pianoroll: dragging start handle before zero shifts MIDI later in time

gtk2_ardour/editor_drag.cc

@@ -7564,13 +7564,34 @@ ClipStartDrag::motion (GdkEvent* event, bool first_move)
 {
 	ArdourCanvas::Rect r (original_rect);
 
-	timepos_t pos (adjusted_current_time (event));
-	editing_context.snap_to_with_modifier (pos, event, Temporal::RoundNearest, ARDOUR::SnapToGrid_Scaled, true);
-	double pix = editing_context.timeline_to_canvas (editing_context.time_to_pixel (pos));
+	double x, y;
+	gdk_event_get_coords (event, &x, &y);
+
+	if (x >= editing_context.timeline_origin()) {
+
+		/* Compute snapped position and adjust rect item if appropriate */
+
+		timepos_t pos = adjusted_current_time (event);
+		editing_context.snap_to_with_modifier (pos, event, Temporal::RoundNearest, ARDOUR::SnapToGrid_Scaled, true);
+		double pix = editing_context.timeline_to_canvas (editing_context.time_to_pixel (pos));
+
+		if (pix >= editing_context.timeline_origin()) {
+			r.x1 = dragging_rect->parent()->canvas_to_item (Duple (pix, 0.0)).x;
+		}
 
-	if (pix > editing_context.timeline_origin()) {
-		r.x1 = dragging_rect->parent()->canvas_to_item (Duple (pix, 0.0)).x;
 	} else {
+
+		/* We need to do our own math here because the normal drag
+		 * coordinates are clamped to zero (no negative values).
+		 */
+
+		x -= editing_context.timeline_origin();
+		timepos_t tp (mce.pixel_to_sample (x));
+		Beats b (tp.beats() * -1);
+		mce.shift_midi (timepos_t (b), false);
+
+		/* ensure the line is in the right place */
+
 		r.x1 = r.x0 + 1.;
 	}
 
@@ -7585,22 +7606,50 @@ ClipStartDrag::finished (GdkEvent* event, bool movement_occured)
 		return;
 	}
 
-	timepos_t pos = adjusted_current_time (event);
+	double x, y;
+	gdk_event_get_coords (event, &x, &y);
 
-	assert (mce.midi_view());
+	if (x >= editing_context.timeline_origin()) {
+
+		timepos_t pos = adjusted_current_time (event);
+		editing_context.snap_to_with_modifier (pos, event, Temporal::RoundNearest, ARDOUR::SnapToGrid_Scaled, true);
+		double pix = editing_context.timeline_to_canvas (editing_context.time_to_pixel (pos));
+
+		if (pix >= editing_context.timeline_origin()) {
+
+			assert (mce.midi_view());
+
+			if (mce.midi_view()->show_source()) {
+				pos = mce.midi_view()->source_beats_to_timeline (pos.beats());
+			}
+
+			editing_context.snap_to_with_modifier (pos, event, Temporal::RoundNearest, ARDOUR::SnapToGrid_Scaled, true);
+			mce.set_trigger_start (pos);
+		}
+
+	} else {
+
+		/* We need to do our own math here because the normal drag
+		 * coordinates are clamped to zero (no negative values).
+		 */
+
+		x -= editing_context.timeline_origin();
+		timepos_t tp (mce.pixel_to_sample (x));
+		Beats b (tp.beats() * -1);
+		mce.shift_midi (timepos_t (b), true);
 
-	if (mce.midi_view()->show_source()) {
-		pos = mce.midi_view()->source_beats_to_timeline (pos.beats());
 	}
-
-	editing_context.snap_to_with_modifier (pos, event, Temporal::RoundNearest, ARDOUR::SnapToGrid_Scaled, true);
-	mce.set_trigger_start (pos);
 }
 
 void
-ClipStartDrag::aborted (bool)
+ClipStartDrag::aborted (bool movement_occured)
 {
 	dragging_rect->set (original_rect);
+
+	if (movement_occured) {
+		/* redraw to get notes back to the right places */
+		mce.shift_midi (timepos_t (Temporal::Beats()), false);
+	}
 }
 
