Re: \override ClefModifier.text has no effect

[David Kastrup]

James Lowe <address@hidden> writes:

> Hello,
>
>
> On 15/08/18 11:19, Malte Meyn wrote:
>> Hi list,
>>
>> I’m not sure: Is this a bug? According to the Internals Reference,
>> ClefModifier has ly:text-interface::print as a stencil and should
>> use the 'text property. But the following doesn’t show “8va” as
>> expected but “8”:
>>
>> \version "2.21.0" % same for 2.19.82, 2.18.2
>> {
>>   % make sure the correct grob is targeted
>>   \override Staff.ClefModifier.color = #red
>>   % nothing happens:
>>   \override Staff.ClefModifier.text = "8va"
>>   \clef "treble^8"
>>   R1
>> }
>>
>> I suppose that there’s a reason for that behaviour (maybe in the
>> definition of the \clef command?) but could be considered a bug
>> nevertheless. I found the following workaround but it’s not very
>> comfortable:
>>
>> {
>>   \override Staff.ClefModifier.before-line-breaking =
>>   #(lambda (grob)
>>      (ly:grob-set-property! grob 'text "8va"))
>>   \clef "treble^8"
>>   R1
>> }
>>
>> Cheers,
>> Malte
>
> We mention (something related to) this in our NR
>
> http://lilypond.org/doc/v2.19/Documentation/notation-big-page.html#clef
>
> Known Issues and warnings - where we actually use a coloured example.
>
> Is this kind of what David was talking about or do we need to improve
> what we state there?

I'd say neither.  The expectation that no grob property will be
overriden given a user-defined default is not borne out by reality.
This works for information established by callbacks, but not generally
for information created by engravers.  Sometimes you can impose such
properties using \overrideProperty, but it's not guaranteed that they
arrive in time.

-- 
David Kastrup