lack of data in *.notes files

[Samuel DA MOTA]

Hi,

I'm working on a toy project based on lilypond a.t.m.
The goal is basically to do something similar to MidiSheetMusic
(http://midisheetmusic.sourceforge.net/index.html) but using the real
lilypond music sheet instead of an equivalent one extracted from the
midi file.

I'm using the event-listener.ly output to easily know which key gets
played. Unfortunately I came across a problem with tied notes.

For example the following two _different_ snippets generates the _same
event-listener output_

--- begin ly file ---
\version "2.18.2"
{
  << { c' c' } \\ { g' ~ g' } >>
}
--- end ly file ---

--- begin ly file ---
\version "2.18.2"
{
  <c' g'> ~ <c' g'>
}
--- end ly file ---

On the first one, only the g is tied (c is repeated), on the second one,
both notes are tied.

However when using lilypong -dinclude-settings=event-listener.ly they
both generates

0.00000000      note    60      4       0.25000000      point-and-click 2 11
0.00000000      note    67      4       0.25000000      point-and-click 5 11
0.00000000      tie
0.25000000      note    60      4       0.25000000      point-and-click 12 11
0.25000000      note    67      4       0.25000000      point-and-click 15 11

Therefore, is there a way to modify the event-listener so that it can
accurately tell about the ties. For example having the following output would
be nice:

0.00000000      note    60      4       0.25000000      tied_to_the_next_note
and / or
0.25000000      note    60      4       0.25000000      
not_played__note_is_tied_to_previous_one

Best regards,
--
Sam