How to move items with in VBox(Change order by Dragging) in JavaFX?

Question

i want to drag TitledPane with in a VBox.I have n number of Titlepane's in a VBox. I want to change the order of them when dragded.I tried with some of MouseEvents and DragEvents. But its not working for me.

But i need the indexes of which Titledpane is moved to which place. Based on that i need to do something in backend. Please help me.

Thanks

Answer 1

This works for me...

private static final String TAB_DRAG_KEY = "titledpane";
private ObjectProperty<TitledPane> draggingTab;
@Override
public void start(Stage primaryStage) throws Exception {
    draggingTab = new SimpleObjectProperty<TitledPane>();
    VBox vbox=new VBox();
    for(int i=0;i<4;i++) {
        final TitledPane pane=new TitledPane();
        pane.setText("pane"+(i+1));
        vbox.getChildren().add(pane);
        pane.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) {
                    event.acceptTransferModes(TransferMode.MOVE);
                    event.consume();
                }
            }
        });
        pane.setOnDragDropped(new EventHandler<DragEvent>() {
            public void handle(final DragEvent event) {
                Dragboard db = event.getDragboard();
                boolean success = false;
                if (db.hasString()) {
                    Pane parent = (Pane) pane.getParent();
                    Object source = event.getGestureSource();
                    int sourceIndex = parent.getChildren().indexOf(source);
                    int targetIndex = parent.getChildren().indexOf(pane);
                    List<Node> nodes = new ArrayList<Node>(parent.getChildren());
                    if (sourceIndex < targetIndex) {
                        Collections.rotate(
                                nodes.subList(sourceIndex, targetIndex + 1), -1);
                    } else {
                        Collections.rotate(
                                nodes.subList(targetIndex, sourceIndex + 1), 1);
                    }
                    parent.getChildren().clear();
                    parent.getChildren().addAll(nodes);
                    success = true;
                }
                event.setDropCompleted(success);
                event.consume();
            }
        });
        pane.setOnDragDetected(new EventHandler<MouseEvent>() {
            @Override
            public void handle(MouseEvent event) {
                Dragboard dragboard = pane.startDragAndDrop(TransferMode.MOVE);
                ClipboardContent clipboardContent = new ClipboardContent();
                clipboardContent.putString(TAB_DRAG_KEY);
                dragboard.setContent(clipboardContent);
                draggingTab.set(pane);
                event.consume();
            }
        }); 
    }
    TitledPane pane=new TitledPane("MAIN",vbox);
    primaryStage.setScene(new Scene(pane, 890, 570));
    primaryStage.show();
}