Simple example of drag and drop replacement (similar to how tabs work)

DnDSample.java

package org.almibe.multipage.demo;

import javafx.application.Application;
import javafx.scene.Node;
import javafx.scene.Scene;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.HBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.List;

public class DnDSample extends Application {
    public static void main(String[] args) {
        launch(args);
    }

    private MouseEvent dragDetected;

    @Override
    public void start(Stage primaryStage) {
        HBox display = new HBox();

        List<Rectangle> rectangleList = createList(display);

        display.getChildren().addAll(rectangleList);

        primaryStage.setScene(new Scene(display, 1000, 450));
        primaryStage.show();
    }

    public List<Rectangle> createList(HBox hBox) {
        List<Rectangle> rectangles = new ArrayList<>();
        rectangles.add(new Rectangle(200, 250, Color.GRAY));
        rectangles.add(new Rectangle(200, 250, Color.BLUEVIOLET));
        rectangles.add(new Rectangle(200, 250, Color.SALMON));
        rectangles.add(new Rectangle(200, 250, Color.PALEGREEN));

        for (Rectangle rectangle : rectangles) {

            rectangle.setOnMouseReleased(event -> event.consume());
            rectangle.setOnDragDetected(event -> {
                rectangle.startFullDrag();
                dragDetected = event;
                event.consume();
            });
            rectangle.setOnMouseDragged(event -> event.consume());
            rectangle.setOnMouseDragEntered(event -> {
                Rectangle sourceRectangle = ((Rectangle)event.getGestureSource());
                Rectangle targetRectangle = ((Rectangle)event.getTarget());
                if (sourceRectangle == targetRectangle) return;
                int sourceIndex = hBox.getChildren().indexOf(sourceRectangle);
                int targetIndex = hBox.getChildren().indexOf(targetRectangle);

//                Collections.swap(hBox.getChildren(), sourceIndex, targetIndex);
            if (sourceIndex > targetIndex) {
                hBox.getChildren().remove(sourceRectangle);
                hBox.getChildren().add(targetIndex, sourceRectangle);
                //multiPageDisplay.setSelectedPage(sourceRectangle);
                //MouseDragEvent.fireEvent(sourceRectangle, dragDetected);
            } else {
                for(int i = sourceIndex+1; i-1 < targetIndex; i++) {
                    Node removedNode = hBox.getChildren().remove(i);
                    hBox.getChildren().add(i-1, removedNode);
                }
                //multiPageDisplay.setSelectedPage(sourceRectangle);
                //MouseDragEvent.fireEvent(sourceRectangle,dragDetected);
            }
                //rectangle.setMouseTransparent(false);
                event.consume();
            });
            rectangle.setOnMouseDragReleased(event -> event.consume());
        }

        return rectangles;
    }
}