Implement framework for post-fix text (de)cresc spanners (backend only)

The main problem why \decr or \dim were prefix operators was that the
new dynamic engraver was reading only the properties of the Engraver
itself, so there was no way to create a CrescendoEvent and at the same
time specify the hairpin/text behavior.

This patch makes the New_dynamic_engraver also look at the properties
of the (Dec|C)recendoEvent and prefer a setting from there. If the event
does not have a property (which will be the case most of the time), the
Engraver's settings are used (i.e. same behavior as now).

With this change, e.g. \dim can be defined as
dim = #(make-music 'DecrescendoEvent 'span-direction START
            'span-type text 'span-text "dim.")
and used as postfix like a4\dim without the need of any overrides
before the affected note.

This is just the backend commit, implementing processing of the event's
properties. The definition of \cresc is still unchanged, leaving the old
prefix notation in place, until we find  good upgrade path.

Also add regtests for text cresc spanners and add the regtest to the
snippets.

diff --git a/Documentation/snippets/new/dynamics-custom-text-spanner-postfix.ly b/Documentation/snippets/new/dynamics-custom-text-spanner-postfix.ly
new file mode 100644 (file)
index 0000000..f3f26b0
--- /dev/null
+++ b/Documentation/snippets/new/dynamics-custom-text-spanner-postfix.ly
@@ -0,0 +1,26 @@
+\version "2.13.4"
+
+\header {
+texidoc = "Postfix functions for custom crescendo text spanners.  The spanners
+should start on the first note of the measure.  One has to use -\mycresc,
+otherwise the spanner start will rather be assigned to the next note."
+}
+
+% Two functions for (de)crescendo spanners where you can explicitly give the
+% spanner text.
+mycresc = #(define-music-function (parser location mymarkup) (string?)
+  (make-music 'CrescendoEvent 'span-direction START
+              'span-type 'text 'span-text mymarkup))
+mydecresc = #(define-music-function (parser location mymarkup) (string?)
+  (make-music 'DecrescendoEvent 'span-direction START
+              'span-type 'text 'span-text mymarkup))
+
+\relative c' {
+  c4-\mycresc "custom cresc" c4 c4 c4 |
+  c4 c4 c4 c4 |
+  c4-\mydecresc "custom decresc" c4 c4 c4 |
+  c4 c4\! c4 c4
+}
+
+
+

diff --git a/Documentation/snippets/new/dynamics-text-spanner-postfix.ly b/Documentation/snippets/new/dynamics-text-spanner-postfix.ly
new file mode 100644 (file)
index 0000000..2b1044c
--- /dev/null
+++ b/Documentation/snippets/new/dynamics-text-spanner-postfix.ly
@@ -0,0 +1,27 @@
+\version "2.13.4"
+
+\header {
+texidoc = "The \cresc, \dim and \decresc spanners can now be redefined as
+postfix operators and produce one text spanner.  Defining custom spanners is
+also easy.  Hairpin and text crescendi can be easily mixed. \< and \> produce
+hairpins by default, \cresc etc. produce text spanners by default."
+}
+
+% Some sample text dynamic spanners, to be used as postfix operators
+crpoco = #(make-music 'CrescendoEvent 'span-direction START
+                      'span-type 'text 'span-text "cresc. poco a poco")
+% Redefine the existing \cresc, \dim and \decresc commands to use postfix syntax
+cresc = #(make-music 'CrescendoEvent 'span-direction START
+                     'span-type 'text 'span-text "cresc.")
+dim = #(make-music 'DecrescendoEvent 'span-direction START
+                   'span-type 'text 'span-text "dim.")
+decresc = #(make-music 'DecrescendoEvent 'span-direction START
+                       'span-type 'text 'span-text "decresc.")
+
+\relative c' {
+  c4\cresc d4 e4 f4 |
+  g4 a4\! b4\crpoco c4 |
+  c4 d4 e4 f4 |
+  g4 a4\! b4\< c4 |
+  g4\dim a4 b4\decresc c4\!
+}

diff --git a/input/regression/dynamics-custom-text-spanner-postfix.ly b/input/regression/dynamics-custom-text-spanner-postfix.ly
new file mode 100644 (file)
index 0000000..f3f26b0
--- /dev/null
+++ b/input/regression/dynamics-custom-text-spanner-postfix.ly
@@ -0,0 +1,26 @@
+\version "2.13.4"
+
+\header {
+texidoc = "Postfix functions for custom crescendo text spanners.  The spanners
+should start on the first note of the measure.  One has to use -\mycresc,
+otherwise the spanner start will rather be assigned to the next note."
+}
+
+% Two functions for (de)crescendo spanners where you can explicitly give the
+% spanner text.
+mycresc = #(define-music-function (parser location mymarkup) (string?)
+  (make-music 'CrescendoEvent 'span-direction START
+              'span-type 'text 'span-text mymarkup))
+mydecresc = #(define-music-function (parser location mymarkup) (string?)
+  (make-music 'DecrescendoEvent 'span-direction START
+              'span-type 'text 'span-text mymarkup))
+
+\relative c' {
+  c4-\mycresc "custom cresc" c4 c4 c4 |
+  c4 c4 c4 c4 |
+  c4-\mydecresc "custom decresc" c4 c4 c4 |
+  c4 c4\! c4 c4
+}
+
+
+

