问题
I have JTable with some rows. I want when move one row with mouse(drag and drop) that row to move together with mouse and table rows to be reorder when mouse move(like moving JTable's columns). This jsfiddle is exactly what i want but i have to do it in java swing(or gif image below. Example is from here but I can't understand it).
My TransferHandler :
public class TableRowTransferHandler extends TransferHandler {
private final DataFlavor localObjectFlavor = new ActivationDataFlavor(Integer.class, "application/x-java-Integer;class=java.lang.Integer", "Integer Row Index");
private JTable table = null;
private static final Logger logger = Logger.getLogger(TableRowTransferHandler.class.getName());
public TableRowTransferHandler(JTable table) {
this.table = table;
}
@Override
protected Transferable createTransferable(JComponent c) {
assert (c == table);
return new DataHandler(table.getSelectedRow(), localObjectFlavor.getMimeType());
}
@Override
public boolean canImport(TransferHandler.TransferSupport info) {
boolean b = info.getComponent() == table && info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(b ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return b;
}
@Override
public int getSourceActions(JComponent c) {
return TransferHandler.COPY_OR_MOVE;
}
@Override
public boolean importData(TransferHandler.TransferSupport info) {
JTable target = (JTable) info.getComponent();
JTable.DropLocation dl = (JTable.DropLocation) info.getDropLocation();
int index = dl.getRow();
int max = table.getModel().getRowCount();
if (index < 0 || index > max) {
index = max;
}
target.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
try {
Integer rowFrom = (Integer) info.getTransferable().getTransferData(localObjectFlavor);
if (rowFrom != -1 && rowFrom != index) {
((Reorderable) table.getModel()).reorder(rowFrom, index);
if (index > rowFrom) {
index--;
}
target.getSelectionModel().addSelectionInterval(index, index);
return true;
}
} catch (UnsupportedFlavorException | IOException e) {
e.printStackTrace();
logger.log(Level.SEVERE, null, e);
}
return false;
}
@Override
protected void exportDone(JComponent c, Transferable t, int act) {
if ((act == TransferHandler.MOVE) || (act == TransferHandler.NONE)) {
table.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
}
}
That is a simple settings that i use to JTable:
childrenTable.setDragEnabled(true);
childrenTable.setDropMode(DropMode.INSERT);
childrenTable.setTransferHandler(new TableRowTransferHandler(childrenTable));
childrenTable.setRowSelectionAllowed(true);
childrenTable.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
At the moment when you move row with mouse between rows only have one bold line(Like this in red ellipse below in image). If it is impossible to do rows to move like this, i want this bold line to appear to whole row (not only in one cell).
回答1:
Read the section from the Swing tutorial on Drag and Drop for the basics.
Here is some old code I found somewhere on the web with a custom TransferHandler to support a JTable:
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
import java.io.IOException;
public class DnD_Demo extends JFrame {
public DnD_Demo() {
setTitle("DnD Demo (Version 3)");
JTextArea tips = new JTextArea("1. Select a row in Table A. " +
"Press the row again and drag. \n " +
"As you drag the cursor icon over Table B, the row that is currently under the cursor highlights " +
"- the new data will be inserted after the selected row. \n " +
"Drop the row onto Table B. Note that the row has been removed from Table A, " +
"and now appears in Table B. \n" +
"2. Select two rows from Table A and drop onto Table B. " +
"Now there are two new rows in Table B. ");
tips.setEditable(false);
tips.setBackground(new Color(255,255,204));
tips.setBorder(new LineBorder(Color.orange,5));
getContentPane().add(tips,BorderLayout.NORTH);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel(new GridLayout(2,1));
panel.add(createTable("Table A"));
panel.add(createTable("Table B"));
getContentPane().add(panel,BorderLayout.CENTER);
pack();
}
private JPanel createTable(String tableId) {
DefaultTableModel model = new DefaultTableModel();
model.addColumn("Column 0");
