From 198f97e1260b790635df3f27b3575d185ea87457 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Mon, 7 Sep 2020 06:44:47 +0200
Subject: [PATCH] Ask before showing 2k automation lanes

---
 gtk2_ardour/midi_time_axis.cc | 16 ++++++++++++++++
 gtk2_ardour/midi_time_axis.h  |  1 +
 2 files changed, 17 insertions(+)

diff --git a/gtk2_ardour/midi_time_axis.cc b/gtk2_ardour/midi_time_axis.cc
index ae7dd8f24a..a7289b2685 100644
--- a/gtk2_ardour/midi_time_axis.cc
+++ b/gtk2_ardour/midi_time_axis.cc
@@ -44,6 +44,7 @@
 #include "pbd/enumwriter.h"
 #include "pbd/memento_command.h"
 #include "pbd/stateful_diff_command.h"
+#include "pbd/unwind.h"
 
 #include "gtkmm2ext/gtk_ui.h"
 #include "gtkmm2ext/utils.h"
@@ -72,6 +73,7 @@
 #include "ardour/track.h"
 #include "ardour/types.h"
 
+#include "ardour_message.h"
 #include "automation_line.h"
 #include "automation_time_axis.h"
 #include "editor.h"
@@ -119,6 +121,7 @@ MidiTimeAxisView::MidiTimeAxisView (PublicEditor& ed, Session* sess, ArdourCanva
 	: SessionHandlePtr (sess)
 	, RouteTimeAxisView (ed, sess, canvas)
 	, _ignore_signals(false)
+	, _asked_all_automation(false)
 	, _range_scroomer(0)
 	, _piano_roll_header(0)
 	, _note_mode(Sustained)
@@ -1202,6 +1205,19 @@ MidiTimeAxisView::show_all_automation (bool apply_to_selection)
 {
 	using namespace MIDI::Name;
 
+	if (!_asked_all_automation) {
+		ArdourMessageDialog md (_("Are you sure you want to\nshow all MIDI automation lanes?"), false, MESSAGE_QUESTION, BUTTONS_YES_NO);
+
+		md.set_title (_("Show All Automation"));
+
+		md.set_secondary_text (_("There are a total of 16 MIDI channels times 128 Control-Change parameters, not including other MIDI controls. Showing all will add more than 2000 automation lanes which is not generally useful. This will take some time and also slow down Ardour's GUI signficantly."));
+		if (md.run () != RESPONSE_YES) {
+			return;
+		}
+	}
+
+	PBD::Unwinder<bool> uw (_asked_all_automation, true);
+
 	if (apply_to_selection) {
 		_editor.get_selection().tracks.foreach_midi_time_axis (
 			boost::bind (&MidiTimeAxisView::show_all_automation, _1, false));
diff --git a/gtk2_ardour/midi_time_axis.h b/gtk2_ardour/midi_time_axis.h
index 8f3a7cc0a7..fd4e168964 100644
--- a/gtk2_ardour/midi_time_axis.h
+++ b/gtk2_ardour/midi_time_axis.h
@@ -145,6 +145,7 @@ private:
 	void update_midi_controls_visibility (uint32_t);
 
 	bool                          _ignore_signals;
+	bool                          _asked_all_automation;
 	std::string                   _effective_model;
 	std::string                   _effective_mode;
 	MidiScroomer*                 _range_scroomer;