diff --git a/input/regression/dynamics-text-spanner-postfix.ly b/input/regression/dynamics-text-spanner-postfix.ly
new file mode 100644 (file)
index 0000000..2b1044c
--- /dev/null
+++ b/input/regression/dynamics-text-spanner-postfix.ly
@@ -0,0 +1,27 @@
+\version "2.13.4"
+
+\header {
+texidoc = "The \cresc, \dim and \decresc spanners can now be redefined as
+postfix operators and produce one text spanner.  Defining custom spanners is
+also easy.  Hairpin and text crescendi can be easily mixed. \< and \> produce
+hairpins by default, \cresc etc. produce text spanners by default."
+}
+
+% Some sample text dynamic spanners, to be used as postfix operators
+crpoco = #(make-music 'CrescendoEvent 'span-direction START
+                      'span-type 'text 'span-text "cresc. poco a poco")
+% Redefine the existing \cresc, \dim and \decresc commands to use postfix syntax
+cresc = #(make-music 'CrescendoEvent 'span-direction START
+                     'span-type 'text 'span-text "cresc.")
+dim = #(make-music 'DecrescendoEvent 'span-direction START
+                   'span-type 'text 'span-text "dim.")
+decresc = #(make-music 'DecrescendoEvent 'span-direction START
+                       'span-type 'text 'span-text "decresc.")
+
+\relative c' {
+  c4\cresc d4 e4 f4 |
+  g4 a4\! b4\crpoco c4 |
+  c4 d4 e4 f4 |
+  g4 a4\! b4\< c4 |
+  g4\dim a4 b4\decresc c4\!
+}

diff --git a/lily/new-dynamic-engraver.cc b/lily/new-dynamic-engraver.cc
index 8c8fce980044c14834050ff7b3d9fb4fce1838e8..54aa8a8c6df363dca7a4ec59dfd95c0d2967cf53 100644 (file)
--- a/lily/new-dynamic-engraver.cc
+++ b/lily/new-dynamic-engraver.cc
@@ -33,6 +33,8 @@ protected:
   virtual void process_music ();
   virtual void stop_translation_timestep ();
 private:
+  SCM get_property_setting (Stream_event *evt, char const *evprop, char const *ctxprop);
+
   Drul_array<Stream_event *> accepted_spanevents_drul_;
   Spanner *current_spanner_;
   Spanner *finished_spanner_;
@@ -68,6 +70,14 @@ New_dynamic_engraver::listen_span_dynamic (Stream_event *ev)
   ASSIGN_EVENT_ONCE (accepted_spanevents_drul_[d], ev);
 }
 
+SCM
+New_dynamic_engraver::get_property_setting (Stream_event *evt, char const *evprop, char const *ctxprop)
+{
+  SCM spanner_type = evt->get_property (evprop);
+  if (spanner_type == SCM_EOL)
+    spanner_type = get_property (ctxprop);
+  return spanner_type;
+}
 
 void
 New_dynamic_engraver::process_music ()
@@ -105,7 +115,8 @@ New_dynamic_engraver::process_music ()
          return;
        }
       
-      SCM cresc_type = get_property ((start_type + "Spanner").c_str ());
+      SCM cresc_type = get_property_setting (current_span_event_, "span-type",
+                                       (start_type + "Spanner").c_str ());
 
       if (cresc_type == ly_symbol2scm ("text"))
        {
@@ -113,7 +124,8 @@ New_dynamic_engraver::process_music ()
            = make_spanner ("DynamicTextSpanner",
                            accepted_spanevents_drul_[START]->self_scm ());
 
-         SCM text = get_property ((start_type + "Text").c_str ());
+         SCM text = get_property_setting (current_span_event_, "span-text",
+                                       (start_type + "Text").c_str ());
          if (Text_interface::is_markup (text))
            {
              current_spanner_->set_property ("text", text);

diff --git a/scm/define-music-properties.scm b/scm/define-music-properties.scm
index 3d11e06c1c4be58851535218118043593abec0e3..05f9e2b221e8c518334273b06f26f78c356e650e 100644 (file)
--- a/scm/define-music-properties.scm
+++ b/scm/define-music-properties.scm
@@ -139,9 +139,11 @@ or down-stem?")
      (repeat-count ,integer? "Do a @code{\\repeat} how often?")
 
      (span-direction ,ly:dir? "Does this start or stop a spanner?")
-     (span-type ,string? "What kind of spanner should be created?
+     (span-type ,string? "What kind of spanner should be created? E.g. ligature
+for ligatures, or text or hairpin for (de-)crescendi.
 
 TODO: Consider making type into symbol.")
+     (span-text ,string? "The displayed text for text spanners (e.g. cresc.)")
      (split-list ,list? "Splitting moments for part combiner.")
      (start-callback ,procedure? "Function to compute the negative length
 of starting grace notes.  This property can only be defined as initializer