to see the settings for each grob description. Grob descriptions
are modified with @code{\override}.
-@code{\override} is actually a shorthand;
+The syntax for the @code{\override} command is
@example
-\override @var{context}.@var{GrobName} #'@var{property} = #@var{value}
+\override [@var{context}.]@var{GrobName}.@var{property} = #@var{value}
@end example
-@noindent
-is more or less equivalent to
-
-@c leave this long line -gp
-@example
-\set @var{context}.@var{GrobName} =
- #(cons (cons '@var{property} @var{value})
- <previous value of @var{context}.@var{GrobName}>)
-@end example
-
-The value of @code{context}.@code{GrobName} (the alist) is used to initialize
-the properties of individual grobs. Grobs have
-properties, named in Scheme style, with
-@code{dashed-words}. The values of grob properties change
-during the formatting process: formatting basically amounts
-to computing properties using callback functions.
-
For example, we can increase the thickness of a note stem by
overriding the @code{thickness} property of the @code{Stem}
object:
}
@end lilypond
+Some tweakable options are called @q{subproperties} and reside inside
+properties. To tweak those, use commands in the form
+
+@example
+\override Stem.details.beamed-lengths = #'(4 4 3)
+@end example
+
+or to modify the ends of spanners, use a form like these
+
+@example
+\override TextSpanner.bound-details.left.text = #"left text"
+\override TextSpanner.bound-details.right.text = #"right text"
+@end example
+
@funindex \revert
@cindex reverting overrides
@cindex overrides, reverting
-The effects of @code{\override} can be undone by @code{\revert}:
+The effects of @code{\override} can be undone by @code{\revert}.
+
+The syntax for the @code{\revert} command is
+
+@example
+\revert [@var{context}.]@var{GrobName}.@var{property}
+@end example
+
+For example,
@lilypond[quote,verbatim,relative=2]
c4
@item a sensible value: here @code{3.0}.
@end itemize
-Some tweakable options are called @q{subproperties} and reside inside
-properties. To tweak those, use commands in the form
-
-@example
-\override Stem.details.beamed-lengths = #'(4 4 3)
-@end example
-
@cindex internal documentation
@cindex finding graphical objects
@cindex graphical object descriptions
syntax:
@example
-\tweak @var{layout-object} #'@var{grob-property} @var{value}
+\tweak [@var{layout-object}.]@var{grob-property} @var{value}
@end example
Specifying @var{layout-object} is optional.
-But the main use of the @code{\tweak} command is to modify just
+The main use of the @code{\tweak} command is to modify just
one of a number of notation elements which start at the same musical
moment, like the notes of a chord, or tuplet brackets which start
at the same time.
@code{NoteHead} layout objects rather than by music elements in the
input stream.
-Such indirectly created layout objects can be tweaked using the explicit
-form of the @code{\tweak} command:
+Such indirectly created layout objects can be tweaked using the form
+of the @code{\tweak} command in which the grob name is specified
+explicitly:
@lilypond[relative=2,verbatim,quote]
\tweak Stem.color #red