Re: [frogs] Re: tablature: ties and harmonics (issue1669041)

[Marc Hohl]

Carl Sorensen schrieb:
> [...]
> > > http://codereview.appspot.com/1669041/diff/26001/27004#newcode130
> > > scm/define-grob-properties.scm:130: (bracket-width ,number? "Width of
> > > the harmonic angle bracket.")
> > > Why do we need bracket-width?  Why can't we just use the pre-existing
> > > width property?
> > >       
> > Hm, Neil proposed to use a more descriptive name for this property, IIUC.
> > Done.
> >     
>
> Well, if we want to have this be part of the parenthesis-interface, then we
> may want to go ahead with bracket-width.
>   
Ok, done.
>   
> [...]
> If instead of making the whiteout and the stencil different stencils, we
> combined them, then parenthesize-stencil would work great.  But this might
> not be possible if we need to have the stencil and the whiteout on separate
> layers.  As an alternative, parenthesize-stencil could be modified to take
> white-padding as an argument.  There's nothing that says we can't modify
> scm/stencil.scm so that it works better for tablature.  It's much better,
> IMO, to have one general-purpose piece of code than to have two separate
> special-purpose code chunks.
>   
So I tried to extend the parenthesize-stencil function in scm/stencil.scm.
It compiles without error, but the regression file is cluttered up.

I feel that this is not the right approach, either. I still don't understand
why I have to shift the TabNoteHead #'layer at all. As far as I see it,
HarmonicParenthesesItem #'stencils is a list of stencils, containing the
left and the right angle bracket, which are placed either side of the
TabNoteHead #'stencil. So the order in which the stancils are placed
should not change anything at all, but if the TabNoteHead #'stencil is set
*before* the HarmonicParenthesesItem #'stencils, it seems that some
whitespace occurs between the angle brackets, overriding the
already placed TabNoteHead.
If on the other hand the whiteout would not appear, we could just use the
parenthesize-tab-note-head function defined in scm/tablature.scm.
This function could detect whether we have a harmonic and in this case
would place the parentheses just further apart.

Furthermore, I have a bad feeling to misuse your time reviewing my patch
for error seeking issues, but I am stuck here. I like the general idea of
not defining the same functionality over and over again, but on the 
other hand,
the parenthesize-stencil function in scm/stencil.scm does not seem to
be used anywhere else ...

Thanks in advance,

Marc