Author: Tomas Rutkauskas

How to get the caret position of a Memo or RichEdit control? I don't mean any 
character position expressed in row and column, I mean it in pixels!

Answer:

You get the caret position in pixels (client relative) from an edit, memo or 
richedit control by sending it a EM_POSFROMCHAR message. The message parameters are 
different for a TRichEdit and TMemo/ TEdit.

1   {TRichEdit}
2   
3   var
4     pt: TPoint;
5   begin
6     with richedit1 do
7     begin
8       Perform(messages.EM_POSFROMCHAR, WPARAM(@pt), selstart);
9       label1.caption := Format('(%d, %d)', [pt.x, pt.y]);
10    end;
11  end;
12  
13  {TMemo and TEdit}
14  
15  var
16    r: LongInt;
17  begin
18    with memo1 do
19    begin
20      r := Perform(messages.EM_POSFROMCHAR, selstart, 0);
21      if r >= 0 then
22      begin
23        label1.caption := IntToStr(HiWord(r));
24        label2.caption := IntToStr(LoWord(r));
25      end;
26    end;
27  end;


The win32.hlp entries for this message are really messed up, on older versions they only showed the memo variant, on newer (e.g. the one that comes with D5) they show only the richedit variant.