Optimize automation-event process splitting
[ardour.git] / gtk2_ardour / engine_dialog.cc
index 748561f83d22dfce06ce877551b7c27e2bb19585..1389e815effe1579b3c06e196ce6a0465334a543 100644 (file)
@@ -27,6 +27,7 @@
 #include <gtkmm/messagedialog.h>
 
 #include "pbd/error.h"
+#include "pbd/locale_guard.h"
 #include "pbd/xml++.h"
 #include "pbd/unwind.h"
 #include "pbd/failed_constructor.h"
 #include "ardour_ui.h"
 #include "engine_dialog.h"
 #include "gui_thread.h"
+#include "ui_config.h"
+#include "public_editor.h"
 #include "utils.h"
-#include "i18n.h"
+#include "pbd/i18n.h"
+#include "splash.h"
 
 using namespace std;
 using namespace Gtk;
 using namespace Gtkmm2ext;
 using namespace PBD;
 using namespace Glib;
+using namespace ArdourWidgets;
 using namespace ARDOUR_UI_UTILS;
 
 #define DEBUG_ECONTROL(msg) DEBUG_TRACE (PBD::DEBUG::EngineControl, string_compose ("%1: %2\n", __LINE__, msg));
@@ -276,6 +281,8 @@ EngineControl::EngineControl ()
        start_stop_button.set_sensitive (false);
        start_stop_button.set_name ("generic button");
        start_stop_button.set_can_focus(true);
+       start_stop_button.set_can_default(true);
+       start_stop_button.set_act_on_release (false);
 
        update_devices_button.signal_clicked.connect (mem_fun (*this, &EngineControl::update_devices_button_clicked));
        update_devices_button.set_sensitive (false);
@@ -287,9 +294,6 @@ EngineControl::EngineControl ()
        use_buffered_io_button.set_name ("generic button");
        use_buffered_io_button.set_can_focus(true);
 
-       cancel_button = add_button (Gtk::Stock::CLOSE, Gtk::RESPONSE_CANCEL);
-       ok_button = add_button (Gtk::Stock::OK, Gtk::RESPONSE_OK);
-
        /* Pick up any existing audio setup configuration, if appropriate */
 
        XMLNode* audio_setup = ARDOUR::Config->extra_xml ("AudioMIDISetup");
@@ -398,8 +402,8 @@ EngineControl::unblock_changed_signals ()
 
 EngineControl::SignalBlocker::SignalBlocker (EngineControl& engine_control,
                                              const std::string& reason)
-    : ec (engine_control)
-    , m_reason (reason)
+       : ec (engine_control)
+       , m_reason (reason)
 {
        DEBUG_ECONTROL (string_compose ("SignalBlocker: %1", m_reason));
        ec.block_changed_signals ();
@@ -420,7 +424,20 @@ EngineControl::on_show ()
                backend_changed ();
        }
        device_changed ();
-       ok_button->grab_focus();
+       start_stop_button.grab_focus();
+}
+
+void
+EngineControl::on_map ()
+{
+       if (!ARDOUR_UI::instance()->the_session () && !PublicEditor::_instance) {
+               set_type_hint (Gdk::WINDOW_TYPE_HINT_NORMAL);
+       } else if (UIConfiguration::instance().get_all_floating_windows_are_dialogs()) {
+               set_type_hint (Gdk::WINDOW_TYPE_HINT_DIALOG);
+       } else {
+               set_type_hint (Gdk::WINDOW_TYPE_HINT_UTILITY);
+       }
+       ArdourDialog::on_map ();
 }
 
 bool
@@ -459,49 +476,6 @@ EngineControl::stop_engine (bool for_latency)
        return true;
 }
 
