From 415721fa5b48f3c3dc164ac60095c095c4e48ad0 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 27 Nov 2018 23:57:53 +0100
Subject: [PATCH] Prepare central engine check and user notification

---
 gtk2_ardour/utils.cc | 35 +++++++++++++++++++++++++++++++++++
 gtk2_ardour/utils.h  |  5 +++++
 2 files changed, 40 insertions(+)

diff --git a/gtk2_ardour/utils.cc b/gtk2_ardour/utils.cc
index 97c36b7faf..b1b6870ada 100644
--- a/gtk2_ardour/utils.cc
+++ b/gtk2_ardour/utils.cc
@@ -43,6 +43,7 @@
 #include "pbd/file_utils.h"
 #include "pbd/stacktrace.h"
 
+#include "ardour/audioengine.h"
 #include "ardour/filesystem_paths.h"
 #include "ardour/search_paths.h"
 
@@ -51,6 +52,7 @@
 
 #include "canvas/item.h"
 
+#include "actions.h"
 #include "debug.h"
 #include "public_editor.h"
 #include "keyboard.h"
@@ -99,6 +101,39 @@ ARDOUR_UI_UTILS::just_hide_it (GdkEventAny */*ev*/, Gtk::Window *win)
 	return 0;
 }
 
+static bool
+idle_notify_engine_stopped ()
+{
+	Glib::RefPtr<Action> act = ActionManager::get_action ("Window", "toggle-audio-midi-setup");
+	Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic(act);
+
+	MessageDialog msg (
+			_("The current operation is not possible because of an error communicating with the audio hardware."),
+			false, Gtk::MESSAGE_WARNING, Gtk::BUTTONS_NONE, true);
+
+	msg.add_button (_("Cancel"), Gtk::RESPONSE_CANCEL);
+
+	if (tact && !tact->get_active()) {
+		msg.add_button (_("Configure Hardware"), Gtk::RESPONSE_OK);
+	}
+
+	if (msg.run () == Gtk::RESPONSE_OK) {
+		tact->set_active ();
+	}
+	return false; /* do not call again */
+}
+
+bool
+ARDOUR_UI_UTILS::no_engine_notify ()
+{
+	if (ARDOUR::AudioEngine::instance()->running ()) {
+		return false; // 0 == OK
+	}
+	Glib::signal_idle().connect (sigc::ptr_fun (&idle_notify_engine_stopped));
+	return true;
+}
+
+
 /* xpm2rgb copied from nixieclock, which bore the legend:
 
     nixieclock - a nixie desktop timepiece
diff --git a/gtk2_ardour/utils.h b/gtk2_ardour/utils.h
index 6713844ba6..47967ae3b5 100644
--- a/gtk2_ardour/utils.h
+++ b/gtk2_ardour/utils.h
@@ -52,6 +52,11 @@ namespace ARDOUR_UI_UTILS {
 gint   just_hide_it (GdkEventAny*, Gtk::Window*);
 void add_item_with_sensitivity (Gtk::Menu_Helpers::MenuList &, Gtk::Menu_Helpers::MenuElem, bool);
 
+/* return 0 (false) if there is no error (engine runs).
+ * otherwise queue an idle user-notificaion and return true.
+ */
+bool no_engine_notify ();
+
 unsigned char* xpm2rgb  (const char** xpm, uint32_t& w, uint32_t& h);
 unsigned char* xpm2rgba (const char** xpm, uint32_t& w, uint32_t& h);