty()) {
      TableRowSorter.SortKey sortKey = keys.get(0);
      if (sortKey.getColumn() == column &&
          sortKey.getSortOrder() == SortOrder.DESCENDING) {
        flag = -1;
      }
    }
    if (a.isDirectory() && !b.isDirectory()) {
      return -1 * flag;
    } else if (!a.isDirectory() && b.isDirectory()) {
      return 1 * flag;
    } else {
      return super.compare(a, b);
    }
  }
}

References

• JTable group directories first sorting(Japanese)

Drag and Drop between JLists

• download example.jar
• download src.zip
• repository

Code

class ListItemTransferHandler extends TransferHandler {
  protected final DataFlavor localObjectFlavor;
  protected JList<?> source;
  protected int[] indices;
  protected int addIndex = -1;
  protected int addCount;

  protected ListItemTransferHandler() {
    super();
    localObjectFlavor = new DataFlavor(List.class, "List of items");
  }

  @Override protected Transferable createTransferable(JComponent c) {
    source = (JList<?>) c;
    indices = source.getSelectedIndices();
    List<?> transferredObjects = source.getSelectedValuesList();
    return new Transferable() {
      @Override public DataFlavor[] getTransferDataFlavors() {
        return new DataFlavor[] {localObjectFlavor};
      }

      @Override public boolean isDataFlavorSupported(DataFlavor flavor) {
        return Objects.equals(localObjectFlavor, flavor);
      }

      @Override public Object getTransferData(DataFlavor flavor)
          throws UnsupportedFlavorException, IOException {
        if (isDataFlavorSupported(flavor)) {
          return transferredObjects;
        } else {
          throw new UnsupportedFlavorException(flavor);
        }
      }
    };
  }

  @Override public boolean canImport(TransferHandler.TransferSupport info) {
    return info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
  }

  @Override public int getSourceActions(JComponent c) {
    return TransferHandler.MOVE;
  }

  @SuppressWarnings("unchecked")
  @Override public boolean importData(TransferHandler.TransferSupport info) {
    TransferHandler.DropLocation tdl = info.getDropLocation();
    if (!(tdl instanceof JList.DropLocation)) {
      return false;
    }
    JList.DropLocation dl = (JList.DropLocation) tdl;
    JList<?> target = (JList<?>) info.getComponent();
    DefaultListModel listModel = (DefaultListModel) target.getModel();
    int max = listModel.getSize();
    int index = dl.getIndex();
    index = index < 0 ? max : index;
    index = Math.min(index, max);
    addIndex = index;
    try {
      List<?> values = (List<?>) info.getTransferable().getTransferData(
        localObjectFlavor);
      for (Object o : values) {
        int i = index++;
        listModel.add(i, o);
        target.addSelectionInterval(i, i);
      }
      // ---->
      addCount = target.equals(source) ? values.size() : 0;
      // <----
      return true;
    } catch (UnsupportedFlavorException | IOException ex) {
      ex.printStackTrace();
    }
    return false;
  }
  // ...

References

• Demo - BasicDnD (The Java™ Tutorials > Creating a GUI With JFC/Swing > Drag and Drop and Data Transfer)
• Drag and Drop between JLists(Japanese)

TabTransferHandler

• download example.jar
• download src.zip
• repository

Code

class TabTransferHandler extends TransferHandler {
  private final DataFlavor localObjectFlavor = new DataFlavor(DnDTabData.class, "DnDTabData");
  private DnDTabbedPane source = null;

  @Override protected Transferable createTransferable(JComponent c) {
    System.out.println("createTransferable");
    if (c instanceof DnDTabbedPane) source = (DnDTabbedPane) c;
    return new Transferable() {
      @Override public DataFlavor[] getTransferDataFlavors() {
        return new DataFlavor[] {localObjectFlavor};
      }

      @Override public boolean isDataFlavorSupported(DataFlavor flavor) {
        return Objects.equals(localObjectFlavor, flavor);
      }

      @Override public Object getTransferData(DataFlavor flavor) 
            throws UnsupportedFlavorException, IOException {
        if (isDataFlavorSupported(flavor)) {
          return new DnDTabData(source);
        } else {
           throw new UnsupportedFlavorException(flavor);
        }
      }
    };
  }

