Suspend transport timecode transmission during playhead drag. Should fix #3324.

git-svn-id: svn://localhost/ardour2/branches/3.0@7528 d708f5d6-7413-0410-9779-e7cbd77b26cf

5 files changed, 41 insertions, 4 deletions

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 98bf0145c2..7d822e64bc 100644
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -780,6 +780,10 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 
         bool step_editing() const { return (_step_editors > 0); }
 
+	void request_suspend_timecode_transmission ();
+	void request_resume_timecode_transmission ();
+	bool timecode_transmission_suspended () const;
+
   protected:
 	friend class AudioEngine;
 	void set_block_size (nframes_t nframes);
@@ -1421,6 +1425,9 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
 
         void step_edit_status_change (bool);
         uint32_t _step_editors;
+
+	/** true if timecode transmission by the transport is suspended, otherwise false */
+	mutable gint _suspend_timecode_transmission;
 };
 
 } // namespace ARDOUR
diff --git a/libs/ardour/ardour/session_event.h b/libs/ardour/ardour/session_event.h
index e2027298fb..396f4e778b 100644
--- a/libs/ardour/ardour/session_event.h
+++ b/libs/ardour/ardour/session_event.h
@@ -36,6 +36,7 @@ struct SessionEvent {
 	    RealTimeOperation,
             AdjustPlaybackBuffering,
             AdjustCaptureBuffering,
+	    SetTimecodeTransmission,
 
 	    /* only one of each of these events can be queued at any one time */
 	    
diff --git a/libs/ardour/session.cc b/libs/ardour/session.cc
index 3bee1bc49e..6e557e6d49 100644
--- a/libs/ardour/session.cc
+++ b/libs/ardour/session.cc
@@ -154,8 +154,8 @@ Session::Session (AudioEngine &eng,
 	  click_emphasis_data (0),
 	  main_outs (0),
 	  _metadata (new SessionMetadata()),
-	  _have_rec_enabled_track (false)
-
+	  _have_rec_enabled_track (false),
+	  _suspend_timecode_transmission (0)
 {
 	playlists.reset (new SessionPlaylists);
 	
@@ -4006,3 +4006,4 @@ Session::step_edit_status_change (bool yn)
                 StepEditStatusChange (val);
         }
 }
+
diff --git a/libs/ardour/session_process.cc b/libs/ardour/session_process.cc
index 546963516e..f4f2c5ad0e 100644
--- a/libs/ardour/session_process.cc
+++ b/libs/ardour/session_process.cc
@@ -311,7 +311,7 @@ Session::process_with_events (nframes_t nframes)
 			return;
 		}
 
-		if (!_exporting) {
+		if (!_exporting && !timecode_transmission_suspended()) {
 			send_midi_time_code_for_cycle (nframes);
 		}
 
@@ -762,7 +762,7 @@ Session::process_without_events (nframes_t nframes)
 		return;
 	}
 
-	if (!_exporting) {
+	if (!_exporting && !timecode_transmission_suspended()) {
 		send_midi_time_code_for_cycle (nframes);
 	}
 
@@ -1099,6 +1099,10 @@ Session::process_event (SessionEvent* ev)
                 schedule_capture_buffering_adjustment ();
                 break;
 
+	case SessionEvent::SetTimecodeTransmission:
+		g_atomic_int_set (&_suspend_timecode_transmission, ev->yes_or_no ? 0 : 1);
+		break;
+
 	default:
 	  fatal << string_compose(_("Programming error: illegal event type in process_event (%1)"), ev->type) << endmsg;
 		/*NOTREACHED*/
diff --git a/libs/ardour/session_transport.cc b/libs/ardour/session_transport.cc
index 2897c5cd8f..b722bc04a7 100644
--- a/libs/ardour/session_transport.cc
+++ b/libs/ardour/session_transport.cc
@@ -1568,3 +1568,27 @@ Session::send_mmc_locate (nframes64_t t)
 	timecode_time_subframes (t, time);
 	MIDI::Manager::instance()->mmc()->send (MIDI::MachineControlCommand (time));
 }
+
+/** Ask the transport to not send timecode until further notice.  The suspension
+ *  will come into effect some finite time after this call, and timecode_transmission_suspended()
+ *  should be checked by the caller to find out when.
+ */
+void
+Session::request_suspend_timecode_transmission ()
+{
+	SessionEvent* ev = new SessionEvent (SessionEvent::SetTimecodeTransmission, SessionEvent::Add, SessionEvent::Immediate, 0, 0, false);
+	queue_event (ev);
+}
+
+void
+Session::request_resume_timecode_transmission ()
+{
+	SessionEvent* ev = new SessionEvent (SessionEvent::SetTimecodeTransmission, SessionEvent::Add, SessionEvent::Immediate, 0, 0, true);
+	queue_event (ev);
+}
+
+bool
+Session::timecode_transmission_suspended () const
+{
+	return g_atomic_int_get (&_suspend_timecode_transmission) == 1;
+}