Combo box Item hover callback?

Anytime the user hovers over a new item in the combobox I would like update my main scene visually. What is the best way to do this?

Pretty easy to roll a simple class that has a timer and a mouse listener, and checks for it hovering.

But when would I start and end the timer? And how do find the current item that is being hovered over? Do I have to subclass combobox or can I make a separate class for this?

I think Jules meant that you have the timer running while your combobox is visible, and use it to check if the mouse cursor is over your combobox. If so you can fire the function that does your hover stuff.

I think I was unclear in the title, When the user clicks on a combobox it opens a dropdown menu. In the drop down menu I need to get the menu item that he is currently hovering over. Whats the function I would use to get the currently hovered Item?

Maybe a better approach would be to override ComboBox::addItemsToMenu to put custom components into your menu, and then those custom components could do something appropriate when they are highlighted.