JPopover

JPopover popover = new JPopover();
popover.setTitle("Help")
       .setBody("This is some helpful information about this feature.")
       .setPosition(JPopover.Position.TOP);

Button helpButton = new JButton("?");
helpButton.setOnAction(e -> popover.show(helpButton));

JPopover popover = new JPopover();
popover.setTitle("Notification")
       .setBody("You have 3 new messages.")
       .setTheme(JPopover.Theme.DARK)
       .setPosition(JPopover.Position.BOTTOM);

popover.show(iconButton);

JPopover confirmPopover = new JPopover();
confirmPopover.setBody("Delete this item?")
              .setConfirmationMode("Yes", "No", () -> {
                  deleteItem();
              })
              .setPosition(JPopover.Position.TOP);

Button deleteBtn = new JButton("Delete");
deleteBtn.setOnAction(e -> confirmPopover.show(deleteBtn));

VBox customContent = new VBox(8);
customContent.getChildren().addAll(
    new JLabel("Custom Content").addClass("font-bold"),
    new JLabel("Line 1"),
    new JLabel("Line 2"),
    new JButton("Action")
);

JPopover popover = new JPopover();
popover.setContentNode(customContent)
       .setPosition(JPopover.Position.RIGHT);

popover.show(targetNode);

// Top
new JPopover()
    .setBody("Above the button")
    .setPosition(JPopover.Position.TOP)
    .show(button);

// Right
new JPopover()
    .setBody("To the right")
    .setPosition(JPopover.Position.RIGHT)
    .show(button);

// Bottom
new JPopover()
    .setBody("Below the button")
    .setPosition(JPopover.Position.BOTTOM)
    .show(button);

// Left
new JPopover()
    .setBody("To the left")
    .setPosition(JPopover.Position.LEFT)
    .show(button);