-void
-EngineControl::on_response (int response_id)
-{
-       ArdourDialog::on_response (response_id);
-
-       switch (response_id) {
-       case RESPONSE_OK:
-               if (!start_engine()) {
-                       return;
-               } else {
-                       hide();
-               }
-#ifdef PLATFORM_WINDOWS
-
-               // But if there's no session open, this can produce
-               // a long gap when nothing appears to be happening.
-               // Let's show the splash image while we're waiting.
-               if (!ARDOUR_COMMAND_LINE::no_splash) {
-                       if (ARDOUR_UI::instance()) {
-                               if (!ARDOUR_UI::instance()->session_loaded) {
-                                       ARDOUR_UI::instance()->show_splash();
-                               }
-                       }
-               }
-#endif
-               break;
-       case RESPONSE_DELETE_EVENT: {
-               GdkEventButton ev;
-               ev.type = GDK_BUTTON_PRESS;
-               ev.button = 1;
-               on_delete_event((GdkEventAny*)&ev);
-               break;
-       }
-       case RESPONSE_CANCEL:
-               if (ARDOUR_UI::instance() && ARDOUR_UI::instance()->session_loaded) {
-                       ARDOUR_UI::instance()->check_audioengine(*this);
-               }
-       // fall through
-       default:
-               hide();
-       }
-}
-
 void
 EngineControl::build_notebook ()
 {
@@ -798,13 +772,13 @@ EngineControl::update_sensitivity ()
 {
        boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
        if (!backend) {
-               ok_button->set_sensitive (false);
                start_stop_button.set_sensitive (false);
                return;
        }
 
        bool valid = true;
        size_t devices_available = 0;
+       bool engine_running = ARDOUR::AudioEngine::instance()->running();
 
        if (backend->use_separate_input_and_output_devices ()) {
                devices_available += get_popdown_string_count (input_device_combo);
@@ -822,29 +796,17 @@ EngineControl::update_sensitivity ()
        } else {
                input_latency.set_sensitive (true);
                output_latency.set_sensitive (true);
-               input_channels.set_sensitive (true);
-               output_channels.set_sensitive (true);
+               input_channels.set_sensitive (!engine_running);
+               output_channels.set_sensitive (!engine_running);
        }
 
        if (get_popdown_string_count (buffer_size_combo) > 0) {
-               if (!ARDOUR::AudioEngine::instance()->running()) {
+               if (!engine_running) {
                        buffer_size_combo.set_sensitive (valid);
-               } else if (backend->can_change_sample_rate_when_running()) {
+               } else if (backend->can_change_buffer_size_when_running ()) {
                        buffer_size_combo.set_sensitive (valid || !_have_control);
                } else {
-#if 1
-                       /* TODO
-                        * Currently there is no way to manually stop the
-                        * engine in order to re-configure it.
-                        * This needs to remain sensitive for now.
-                        *
-                        * (it's also handy to implicily
-                        * re-start the engine)
-                        */
-                       buffer_size_combo.set_sensitive (true);
-#else
                        buffer_size_combo.set_sensitive (false);
-#endif
                }
        } else {
                buffer_size_combo.set_sensitive (false);
@@ -852,18 +814,24 @@ EngineControl::update_sensitivity ()
        }
 
        if (get_popdown_string_count (sample_rate_combo) > 0) {
-               if (!ARDOUR::AudioEngine::instance()->running()) {
-                       sample_rate_combo.set_sensitive (true);
-               } else {
-                       sample_rate_combo.set_sensitive (false);
+               bool allow_to_set_rate = false;
+               if (!engine_running) {
+                       if (!ARDOUR_UI::instance()->the_session ()) {
+                               // engine is not running, no session loaded -> anything goes.
+                               allow_to_set_rate = true;
+                       } else if (_desired_sample_rate > 0 && get_rate () != _desired_sample_rate) {
+                               // only allow to change if the current setting is not the native session rate.
+                               allow_to_set_rate = true;
+                       }
                }
+               sample_rate_combo.set_sensitive (allow_to_set_rate);
        } else {
                sample_rate_combo.set_sensitive (false);
                valid = false;
        }
 
        if (get_popdown_string_count (nperiods_combo) > 0) {
-               if (!ARDOUR::AudioEngine::instance()->running()) {
+               if (!engine_running) {
                        nperiods_combo.set_sensitive (true);
                } else {
                        nperiods_combo.set_sensitive (false);
@@ -875,7 +843,7 @@ EngineControl::update_sensitivity ()
        if (_have_control) {
                start_stop_button.set_sensitive(true);
                start_stop_button.show();
-               if (ARDOUR::AudioEngine::instance()->running()) {
+               if (engine_running) {
                        start_stop_button.set_text("Stop");
                        update_devices_button.set_sensitive(false);
                        use_buffered_io_button.set_sensitive(false);
@@ -903,7 +871,7 @@ EngineControl::update_sensitivity ()
                start_stop_button.hide();
        }
 
