Re: Set indent based on instrument name (issue 6457049)

[Phil Holmes]

----- Original Message ----- 
From: "David Kastrup" <address@hidden>
To: <address@hidden>
Sent: Tuesday, July 31, 2012 2:47 PM
Subject: Re: Set indent based on instrument name (issue 6457049)


> Graham Percival <address@hidden> writes:
>
> > On Tue, Jul 31, 2012 at 02:14:17PM +0200, David Kastrup wrote:
> > > And if you think this is purely hypothetical, check out
> > > Documentation/snippets/incipit.ly.
> >
> > David, thank you for identifying a specific problematic example.
> >
> > > There are exceptions to every rule.  But if you are calling for an
> > > exception because you lack the skills for following the rule, it is
> > > unlikely that your skills are sufficient for correctly identifying the
> > > exception.
> >
> > I think this is a bit too far.  Phil is trying to solve a
> > long-standing *extremely* annoying bug for documentation writers
> > which has not attracted much attention from "real" programmers.
>
> I can't actually help here since either problem description or what the
> patch is trying to achieve is utterly absent from the issue.
>
> <URL:http://code.google.com/p/lilypond/issues/detail?id=2703>
>
> "Set indent based on instrument name" is all that is described
> anywhere.  _How_ the indent is supposed to be based on instrument names,
> _when_ it is supposed to be based on instrument names, _what_ instrument
> names it is supposed to be base on, _which_ indent is supposed to be
> based on instrument names, _what_ problem this is trying to solve:
>
> I draw a blank.  I can't even suggest what variables and organization to
> use here since I have no clue what the problem is, and what the solution
> tries to achieve.

Apologies - I intended to link to 
http://code.google.com/p/lilypond/issues/detail?id=766 but clearly omitted 
to do so.

The problem is that the left indent of staves is fixed with no consideration 
of whether there is an instrument name to fit into that indent.  So we can 
just about get away with "Violin", but any name like "Baroque violin with 
horse hair strings" simply falls off the left of the paper unless indent is 
manually adjusted.  The same is true of short indent/short instrument name. 
In the same way that lilypond moves music to avoid clashes and overlaps, it 
should automatically adjust indent to accommodate the instrument names used. 
IMHO it's the current worst example of poor typesetting that lilypond 
provides.

What's worse is that the images used in the documentation _do_ shift right 
to accommodate instrument names, with the result that the image pushes off 
the left of the page, and black bars result.  This means that _every_ 
snippet with an instrument name requires experimentation and hand crafting 
to make it fit the docs.  Ugh.

> > I don't think that he realizes that he's asking for an exemption,
> > so no need to be rude about it.  Please either give us some hints
> > about how to store the information in an acceptable manner,
>
> I can't since I have no idea what the code is supposed to do.  At the
> current point of time I am pretty much reduced to stating that whatever
> the code may be trying to do, it will not work reliably, and point out
> why.
>
> But I can't help doing it right if I don't even get a chance to guess
> _what_ to do right.
>
> > or wait until Keith or Mike or somebody else has time to help.  Phil
> > is *precisely* the kind of person that we want to be helping with
> > lilypond, so please don't discourage him.
>
> Well, he is trying to take a shortcut here.  I can tell him that the
> shortcut is a dead end, but I since I have no idea where he actually
> wants to go, I can't suggest an alternative path.
>
> --
> David Kastrup


I'm not trying to take a shortcut - I'm wandering down the only road I can 
find.  I first asked for some pointers as to how to do this a week ago, and 
since then I've been trying to work out a solution.  It took me all day on 
Sunday to get the version that counted letters, and all day yesterday to 
work out how to go from markup->SCM->stencil->interval->length.  I actually 
think that's a fair improvement and I'm pretty pleased with progress so far.

I now understand I need to either store the indent length in something to do 
with a score context, or re-initialise it whenever a new score is created. 
I'll have a go at working out how to do that, but I don't even understand 
how to access contexts from c++, so it seems like it would be a continuing 
number of days of poring over the code to find out.

Any pointers (pun not intended) you could give to help me on my way would be 
appreciated.

--
Phil Holmes