Size of Item of a wxSimpleHtmlListbox

[Alejandro]

Hi,
    I need to know the size(width, height) of an item of a 
wxSimpleHtmlListBox, and I tried to used the method 
wxVListBox::OnMeasureItem but is protected. Is that ok?
In the mean time how could I get the size of an item?

Anyway the problem is that when compile, that method is protected. Is 
any special reason for that?

Regards
Alejandro.