-       if (ARDOUR::AudioEngine::instance()->running() && _have_control) {
+       if (engine_running && _have_control) {
                input_device_combo.set_sensitive (false);
                output_device_combo.set_sensitive (false);
                device_combo.set_sensitive (false);
@@ -919,11 +887,7 @@ EngineControl::update_sensitivity ()
                }
        }
 
-       if (valid || !_have_control) {
-               ok_button->set_sensitive (true);
-       } else {
-               ok_button->set_sensitive (false);
-       }
+       midi_option_combo.set_sensitive (!engine_running);
 }
 
 void
@@ -1068,6 +1032,7 @@ EngineControl::backend_changed ()
 
        if (!_have_control) {
                // set settings from backend that we do have control over
+               set_buffersize_popdown_strings ();
                set_active_text_if_present (buffer_size_combo, bufsize_as_string (backend->buffer_size()));
        }
 
@@ -1075,9 +1040,14 @@ EngineControl::backend_changed ()
                // set driver & devices
                State state = get_matching_state (backend_combo.get_active_text());
                if (state) {
+                       DEBUG_ECONTROL ("backend-changed(): found prior state for backend");
                        PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
                        set_current_state (state);
+               } else {
+                       DEBUG_ECONTROL ("backend-changed(): no prior state for backend");
                }
+       } else {
+               DEBUG_ECONTROL (string_compose ("backend-changed(): _have_control=%1 ignore_changes=%2", _have_control, ignore_changes));
        }
 
        if (!ignore_changes) {
@@ -1392,7 +1362,17 @@ EngineControl::set_samplerate_popdown_strings ()
        set_popdown_strings (sample_rate_combo, s);
 
        if (!s.empty()) {
-               if (desired.empty ()) {
+               if (ARDOUR::AudioEngine::instance()->running()) {
+                       sample_rate_combo.set_active_text (rate_as_string (backend->sample_rate()));
+               } else if (ARDOUR_UI::instance()->the_session ()) {
+                       float active_sr = ARDOUR_UI::instance()->the_session()->nominal_sample_rate ();
+
+                       if (std::find (sr.begin (), sr.end (), active_sr) == sr.end ()) {
+                               active_sr = sr.front ();
+                       }
+
+                       sample_rate_combo.set_active_text (rate_as_string (active_sr));
+               } else if (desired.empty ()) {
                        float new_active_sr = backend->default_sample_rate ();
 
                        if (std::find (sr.begin (), sr.end (), new_active_sr) == sr.end ()) {
@@ -1403,7 +1383,6 @@ EngineControl::set_samplerate_popdown_strings ()
                } else {
                        sample_rate_combo.set_active_text (desired);
                }
-
        }
        update_sensitivity ();
 }
@@ -1459,7 +1438,7 @@ EngineControl::set_buffersize_popdown_strings ()
                s.push_back (bufsize_as_string (*x));
        }
 
-       uint32_t previous_size = 0;
+       uint32_t previous_size = backend->buffer_size ();
        if (!buffer_size_combo.get_active_text().empty()) {
                previous_size = get_buffer_size ();
        }
@@ -1505,13 +1484,13 @@ EngineControl::set_nperiods_popdown_strings ()
        }
 
        for (vector<uint32_t>::const_iterator x = np.begin(); x != np.end(); ++x) {
-               s.push_back (nperiods_as_string (*x));
+               s.push_back (to_string (*x));
        }
 
        set_popdown_strings (nperiods_combo, s);
 
        if (!s.empty()) {
-               set_active_text_if_present (nperiods_combo, nperiods_as_string (backend->period_size())); // XXX 
+               set_active_text_if_present (nperiods_combo, to_string (backend->period_size())); // XXX
        }
 
        update_sensitivity ();
@@ -1583,6 +1562,24 @@ void
 EngineControl::input_device_changed ()
 {
        DEBUG_ECONTROL ("input_device_changed");
+
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       if (backend && backend->match_input_output_devices_or_none ()) {
+               const std::string& dev_none = ARDOUR::AudioBackend::get_standard_device_name (ARDOUR::AudioBackend::DeviceNone);
+
+               if (get_output_device_name () != dev_none
+                               && get_input_device_name () != dev_none
+                               && get_input_device_name () != get_output_device_name ()) {
+                       block_changed_signals ();
+                       if (contains_value (output_device_combo, get_input_device_name ())) {
+                               output_device_combo.set_active_text (get_input_device_name ());
+                       } else {
+                               assert (contains_value (output_device_combo, dev_none));
+                               output_device_combo.set_active_text (dev_none);
+                       }
+                       unblock_changed_signals ();
+               }
+       }
        device_changed ();
 }
 
