From 90a0f0af89a4c986fd1eb2b5487f4dd8b4a6eeec Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Thu, 1 Jul 2021 03:12:27 +0200
Subject: [PATCH] CUE monitor during record w/preroll

---
 libs/ardour/ardour/session_event.h | 1 +
 libs/ardour/route.cc               | 6 +++++-
 libs/ardour/session_process.cc     | 4 ++++
 libs/ardour/session_transport.cc   | 6 ++++++
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/libs/ardour/ardour/session_event.h b/libs/ardour/ardour/session_event.h
index ac54c97bc1..4731128dad 100644
--- a/libs/ardour/ardour/session_event.h
+++ b/libs/ardour/ardour/session_event.h
@@ -65,6 +65,7 @@ public:
 		SetTransportMaster,
 		StartRoll,
 		EndRoll,
+		TransportStateChange,
 
 		/* only one of each of these events can be queued at any one time */
 
diff --git a/libs/ardour/route.cc b/libs/ardour/route.cc
index ec672d9c9b..1f20cae585 100644
--- a/libs/ardour/route.cc
+++ b/libs/ardour/route.cc
@@ -6284,6 +6284,11 @@ Route::monitoring_state () const
 			return MonitoringDisk | get_input_monitoring_state (false, false);
 		} else {
 			/* recording */
+			const samplecnt_t prtl = _session.preroll_record_trim_len ();
+			if (session_rec && roll && prtl > 0 && _disk_writer->get_captured_samples () < prtl) {
+				/* CUE monitor during pre-roll */
+				return MonitoringDisk | get_input_monitoring_state (true, false);
+			}
 			return get_input_monitoring_state (true, false);
 		}
 
@@ -6306,4 +6311,3 @@ Route::monitoring_state () const
 	abort(); /* NOTREACHED */
 	return MonitoringSilence;
 }
-
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index afd2fc84ff..894a86d294 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -979,6 +979,10 @@ Session::process_event (SessionEvent* ev)
 			overwrite_some_buffers (boost::shared_ptr<Track>(), ev->overwrite);
 		break;
 
+	case SessionEvent::TransportStateChange:
+		TransportStateChange (); /* EMIT SIGNAL */
+		break;
+
 	case SessionEvent::Audition:
 		set_audition (ev->region);
 		// drop reference to region
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index 83df2f6cae..e6f3f5d9bd 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -893,6 +893,12 @@ Session::request_preroll_record_trim (samplepos_t rec_in, samplecnt_t preroll)
 	maybe_enable_record ();
 	request_locate (pos, MustRoll);
 	set_requested_return_sample (rec_in);
+
+	if (pos < rec_in) {
+		/* Notify GUI to update monitor state display */
+		SessionEvent* ev = new SessionEvent (SessionEvent::TransportStateChange, SessionEvent::Add, rec_in, rec_in, 1.0);
+		queue_event (ev);
+	}
 }
 
 void