Once again I don't understand...

[Han-Wen Nienhuys]

address@hidden writes:
> When the score starts with a StaffGroup the BarNumbers are too close to
> the Staff. Therefore I decided to move them a bit away.
> I tried adding a raise (text interface) but nothing happened. Why?
> Then (for fun) I tried adding a padding (side position interface) and IT
> WORKED - even though the BarNumbers don't implement that interface. Why?

Because BarNumber really does a have side-position: 

        void
        Bar_number_engraver::create_items ()
        {
          if (text_p_)
            return;

          SCM b = get_property ("BarNumber");
          text_p_ = new Item (b);
          Side_position::set_axis(text_p_,Y_AXIS);
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

I added side-position-interface to the Scheme description as
well. Hope that helps.


BTW, maybe we should change the naming from interface to something
else, since BarNumber doesn't "implement an interface". An "interface"
is just a group of functions and variables.  A few of those are
combined to form the BarNumber, so it's really the otehr way around:
side-position-interface implements BarNumber.

What's a better name for this?  Something like "building block"

> After that I figured out that the "correct way" was to add an extra
> offset, by the way. That also worked.

There is no officially "correct way", but I think that adding a
padding is cleaner.


--
Han-Wen Nienhuys   |   address@hidden    | http://www.cs.uu.nl/~hanwen/