@@ -1590,29 +1587,32 @@ void
 EngineControl::output_device_changed ()
 {
        DEBUG_ECONTROL ("output_device_changed");
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       if (backend && backend->match_input_output_devices_or_none ()) {
+               const std::string& dev_none = ARDOUR::AudioBackend::get_standard_device_name (ARDOUR::AudioBackend::DeviceNone);
+
+               if (get_input_device_name () != dev_none
+                               && get_input_device_name () != dev_none
+                               && get_input_device_name () != get_output_device_name ()) {
+                       block_changed_signals ();
+                       if (contains_value (input_device_combo, get_output_device_name ())) {
+                               input_device_combo.set_active_text (get_output_device_name ());
+                       } else {
+                               assert (contains_value (input_device_combo, dev_none));
+                               input_device_combo.set_active_text (dev_none);
+                       }
+                       unblock_changed_signals ();
+               }
+       }
        device_changed ();
 }
 
 string
 EngineControl::bufsize_as_string (uint32_t sz)
 {
-       /* Translators: "samples" is always plural here, so no
-          need for plural+singular forms.
-        */
-       char buf[64];
-       snprintf (buf, sizeof (buf), "%u %s", sz, P_("sample", "samples", sz));
-       return buf;
-}
-
-string
-EngineControl::nperiods_as_string (uint32_t np)
-{
-       char buf[8];
-       snprintf (buf, sizeof (buf), "%u", np);
-       return buf;
+       return string_compose (P_("%1 sample", "%1 samples", sz), to_string(sz));
 }
 
-
 void
 EngineControl::sample_rate_changed ()
 {
@@ -1629,6 +1629,12 @@ void
 EngineControl::buffer_size_changed ()
 {
        DEBUG_ECONTROL ("buffer_size_changed");
+       if (ARDOUR::AudioEngine::instance()->running()) {
+               boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+               if (backend && backend->can_change_buffer_size_when_running ()) {
+                       backend->set_buffer_size (get_buffer_size());
+               }
+       }
        show_buffer_duration ();
 }
 
@@ -1793,6 +1799,7 @@ bool EngineControl::equivalent_states (const EngineControl::State& state1,
        return false;
 }
 
+// sort active first, then most recently used to the beginning of the list
 bool
 EngineControl::state_sort_cmp (const State &a, const State &b) {
        if (a->active) {
@@ -1802,7 +1809,7 @@ EngineControl::state_sort_cmp (const State &a, const State &b) {
                return false;
        }
        else {
-               return a->lru < b->lru;
+               return a->lru > b->lru;
        }
 }
 
@@ -1863,7 +1870,7 @@ EngineControl::store_state (State state)
 void
 EngineControl::maybe_display_saved_state ()
 {
-       if (!_have_control) {
+       if (!_have_control || ARDOUR::AudioEngine::instance()->running ()) {
                return;
        }
 
@@ -1873,12 +1880,12 @@ EngineControl::maybe_display_saved_state ()
                DEBUG_ECONTROL ("Restoring saved state");
                PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
 
-               if (!_desired_sample_rate) {
+               if (0 == _desired_sample_rate && sample_rate_combo.get_sensitive ()) {
                        sample_rate_combo.set_active_text (rate_as_string (state->sample_rate));
                }
                set_active_text_if_present (buffer_size_combo, bufsize_as_string (state->buffer_size));
 
-               set_active_text_if_present (nperiods_combo, nperiods_as_string (state->n_periods));
+               set_active_text_if_present (nperiods_combo, to_string(state->n_periods));
                /* call this explicitly because we're ignoring changes to
                   the controls at this point.
                 */
@@ -1912,30 +1919,31 @@ EngineControl::get_state ()
 
                        XMLNode* node = new XMLNode ("State");
 
