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6.4.4 New markup list command definition
Markup list commands are defined with the
define-markup-list-command Scheme macro, which is similar to the
define-markup-command macro described in
New markup command definition, except that where the latter returns
a single stencil, the former returns a list stencils.
In the following example, a \paragraph markup list command is
defined, which returns a list of justified lines, the first one being
indented. The indent width is taken from the props argument.
#(define-markup-list-command (paragraph layout props args) (markup-list?)
(let ((indent (chain-assoc-get 'par-indent props 2)))
(interpret-markup-list layout props
(make-justified-lines-markup-list (cons (make-hspace-markup indent)
args)))))
Besides the usual layout and props arguments, the
paragraph markup list command takes a markup list argument, named
args. The predicate for markup lists is markup-list?.
First, the function gets the indent width, a property here named
par-indent, from the property list props If the property
is not found, the default value is 2. Then, a list of justified
lines is made using the make-justified-lines-markup-list
function, which is related to the \justified-lines
built-in markup list command. An horizontal space is added at the
beginning using the make-hspace-markup function. Finally, the
markup list is interpreted using the interpret-markup-list
function.
This new markup list command can be used as follows:
\markuplines {
\paragraph {
The art of music typography is called \italic {(plate) engraving.}
The term derives from the traditional process of music printing.
Just a few decades ago, sheet music was made by cutting and stamping
the music into a zinc or pewter plate in mirror image.
}
\override-lines #'(par-indent . 4) \paragraph {
The plate would be inked, the depressions caused by the cutting
and stamping would hold ink. An image was formed by pressing paper
to the plate. The stamping and cutting was completely done by
hand.
}
}
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Other languages: espaƱol.