Re: Align bracket not to notes but to enclosing bars

[Urs Liska]

Hi David,

Am 04.02.19 um 14:20 schrieb David Nalesnik:
> Hi Urs,
>
> On Mon, Feb 4, 2019 at 6:12 AM Urs Liska <address@hidden> wrote:
> > I have created a command that uses \startGroup and \stopGroup to print 
> > annotated horizontal brackets:
> >
> > % Create a horizontal bracket with included text.
> > % If no text is desired an empty string has to be given.
> > % By default the bracket is above the staff, otherwise
> > % #DOWN has to be given as optional argument.
> >
> > \layout {
> >    \context {
> >      \Voice
> >      \consists "Horizontal_bracket_engraver"
> >      \override HorizontalBracket.bracket-flare = #'(0 . 0)
> >      \override HorizontalBracket.staff-padding = 4.5
> >    }
> > }
> >
> > startBracket =
> > #(define-event-function (direction text)((ly:dir? UP) markup?)
> >     #{
> >       -\tweak HorizontalBracketText.text #text
> >       -\tweak HorizontalBracketText.direction #(* -1 direction)
> >       -\tweak HorizontalBracketText.Y-offset #(if (= direction UP) -2.5 1)
> >       -\tweak direction #direction
> >       \startGroup
> >     #})
> >
> > stopBracket = \stopGroup
> >
> > \relative {
> >    g'4 g e d
> >    c \startBracket "Hello" d e f |
> >    g1 \stopBracket
> > }
> >
> > (results attached as document.png).
> >
> > However, in addition to that I need a way to align the start and end of that 
> > bracket not to the notes like in the example but to the enclosing measures, and 
> > optionally the whole staffline.
> >
> > Is there any reasonable approach to doing that short of custom-printing a 
> > stencil by searching the current staff to find the neighbouring barlines (it is 
> > guaranteed that there are no line breaks)? The only advantage of going that way 
> > would be to have more control over how it actually looks like ...
> I believe you will need to look for the bar lines (or the containing
> NonMusicalPaperColumns).


What I was afraid of :-(

Fortunately I have collected some experience with that through a past 
project, and looking into its code base may get me up to (some) speed again.


>   Here's a (still-working as of 2.19.82)
> example which uses the MeasureCounter and a custom stencil:
> http://lists.gnu.org/archive/html/lilypond-user/2014-10/msg00446.html.
> It may be usable as a source of code for your task.  At the moment I
> unfortunately can't devote time to a more thorough-going
> recommendation!


Thank you, I will look into that ASAP.


> (I do have an old patch which actually creates a
> MeasureAttachedSpanner which I held off submitting until after a new
> major release.  If I can get it to apply to current master I could
> send it to you.  It does what you want without "co-opting" other
> spanners, and has the ability to align endpoints in different ways.
> This will give me a LilyPond task to get me back going after a long
> hiatus!)


I'm a bit undecided about this. I assume (from your wording) that this 
is a C++ patch that requires compiling LilyPond? If so I will probably 
be unable to use it because my code has to be publicly shareable. OTOH 
it can't wait until it works with a released LilyPond (which may take 
some time).

But if you'd be willing to work on this I'd be happy to test and 
comment, as my current project shows me there's a need for this, and 
it's really hard to make LilyPond do it ...

Best
Urs

> Best,
> David