-                       node->add_property ("backend", (*i)->backend);
-                       node->add_property ("driver", (*i)->driver);
-                       node->add_property ("device", (*i)->device);
-                       node->add_property ("input-device", (*i)->input_device);
-                       node->add_property ("output-device", (*i)->output_device);
-                       node->add_property ("sample-rate", (*i)->sample_rate);
-                       node->add_property ("buffer-size", (*i)->buffer_size);
-                       node->add_property ("n-periods", (*i)->n_periods);
-                       node->add_property ("input-latency", (*i)->input_latency);
-                       node->add_property ("output-latency", (*i)->output_latency);
-                       node->add_property ("input-channels", (*i)->input_channels);
-                       node->add_property ("output-channels", (*i)->output_channels);
-                       node->add_property ("active", (*i)->active ? "yes" : "no");
-                       node->add_property ("use-buffered-io", (*i)->use_buffered_io ? "yes" : "no");
-                       node->add_property ("midi-option", (*i)->midi_option);
-                       node->add_property ("lru", (*i)->active ? time (NULL) : (*i)->lru);
+                       node->set_property ("backend", (*i)->backend);
+                       node->set_property ("driver", (*i)->driver);
+                       node->set_property ("device", (*i)->device);
+                       node->set_property ("input-device", (*i)->input_device);
+                       node->set_property ("output-device", (*i)->output_device);
+                       node->set_property ("sample-rate", (*i)->sample_rate);
+                       node->set_property ("buffer-size", (*i)->buffer_size);
+                       node->set_property ("n-periods", (*i)->n_periods);
+                       node->set_property ("input-latency", (*i)->input_latency);
+                       node->set_property ("output-latency", (*i)->output_latency);
+                       node->set_property ("input-channels", (*i)->input_channels);
+                       node->set_property ("output-channels", (*i)->output_channels);
+                       node->set_property ("active", (*i)->active);
+                       node->set_property ("use-buffered-io", (*i)->use_buffered_io);
+                       node->set_property ("midi-option", (*i)->midi_option);
+                       int32_t lru_val = (*i)->active ? time (NULL) : (*i)->lru;
+                       node->set_property ("lru", lru_val );
 
                        XMLNode* midi_devices = new XMLNode ("MIDIDevices");
                        for (std::vector<MidiDeviceSettings>::const_iterator p = (*i)->midi_devices.begin(); p != (*i)->midi_devices.end(); ++p) {
                                XMLNode* midi_device_stuff = new XMLNode ("MIDIDevice");
-                               midi_device_stuff->add_property (X_("name"), (*p)->name);
-                               midi_device_stuff->add_property (X_("enabled"), (*p)->enabled);
-                               midi_device_stuff->add_property (X_("input-latency"), (*p)->input_latency);
-                               midi_device_stuff->add_property (X_("output-latency"), (*p)->output_latency);
+                               midi_device_stuff->set_property (X_("name"), (*p)->name);
+                               midi_device_stuff->set_property (X_("enabled"), (*p)->enabled);
+                               midi_device_stuff->set_property (X_("input-latency"), (*p)->input_latency);
+                               midi_device_stuff->set_property (X_("output-latency"), (*p)->output_latency);
                                midi_devices->add_child_nocopy (*midi_device_stuff);
                        }
                        node->add_child_nocopy (*midi_devices);
@@ -1972,9 +1980,6 @@ EngineControl::set_state (const XMLNode& root)
        XMLNodeConstIterator citer, cciter;
        XMLNode const * child;
        XMLNode const * grandchild;
-       XMLProperty const * prop = NULL;
-
-       fprintf (stderr, "EngineControl::set_state\n");
 
        if (root.name() != "AudioMIDISetup") {
                return false;
@@ -2003,132 +2008,68 @@ EngineControl::set_state (const XMLNode& root)
                                continue;
                        }
 
-                       if ((prop = grandchild->property ("backend")) == 0) {
+                       if (!grandchild->get_property ("backend", state->backend)) {
                                continue;
                        }
-                       state->backend = prop->value ();
 
