+
+Real
+Staff_symbol::get_ledger_line_thickness (Grob *me)
+{
+ SCM lt_pair = me->get_property ("ledger-line-thickness");
+ Offset z = robust_scm2offset (lt_pair, Offset (1.0, 0.1));
+
+ return z[X_AXIS] * get_line_thickness (me) + z[Y_AXIS] * staff_space (me);
+}
+
+ADD_INTERFACE (Staff_symbol, "staff-symbol-interface",
+ "This spanner draws the lines of a staff. "
+ "A staff symbol definines a vertical unit, the staff space. "
+ "Quantities that go by a half staff space are called positions "
+ "The center (i.e. middle line "
+ "or space) is position 0. The length of the symbol may be set by hand "
+ "through the @code{width} property. ",
+
+ "ledger-line-thickness width staff-space thickness line-count");