several related changes to get visible channel control working in MidiView/Pianoroll

gtk2_ardour/midi_view.cc

@@ -746,6 +746,10 @@ MidiView::channel_edit ()
 	}
 
 	apply_note_diff ();
+
+	if (_visible_channel >= 0 && _visible_channel != new_channel) {
+		set_visible_channel (new_channel, false);
+	}
 }
 
 void
@@ -1283,24 +1287,10 @@ MidiView::view_changed()
 	size_end_rect ();
 }
 
-void
-MidiView::visible_channel_changed ()
+bool
+MidiView::note_editable (std::shared_ptr<const NoteType>  note) const
 {
-	if (!display_is_enabled()) {
-		return;
-	}
-
-	if (!_model) {
-		return;
-	}
-
-	for (auto & [note, gui] : _events) {
-
-		if (gui->item()->visible()) {
-			color_note (gui, note->channel());
-			gui->set_ignore_events (note->channel() != _visible_channel);
-		}
-	}
+	return (_visible_channel < 0) || (note->channel() == _visible_channel);
 }
 
 void
@@ -1789,8 +1779,8 @@ MidiView::update_sustained (Note* ev)
 		ev->set_outline_all ();
 	}
 
-
 	color_note (ev, note->channel());
+	ev->set_ignore_events (!note_editable (note));
 }
 
 void
@@ -1799,8 +1789,8 @@ MidiView::color_note (NoteBase* ev, int channel)
 	// Update color in case velocity has changed
 	uint32_t base_color = ev->base_color();
 
-	if (channel != _visible_channel) {
-		base_color = Gtkmm2ext::change_alpha (base_color, 0.2);
+	if (!note_editable (ev->note())) {
+		base_color = Gtkmm2ext::change_alpha (base_color, 0.15);
 	}
 
 	ev->set_fill_color (base_color);
@@ -1940,6 +1930,9 @@ MidiView::update_hit (Hit* ev)
 	const uint32_t base_col = ev->base_color();
 	ev->set_fill_color(base_col);
 	ev->set_outline_color(ev->calculate_outline(base_col, ev->selected()));
+
+	color_note (ev, _visible_channel);
+	ev->set_ignore_events (!note_editable (note));
 }
 
 /** Add a MIDI note to the view (with length).
@@ -2327,10 +2320,11 @@ MidiView::clear_selection_internal ()
 {
 	DEBUG_TRACE(DEBUG::Selection, "MRV::clear_selection_internal\n");
 
-	for (auto & sel : _selection) {
-		sel->set_selected (false);
-		sel->hide_velocity();
-		ghost_sync_selection (sel);
+	for (auto & note : _selection) {
+		note->set_selected (false);
+		color_note (note, _visible_channel);
+		note->hide_velocity();
+		ghost_sync_selection (note);
 	}
 	_selection.clear();
 }
@@ -2627,15 +2621,15 @@ MidiView::update_drag_selection(timepos_t const & start, timepos_t const & end,
 	// adjusting things that are in the area that appears/disappeared.
 	// We probably need a tree to be able to find events in O(log(n)) time.
 
-	for (Events::iterator i = _events.begin(); i != _events.end(); ++i) {
-		if (i->second->x0() < x1 && i->second->x1() > x0 && i->second->y0() < y1 && i->second->y1() > y0) {
+	for (auto & [ note, gui ] : _events) {
+		if (gui->x0() < x1 && gui->x1() > x0 && gui->y0() < y1 && gui->y1() > y0) {
 			// Rectangles intersect
-			if (!i->second->selected()) {
-				add_to_selection (i->second);
+			if (!gui->selected() && note_editable (note)) {
+				add_to_selection (gui);
 			}
-		} else if (i->second->selected() && !extend) {
+		} else if (gui->selected() && !extend) {
 			// Rectangles do not intersect
-			remove_from_selection (i->second);
+			remove_from_selection (gui);
 		}
 	}
 
@@ -3518,6 +3512,8 @@ MidiView::change_note_channel (NoteBase* event, int8_t chn, bool relative)
 	}
 
 	note_diff_add_change (event, MidiModel::NoteDiffCommand::Channel, new_channel);
+
+	
 }
 
 void
@@ -5240,10 +5236,30 @@ MidiView::set_visibility_note_range (MidiViewBackground::VisibleNoteRange nvr, b
 }
 
