Maybe in this way. I added inner class MyLabel
and console output in your handlerLabel
. Ctrl+v this under your main
. It will print to console the original
String
property of each MyLabels
.
public class MyLabel extends JLabel {
String original;
public MyLabel (String text)
{
super(text);
this.original=text;
}
public String getOriginal() {
return original;
}
public void setOriginal(String original) {
this.original = original;
}
}
public deneme2() {
JPanel panel= new JPanel();
MouseListener listener = (MouseListener) new DragMouseAdapter();
MyLabel label1 = new MyLabel("Label1111111");
handlerLabel(label1);
label1.addMouseListener(listener);
panel.add(label1);
MyLabel label2 = new MyLabel("Label2222222");
handlerLabel(label2);
label2.addMouseListener(listener);
panel.add(label2);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
contentPane.add(panel);
setContentPane(contentPane);
}
private void handlerLabel(MyLabel lbl) {
lbl.setTransferHandler(new TransferHandler("text") {
@Override
protected void exportDone(JComponent source, Transferable data, int action) {
if (action == COPY) {
System.out.println(((MyLabel) lbl.getDropTarget().getDropTargetContext().getComponent()).getOriginal());
}
}
});
}
Edit: check this out. Ctrl+V this under your main. It will print to console text of source label and text of target label, also the original
property. Class MyLabel
implements DropTargetListener
, which is then registered by new DropTarget(this, this)
. Then we define what will happen in overriden drop
method.
public class MyLabel extends JLabel implements DropTargetListener {
String original;
public MyLabel(String text) {
super(text);
this.original = text;
new DropTarget(this, this);
this.setTransferHandler(new TransferHandler("text"));
final MouseListener listener = new MouseAdapter() {
@Override
public void mousePressed(final MouseEvent me) {
final MyLabel label = (MyLabel) me.getSource();
final TransferHandler handler = label.getTransferHandler();
handler.exportAsDrag(label, me, TransferHandler.COPY);
}
};
this.addMouseListener(listener);
}
public String getOriginal() {
return original;
}
public void setOriginal(String original) {
this.original = original;
}
@Override
public void dragEnter(DropTargetDragEvent dtde) {
}
@Override
public void dragOver(DropTargetDragEvent dtde) {
}
@Override
public void dropActionChanged(DropTargetDragEvent dtde) {
}
@Override
public void dragExit(DropTargetEvent dte) {
}
@Override
public void drop(DropTargetDropEvent dtde) {
try {
final String sourceString = (String) dtde.getTransferable().getTransferData(new DataFlavor("application/x-java-jvm-local-objectref; class=java.lang.String"));
System.out.println("Source: " + sourceString + " target: " + this.getText());
this.setText(sourceString);
System.out.println("Original target: "+this.getOriginal());
} catch (final UnsupportedFlavorException | IOException | ClassNotFoundException e) {
e.printStackTrace();
}
}
}
public deneme2() {
JPanel panel = new JPanel();
MyLabel label1 = new MyLabel("Label1111111a");
panel.add(label1);
MyLabel label2 = new MyLabel("Label2222222b");
panel.add(label2);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
contentPane.add(panel);
setContentPane(contentPane);
}
}
EDIT2: Following code generates this result see result at the end of this answer:
or

It also prints original
property to console. Those could be organised differently (MyLabel
, MyLabelTransferable
, MyLabelDropTargetListener
, MyLabelTransferHandler
classes, just to give an idea for future refactoring) but it works in this way too. Consider it a quickfix for your use case.
