Allow trim of midi regions to before the start of the source. Fixes #3156.

git-svn-id: svn://localhost/ardour2/branches/3.0@8212 d708f5d6-7413-0410-9779-e7cbd77b26cf

gtk2_ardour/editor_drag.cc

@@ -1533,6 +1533,7 @@ TrimDrag::start_grab (GdkEvent* event, Gdk::Cursor*)
 	framepos_t const pf = adjusted_current_frame (event);
 
 	if (Keyboard::modifier_state_equals (event->button.state, Keyboard::PrimaryModifier)) {
+		/* Move the contents of the region around without changing the region bounds */
 		_operation = ContentsTrim;
 		Drag::start_grab (event, _editor->cursors()->trimmer);
 	} else {
@@ -1723,6 +1724,7 @@ TrimDrag::finished (GdkEvent* event, bool movement_occurred)
 		if (_operation == StartTrim) {
 			i->view->trim_front_ending ();
 		}
+		
 		i->view->region()->resume_property_changes ();
 	}
 }

gtk2_ardour/midi_region_view.cc

@@ -3246,4 +3246,9 @@ MidiRegionView::trim_front_ending ()
 	_note_group->reparent (*group);
 	delete _temporary_note_group;
 	_temporary_note_group = 0;
+
+	if (_region->start() < 0) {
+		/* Trim drag made start time -ve; fix this */
+		midi_region()->fix_negative_start ();
+	}
 }

libs/ardour/ardour/midi_region.h

@@ -107,13 +107,20 @@ class MidiRegion : public Region
 	boost::shared_ptr<MidiModel> model()             { return midi_source()->model(); }
 	boost::shared_ptr<const MidiModel> model() const { return midi_source()->model(); }
 
+	void fix_negative_start ();
+
+  protected:
+	
+	virtual bool can_trim_start_before_source_start () const {
+		return true;
+	}
+
   private:
 	friend class RegionFactory;
 
 	MidiRegion (const SourceList&);
 	MidiRegion (boost::shared_ptr<const MidiRegion>, frameoffset_t offset = 0, bool offset_relative = true);
 
-  private:
 	framecnt_t _read_at (const SourceList&, Evoral::EventSink<framepos_t>& dst,
 			     framepos_t position,
 			     framecnt_t dur,

libs/ardour/ardour/region.h

@@ -315,6 +315,10 @@ class Region
 	/** Constructor for derived types only */
 	Region (Session& s, framepos_t start, framecnt_t length, const std::string& name, DataType);
 
+	virtual bool can_trim_start_before_source_start () const {
+		return false;
+	}
+
   protected:
 	void send_change (const PBD::PropertyChange&);
         void mid_thaw (const PBD::PropertyChange&);

libs/ardour/midi_region.cc

@@ -306,9 +306,22 @@ MidiRegion::model_automation_state_changed (Evoral::Parameter const & p)
 	}
 
 	/* the source will have an iterator into the model, and that iterator will have been set up
-	   for a given set of filtered_paramters, so now that we've changed that list we must invalidate
+	   for a given set of filtered_parameters, so now that we've changed that list we must invalidate
 	   the iterator.
 	*/
 	Glib::Mutex::Lock lm (midi_source(0)->mutex());
 	midi_source(0)->invalidate ();
 }
+
+/** This is called when a trim drag has resulted in a -ve _start time for this region.
+ *  Fix it up by adding some empty space to the source.
+ */
+void
+MidiRegion::fix_negative_start ()
+{
+        BeatsFramesConverter c (_session.tempo_map(), _position);
+
+	MidiModel::WriteLock lock (model()->edit_lock ());
+	model()->insert_silence_at_start (c.from (-_start));
+	_start = 0;
+}

libs/ardour/region.cc

@@ -732,13 +732,7 @@ Region::trim_start (framepos_t new_position, void */*src*/)
 		return;
 	}
 	framepos_t new_start;
-	frameoffset_t start_shift;
+	frameoffset_t const start_shift = new_position - _position;
-
-	if (new_position > _position) {
-		start_shift = new_position - _position;
-	} else {
-		start_shift = -(_position - new_position);
-	}
 
 	if (start_shift > 0) {
 
@@ -759,6 +753,7 @@ Region::trim_start (framepos_t new_position, void */*src*/)
 		} else {
 			new_start = _start + start_shift;
 		}
+		
 	} else {
 		return;
 	}
@@ -813,9 +808,10 @@ Region::modify_front (framepos_t new_position, bool reset_fade, void *src)
 		framecnt_t newlen = 0;
 		framepos_t delta = 0;
 