model.addColumn("Column 1");
model.addColumn("Column 2");
model.addColumn("Column 3");
model.addRow(new String[]{tableId+" 00", tableId+" 01", tableId+" 02", tableId+" 03"});
model.addRow(new String[]{tableId+" 10", tableId+" 11", tableId+" 12", tableId+" 13"});
model.addRow(new String[]{tableId+" 20", tableId+" 21", tableId+" 22", tableId+" 23"});
model.addRow(new String[]{tableId+" 30", tableId+" 31", tableId+" 32", tableId+" 33"});
JTable table = new JTable(model);
table.getTableHeader().setReorderingAllowed(false);
table.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
JScrollPane scrollPane = new JScrollPane(table);
scrollPane.setPreferredSize(new Dimension(400,100));
table.setDragEnabled(true);
table.setTransferHandler(new TableTransferHandler());
JPanel panel = new JPanel();
panel.add(scrollPane);
panel.setBorder(BorderFactory.createTitledBorder(tableId));
return panel;
}
public static void main(String[] args) {
new DnD_Demo().setVisible(true);
}
abstract class StringTransferHandler extends TransferHandler {
protected abstract String exportString(JComponent c);
protected abstract void importString(JComponent c, String str);
protected abstract void cleanup(JComponent c, boolean remove);
protected Transferable createTransferable(JComponent c) {
return new StringSelection(exportString(c));
}
public int getSourceActions(JComponent c) {
return COPY_OR_MOVE;
}
public boolean importData(JComponent c, Transferable t) {
if (canImport(c, t.getTransferDataFlavors())) {
try {
String str = (String)t.getTransferData(DataFlavor.stringFlavor);
importString(c, str);
return true;
} catch (UnsupportedFlavorException ufe) {
} catch (IOException ioe) {
}
}
return false;
}
protected void exportDone(JComponent c, Transferable data, int action) {
cleanup(c, action == MOVE);
}
public boolean canImport(JComponent c, DataFlavor[] flavors) {
for (int i = 0; i < flavors.length; i++) {
if (DataFlavor.stringFlavor.equals(flavors[i])) {
return true;
}
}
return false;
}
}
class TableTransferHandler extends StringTransferHandler {
public JTable target;
public int[] rows = null;
public int addIndex = -1; //Location where items were added
public int addCount = 0; //Number of items added.
protected String exportString(JComponent c) {
JTable table = (JTable)c;
rows = table.getSelectedRows();
int colCount = table.getColumnCount();
StringBuffer buff = new StringBuffer();
for (int i = 0; i < rows.length; i++) {
for (int j = 0; j < colCount; j++) {
Object val = table.getValueAt(rows[i], j);
buff.append(val == null ? "" : val.toString());
if (j != colCount - 1) {
buff.append(",");
}
}
if (i != rows.length - 1) {
buff.append("\n");
}
}
return buff.toString();
}
protected void importString(JComponent c, String str) {
target = (JTable)c;
DefaultTableModel model = (DefaultTableModel)target.getModel();
int index = target.getSelectedRow();
//Prevent the user from dropping data back on itself.
//For example, if the user is moving rows #4,#5,#6 and #7 and
//attempts to insert the rows after row #5, this would
//be problematic when removing the original rows.
//So this is not allowed.
if (rows != null && index >= rows[0] - 1 &&
index <= rows[rows.length - 1]) {
rows = null;
return;
}
int max = model.getRowCount();
if (index < 0) {
index = max;
} else {
index++;
if (index > max) {
index = max;
}
}
addIndex = index;
String[] values = str.split("\n");
addCount = values.length;
int colCount = target.getColumnCount();
for (int i = 0; i < values.length ; i++) {
model.insertRow(index++, values[i].split(","));
}
//If we are moving items around in the same table, we
//need to adjust the rows accordingly, since those
//after the insertion point have moved.
if (rows!= null && addCount > 0) {
for (int i = 0; i < rows.length; i++) {
if (rows[i] > addIndex) {
rows[i] += addCount;
}
}
}
}
protected void cleanup(JComponent c, boolean remove) {
JTable source = (JTable)c;
if (remove && rows != null) {
DefaultTableModel model =
(DefaultTableModel)source.getModel();
for (int i = rows.length - 1; i >= 0; i--) {
model.removeRow(rows[i]);
}
}
rows = null;
addCount = 0;
addIndex = -1;
}
}
}
回答2:
I think that ListTransferHandler.java for item swapping of JList in the Swing tutorial will be also helpful.
