Re: [Denemo-devel] Bookpart command

[Andreas Schneider]

Am 05.07.2016 um 10:41 schrieb Richard Shann:
> On Sun, 2016-07-03 at 20:14 +0200, Andreas Schneider wrote:
>> Thank you for creating an advanced version of the command. In most cases
>> it works really well.
>>
>> There are a few small things I noticed:
>> * If you put the end at the same movement as the beginning it does not
>> work. (A chapter with only one movement may sometimes be needed.)
> 
> If I understand correctly there is no need for this, you just leave that
> movement alone, giving it a title. It makes the single-movement book a
> bit irregular but was easier to deal with.

For me, chapters group movements of a special type. Sometimes there may
be only one movement of a certain type. For the first movement in a
chapter there is first the heading of the chapter and then the heading
of the movement, regardless if the given chapter contains one or more
movement(s).
I am thinking about how one can overcome the restriction that a chapter
cannot end at the same movement where it starts. First of all, your
solution is clever because it does not need a reference (e.g. to the
movement number where the end is) that may void if movements are
inserted or deleted, and because it automatically prevents starting a
chapter where a chapter end is already present. At the moment you cannot
begin and end a chapter at the same movement because you use the same
tag for both begin and end. When using a different tag, that restriction
would not be present any longer. Is there a directive to get the number
of movements in a score? Maybe I can come up with some code. Or do you
think that approach is not wise?

>> * If you give an end movement number that is larger than the number of
>> movements and thus does not exist, the script does an infinite loop. In
>> that case the end movement should be set to the last present movement
>> and a warning be given.
> 
> I've fixed this.
> 
>> * If you give an end movement that is before the start movement, the
>> lilypond code is erroneous. That should be checked and an error message
>> given.  For example before line 32: (if (< end (d-GetMovement))
>> (d-InfoDialog "Chapter end cannot be before chapter start!") (begin ... ))
> 
> that fix also prevents bad code generation in this case

I suggest to give a message to the user in this case, e.g. by inserting
(d-WarningDialog (string-append (_ "Invalid movement number: ") end ))
as else branch of the (if ...) starting in line 28.

>> * The end movement cannot be changed. (This becomes important if one
>> insert a movement at the end of a chapter.) If you click on EndChapter,
>> you just get an information dialog. It would be more convenient be told
>> the movement number where the corresponding start is and given the
>> option to move the EndChapter to another movement. Workaround is to
>> delete and re-insert.
> 
> Hmm, it seems you have to delete the start as well as the end and the
> re-instate. At a minimum it should give the opportunity to move the end
> book part on to the following movement. Bug report? And the command is
> putting buttons onto the Titles etc button bar which aren't getting
> removed, this is to do with the overrides set.