  @Override public boolean canImport(TransferSupport support) {
    // System.out.println("canImport");
    if (!support.isDrop() || !support.isDataFlavorSupported(localObjectFlavor)) {
      return false;
    }
    support.setDropAction(TransferHandler.MOVE);
    DropLocation tdl = support.getDropLocation();
    Point pt = tdl.getDropPoint();
    DnDTabbedPane target = (DnDTabbedPane) support.getComponent();
    target.autoScrollTest(pt);
    DnDTabbedPane.DropLocation dl =
      (DnDTabbedPane.DropLocation) target.dropLocationForPoint(pt);
    int idx = dl.getIndex();
    boolean isDroppable = false;

    if (target == source) {
      isDroppable = target.getTabAreaBounds().contains(pt) && idx >= 0 &&
                   idx != target.dragTabIndex && idx != target.dragTabIndex + 1;
    } else {
      if (source != null && target != source.getComponentAt(source.dragTabIndex)) {
        isDroppable = target.getTabAreaBounds().contains(pt) && idx >= 0;
      }
    }

    Component c = target.getRootPane().getGlassPane();
    c.setCursor(isDroppable?DragSource.DefaultMoveDrop:DragSource.DefaultMoveNoDrop);
    if (isDroppable) {
      support.setShowDropLocation(true);
      dl.setDroppable(true);
      target.setDropLocation(dl, null, true);
      return true;
    } else {
      support.setShowDropLocation(false);
      dl.setDroppable(false);
      target.setDropLocation(dl, null, false);
      return false;
    }
  }

  private BufferedImage makeDragTabImage(DnDTabbedPane tabbedPane) {
    Rectangle rect = tabbedPane.getBoundsAt(tabbedPane.dragTabIndex);
    BufferedImage image = new BufferedImage(
      tabbedPane.getWidth(), tabbedPane.getHeight(), BufferedImage.TYPE_INT_ARGB);
    Graphics g = image.getGraphics();
    tabbedPane.paint(g);
    g.dispose();
    if (rect.x < 0) {
      rect.translate(-rect.x, 0);
    }
    if (rect.y < 0) {
      rect.translate(0, -rect.y);
    }
    if (rect.x + rect.width > image.getWidth()) {
      rect.width = image.getWidth() - rect.x;
    }
    if (rect.y + rect.height > image.getHeight()) {
      rect.height = image.getHeight() - rect.y;
    }
    return image.getSubimage(rect.x, rect.y, rect.width, rect.height);
  }

  @Override public int getSourceActions(JComponent c) {
    System.out.println("getSourceActions");
    if (c instanceof DnDTabbedPane) {
      DnDTabbedPane src = (DnDTabbedPane) c;
      c.getRootPane().setGlassPane(new GhostGlassPane(src));
      if (src.dragTabIndex < 0) {
        return TransferHandler.NONE;
      }
      setDragImage(makeDragTabImage(src));
      c.getRootPane().getGlassPane().setVisible(true);
      return TransferHandler.MOVE;
    }
    return TransferHandler.NONE;
  }

  @Override public boolean importData(TransferSupport support) {
    System.out.println("importData");

    DnDTabbedPane target = (DnDTabbedPane) support.getComponent();
    DnDTabbedPane.DropLocation dl = target.getDropLocation();
    try {
      DnDTabbedPane source = (DnDTabbedPane) support.getTransferable()
        .getTransferData(localObjectFlavor);
      int index = dl.getIndex(); //boolean insert = dl.isInsert();
      if (target == source) {
        source.convertTab(source.dragTabIndex, index);
      } else {
        source.exportTab(source.dragTabIndex, target, index);
      }
      return true;
    } catch (UnsupportedFlavorException ufe) {
      ufe.printStackTrace();
    } catch (IOException ioe) {
      ioe.printStackTrace();
    }
    return false;
  }

  @Override protected void exportDone(JComponent c, Transferable data, int action) {
    System.out.println("exportDone");
    DnDTabbedPane src = (DnDTabbedPane) c;
    c.getRootPane().getGlassPane().setVisible(false);
    src.setDropLocation(null, null, false);
  }
}

References

• DnDTabbedPane
• DnDExportTabbedPane(Japanese)

Drag rows from one JTable to another JTable

• download example.jar
• download src.zip
• repository

Code

class TableRowTransferHandler extends TransferHandler {
  private final DataFlavor localObjectFlavor;
  private int[] indices;
  private int addIndex = -1; // Location where items were added
  private int addCount; // Number of items added.
  private JComponent source;

  public TableRowTransferHandler() {
    super();
    localObjectFlavor = new DataFlavor(Object[].class, "Array of items");
  }