Here is an example that I modified ListTransferHandler for JTable:
import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.dnd.*;
import java.awt.event.*;
import java.io.IOException;
import java.util.*;
import java.util.List;
import javax.activation.*;
import javax.swing.*;
import javax.swing.table.*;
public final class TableRowsDnDTest {
private final TransferHandler handler = new TableRowTransferHandler();
private final String[] columnNames = {"String", "Integer", "Boolean"};
private final Object[][] data = {
{"AAA", 12, true}, {"aaa", 1, false},
{"BBB", 13, true}, {"bbb", 2, false},
{"CCC", 15, true}, {"ccc", 3, false},
{"DDD", 17, true}, {"ddd", 4, false},
{"EEE", 18, true}, {"eee", 5, false},
{"FFF", 19, true}, {"fff", 6, false},
{"GGG", 92, true}, {"ggg", 0, false}
};
private final TableModel model = new DefaultTableModel(data, columnNames) {
@Override public Class<?> getColumnClass(int column) {
switch (column) {
case 0:
return String.class;
case 1:
return Number.class;
case 2:
return Boolean.class;
default:
return super.getColumnClass(column);
}
}
};
private final JTable table = new JTable(model);
public JComponent makeUI() {
table.getSelectionModel().setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
table.setTransferHandler(handler);
table.setDropMode(DropMode.INSERT_ROWS);
table.setDragEnabled(true);
table.setFillsViewportHeight(true);
//table.setAutoCreateRowSorter(true); //XXX
//Disable row Cut, Copy, Paste
ActionMap map = table.getActionMap();
Action dummy = new AbstractAction() {
@Override public void actionPerformed(ActionEvent e) { /* Dummy action */ }
};
map.put(TransferHandler.getCutAction().getValue(Action.NAME), dummy);
map.put(TransferHandler.getCopyAction().getValue(Action.NAME), dummy);
map.put(TransferHandler.getPasteAction().getValue(Action.NAME), dummy);
JPanel p = new JPanel(new BorderLayout());
p.add(new JScrollPane(table));
p.setBorder(BorderFactory.createTitledBorder("Drag & Drop JTable"));
return p;
}
public static void main(String... args) {
EventQueue.invokeLater(() -> {
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new TableRowsDnDTest().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
});
}
}
//Demo - BasicDnD (Drag and Drop and Data Transfer) https://docs.oracle.com/javase/tutorial/uiswing/dnd/basicdemo.html
//Demo - DropDemo (Drag and Drop and Data Transfer) https://docs.oracle.com/javase/tutorial/uiswing/dnd/dropmodedemo.html
//@see https://docs.oracle.com/javase/tutorial/uiswing/examples/dnd/DropDemoProject/src/dnd/ListTransferHandler.java
//@see https://github.com/aterai/java-swing-tips/blob/master/DnDReorderTable/src/java/example/TableRowsDnDTest.java
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.
protected TableRowTransferHandler() {
super();
localObjectFlavor = new ActivationDataFlavor(Object[].class, DataFlavor.javaJVMLocalObjectMimeType, "Array of items");
}
@Override protected Transferable createTransferable(JComponent 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().get(i));
}
Object[] transferedObjects = list.toArray();
return new DataHandler(transferedObjects, localObjectFlavor.getMimeType());
}
@Override public boolean canImport(TransferHandler.TransferSupport info) {
JTable table = (JTable) info.getComponent();
boolean isDropable = info.isDrop() && info.isDataFlavorSupported(localObjectFlavor);
table.setCursor(isDropable ? DragSource.DefaultMoveDrop : DragSource.DefaultMoveNoDrop);
return isDropable;
}
@Override public int getSourceActions(JComponent c) {
return TransferHandler.MOVE;
}
@Override public boolean importData(TransferHandler.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();
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);
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 == TransferHandler.MOVE);
}
//If the remove argument is true, the drop has been
//successful and it's time to remove the selected items
//from the list. If the remove argument is false, it
//was a Copy operation and the original list is left
//intact.
protected void cleanup(JComponent c, boolean remove) {
if (remove && indices != null) {
c.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
DefaultTableModel model = (DefaultTableModel)((JTable) c).getModel();
//If we are moving items around in the same list, we
//need to adjust the indices accordingly, since those
//after the insertion point have moved.
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;
}
}
来源：https://stackoverflow.com/questions/42556279/move-row-with-mouse-in-jtable