Adapted from * http://stackoverflow.com/questions/638807/how-do-i-drag-and-drop-a-row-in-a-jtable * with the addition of keyboard support (ctrl-X and ctrl-V) for moving, * moving of multiple rows, and a couple of bug fixes. */ public class TableRowTransferHandler extends TransferHandler { private final JTable table; private final DataFlavor dataFlavor; private boolean validClip; private static class RowRange { int first; int last; RowRange (int first, int last) { this.first = first; this.last = last; } } private class RowRangeTransferable implements Transferable { private RowRange rowRange; public RowRangeTransferable (RowRange rowRange) { this.rowRange = rowRange; } @Override public Object getTransferData (DataFlavor flavor) throws UnsupportedFlavorException { if (flavor != dataFlavor) throw new UnsupportedFlavorException (flavor); return rowRange; } @Override public DataFlavor [] getTransferDataFlavors () { DataFlavor [] flavors = new DataFlavor [1]; flavors [0] = dataFlavor; return flavors; } @Override public boolean isDataFlavorSupported (DataFlavor flavor) { return flavor == dataFlavor; } } /** * Constructs a transfer handler for the supplied table. *
The table model must implement the {@link Reorderable} interface * to do the actual moving of table rows. * @param table the table */ private TableRowTransferHandler (JTable table) { TableModel model = table.getModel (); if (!(model instanceof Reorderable)) { throw new IllegalArgumentException ( "Table must implement Reorderable"); } this.table = table; dataFlavor = new DataFlavor (RowRange.class, "Integer Row Indices"); validClip = false; // Set up Ctrl-X and Ctrl-V to perform cut and paste actions // respectively. The actions are already in the ActionMap (provided // by Swing). InputMap inputMap = table.getInputMap (JComponent.WHEN_IN_FOCUSED_WINDOW); inputMap.put ( KeyStroke.getKeyStroke (KeyEvent.VK_X, InputEvent.CTRL_DOWN_MASK), "cut"); inputMap.put ( KeyStroke.getKeyStroke (KeyEvent.VK_V, InputEvent.CTRL_DOWN_MASK), "paste"); // Enable drag & drop. table.setDragEnabled (true); table.setDropMode (DropMode.INSERT_ROWS); // Listen for row insertions & deletions so that we can invalidate // any clip made using Ctrl-X. // Note that this includes any moves done via this transfer handler, // so Ctrl-V can only be used once for each use of Ctrl-X. model.addTableModelListener ( new TableModelListener () { public void tableChanged (TableModelEvent e) { validClip = false; } }); } /** * Sets a transfer handler on the specified table. *
The table model must implement the {@link Reorderable} interface * to do the actual moving of table rows. * @param table table. */ public static void setHandler (JTable table) { table.setTransferHandler (new TableRowTransferHandler (table)); } //--------- Export methods --------------- @Override public int getSourceActions (JComponent c) { // Only moves are supported. return TransferHandler.MOVE; } @Override protected Transferable createTransferable (JComponent c) { assert c == table; // Since we are only supporting moves of rows within the table, the // only data we need to export are the row indices. int [] rows = table.getSelectedRows (); if (rows.length == 0) return null; // Check that the selected rows are contiguous. for (int i = 1 ; i < rows.length ; i++) { if (rows [i] != rows [i - 1] + 1) return null; } validClip = true; RowRange range = new RowRange (rows [0], rows [rows.length - 1]); return new RowRangeTransferable (range); } @Override protected void exportDone (JComponent c, Transferable t, int act) { // The actual move of the row is done by the importData method, so // the only cleanup required is resetting the cursor. if (act == TransferHandler.MOVE || act == TransferHandler.NONE) { table.setCursor ( Cursor.getPredefinedCursor (Cursor.DEFAULT_CURSOR)); } } //--------- Import methods --------------- @Override public boolean canImport (TransferHandler.TransferSupport info) { assert (JTable) info.getComponent () == table; // According to the Java API, this method is only called during // dragging (and not before pasting). So 'info.isDrop ()' will // presumably always be true - but test it anyway, just in case. boolean b = validClip && info.isDrop () && info.isDataFlavorSupported (dataFlavor); if (b) { JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation (); int toRow = dl.getRow (); try { Transferable trans = info.getTransferable (); RowRange range = (RowRange) trans.getTransferData (dataFlavor); if (toRow >= range.first && toRow <= range.last) b = false; } catch (Exception e) { b = false; } } // Change the cursor even if we are returning false. We want to display // the "no drop" cursor if the user tries to drag something // inappropriate onto the table. table.setCursor (b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop); return b; } @Override public boolean importData (TransferHandler.TransferSupport info) { assert (JTable) info.getComponent () == table; if (!(validClip && info.isDataFlavorSupported (dataFlavor))) return false; int toRow; if (info.isDrop ()) { // Drop action. JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation (); toRow = dl.getRow (); } else { // Paste action. toRow = table.getSelectedRow () + 1; } int max = table.getModel ().getRowCount(); if (toRow < 0 || toRow > max) toRow = max; table.setCursor (Cursor.getPredefinedCursor (Cursor.DEFAULT_CURSOR)); try { Transferable trans = info.getTransferable (); RowRange range = (RowRange) trans.getTransferData (dataFlavor); if (toRow >= range.first && toRow <= range.last) return false; ((Reorderable) table.getModel ()).reorder (range.first, range.last, toRow); // Update the range so that it still refers to the same data, in // case the user pastes it again. if (toRow > range.first) toRow -= range.last - range.first + 1; range.last = toRow + (range.last - range.first); range.first = toRow; // Select the rows in their new position. table.getSelectionModel ().setSelectionInterval (range.first, range.last); return true; } catch (Exception e) { e.printStackTrace (); } return false; } }