Issue 3997: \magnifyMusic: don't modify nested properties; reformat code.

In response to David's objections here:
http://codereview.appspot.com/103890046/#msg9

See http://code.google.com/p/lilypond/issues/detail?id=3997

[Mark Polesky, 2014-07-07 20:48:17]

continued from http://codereview.appspot.com/103890046/#msg11

On 2014/07/07 18:22:09, dak wrote:
>
https://codereview.appspot.com/103890046/diff/250001/ly/music-functions-init....
> ly/music-functions-init.ly:718: \context Voice {
> This would create a new Staff when using
> \new TabStaff { \magnifyMusic ...
> 
> It would seem safer to use \context Bottom instead.

Wow, I didn't even know there was a context called Bottom.  Anyway, this raises
a new question: How do I tweak the distance between the half-note's two stems in
tablature?

\new TabStaff {
  \tabFullNotation
  c2
}

Thanks,
Mark

[dak, 2014-07-07 21:09:21]

On 2014/07/07 20:48:17, Mark Polesky wrote:
> continued from http://codereview.appspot.com/103890046/#msg11
> 
> On 2014/07/07 18:22:09, dak wrote:
> >
>
https://codereview.appspot.com/103890046/diff/250001/ly/music-functions-init....
> > ly/music-functions-init.ly:718: \context Voice {
> > This would create a new Staff when using
> > \new TabStaff { \magnifyMusic ...
> > 
> > It would seem safer to use \context Bottom instead.
> 
> Wow, I didn't even know there was a context called Bottom.

There isn't.  Bottom is only an alias for any context that has no \defaultchild.
 So \context Bottom basically creates implicit child contexts until bottoming
out.

[thomasmorley651, 2014-07-07 23:12:48]

On 2014/07/07 20:48:17, Mark Polesky wrote:
[...]
> 
>  this raises
> a new question: How do I tweak the distance between the half-note's two stems
in
> tablature?
> 
> \new TabStaff {
>   \tabFullNotation
>   c2
> }

You can't.
It's hardcoded with tabvoice::draw-double-stem-for-half-notes in tablature.scm

Personally I'd prefer the double stem centered on the TabNoteHead.
Something at the lines of:

(define-public (tabvoice::draw-double-stem-for-half-notes grob)
  (let ((stem (ly:stem::print grob)))
    ;; is the note a (dotted) half note?
    (if (= 1 (ly:grob-property grob 'duration-log))
        ;; yes -> draw double stem
        (ly:stencil-add
            (ly:stencil-translate-axis stem -0.315 X)
            (ly:stencil-translate-axis stem 0.315 X)) 
        ;; no -> draw simple stem
        stem)))

And while on it, the value 0.315 could be taken from a property or an optional
argument.

[Mark Polesky, 2014-07-09 00:16:50]

Good idea, Harm.  I started a new issue to take care of that:

http://code.google.com/p/lilypond/issues/detail?id=3999
http://codereview.appspot.com/101690043/


On Mon, Jul 7, 2014 at 4:12 PM, <thomasmorley65@gmail.com> wrote:

> On 2014/07/07 20:48:17, Mark Polesky wrote:
> [...]
>
>
>    this raises
>> a new question: How do I tweak the distance between the half-note's
>>
> two stems in
>
>> tablature?
>>
>
>  \new TabStaff {
>>    \tabFullNotation
>>    c2
>> }
>>
>
> You can't.
> It's hardcoded with tabvoice::draw-double-stem-for-half-notes in
> tablature.scm
>
> Personally I'd prefer the double stem centered on the TabNoteHead.
> Something at the lines of:
>
> (define-public (tabvoice::draw-double-stem-for-half-notes grob)
>   (let ((stem (ly:stem::print grob)))
>     ;; is the note a (dotted) half note?
>     (if (= 1 (ly:grob-property grob 'duration-log))
>         ;; yes -> draw double stem
>         (ly:stencil-add
>             (ly:stencil-translate-axis stem -0.315 X)
>             (ly:stencil-translate-axis stem 0.315 X))
>         ;; no -> draw simple stem
>         stem)))
>
> And while on it, the value 0.315 could be taken from a property or an
> optional argument.
>
>
> https://codereview.appspot.com/110840044/
>

[Mark Polesky, 2014-07-09 21:23:11]

On 2014/07/09 00:16:50, Mark Polesky wrote:
> Good idea, Harm.  I started a new issue to take care of that:
> 
> http://code.google.com/p/lilypond/issues/detail?id=3999
> http://codereview.appspot.com/101690043/

Oops, wrong links.  

Tracker:  http://code.google.com/p/lilypond/issues/detail?id=3999
Rietveld: http://codereview.appspot.com/110960043/

Although, come on...  What were the chances that two of my current Rietveld
patches would have the exact same numbers in different orders?

http://codereview.appspot.com/101690043/
http://codereview.appspot.com/110960043/