source file of the GNU LilyPond music typesetter
- (c) 1997--2002 Han-Wen Nienhuys <hanwen@cs.uu.nl>
+ (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
*/
-
#include "paper-score.hh"
#include "warn.hh"
#include "item.hh"
ADD_INTERFACE(Item,
"item-interface",
- "
-
-Grobs can be distinguished in their role in the horizontal spacing.
-Many grobs define constraints on the spacing by their sizes. For
-example, note heads, clefs, stems, and all other symbols with a fixed
-shape. These grobs form a subtype called @code{Item}.
-
-",
+ "\n"
+ "\n"
+ "Grobs can be distinguished in their role in the horizontal spacing.\n"
+ "Many grobs define constraints on the spacing by their sizes. For\n"
+ "example, note heads, clefs, stems, and all other symbols with a fixed\n"
+ "shape. These grobs form a subtype called @code{Item}.\n"
+ "\n"
+ "\n"
+ "Some items need special treatment for line breaking. For example, a\n"
+ "clef is normally only printed at the start of a line (i.e. after a\n"
+ "line break). To model this, `breakable' items (clef, key signature,\n"
+ "bar lines, etc.) are copied twice. Then we have three versions of each\n"
+ "breakable item: one version if there is no line break, one version\n"
+ "that is printed before the line break (at the end of a system), one\n"
+ "version that is printed after the line break.\n"
+ "\n"
+ "Whether these versions are visible and take up space, is determined by\n"
+ "the outcome of the @code{break-visibility}. This grob property is a\n"
+ "function taking a direction (-1, 0 or 1) as argument. It returns a\n"
+ "cons of booleans, signifying whether this grob should be transparent\n"
+ "and have no extent.\n"
+ "\n"
+ "The following variables for break-visibility are predefined:\n"
+ "@example\n"
+ " grob will show: before no after\n"
+ " break break break\n"
+ " all-invisible no no no\n"
+ " begin-of-line-visible no no yes\n"
+ " end-of-line-visible yes no no\n"
+ " all-visible yes yes yes\n"
+ " begin-of-line-invisible yes yes no\n"
+ " end-of-line-invisible no yes yes\n"
+ "@end example\n"
+ ,
"no-spacing-rods break-visibility breakable")