From 024dedc446640e871eaa506a9809ec474f2295b3 Mon Sep 17 00:00:00 2001
From: Paul Davis <paul@linuxaudiosystems.com>
Date: Tue, 3 Jun 2025 12:14:21 -0600
Subject: [PATCH] pianoroll: clarify and resolve some issues caused by
 confusion over what type the _view member has

---
 gtk2_ardour/piano_roll_header.cc | 18 +++++++++++++++++-
 gtk2_ardour/piano_roll_header.h  |  5 +++++
 gtk2_ardour/prh_base.cc          | 27 ++++-----------------------
 gtk2_ardour/prh_base.h           |  2 +-
 4 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/gtk2_ardour/piano_roll_header.cc b/gtk2_ardour/piano_roll_header.cc
index 4d9dc9c4cc..8b751e9766 100644
--- a/gtk2_ardour/piano_roll_header.cc
+++ b/gtk2_ardour/piano_roll_header.cc
@@ -44,7 +44,10 @@ using namespace Gtkmm2ext;
 PianoRollHeader::PianoRollHeader (MidiViewBackground& bg)
 	: PianoRollHeaderBase (bg)
  {
-	alloc_layouts (get_pango_context ());
+	 stream_view = dynamic_cast<MidiStreamView*> (&bg);
+	 assert (stream_view);
+
+	 alloc_layouts (get_pango_context ());
 
 	_adj.set_lower(0);
 	_adj.set_upper(127);
@@ -153,3 +156,16 @@ PianoRollHeader::cursor_window()
 {
 	return get_window ();
 }
+
+void
+PianoRollHeader::instrument_info_change ()
+{
+	PianoRollHeaderBase::instrument_info_change ();
+
+	/* need this to get editor to potentially sync all
+	   track header widths if our piano roll header changes
+	   width.
+	*/
+
+	stream_view->trackview().stripable()->gui_changed ("visible_tracks", (void *) 0); /* EMIT SIGNAL */
+}
diff --git a/gtk2_ardour/piano_roll_header.h b/gtk2_ardour/piano_roll_header.h
index 1a405c3485..64311c3a35 100644
--- a/gtk2_ardour/piano_roll_header.h
+++ b/gtk2_ardour/piano_roll_header.h
@@ -47,5 +47,10 @@ class PianoRollHeader : public Gtk::DrawingArea, public PianoRollHeaderBase {
 	void do_grab() { add_modal_grab(); }
 	void do_ungrab() { remove_modal_grab(); }
 	Glib::RefPtr<Gdk::Window> cursor_window();
+
+	void instrument_info_change ();
+
+ private:
+	MidiStreamView* stream_view;
 };
 
diff --git a/gtk2_ardour/prh_base.cc b/gtk2_ardour/prh_base.cc
index f0865b549c..dc33f11985 100644
--- a/gtk2_ardour/prh_base.cc
+++ b/gtk2_ardour/prh_base.cc
@@ -92,9 +92,7 @@ void
 PianoRollHeaderBase::set_view (MidiView* v)
 {
 	_view = v;
-	if (_view) {
-		_view->midi_context().NoteRangeChanged.connect (sigc::mem_fun (*this, &PianoRollHeaderBase::note_range_changed));
-	}
+	_midi_context.NoteRangeChanged.connect (sigc::mem_fun (*this, &PianoRollHeaderBase::note_range_changed));
 }
 
 bool
@@ -485,16 +483,6 @@ PianoRollHeaderBase::instrument_info_change ()
 	}
 
 	_queue_resize ();
-
-	/* need this to get editor to potentially sync all
-	   track header widths if our piano roll header changes
-	   width.
-	*/
-
-	if (_view) {
-		_view->midi_track()->gui_changed ("visible_tracks", (void *) 0); /* EMIT SIGNAL */
-	}
-
 }
 
 PianoRollHeaderBase::NoteName
@@ -645,17 +633,13 @@ PianoRollHeaderBase::button_press_handler (GdkEventButton* ev)
 	double ignore;
 	event_transform (ignore, evy);
 
-	if (!_view) {
-		return false;
-	}
-
 	/* Convert canvas-coordinates to item coordinates */
 
 	_scroomer_button_state = _scroomer_state;
 
 	if (ev->button == 1 && ev->x <= _scroomer_size){
 
-		if (ev->type == GDK_2BUTTON_PRESS) {
+		if (ev->type == GDK_2BUTTON_PRESS && _view) {
 			_view->set_visibility_note_range (MidiStreamView::ContentsRange, false);
 			return true;
 		}
@@ -780,11 +764,8 @@ PianoRollHeaderBase::enter_handler (GdkEventCrossing* ev)
 bool
 PianoRollHeaderBase::leave_handler (GdkEventCrossing*)
 {
-	if (!_scroomer_drag){
-		if (_view) {
-			/* XXX we used to pop the cursor stack here */
-		}
-	}
+	set_cursor (nullptr);
+
 	invalidate_note_range(_highlighted_note, _highlighted_note);
 
 	if (_clicked_note != NO_MIDI_NOTE) {
diff --git a/gtk2_ardour/prh_base.h b/gtk2_ardour/prh_base.h
index 395f99155a..a5a2fd3268 100644
--- a/gtk2_ardour/prh_base.h
+++ b/gtk2_ardour/prh_base.h
@@ -47,7 +47,7 @@ class PianoRollHeaderBase : virtual public sigc::trackable {
 
 	void render (ArdourCanvas::Rect const & self, ArdourCanvas::Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
 
-	void instrument_info_change ();
+	virtual void instrument_info_change ();
 
 	void note_range_changed();
 	void set_note_highlight (uint8_t note);