Make the points draggable and store the new coordinates JavaFx

Question

I have this:

Circle circle = null; 
List<Circle> circles = new ArrayList<>();

for(List row: list)  //list is list of coordinates i.e. [[200,100],[10,5.5],[15,100],[200,25]...]        
{
    circle = new Circle((double) row.get(0), (double) row.get(1), 4f);
    circle.setFill(Color.BLUE);

    Tooltip toolTipx = new Tooltip("The point is : " + (double) row.get(0));
    Tooltip.install(circle, toolTipx);

    circles.add(circle);
}
        
System.out.println(circles.size());
Pane pane = new Pane();
pane.getChildren().addAll(circles);

This plots the said points on the window perfectly and the tooltip depicts the coordinate of the point.

Now, what I want is to create the plotted points draggable. So that I can drag the points anywhere in the window and the new location(coordinates of the dragged points) is stored to show in the tooltip or in a fixed Label at the end of the window.

I came across this (makeDraggable()), but couldn't find a starting point for me.

How can I achieve this? Thanks.

Answer 1

Used :

circle.setOnMouseDragged( event -> {
             circle.setCenterX(event.getX());
            circle.setCenterY(event.getY());
            });

to trigger the mouseDragging event on any created circles/points. Then, simply reset the centerX and centerY with event.getX()(the destination X point) and event.getY()(the destination Y point).

My Full Code :

public void start(Stage stage) throws IOException 
    {    
            Label b = new Label("The coordinates are : "); 
            b.setLayoutX(190);
            b.setLayoutY(280);
            
            Label value = new Label(); 
            value.setLayoutX(320);
            value.setLayoutY(280);
            
          List<Circle> circles = new ArrayList<>();
        for(List row: list) 
        {
            Circle circle = new Circle((double) row.get(0), (double) row.get(1), 5f);
            circle.setFill(Color.BLUE);
            
            //this did the trick for me
            circle.setOnMouseDragged( event -> {
             circle.setCenterX(event.getX());
            circle.setCenterY(event.getY());
            });
            
            //for printing the values in a Label
             circle.setOnMouseClicked(new EventHandler<MouseEvent>() {
                    public void handle(MouseEvent event) {
                        System.out.println("Clicked");
                        value.setText(circle.getCenterX()+" , "+circle.getCenterY());
                    }
                });
            
            circles.add(circle);
        }
       
        System.out.println(circles.size());
        Pane pane = new Pane();

        pane.getChildren().addAll(circles);
        pane.getChildren().add(b);
        pane.getChildren().add(value);
 Scene scene = new Scene(pane, 600, 300);  
      
      //Setting title to the Stage 
      stage.setTitle("Show Points"); 
         
      //Adding scene to the stage 
      stage.setScene(scene); 

      scene.getStylesheets().add(Main.class.getResource("application.css").toExternalForm());
      //Displaying the contents of the stage 
      stage.show(); 
            
    } //end of start
    
    public static void main(String[] args) throws IOException {
        launch(args);
    }