Swing/DragRowsAnotherTable のバックアップ(No.19)

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[] transferedObjects = 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) {
    if (!canImport(info)) {
      return false;
    }
    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.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
    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]);
        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.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
      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;
  }
}