% Prepare the Matlab listbox uicontrol
hFig = figure;
listItems = {'apple','orange','banana','lemon','cherry','pear','melon'};
hListbox = uicontrol(hFig, 'style','listbox', 'pos',[20,20,60,60], 'string',listItems);
% Get the listbox's underlying Java control
jScrollPane = findjobj(hListbox);
% We got the scrollpane container - get its actual contained listbox control
jListbox = jScrollPane.getViewport.getComponent(0);
% Convert to a callback-able reference handle
jListbox = handle(jListbox, 'CallbackProperties');
% Set the mouse-movement event callback
set(jListbox, 'MouseMovedCallback', {@mouseMovedCallback,hListbox});
% Mouse-movement callback
function mouseMovedCallback(jListbox, jEventData, hListbox)
% Get the currently-hovered list-item
mousePos = java.awt.Point(jEventData.getX, jEventData.getY);
hoverIndex = jListbox.locationToIndex(mousePos) + 1;
listValues = get(hListbox,'string');
hoverValue = listValues{hoverIndex};
% Modify the tooltip based on the hovered item
msgStr = sprintf('<html>item #%d: <b>%s</b></html>', hoverIndex, hoverValue);
set(hListbox, 'Tooltip',msgStr);
end % mouseMovedCallback