-                       if ((prop = grandchild->property ("driver")) == 0) {
+                       // If any of the required properties are not found in the state node
+                       // then continue/skip to the next engine state
+                       if (!grandchild->get_property ("driver", state->driver) ||
+                           !grandchild->get_property ("device", state->device) ||
+                           !grandchild->get_property ("input-device", state->input_device) ||
+                           !grandchild->get_property ("output-device", state->output_device) ||
+                           !grandchild->get_property ("sample-rate", state->sample_rate) ||
+                           !grandchild->get_property ("buffer-size", state->buffer_size) ||
+                           !grandchild->get_property ("input-latency", state->input_latency) ||
+                           !grandchild->get_property ("output-latency", state->output_latency) ||
+                           !grandchild->get_property ("input-channels", state->input_channels) ||
+                           !grandchild->get_property ("output-channels", state->output_channels) ||
+                           !grandchild->get_property ("active", state->active) ||
+                           !grandchild->get_property ("use-buffered-io", state->use_buffered_io) ||
+                           !grandchild->get_property ("midi-option", state->midi_option)) {
                                continue;
                        }
-                       state->driver = prop->value ();
 
-                       if ((prop = grandchild->property ("device")) == 0) {
-                               continue;
-                       }
-                       state->device = prop->value ();
-
-                       if ((prop = grandchild->property ("input-device")) == 0) {
-                               continue;
-                       }
-                       state->input_device = prop->value ();
-
-                       if ((prop = grandchild->property ("output-device")) == 0) {
-                               continue;
-                       }
-                       state->output_device = prop->value ();
-
-                       if ((prop = grandchild->property ("sample-rate")) == 0) {
-                               continue;
-                       }
-                       state->sample_rate = atof (prop->value ());
-
-                       if ((prop = grandchild->property ("buffer-size")) == 0) {
-                               continue;
-                       }
-                       state->buffer_size = atoi (prop->value ());
-
-                       if ((prop = grandchild->property ("n-periods")) == 0) {
+                       if (!grandchild->get_property ("n-periods", state->n_periods)) {
                                // optional (new value in 4.5)
                                state->n_periods = 0;
-                       } else {
-                               state->n_periods = atoi (prop->value ());
-                       }
-
-                       if ((prop = grandchild->property ("input-latency")) == 0) {
-                               continue;
-                       }
-                       state->input_latency = atoi (prop->value ());
-
-                       if ((prop = grandchild->property ("output-latency")) == 0) {
-                               continue;
-                       }
-                       state->output_latency = atoi (prop->value ());
-
-                       if ((prop = grandchild->property ("input-channels")) == 0) {
-                               continue;
-                       }
-                       state->input_channels = atoi (prop->value ());
-
-                       if ((prop = grandchild->property ("output-channels")) == 0) {
-                               continue;
-                       }
-                       state->output_channels = atoi (prop->value ());
-
-                       if ((prop = grandchild->property ("active")) == 0) {
-                               continue;
-                       }
-                       state->active = string_is_affirmative (prop->value ());
-
-                       if ((prop = grandchild->property ("use-buffered-io")) == 0) {
-                               continue;
                        }
-                       state->use_buffered_io = string_is_affirmative (prop->value ());
-
-                       if ((prop = grandchild->property ("midi-option")) == 0) {
-                               continue;
-                       }
-                       state->midi_option = prop->value ();
 
                        state->midi_devices.clear();
                        XMLNode* midinode;
                        if ((midinode = ARDOUR::find_named_node (*grandchild, "MIDIDevices")) != 0) {
                                const XMLNodeList mnc = midinode->children();
                                for (XMLNodeList::const_iterator n = mnc.begin(); n != mnc.end(); ++n) {
-                                       if ((*n)->property (X_("name")) == 0
-                                                       || (*n)->property (X_("enabled")) == 0
-                                                       || (*n)->property (X_("input-latency")) == 0
-                                                       || (*n)->property (X_("output-latency")) == 0
-                                                ) {
+                                       std::string name;
+                                       bool enabled;
+                                       uint32_t input_latency;
+                                       uint32_t output_latency;
+
+                                       if (!(*n)->get_property (X_("name"), name) ||
+                                           !(*n)->get_property (X_("enabled"), enabled) ||
+                                           !(*n)->get_property (X_("input-latency"), input_latency) ||
+                                           !(*n)->get_property (X_("output-latency"), output_latency)) {
                                                continue;
                                        }
 