 void
-MidiView::set_visible_channel (int chn)
+MidiView::set_visible_channel (int chn, bool clear_selection)
 {
 	_visible_channel = chn;
-	visible_channel_changed ();
+	VisibleChannelChanged(); /* EMIT SIGNAL */
+
+	if (!display_is_enabled()) {
+		return;
+	}
+
+	if (!_model) {
+		return;
+	}
+
+	for (auto & [note, gui] : _events) {
+
+		if (gui->item()->visible()) {
+			color_note (gui, note->channel());
+			gui->set_ignore_events (!note_editable (note));
+		}
+	}
+
+	if (clear_selection) {
+		clear_selection_internal ();
+	}
 }
 
 void

gtk2_ardour/midi_view.h

@@ -377,7 +377,8 @@ class MidiView : public virtual sigc::trackable, public LineMerger
 	virtual bool midi_canvas_group_event(GdkEvent* ev);
 
 	int visible_channel() const { return _visible_channel; }
-	void set_visible_channel (int);
+	void set_visible_channel (int, bool clear_selection = true);
+	PBD::Signal<void()> VisibleChannelChanged;
 
   protected:
 	void init (std::shared_ptr<ARDOUR::MidiTrack>);
@@ -389,6 +390,7 @@ class MidiView : public virtual sigc::trackable, public LineMerger
 	virtual void reset_width_dependent_items (double pixel_width);
 
 	void redisplay (bool view_only);
+	bool note_editable (std::shared_ptr<const NoteType>) const;
 
   protected:
 	friend class EditingContext;
@@ -688,7 +690,6 @@ class MidiView : public virtual sigc::trackable, public LineMerger
 	virtual void add_control_points_to_selection (Temporal::timepos_t const &, Temporal::timepos_t const &, double y0, double y1) {}
 
 	void color_note (NoteBase*, int channel);
-	void visible_channel_changed ();
 };
 
 

gtk2_ardour/pianoroll.cc

@@ -17,6 +17,7 @@
  */
 
 #include "pbd/stateful_diff_command.h"
+#include "pbd/unwind.h"
 
 #include "ardour/midi_region.h"
 #include "ardour/midi_track.h"
@@ -74,6 +75,7 @@ Pianoroll::Pianoroll (std::string const & name)
 	, bar_adjustment (4, 1, 32, 1, 4)
 	, bar_spinner (bar_adjustment)
 	, length_label (X_("Record (Bars):"))
+	, ignore_channel_changes (false)
 {
 	mouse_mode = Editing::MouseContent;
 	autoscroll_vertical_allowed = false;
@@ -434,6 +436,8 @@ Pianoroll::build_upper_toolbar ()
 void
 Pianoroll::set_visible_channel (int n)
 {
+	PBD::Unwinder<bool> uw (ignore_channel_changes, true);
+
 	_visible_channel = n;
 	visible_channel_selector.set_active (string_compose ("%1", _visible_channel + 1));
 
@@ -539,6 +543,7 @@ Pianoroll::build_canvas ()
 
 	view = new PianorollMidiView (nullptr, *data_group, *no_scroll_group, *this, *bg, 0xff0000ff);
 	view->AutomationStateChange.connect (sigc::mem_fun (*this, &Pianoroll::automation_state_changed));
+	view->VisibleChannelChanged.connect (view_connections, invalidator (*this), std::bind (&Pianoroll::visible_channel_changed, this), gui_context());
 
 	bg->set_view (view);
 	prh->set_view (view);
@@ -574,6 +579,24 @@ Pianoroll::build_canvas ()
 	bindings_changed ();
 }
 
+void
+Pianoroll::visible_channel_changed ()
+{
+	if (ignore_channel_changes) {
+		/* We're changing it */
+		return;
+	}
+
+	/* Something else changed it */
+
+	if (!view) {
+		return; /* Ought to be impossible */
+	}
+
+	_visible_channel = view->visible_channel();
+	visible_channel_selector.set_active (string_compose ("%1", view->visible_channel() + 1));
+}
+
 void
 Pianoroll::bindings_changed ()
 {

gtk2_ardour/pianoroll.h

@@ -252,6 +252,7 @@ class Pianoroll : public CueEditor
 
 	sigc::connection _update_connection;
 	PBD::ScopedConnectionList object_connections;
+	PBD::ScopedConnectionList view_connections;
 	void maybe_update ();
 	void trigger_prop_change (PBD::PropertyChange const &);
 
@@ -304,4 +305,7 @@ class Pianoroll : public CueEditor
 	void add_multi_controller_item (Gtk::Menu_Helpers::MenuList& ctl_items, uint16_t channels, int ctl, const std::string& name, ArdourWidgets::MetaButton*);
 	void reset_user_cc_choice (std::string, Evoral::Parameter param, ArdourWidgets::MetaButton*);
 
+	bool ignore_channel_changes;
+	void visible_channel_changed ();
+
 };