  @Override protected Transferable createTransferable(JComponent c) {
    source = c;
    JTable table = (JTable) c;
    DefaultTableModel model = (DefaultTableModel) table.getModel();
    List<Object> list = new ArrayList<>();
    indices = table.getSelectedRows();
    for (int i : indices) {
      list.add(model.getDataVector().elementAt(i));
    }
    Object[] transferredObjects = list.toArray();
    return new Transferable() {
      @Override public DataFlavor[] getTransferDataFlavors() {
        return new DataFlavor[] {FLAVOR};
      }

      @Override public boolean isDataFlavorSupported(DataFlavor flavor) {
        return Objects.equals(FLAVOR, flavor);
      }

      @Override public Object getTransferData(DataFlavor flavor)
            throws UnsupportedFlavorException, IOException {
        if (isDataFlavorSupported(flavor)) {
          return nodes;
        } else {
          throw new UnsupportedFlavorException(flavor);
        }
      }
    };
  }

  @Override public boolean canImport(TransferSupport info) {
    JTable table = (JTable) info.getComponent();
    boolean isDroppable = info.isDrop()
      && info.isDataFlavorSupported(localObjectFlavor);
    // XXX bug?
    table.setCursor(isDroppable ? DragSource.DefaultMoveDrop
                                : DragSource.DefaultMoveNoDrop);
    return isDroppable;
  }

  @Override public int getSourceActions(JComponent c) {
    return TransferHandler.MOVE; //TransferHandler.COPY_OR_MOVE;
  }

  @Override public boolean importData(TransferSupport info) {
    TransferHandler.DropLocation tdl = info.getDropLocation();
    if (!(tdl instanceof JTable.DropLocation)) {
      return false;
    }
    JTable.DropLocation dl = (JTable.DropLocation) tdl;
    JTable target = (JTable) info.getComponent();
    DefaultTableModel model = (DefaultTableModel) target.getModel();
    int index = dl.getRow();
    // boolean insert = dl.isInsert();
    int max = model.getRowCount();
    if (index < 0 || index > max) {
      index = max;
    }
    addIndex = index;
    target.setCursor(Cursor.getDefaultCursor());
    try {
      Object[] values =
        (Object[]) info.getTransferable().getTransferData(localObjectFlavor);
      if (Objects.equals(source, target)) {
        addCount = values.length;
      }
      for (int i = 0; i < values.length; i++) {
        int idx = index++;
        // model.insertRow(idx, (Vector<?>) values[i]);
        model.insertRow(i, ((List<?>) o).toArray(new Object[0]));
        target.getSelectionModel().addSelectionInterval(idx, idx);
      }
      return true;
    } catch (UnsupportedFlavorException | IOException ex) {
      ex.printStackTrace();
    }
    return false;
  }

  @Override protected void exportDone(
      JComponent c, Transferable data, int action) {
    cleanup(c, action == MOVE);
  }

  private void cleanup(JComponent c, boolean remove) {
    if (remove && indices != null) {
      c.setCursor(Cursor.getDefaultCursor());
      DefaultTableModel model = (DefaultTableModel) ((JTable) c).getModel();
      if (addCount > 0) {
        for (int i = 0; i < indices.length; i++) {
          if (indices[i] >= addIndex) {
            indices[i] += addCount;
          }
        }
      }
      for (int i = indices.length - 1; i >= 0; i--) {
        model.removeRow(indices[i]);
      }
    }
    indices = null;
    addCount = 0;
    addIndex = -1;
  }
}

References

• Drag rows from one JTable to another JTable(Japanese)

rubber band selection, drag and drop reordering

• download example.jar
• download src.zip
• repository

Code

JList list = new JList(model);
list.setLayoutOrientation(JList.HORIZONTAL_WRAP);
list.setVisibleRowCount(0);
list.setFixedCellWidth(62);
list.setFixedCellHeight(62);
list.setCellRenderer(new IconListCellRenderer());
RubberBandingListener rbl = new RubberBandingListener();
list.addMouseMotionListener(rbl);
list.addMouseListener(rbl);
list.getSelectionModel().setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
list.setTransferHandler(new ListItemTransferHandler());
list.setDropMode(DropMode.INSERT);

References

• Demo - BasicDnD (The Java™ Tutorials > Creating a GUI With JFC/Swing > Drag and Drop and Data Transfer)
• Drag and drop for non-String objects
• XP Style Icons - Windows Application Icon, Software XP Icons
• rubber band selection, drag and drop reordering(Japanese)