-                                       MidiDeviceSettings ptr (new MidiDeviceSetting(
-                                                               (*n)->property (X_("name"))->value (),
-                                                               string_is_affirmative ((*n)->property (X_("enabled"))->value ()),
-                                                               atoi ((*n)->property (X_("input-latency"))->value ()),
-                                                               atoi ((*n)->property (X_("output-latency"))->value ())
-                                                               ));
+                                       MidiDeviceSettings ptr (
+                                           new MidiDeviceSetting (name, enabled, input_latency, output_latency));
                                        state->midi_devices.push_back (ptr);
                                }
                        }
 
-                       if ((prop = grandchild->property ("lru"))) {
-                               state->lru = atoi (prop->value ());
+                       int32_t lru_val;
+                       if (grandchild->get_property ("lru", lru_val)) {
+                               state->lru = lru_val;
                        }
 
-#if 1
-                       /* remove accumulated duplicates (due to bug in ealier version)
-                        * this can be removed again before release
-                        */
-                       for (StateList::iterator i = states.begin(); i != states.end();) {
-                               if ((*i)->backend == state->backend &&
-                                               (*i)->driver == state->driver &&
-                                               (*i)->device == state->device) {
-                                       i =  states.erase(i);
-                               } else {
-                                       ++i;
-                               }
-                       }
-#endif
-
                        states.push_back (state);
                }
        }
 
        /* now see if there was an active state and switch the setup to it */
 
-       // purge states of backend that are not available in this built
+       /* purge states of backend that are not available in this built */
        vector<const ARDOUR::AudioBackendInfo*> backends = ARDOUR::AudioEngine::instance()->available_backends();
        vector<std::string> backend_names;
 
@@ -2145,6 +2086,28 @@ EngineControl::set_state (const XMLNode& root)
 
        states.sort (state_sort_cmp);
 
+       /* purge old states referring to the same backend */
+       const time_t now = time (NULL);
+       for (vector<std::string>::const_iterator bi = backend_names.begin(); bi != backend_names.end(); ++bi) {
+               bool first = true;
+               for (StateList::iterator i = states.begin(); i != states.end();) {
+                       if ((*i)->backend != *bi) {
+                               ++i; continue;
+                       }
+                       // keep at latest one for every audio-system
+                       if (first) {
+                               first = false;
+                               ++i; continue;
+                       }
+                       // also keep states used in the last 90 days.
+                       if ((now - (*i)->lru) < 86400 * 90) {
+                               ++i; continue;
+                       }
+                       assert (!(*i)->active);
+                       i = states.erase(i);
+               }
+       }
+
        for (StateList::const_iterator i = states.begin(); i != states.end(); ++i) {
 
                if ((*i)->active) {
@@ -2242,9 +2205,11 @@ EngineControl::set_current_state (const State& state)
        device_combo.set_active_text (state->device);
        input_device_combo.set_active_text (state->input_device);
        output_device_combo.set_active_text (state->output_device);
-       sample_rate_combo.set_active_text (rate_as_string (state->sample_rate));
+       if (0 == _desired_sample_rate && sample_rate_combo.get_sensitive ()) {
+               sample_rate_combo.set_active_text (rate_as_string (state->sample_rate));
+       }
        set_active_text_if_present (buffer_size_combo, bufsize_as_string (state->buffer_size));
-       set_active_text_if_present (nperiods_combo, nperiods_as_string (state->n_periods));
+       set_active_text_if_present (nperiods_combo, to_string (state->n_periods));
        input_latency.set_value (state->input_latency);
        output_latency.set_value (state->output_latency);
        midi_option_combo.set_active_text (state->midi_option);
@@ -2367,6 +2332,8 @@ EngineControl::push_state_to_backend (bool start)
                        change_channels = true;
                        change_latency = true;
                        change_midi = true;
+                       change_buffered_io = backend->can_use_buffered_io();
+                       change_channels = true;
                        change_nperiods = backend->can_set_period_size() && get_popdown_string_count (nperiods_combo) > 0;
                }
 
