Generate undo record for crossfade edits, and provide signalling to update the view when such things are undone. Partially fixes #3257.

git-svn-id: svn://localhost/ardour2/branches/3.0@7309 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/crossfade_edit.cc

@@ -27,6 +27,7 @@
 
 #include <libgnomecanvasmm/line.h>
 
+#include "pbd/memento_command.h"
 #include "ardour/automation_list.h"
 #include "evoral/Curve.hpp"
 #include "ardour/crossfade.h"
@@ -783,7 +784,14 @@ CrossfadeEditor::apply_preset (Preset *preset)
 void
 CrossfadeEditor::apply ()
 {
+	_session->begin_reversible_command (_("Edit crossfade"));
+
+	XMLNode& before = xfade->get_state ();
+
 	_apply_to (xfade);
+
+	_session->add_command (new MementoCommand<Crossfade> (*xfade.get(), &before, &xfade->get_state()));
+	_session->commit_reversible_command ();
 }
 
 void

gtk2_ardour/crossfade_view.cc

@@ -84,6 +84,7 @@ CrossfadeView::CrossfadeView (ArdourCanvas::Group *parent,
 	crossfade_changed (all_crossfade_properties);
 
 	crossfade->PropertyChanged.connect (*this, invalidator (*this), ui_bind (&CrossfadeView::crossfade_changed, this, _1), gui_context());
+	crossfade->FadesChanged.connect (*this, invalidator (*this), ui_bind (&CrossfadeView::crossfade_fades_changed, this), gui_context());
 	ColorsChanged.connect (sigc::mem_fun (*this, &CrossfadeView::color_handler));
 }
 
@@ -261,3 +262,9 @@ CrossfadeView::fake_hide ()
 {
 	group->hide();
 }
+
+void
+CrossfadeView::crossfade_fades_changed ()
+{
+	redraw_curves ();
+}

gtk2_ardour/crossfade_view.h

@@ -72,6 +72,7 @@ struct CrossfadeView : public TimeAxisViewItem
     ArdourCanvas::Item *active_button;
 
     void crossfade_changed (const PBD::PropertyChange&);
+    void crossfade_fades_changed ();
     void active_changed ();
     void redraw_curves ();
     void color_handler ();

gtk2_ardour/editor.cc

@@ -1646,7 +1646,7 @@ Editor::add_crossfade_context_items (AudioStreamView* /*view*/, boost::shared_pt
 	}
 
 	items.push_back (MenuElem (str, sigc::bind (sigc::mem_fun(*this, &Editor::toggle_xfade_active), boost::weak_ptr<Crossfade> (xfade))));
-	items.push_back (MenuElem (_("Edit"), sigc::bind (sigc::mem_fun(*this, &Editor::edit_xfade), boost::weak_ptr<Crossfade> (xfade))));
+	items.push_back (MenuElem (_("Edit..."), sigc::bind (sigc::mem_fun(*this, &Editor::edit_xfade), boost::weak_ptr<Crossfade> (xfade))));
 
 	if (xfade->can_follow_overlap()) {
 

libs/ardour/ardour/crossfade.h

@@ -142,6 +142,9 @@ class Crossfade : public ARDOUR::AudioRegion
 	static framecnt_t short_xfade_length() { return _short_xfade_length; }
 	static void set_short_xfade_length (framecnt_t n);
 
+	/** emitted when the actual fade curves change, as opposed to one of the Stateful properties */
+	PBD::Signal0<void> FadesChanged;
+
   private:
 	friend struct CrossfadeComparePtr;
 	friend class AudioPlaylist;

libs/ardour/crossfade.cc

@@ -865,6 +865,7 @@ Crossfade::set_state (const XMLNode& node, int /*version*/)
 	_fade_out.thaw ();
 
 	PropertyChanged (what_changed); /* EMIT SIGNAL */
+	FadesChanged (); /* EMIT SIGNAL */
 
 	return 0;
 }