Re: Finetuning TextSpanner beginning and end positions?

[Thomas Morley]

Am Di., 7. Mai 2019 um 00:23 Uhr schrieb Stefano Troncaro
<address@hidden>:
>
> Hi Rick,
>
> Thank you for your answer. I didn't know that 'bound-details had an X 
> property. It does what I need but it can get tedious to use because I need to 
> specify a number from the start of the spanner (or the system if the spanner 
> is broken into many systems). It takes some trial and error to find the right 
> number and all that work is undone if the spacing changes.
>
> That however led me to writing this function that offsets the 'X value of the 
> 'right-bound-info property, which is the procedure that calculates where the 
> spanner ends. I'm copying it here so it can be used if someone finds it 
> useful or is searching for a similar question in the future.
>
>> \version "2.19.83"
>>
>> ALB-OffsetRBNfo-X =
>> #(define-scheme-function (n) (number?)
>>    "Offset the X position at the end of a breakable object that determines 
>> its X position
>>     through the 'right-bound-info procedure."
>>    (lambda (grob)
>>      (let* ((bound-right (ly:spanner-bound grob RIGHT))
>>             (broken-right (= (ly:item-break-dir bound-right) CENTER)))
>>        (if broken-right
>>            (let* ((rbnfo (ly:grob-property grob 'right-bound-info #f))
>>                   (rbnfo (map (lambda (pair)
>>                                 (if (eq? 'X (car pair))
>>                                     (cons 'X (+ (cdr pair) n))
>>                                     pair))
>>                            rbnfo)))
>>              (ly:grob-set-property! grob 'right-bound-info rbnfo))))))
>>
>> \relative {
>>   \override TextSpanner.bound-details.left.text = "sample spanner"
>>   \override TextSpanner.after-line-breaking = \ALB-OffsetRBNfo-X 15
>>   c'\startTextSpan d e f | g a g f \break | e f e d | c1\stopTextSpan
>> }

Why not:

  \override TextSpanner.bound-details.right-broken.padding = 0.25
  \override TextSpanner.bound-details.right.padding = -15

The first to keep the default for right-broken TextSpanner.
(Per default bound-details.right-broken is unset for TextSpanners and
thus copies bound-details.right)
The second to affect bound-details.right.padding as wished.


Cheers,
  Harm