Mouse Drag Auto Scrolling

• download example.jar
• download src.zip
• repository

Code

class ViewportDragScrollListener extends MouseAdapter
                                 implements HierarchyListener {
  private static final int SPEED = 4;
  private static final int DELAY = 10;
  private final Cursor dc;
  private final Cursor hc = Cursor.getPredefinedCursor(Cursor.HAND_CURSOR);
  private final Timer scroller;
  private final JComponent label;
  private Point startPt = new Point();
  private Point move    = new Point();

  public ViewportDragScrollListener(JComponent comp) {
    this.label = comp;
    this.dc = comp.getCursor();
    this.scroller = new Timer(DELAY, new ActionListener() {
      @Override public void actionPerformed(ActionEvent e) {
        Container c = SwingUtilities.getAncestorOfClass(
            JViewport.class, label);
        if (c instanceof JViewport.class) {
          JViewport vport = (JViewport) c;
          Rectangle rect = vport.getViewRect();
          rect.translate(move.x, move.y);
          label.scrollRectToVisible(rect);
        }
      }
    });
  }

  @Override public void hierarchyChanged(HierarchyEvent e) {
    JComponent c = (JComponent) e.getSource();
    if ((e.getChangeFlags() & HierarchyEvent.DISPLAYABILITY_CHANGED) != 0
        && !c.isDisplayable()) {
      scroller.stop();
    }
  }

  @Override public void mouseDragged(MouseEvent e) {
    JViewport vport = (JViewport) e.getSource();
    Point pt = e.getPoint();
    int dx = startPt.x - pt.x;
    int dy = startPt.y - pt.y;
    Rectangle rect = vport.getViewRect();
    rect.translate(dx, dy);
    label.scrollRectToVisible(rect);
    move.setLocation(SPEED * dx, SPEED * dy);
    startPt.setLocation(pt);
  }

  @Override public void mousePressed(MouseEvent e) {
    e.getComponent().setCursor(hc); // label.setCursor(hc);
    startPt.setLocation(e.getPoint());
    move.setLocation(0, 0);
    scroller.stop();
  }

  @Override public void mouseReleased(MouseEvent e) {
    e.getComponent().setCursor(dc); // label.setCursor(dc);
    scroller.start();
  }

  @Override public void mouseExited(MouseEvent e) {
    e.getComponent().setCursor(dc); // label.setCursor(dc);
    move.setLocation(0, 0);
    scroller.stop();
  }
}

References

• http://sozai-free.com/
• Mouse Drag Auto Scrolling(Japanese)
• Java Swing Tips: Mouse Dragging ViewPort Scroll

Drag and Drop the Tabs in JTabbedPane

• download example.jar
• download src.zip
• repository
• alternative version(JDK 1.6 TransferHandler)
• alternative version(JDK 1.7 JLayer)

Code

protected int getTargetTabIndex(Point glassPt) {
  int count = getTabCount();
  if (count == 0) {
    return -1;
  }

  Point tabPt = SwingUtilities.convertPoint(glassPane, glassPt, this);
  boolean isHorizontal = isTopBottomTabPlacement(getTabPlacement());
  for (int i = 0; i < count; ++i) {
    Rectangle r = getBoundsAt(i);

    // First half.
    if (isHorizontal) {
      r.width = r.width / 2 + 1;
    } else {
      r.height = r.height / 2 + 1;
    }
    if (r.contains(tabPt)) {
      return i;
    }

    // Second half.
    if (isHorizontal) {
      r.x += r.width;
    } else {
      r.y += r.height;
    }
    if (r.contains(tabPt)) {
      return i + 1;
    }
  }
  Rectangle r = getBoundsAt(getTabCount() - 1);
  r.translate(r.width * d.x / 2, r.height * d.y / 2);
  return r.contains(tabPt) ? getTabCount() : -1;
}

private void convertTab(int prev, int next) {
  if (next < 0 || prev == next) {
    return;
  }
  Component cmp = getComponentAt(prev);
  Component tab = getTabComponentAt(prev);
  String str    = getTitleAt(prev);
  Icon icon     = getIconAt(prev);
  String tip    = getToolTipTextAt(prev);
  boolean flg   = isEnabledAt(prev);
  int tgtindex  = prev > next ? next : next - 1;
  remove(prev);
  insertTab(str, icon, cmp, tip, tgtindex);
  setEnabledAt(tgtindex, flg);

  // When you drag'n'drop a disabled tab, it finishes enabled and selected.
  // pointed out by dlorde
  if (flg) {
    setSelectedIndex(tgtindex);
  }

  // I have a component in all tabs (jlabel with an X to close the tab)
  // and when i move a tab the component disappear.
  // pointed out by Daniel Dario Morales Salas
  setTabComponentAt(tgtindex, tab);
}

References

• alternative version(JDK 1.6 TransferHandler)
• DnDTabbedPane(Japanese)