-		/* can't trim it back passed where source position zero is located */
+		if (!can_trim_start_before_source_start ()) {
-		
+			/* can't trim it back past where source position zero is located */
 			new_position = max (new_position, source_zero);
+		}
 		
 		if (new_position > _position) {
 			newlen = _length - (new_position - _position);
@@ -887,18 +883,13 @@ Region::trim_to (framepos_t position, framecnt_t length, void *src)
 void
 Region::trim_to_internal (framepos_t position, framecnt_t length, void */*src*/)
 {
-	frameoffset_t start_shift;
 	framepos_t new_start;
 
 	if (locked()) {
 		return;
 	}
 
-	if (position > _position) {
+	frameoffset_t const start_shift = position - _position;
-		start_shift = position - _position;
-	} else {
-		start_shift = -(_position - position);
-	}
 
 	if (start_shift > 0) {
 
@@ -910,7 +901,7 @@ Region::trim_to_internal (framepos_t position, framecnt_t length, void */*src*/)
 
 	} else if (start_shift < 0) {
 
-		if (_start < -start_shift) {
+		if (_start < -start_shift && !can_trim_start_before_source_start ()) {
 			new_start = 0;
 		} else {
 			new_start = _start + start_shift;
@@ -1609,7 +1600,7 @@ Region::can_trim () const
 
         ct = CanTrim (ct | FrontTrimLater | EndTrimEarlier);
 
-        if (start() != 0) {
+        if (start() != 0 || can_trim_start_before_source_start ()) {
                 ct = CanTrim (ct | FrontTrimEarlier);
         }
 

libs/evoral/evoral/Event.hpp

@@ -170,6 +170,9 @@ struct Event {
 	inline const uint8_t* buffer()             const { return _buf; }
 	inline uint8_t*&      buffer()                   { return _buf; }
 
+	void set_time (Time);
+	void set_original_time (Time);
+
         inline event_id_t id() const { return _id; }
         inline void set_id (event_id_t n) { _id = n; }
 

libs/evoral/evoral/Sequence.hpp

@@ -173,6 +173,8 @@ public:
 
 	void set_notes (const Sequence<Time>::Notes& n);
 
+	void insert_silence_at_start (Time);
+
 	typedef std::vector< boost::shared_ptr< Event<Time> > > SysExes;
 	inline       SysExes& sysexes()       { return _sysexes; }
 	inline const SysExes& sysexes() const { return _sysexes; }

libs/evoral/src/Event.cpp

@@ -90,6 +90,20 @@ Event<Timestamp>::~Event() {
 	}
 }
 
+template<typename Timestamp>
+void
+Event<Timestamp>::set_time (Timestamp t)
+{
+	_nominal_time = t;
+}
+
+template<typename Timestamp>
+void
+Event<Timestamp>::set_original_time (Timestamp t)
+{
+	_original_time = t;
+}
+	
 #endif // EVORAL_EVENT_ALLOC
 
 template class Event<Evoral::MusicalTime>;

libs/evoral/src/Sequence.cpp

@@ -1076,6 +1076,26 @@ Sequence<Time>::control_list_marked_dirty ()
 	set_edited (true);
 }
 
+template<typename Time>
+void
+Sequence<Time>::insert_silence_at_start (Time t)
+{
+	for (typename Notes::iterator i = _notes.begin(); i != _notes.end(); ++i) {
+		(*i)->set_time ((*i)->time() + t);
+	}
+
+	for (typename SysExes::iterator i = _sysexes.begin (); i != _sysexes.end(); ++i) {
+		(*i)->set_time ((*i)->time() + t);
+		(*i)->set_original_time ((*i)->original_time() + t);
+	}
+
+	for (typename Controls::iterator i = _controls.begin(); i != _controls.end(); ++i) {
+		i->second->list()->shift (0, t);
+	}
+
+	_edited = true;
+}
+
 template class Sequence<Evoral::MusicalTime>;
 
 } // namespace Evoral