rewrite Self_alignment_interface

lily/new-fingering-engraver.cc

Index: lily/new-fingering-engraver.cc
diff --git a/lily/new-fingering-engraver.cc b/lily/new-fingering-engraver.cc
index a605f0f4ae7e4f574245c84a054e83b93ec58b93..5763daec98e013430c60c7d7ec970abd6639f0bd 100644
--- a/lily/new-fingering-engraver.cc
+++ b/lily/new-fingering-engraver.cc
@@ -288,8 +288,11 @@ New_fingering_engraver::position_scripts (SCM orientations,
         Side_position_interface::add_support (f,
                                               unsmob_grob (ft.head_->get_object ("dot")));
 
-      Self_alignment_interface::set_align_self (f, Y_AXIS);
-      Self_alignment_interface::set_center_parent (f, Y_AXIS);
+      // don't overwrite offset property if it was overridden by the user
+      if (f->get_property (ly_symbol2scm ("Y-offset")) == SCM_EOL)
+        f->set_property (ly_symbol2scm ("Y-offset"),
+                         Self_alignment_interface::y_align_grob (f->self_scm ()));
+
       Side_position_interface::set_axis (f, X_AXIS);
 
       f->set_property ("direction", scm_from_int (hordir));
@@ -307,8 +310,11 @@ New_fingering_engraver::position_scripts (SCM orientations,
           f->set_property ("script-priority",
                            scm_from_int (finger_prio + d * ft.position_));
 
-          Self_alignment_interface::set_align_self (f, X_AXIS);
-          Self_alignment_interface::set_center_parent (f, X_AXIS);
+          // don't overwrite offset property if it was overridden by the user
+          if (f->get_property (ly_symbol2scm ("X-offset")) == SCM_EOL)
+            f->set_property (ly_symbol2scm ("X-offset"),
+                             Self_alignment_interface::x_align_grob (f->self_scm ()));
+
           Side_position_interface::set_axis (f, Y_AXIS);
 
           f->set_property ("direction", scm_from_int (d));