hdr/spanner.hh

   1 /*
   2   spanner.hh -- part of LilyPond
   3
   4   (c) 1996,97 Han-Wen Nienhuys
   5 */
   6
   7 #ifndef SPANNER_HH
   8 #define SPANNER_HH
   9
  10 #include "proto.hh"
  11 #include "staff-elem.hh"
  12
  13
  14 /** a symbol which is attached between two columns. A spanner is a symbol which spans across several columns, so its
  15   final appearance can only be calculated after the breaking problem
  16   is solved.
  17
  18   Examples
  19
  20   - (de)crescendo
  21   - slur
  22   - beam
  23   - bracket
  24
  25
  26   Spanner should know about the items which it should consider:
  27     e.g. slurs should be steep enough to "enclose" all those items. This
  28     is absolutely necessary for beams, since they have to adjust the
  29     length of stems of notes they encompass.
  30
  31     */
  32 struct Spanner:Staff_elem {
  33     PCol *left, *right;
  34
  35
  36     /* *************** */
  37
  38     Spanner();
  39     virtual Interval width()const;
  40     void do_print()const;
  41
  42     Spanner *broken_at(PCol *c1,  PCol *c2) const;
  43     virtual Spanner* spanner() { return this; }
  44 protected:
  45
  46     /**
  47   clone a piece of  this spanner.
  48     PRE
  49     c1 >= start, c2  <= stop
  50     */
  51     virtual Spanner *do_break_at( PCol *c1,  PCol *c2) const=0;
  52     NAME_MEMBERS(Spanner);
  53 };
  54 #endif