GUI limitation: Require engine to add/remove tracks/busses

gtk2_ardour/ardour_ui.cc

@@ -4353,6 +4353,20 @@ ARDOUR_UI::add_route_dialog_response (int r)
 		return;
 	}
 
+	if (!AudioEngine::instance()->running ()) {
+		switch (r) {
+			case AddRouteDialog::Add:
+			case AddRouteDialog::AddAndClose:
+				break;
+			default:
+				return;
+		}
+		add_route_dialog->ArdourDialog::on_response (r);
+		MessageDialog msg (_("Not connected to audio engine - Adding Tracks/Busses is not possible"));
+		msg.run ();
+		return;
+	}
+
 	int count;
 
 	switch (r) {

gtk2_ardour/editor_drag.cc

@@ -1428,6 +1428,11 @@ RegionMoveDrag::finished (GdkEvent* ev, bool movement_occurred)
 RouteTimeAxisView*
 RegionMoveDrag::create_destination_time_axis (boost::shared_ptr<Region> region, TimeAxisView* original)
 {
+	if (!AudioEngine::instance()->running ()) {
+		error << _("Not connected to audio engine - Could not create new track after region placed in the drop zone") << endmsg;
+		return NULL;
+	}
+
 	/* Add a new track of the correct type, and return the RouteTimeAxisView that is created to display the
 	   new track.
 	 */

gtk2_ardour/editor_ops.cc

@@ -45,6 +45,7 @@
 #include "widgets/prompter.h"
 
 #include "ardour/audio_track.h"
+#include "ardour/audioengine.h"
 #include "ardour/audioregion.h"
 #include "ardour/boost_debug.h"
 #include "ardour/dB.h"
@@ -7420,6 +7421,12 @@ Editor::_remove_tracks ()
 		return;
 	}
 
+	if (!AudioEngine::instance()->running ()) {
+		MessageDialog msg (_("Not connected to audio engine - Removing Tracks/Busses is not possible"));
+		msg.run ();
+		return;
+	}
+
 	vector<string> choices;
 	string prompt;
 	int ntracks = 0;

gtk2_ardour/route_ui.cc

@@ -2323,6 +2323,12 @@ RouteUI::manage_pins ()
 void
 RouteUI::fan_out (bool to_busses, bool group)
 {
+	if (!AudioEngine::instance()->running ()) {
+		MessageDialog msg (_("Not connected to audio engine - Fanning out to Tracks/Busses is not possible"));
+		msg.run ();
+		return;
+	}
+
 	DisplaySuspender ds;
 	boost::shared_ptr<ARDOUR::Route> route = _route;
 	boost::shared_ptr<PluginInsert> pi = boost::dynamic_pointer_cast<PluginInsert> (route->the_instrument ());