Guide, node Updating translation committishes..
@end ignore
-@c \version "2.17.30"
+@c \version "2.19.2"
@node Changing defaults
@chapter Changing defaults
@strong{@emph{RhythmicStaff}}
-Like @code{Staff} but for printing rhythms. Pitches are ignored;
-the notes are printed on one line.
+Like @code{Staff} but for printing rhythms. Pitches are ignored
+when engraving; the notes are printed on one line. The MIDI
+rendition retains pitches unchanged.
@strong{@emph{TabStaff}}
within it.
The @qq{accepts} list of a context can be changed with the
-@code{\accepts} and @code{\denies} commands. @code{\accepts} adds a
+@code{\accepts} or @code{\denies} commands. @code{\accepts} adds a
context to the @qq{accepts} list and @code{\denies} removes a context
-from the list. For example, it would not normally be desirable for
-chord names to be nested within a @code{Staff} context, so the
-@code{ChordNames} context is not included by default in the @qq{accepts}
-list of the @code{Staff} context, but if this were to be required it can
-be done:
+from the list.
+
+For example, a square-braced staff group is not usually found within a
+curved-braced staff with connecting staff bars, and a @code{GrandStaff}
+does not accept a @code{StaffGroup} inside it by default.
@lilypond[verbatim,quote]
\score {
- \new Staff {
- c' d' e' f'
- \chords { d1:m7 b1:min7.5- }
- }
+ \new GrandStaff <<
+ \new StaffGroup <<
+ \new Staff { c'1 }
+ \new Staff { d'1 }
+ >>
+ \new Staff { \set Staff.instrumentName = bottom f'1 }
+ >>
}
@end lilypond
+However, by using the @code{\accepts} command, @code{StaffGroup} can be
+added to the @code{GrandStaff} context:
+
@lilypond[verbatim,quote]
\score {
- \new Staff {
- c' d' e' f'
- \chords { d1:m7 b1:min7.5- }
- }
+ \new GrandStaff <<
+ \new StaffGroup <<
+ \new Staff { c'1 }
+ \new Staff { d'1 }
+ >>
+ \new Staff { \set Staff.instrumentName = bottom f'1 }
+ >>
\layout {
\context {
- \Staff
- \accepts "ChordNames"
+ \GrandStaff
+ \accepts "StaffGroup"
}
}
}
@node set versus override
@subsection @code{\set} vs. @code{\override}
-@c TODO -- This section is probably unnecessary now.
-
-@ignore
-We have seen two methods of changing properties: @code{\set} and
-@code{\override}. There are actually two different kinds of
-properties.
-
-@code{fontSize} is a special property: it is equivalent to
-entering @code{\override @dots{} #'font-size} for all pertinent
-objects. Since this is a common change, the special
-property (modified with @code{\set}) was created.
-
-@end ignore
+@c TODO Should't a bunch of that be explained earlier?
+@funindex \set
+@funindex \override
+Both @code{\set} and @code{\override} manipulate properties
+associated with contexts. In either case, properties heed the
+hierarchy of contexts: properties not set in a context itself show
+the values of the respective parent context.
+
+Values and lifetime of context properties are dynamic and only
+available when music is being interpreted, @q{iterated}. At the
+time of context creation, properties are initialized from the
+corresponding context definition and possible context
+modifications. Afterwards, changes are achieved with
+property-setting commands in the music itself.
+
+Now grob definitions are a special category of context properties.
+Since their structure, bookkeeping and use is different from
+ordinary context properties, they are accessed with a different
+set of commands, and treated separately in the documentation.
+
+As opposed to plain context properties, grob definitions are
+subdivided into grob properties. A @qq{grob} (graphical object)
+is usually created by an engraver at the time of interpreting a
+music expression and receives its initial properties from the
+current grob definition of the engraver's context. The engraver
+(or other @q{backend} parts of LilyPond) may subsequently add or
+change properties to the grob, but that does not affect the
+context's grob definition.
+
+What we call @q{grob properties} in the context of user-level
+tweaking are actually the properties of a context's grob
+definition. In contrast to ordinary context properties, grob
+definitions have the bookkeeping required to keep track of its
+parts, the individual grob properties (and even subproperties of
+them) separately so that it is possible to define those parts in
+different contexts and have the overall grob definition at the
+time of grob creation be assembled from pieces provided in
+different contexts among the current context and its parents.
+
+Grob definitions are manipulated using @code{\override} and
+@code{\revert} and have a name starting with a capital letter
+(like @samp{NoteHead}) whereas ordinary context properties are
+manipulated using @code{\set} and @code{\unset} and are named
+starting with a lowercase letter.
+
+@cindex tweak, relation to @code{\override}
+@funindex \tweak
+@funindex \overrideProperty
+The special commands @code{\tweak} and @code{\overrideProperty}
+change grob properties bypassing context properties completely.
+Instead they catch grobs as they are being created and then
+directly set properties on them when they originate from a tweaked
+music event or are of a particular kind, respectively.
@node Modifying alists
@subsection Modifying alists
@lilypond[verbatim,quote,relative=1]
<<
- { e1~ e }
+ { e1~ 1 }
\\
{ r4 <g c,> <g c,> <g c,> }
>>
<<
{
\shape #'((0 . 0.5) (0 . 0.5) (0 . 0.5) (0 . 0.5)) Tie
- e1~ e
+ e1~ 1
}
\\
{ r4 <g c,> <g c,> <g c,> }
projects / lilypond.git / blobdiff