 ClipEndDrag::ClipEndDrag (EditingContext& ec, ArdourCanvas::Rectangle& r, Pianoroll& m)

gtk2_ardour/midi_view.cc

@@ -1260,6 +1260,9 @@ MidiView::model_changed()
 	_marked_for_selection.clear ();
 	_marked_for_velocity.clear ();
 	_pending_note_selection.clear ();
+
+	size_start_rect ();
+	size_end_rect ();
 }
 
 void
@@ -5270,6 +5273,81 @@ MidiView::add_split_notes ()
 	}
 }
 
+void
+MidiView::shift_midi (timepos_t const & t, bool model)
+{
+	/* INTENDED FOR USE IN PIANOROLL CONTEXT ONLY */
+
+	assert (_show_source);
+
+	Beats beats (t.beats());
+
+	if (model) {
+
+		/* Change the model */
+
+		std::string cmd = string_compose (_("Shift MIDI by %1"), beats.str());
+		XMLNode& before (_midi_region->get_state());
+		_editing_context.begin_reversible_command (cmd);
+		_model->insert_silence_at_start (beats, _editing_context.history());
+		XMLNode& after (_midi_region->get_state());
+		_editing_context.add_command (new MementoCommand<MidiRegion> (*(_midi_region.get()), &before, &after));
+		_editing_context.commit_reversible_command ();
+
+	} else {
+
+		/* Only change the view */
+
+		for (auto & [ note, gui ] : _events) {
+			Temporal::Beats note_time_qn;
+			double dx = 0.0;
+
+			if (_show_source) {
+				note_time_qn = note->time ();
+			} else {
+				note_time_qn = _midi_region->source_beats_to_absolute_beats (note->time());
+			}
+
+			if (_midi_context.note_mode() == Sustained) {
+				dx = _editing_context.time_to_pixel_unrounded (timepos_t (note_time_qn + beats));
+
+				/*: ::item_to_canvas() converts to a global canvas
+				 *  coordinate, but ::time_to_pixel() gives us a
+				 *  timeline-relative coordinate.
+				 *
+				 * So we need to adjust ...
+				 */
+
+				dx -= _editing_context.canvas_to_timeline (gui->item()->item_to_canvas (ArdourCanvas::Duple (gui->x0(), 0)).x);
+			} else {
+				/* Hit::x0() is offset by _position.x, unlike Note::x0() */
+				Hit* hit = dynamic_cast<Hit*>(gui);
+				if (hit) {
+					dx = _editing_context.time_to_pixel_unrounded (timepos_t (note_time_qn + beats));
+					dx -= _editing_context.canvas_to_timeline (gui->item()->item_to_canvas (ArdourCanvas::Duple (((hit->x0() + hit->x1()) / 2.0) - hit->position().x, 0)).x);
+				}
+			}
+
+			gui->move_event (dx, 0.0);
+
+			/* update length, which may have changed in pixels at the new location */
+			if (_midi_context.note_mode() == Sustained) {
+				Note* sus = dynamic_cast<Note*> (gui);
+				double len_dx = _editing_context.time_to_pixel_unrounded (timepos_t (note_time_qn) + t + timecnt_t (note->length()));
+
+				/* at this point, len_dx is a timeline-relative pixel
+				 * duration. To convert it back to an item-centric
+				 * coordinate, we need to first convert it to a global
+				 * canvas position.
+				 */
+
+				len_dx = _editing_context.timeline_to_canvas (len_dx);
+				sus->set_x1 (gui->item()->canvas_to_item (ArdourCanvas::Duple (len_dx, 0)).x);
+			}
+		}
+	}
+}
+
 double
 MidiView::height() const
 {

gtk2_ardour/midi_view.h

@@ -358,6 +358,8 @@ class MidiView : public virtual sigc::trackable, public LineMerger
 	void note_deleted (NoteBase*);
 	void clear_note_selection ();
 
+	void shift_midi (Temporal::timepos_t const &, bool model);
+
 	void show_verbose_cursor_for_new_note_value(std::shared_ptr<NoteType> current_note, uint8_t new_note) const;
 
 	std::shared_ptr<ARDOUR::MidiTrack>  midi_track() const { return _midi_track; }

gtk2_ardour/pianoroll.cc

@@ -2822,3 +2822,12 @@ Pianoroll::allow_trim_cursors () const
 	return mouse_mode == Editing::MouseContent || mouse_mode == Editing::MouseTimeFX;
 }
 
+void
+Pianoroll::shift_midi (timepos_t const & t, bool model)
+{
+	if (!view) {
+		return;
+	}
+
+	view->shift_midi (t, model);
+}

gtk2_ardour/pianoroll.h

@@ -142,6 +142,8 @@ class Pianoroll : public CueEditor
 	void set_session (ARDOUR::Session*);
 	bool allow_trim_cursors () const;
 
+	void shift_midi (Temporal::timepos_t const &, bool model);
+
   protected:
 	void load_bindings ();
 	void register_actions ();