JavaFX removing setOnMouseEntered listener does not work properly

[David Go]

Hey all I am having an issue with removing a listener from my button.

Here is the code that I use in order to add the listener to the button:

btnSave.setOnMouseEntered(e -> createPopup());
btnSave.setOnmouseExited(e -> popup.hide());

The way I am removing the listeners from the button:

btnSave.setOnMouseEntered(null);
btnSave.setOnmouseExited(null);

My popup code:

private void createPopup(Event e, Node n) {
    String tip = (String) n.getProperties().get("tip");
    StackPane content = new StackPane(new Label(tip));
    popup = new Popup();

    content.setPadding(new Insets(5, 5, 5, 5));
    content.setBackground(new Background(new BackgroundFill(Color.WHITE, new CornerRadii(5), null)));
    content.setBorder(new Border(new BorderStroke(Color.BLACK, BorderStrokeStyle.SOLID, CornerRadii.EMPTY, BorderWidths.DEFAULT)));

    DropShadow ds = new DropShadow();
    ds.setOffsetY(0.0f);
    ds.setOffsetX(0.0f);
    ds.setColor(Color.BLACK);
      
    content.setEffect(ds);
    
    popup.getContent().add(content);
    
    n.addEventFilter(MouseEvent.MOUSE_MOVED, e2 -> {
        Node node = (Node) e2.getSource();
       
        popup.show(node, e2.getScreenX()+10, e2.getScreenY()+10);
    });
}

This is what it looks like when it starts off, then turned on then back off again. Notice how the tooltip still shows when moving over the button when I have it set to off. It seems to stay on the screen when I move away from the button in the off state.

[Ron McLeod]

I haven't worked with JavaFX, but taking a quick look at the documentation, I don't see where is states that setting the handler function to null removes/unsets a previously defined handler.

Maybe try setting an empty function? :

btnSave.setOnMouseEntered(e -> {});

Or maybe use addEventHandler and removeEventHandler instead? :

btnSave.addEventHandler(MouseEvent.MOUSE_ENTERED, handler);
btnSave.removeEventHandler(MouseEvent.MOUSE_ENTERED, handler);

[David Go]

Ron McLeod wrote:I haven't worked with JavaFX, but taking a quick look at the documentation, I don't see where is states that setting the handler function to null removes/unsets a previously defined handler.

Maybe try setting an empty function? :

btnSave.setOnMouseEntered(e -> {});

Or maybe use addEventHandler and removeEventHandler instead? :

btnSave.addEventHandler(MouseEvent.MOUSE_ENTERED, handler);
btnSave.removeEventHandler(MouseEvent.MOUSE_ENTERED, handler);

Yep that was the issue. Thanks for the heads up Ron!