I wanted an edit that shows format characters ('TAB' and 'CR\LF'). I tried a little with an CEdit but it never worked.
The I found CRTFCtrl::GetCharPos() which will give you the coordinates of a given character in the control. With this function I was able to determin the position of the format characters I wanted to be shown.
The approach is very generic and can be used for other effects.
BUGs: If you drag and drop text with format characters, the selection remains (-> any help with this problem is welcome!)
Download source 12K