[JW Lua] Reading metrics from staves that appear in parts only

[Jan Angermüller]

Jari,

is it possible to read any metrics information for text expressions and 
articulations,
if all of the following is given:

- we are in scroll view of the score
- the metrics information is from a staff that is set to "Force hide 
staff: in Score only"
- no parts are generated yet

I have only been successful, when "Force hide staff" was not selected or 
when parts are created and I am in part view.

Although any position information should be available, as the 
articulation/expression is visible in scroll view.
Probably the metrics that are calculated only use page view information 
and not scroll view information.
Which means I can only manipulate these "hidden" staves, when parts are 
already created and I am in parts view.

It could be faster in scroll view as I can manipulate for example all 
brass instruments that need fixes at once, instead of going through each 
individual brass part, doing the same fixes.

Jan