Author: Jonas Bilinkevicius

How do I scan a TRichEdit from top to bottom and check for lines with a special 
pattern to change color? I only know SelStart and SelLength, but how do I select a 
line at a time?

Answer:

1   var
2     S: string;
3     i: Integer;
4   
5   { ... }
6   with richedit1 do
7   begin
8     lines.beginupdate;
9     try
10      for i := 0 to lines.count - 1 do
11      begin
12        S := Lines[i];
13        if LineShouldBeColored(S) then
14        begin
15          SelStart := Perform(EM_LINEINDEX, i, 0);
16          SelLength := Length(S);
17          SelAttributes.Color := clRed;
18        end;
19      end;
20    finally
21      SelStart := 0;
22      Perform(EM_SCROLLCARET, 0, 0);
23      lines.endupdate;
24    end;
25  end;