First visible line in a Memo/RichEdit

Problem/Question/Abstract:

Ok, I have a Memo with a bunch of lines, but how do I know the first visible line of it?

Answer:

this is very simple

FirstLine := Memo1.Perform(EM_GETFIRSTVISIBLELINE, 0, 0);

The return value is the zero-based index of the uppermost visible line in a multiline edit control. For single-line edit controls, the return value is the zero-based index of the first visible character.