Currently all of the overrun styles for labeled truncate the labeled content.

It would useful to be able to dynamically display all of the labeled content (for example in a popover) when the user mouses over the truncated label.

An example use case would be an overrun label which could be toggled, using a :hover pseudoclass, between an ellipsis truncation and a popover displaying full label content. The toggle could be achieved by modifying the value of the -fx-text-overrun css property.

.label {
  -fx-text-overrun: ellipse;
}

.label:hover {
  -fx-text-overrun: popover;
}

I attached an image (borrowed from the Injellij Idea treeview implementation) to demonstrate the concept - when the user mouses over the overflowed label, the complete label is shown in a popover.