How to drag and drop tab nodes between tab panes

Question

I'm working on example from this tutorial( Drag-and-Drop Feature in JavaFX Applications | JavaFX 2 Tutorials and Documentation ). Based on the tutorial I want to drag tabs between two tabs. So far I managed to create this code but I need some help in order to finish the code.
Source
tabPane = new TabPane();
Tab tabA = new Tab();
   Label tabALabel = new Label("Main Component");
tabPane.setOnDragDetected(new EventHandler<MouseEvent>()
            @Override
            public void handle(MouseEvent event)
                /* drag was detected, start drag-and-drop gesture*/
                System.out.println("onDragDetected");
                /* allow any transfer mode */
                Dragboard db = tabPane.startDragAndDrop(TransferMode.ANY);
                /* put a string on dragboard */
                ClipboardContent content = new ClipboardContent();
                content.put(DataFormat.PLAIN_TEXT, tabPane);
                db.setContent(content);
                event.consume();
What is the proper way to insert the content of the tab as object? Into the tutorial simple text is transferred. How I must modify this line content.put(DataFormat.PLAIN_TEXT, tabPane);?
And what is the proper way to insert the tab after I drag the tab:
Destination
tabPane.setOnDragDropped(new EventHandler<DragEvent>()
            @Override
            public void handle(DragEvent event)
                /* data dropped */
                /* if there is a string data on dragboard, read it and use it */
                Dragboard db = event.getDragboard();
                boolean success = false;
                if (db.hasString())
                    //tabPane.setText(db.getString());
                    Tab tabC = new Tab();
                    tabPane.getTabs().add(tabC);
                    success = true;
                /* let the source know whether the string was successfully
                 * transferred and used */
                event.setDropCompleted(success);
                event.consume();
I suppose that this transfer can be accomplished?
Ref javafx 2 - How to drag and drop tab nodes between tab panes - Stack Overflow

Answer 1

I would use a graphic (instead of text) for the Tabs and call setOnDragDetected on that graphic. That way you know which tab is being dragged. There's no nice way to put the Tab itself into the dragboard as it's not serializable (see https://javafx-jira.kenai.com/browse/RT-29082), so you probably just want to store the tab currently being dragged in a property.
Here's a quick example; it just adds the tab to the end of the current tabs in the dropped pane. If you wanted to insert it into the nearest location to the actual drop you could probably iterate through the tabs and figure the coordinates of each tab's graphic, or something.
import java.util.Random;
import javafx.application.Application;
import javafx.beans.property.ObjectProperty;
import javafx.beans.property.SimpleObjectProperty;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.Tab;
import javafx.scene.control.TabPane;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class DraggingTabPane extends Application {
  private static final String TAB_DRAG_KEY = "tab" ;
  private ObjectProperty<Tab> draggingTab ;
@Override
  public void start(Stage primaryStage) {
  draggingTab = new SimpleObjectProperty<>();
  TabPane tabPane1 = createTabPane();
  TabPane tabPane2 = createTabPane();
  VBox root = new VBox(10);
  root.getChildren().addAll(tabPane1, tabPane2);
  final Random rng = new Random();
  for (int i=1; i<=8; i++) {
    final Tab tab = createTab("Tab "+i);
    final StackPane pane = new StackPane();
      int red = rng.nextInt(256);
      int green = rng.nextInt(256);
      int blue = rng.nextInt(256);
    String style = String.format("-fx-background-color: rgb(%d, %d, %d);", red, green, blue);
    pane.setStyle(style);
    final Label label = new Label("This is tab "+i);
    label.setStyle(String.format("-fx-text-fill: rgb(%d, %d, %d);", 256-red, 256-green, 256-blue));
    pane.getChildren().add(label);
    pane.setMinWidth(600);
    pane.setMinHeight(250);
    tab.setContent(pane);
    if (i<=4) {
      tabPane1.getTabs().add(tab);
    } else {
      tabPane2.getTabs().add(tab);
  primaryStage.setScene(new Scene(root, 600, 600));
  primaryStage.show();
  public static void main(String[] args) {
  launch(args);
  private TabPane createTabPane() {
    final TabPane tabPane = new TabPane();
    tabPane.setOnDragOver(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        final Dragboard dragboard = event.getDragboard();
        if (dragboard.hasString()
            && TAB_DRAG_KEY.equals(dragboard.getString())
            && draggingTab.get() != null
            && draggingTab.get().getTabPane() != tabPane) {
          event.acceptTransferModes(TransferMode.MOVE);
          event.consume();
    tabPane.setOnDragDropped(new EventHandler<DragEvent>() {
      @Override
      public void handle(DragEvent event) {
        final Dragboard dragboard = event.getDragboard();
        if (dragboard.hasString()
            && TAB_DRAG_KEY.equals(dragboard.getString())
            && draggingTab.get() != null
            && draggingTab.get().getTabPane() != tabPane) {
          final Tab tab = draggingTab.get();
          tab.getTabPane().getTabs().remove(tab);
          tabPane.getTabs().add(tab);
          event.setDropCompleted(true);
          draggingTab.set(null);
          event.consume();
    return tabPane ;
  private Tab createTab(String text) {
    final Tab tab = new Tab();
    final Label label = new Label(text);
    tab.setGraphic(label);
    label.setOnDragDetected(new EventHandler<MouseEvent>() {
      @Override
      public void handle(MouseEvent event) {
        Dragboard dragboard = label.startDragAndDrop(TransferMode.MOVE);
        ClipboardContent clipboardContent = new ClipboardContent();
        clipboardContent.putString(TAB_DRAG_KEY);
        dragboard.setContent(clipboardContent);
        draggingTab.set(tab);
        event.consume();
    return tab ;