JavaFX - get index row and index col by OnClick on

Question

This question already has answers here:

Javafx - Determine position of cursor on right click relative to gridpane (1 answer)

How to get GridPane Row and Column IDs on Mouse Entered in each cell of Grid in JavaFX? (1 answer)

JavaFX : How to get column and row index in gridpane? (1 answer)

Closed 2 years ago.

I need to get the index of my specified click over my GridPane called myGrid. If I put a piece on board from my coord like here below, it works.. for example: myGrid.add(new ImageView("othello/images/white.png"), 4, 3);

If I want to take the position of my click on board I use this method without success..

@FXML
   private void clickGrid(MouseEvent event) {
      Node source = (Node)event.getSource() ;
      Integer colIndex = GridPane.getColumnIndex(source);
      Integer rowIndex = GridPane.getRowIndex(source);
      if (colIndex != null && rowIndex != null){
         myGrid.add(new ImageView("othello/images/black.png"), colIndex.intValue(), rowIndex.intValue());
      }     
   }

If I don't use

if (colIndex != null && rowIndex != null)

the error is "Java.NullPointException"

However if I use that in the program, Nothing happens when I try to get the row/col values. Help? Thank you

EDIT: here my FXML