PtText Motion Verify


I attempting to tailor a PtText widget so as to restrict the number and
range of characters that can be selected. I added a “Motion Verify” handler
but I cannot use it to determine if the motion is changing the selection
range or simply moving the text caret around.

So, how can I tell, inside a “Motion Verify” callback, that the motion that
has occurred will change the selection range.

Is there some other way to restrict the selection range?