Hi,
Seems that answers to complicated questions are a bit sparse in these parts, but I'll try again anyway 
I'm wondering if there is any technique to reliably undo a character format application change; that is, an application of properties to a range of text with SetTextProps(). It is fairly simple to remember a list of original properties (PropVals) and the original text range (TextRange), then reapply those original properties to the whole range. However, within a text range, each character can have its own unique set of properties. So, remembering one set of original properties is not enough... seems I have to remember the properties of every single character in the range, the reapply character-by-character, in order to ensure that the new property application is completely undone.
When you apply a character format in the GUI, FM reliably allows an undo, restoring each affected character to its original state. Surely it isn't remembering a PropVals array for every single character (?) I'm just wondering if there is another trick here. It's entirely possible if FM is internally using another trick, it isn't one that I can feasibly replicate.
Thanks,
Russ