So main class is this:
public class Deneme2 extends JFrame {
private static final int COPY = 0;
private static final int NONE = 0;
public static void main(String[] args) {
Deneme2 mainFrame = new Deneme2();
SwingUtilities.invokeLater(() -> {//let's get that frame on EDT rollin lambda style:)
mainFrame.setVisible(true);
});
}
public Deneme2() {
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
MyLabel label1 = new MyLabel("Label1111111a");
panel.add(label1, BorderLayout.WEST);
MyLabel label2 = new MyLabel("Label2222222b");
panel.add(label2, BorderLayout.EAST);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setBounds(100, 100, 450, 300);
panel.setBorder(new EmptyBorder(5, 5, 5, 5));
this.add(panel);
}
}
Then MyLabel.java :
public class MyLabel extends JLabel implements DropTargetListener, Transferable {
String original;
protected static final DataFlavor MYLABEL_DATA_FLAVOR = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType + "; class=\"" + MyLabel.class.getCanonicalName() + "\"",
"MyLabel label");
protected static final DataFlavor[] SUPPORTED_FLAVORS = {MYLABEL_DATA_FLAVOR};
public MyLabel(String text) {
super(text);
this.original = text;
new DropTarget(this, this);
this.setTransferHandler(new MyLabelTransferHandler()); //here we use our custom TransferHandler
final MouseListener listener = new MouseAdapter() {
@Override
public void mousePressed(final MouseEvent me) {
final MyLabel label = (MyLabel) me.getSource();
final TransferHandler handler = label.getTransferHandler();
handler.exportAsDrag(label, me, TransferHandler.COPY);
}
};
this.addMouseListener(listener);
}
public String getOriginal() {
return original;
}
public void setOriginal(String original) {
this.original = original;
}
@Override
public void dragEnter(DropTargetDragEvent dtde) {
if (dtde.getTransferable().isDataFlavorSupported(MyLabel.MYLABEL_DATA_FLAVOR)) {
System.out.println("Drop accept - MyLabel");
dtde.acceptDrag(DnDConstants.ACTION_COPY_OR_MOVE);
} else {
dtde.rejectDrag();
}
}
@Override
public void dragOver(DropTargetDragEvent dtde) {
//System.out.println("Drag over");
}
@Override
public void dropActionChanged(DropTargetDragEvent dtde) {
System.out.println("Action changed");
}
@Override
public void dragExit(DropTargetEvent dte) {
System.out.println("Exited");
}
@Override
public void drop(DropTargetDropEvent dtde) {
System.out.println("Drop detected");
if (dtde.getTransferable().isDataFlavorSupported(MyLabel.MYLABEL_DATA_FLAVOR)) {
Transferable t = dtde.getTransferable();
if (t.isDataFlavorSupported(MyLabel.MYLABEL_DATA_FLAVOR)) {
try {
Object transferData = t.getTransferData(MyLabel.MYLABEL_DATA_FLAVOR);
if (transferData instanceof MyLabel) {
MyLabel mySourceLabel = (MyLabel) transferData;
if (!(mySourceLabel.equals(this))) {
dtde.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE);
this.setText(mySourceLabel.getText());
mySourceLabel.setText("Empty");
System.out.println(mySourceLabel.getOriginal() + " " + this.getOriginal());
} else {
dtde.rejectDrop();
System.out.println("Drop rejected - the same MyLabel");
}
} else {
dtde.rejectDrop();
}
} catch (UnsupportedFlavorException | IOException ex) {
dtde.rejectDrop();
}
} else {
dtde.rejectDrop();
}
}
}
@Override
public DataFlavor[] getTransferDataFlavors() {
return SUPPORTED_FLAVORS;
}
@Override
public boolean isDataFlavorSupported(DataFlavor flavor) {
return flavor.equals(MYLABEL_DATA_FLAVOR) || flavor.equals(DataFlavor.stringFlavor);
}
@Override
public Object getTransferData(DataFlavor flavor) throws UnsupportedFlavorException, IOException {
if (flavor.equals(MYLABEL_DATA_FLAVOR)) {
return this;
} else if (flavor.equals(DataFlavor.stringFlavor)) {
return this.getText();
} else {
throw new UnsupportedFlavorException(flavor);
}
}
}
And then MyLabelTransferHandler.java :
public class MyLabelTransferHandler extends TransferHandler {
@Override
public boolean canImport(TransferHandler.TransferSupport support) {
return (support.getComponent() instanceof MyLabel) && support.isDataFlavorSupported(MyLabel.MYLABEL_DATA_FLAVOR);
}
@Override
public boolean importData(JComponent src, Transferable transferable) {
return src instanceof MyLabel;
}
@Override
public int getSourceActions(JComponent c) {
return DnDConstants.ACTION_COPY;
}
@Override
protected Transferable createTransferable(JComponent c) {
Transferable t = (MyLabel)c;
return t;
}
@Override
protected void exportDone(JComponent source, Transferable data, int action) {
System.out.println("Export done.");
}
}
After final edit result looks like this:

Little clarification:
protected static final DataFlavor MYLABEL_DATA_FLAVOR = new DataFlavor(DataFlavor.javaJVMLocalObjectMimeType + "; class=\"" + MyLabel.class.getCanonicalName() + "\"",
"MyLabel label");
in MyLabel. That's important line. This will make getTransferData()
return the same instance of MyLabel
. If you would do it like:
protected static final DataFlavor MYLABEL_DATA_FLAVOR = new DataFlavor(MyLabel.class, "MyLabel label");
you won't be able to change mySourceLabel
text to "Empty" in overridden drop()
method, since you would be given a copy of that object.
Also Why shouldn't you extend JFrame and other components? . And you can provide checking for "Empty" text (if getText()
returns "Empty", then don't change text in target MyLabel
).