@@ -2428,7 +2395,7 @@ EngineControl::push_state_to_backend (bool start)
        if (change_driver || change_device || change_channels || change_nperiods ||
                        (change_latency && !backend->can_change_systemic_latency_when_running ()) ||
                        (change_rate && !backend->can_change_sample_rate_when_running()) ||
-                       change_midi ||
+                       change_midi || change_buffered_io ||
                        (change_bufsize && !backend->can_change_buffer_size_when_running())) {
                restart_required = true;
        } else {
@@ -2717,7 +2684,15 @@ EngineControl::start_stop_button_clicked ()
        if (ARDOUR::AudioEngine::instance()->running()) {
                ARDOUR::AudioEngine::instance()->stop ();
        } else {
+               if (!ARDOUR_UI::instance()->the_session ()) {
+                       pop_splash ();
+                       hide ();
+                       ARDOUR::GUIIdle ();
+               }
                start_engine ();
+               if (!ARDOUR_UI::instance()->the_session ()) {
+                       ArdourDialog::on_response (RESPONSE_OK);
+               }
        }
 }
 
@@ -2782,12 +2757,8 @@ void
 EngineControl::on_switch_page (GtkNotebookPage*, guint page_num)
 {
        if (page_num == 0) {
-               cancel_button->set_sensitive (true);
                _measure_midi.reset();
                update_sensitivity ();
-       } else {
-               cancel_button->set_sensitive (false);
-               ok_button->set_sensitive (false);
        }
 
        if (page_num == midi_tab) {
@@ -2868,7 +2839,7 @@ EngineControl::check_audio_latency_measurement ()
        }
 
        char buf[256];
-       ARDOUR::framecnt_t const sample_rate = ARDOUR::AudioEngine::instance()->sample_rate();
+       ARDOUR::samplecnt_t const sample_rate = ARDOUR::AudioEngine::instance()->sample_rate();
 
        if (sample_rate == 0) {
                lm_results.set_markup (string_compose (results_markup, _("Disconnected from audio engine")));
@@ -2876,12 +2847,12 @@ EngineControl::check_audio_latency_measurement ()
                return false;
        }
 
-       int frames_total = mtdm->del();
-       int extra = frames_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
+       int samples_total = mtdm->del();
+       int extra = samples_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
 
        snprintf (buf, sizeof (buf), "%s%d samples (%.3lf ms)\n%s%d samples (%.3lf ms)",
                        _("Detected roundtrip latency: "),
-                       frames_total, frames_total * 1000.0f/sample_rate,
+                       samples_total, samples_total * 1000.0f/sample_rate,
                        _("Systemic latency: "),
                        extra, extra * 1000.0f/sample_rate);
 
@@ -2922,7 +2893,7 @@ EngineControl::check_midi_latency_measurement ()
        }
 
        char buf[256];
-       ARDOUR::framecnt_t const sample_rate = ARDOUR::AudioEngine::instance()->sample_rate();
+       ARDOUR::samplecnt_t const sample_rate = ARDOUR::AudioEngine::instance()->sample_rate();
 
        if (sample_rate == 0) {
                lm_results.set_markup (string_compose (results_markup, _("Disconnected from audio engine")));
@@ -2930,11 +2901,11 @@ EngineControl::check_midi_latency_measurement ()
                return false;
        }
 
-       ARDOUR::framecnt_t frames_total = mididm->latency();
-       ARDOUR::framecnt_t extra = frames_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
+       ARDOUR::samplecnt_t samples_total = mididm->latency();
+       ARDOUR::samplecnt_t extra = samples_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
        snprintf (buf, sizeof (buf), "%s%" PRId64" samples (%.1lf ms) dev: %.2f[spl]\n%s%" PRId64" samples (%.1lf ms)",
                        _("Detected roundtrip latency: "),
-                       frames_total, frames_total * 1000.0f / sample_rate, mididm->deviation (),
+                       samples_total, samples_total * 1000.0f / sample_rate, mididm->deviation (),
                        _("Systemic latency: "),
                        extra, extra * 1000.0f / sample_rate);
 
@@ -3022,23 +2993,28 @@ EngineControl::latency_button_clicked ()
 void
 EngineControl::latency_back_button_clicked ()
 {
-       ARDOUR::AudioEngine::instance()->stop(true);
+       ARDOUR::AudioEngine::instance()->stop_latency_detection ();
        notebook.set_current_page(0);
 }
 
 void
 EngineControl::use_latency_button_clicked ()
 {
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
        if (_measure_midi) {
                ARDOUR::MIDIDM* mididm = ARDOUR::AudioEngine::instance()->mididm ();
                if (!mididm) {
                        return;
                }
-               ARDOUR::framecnt_t frames_total = mididm->latency();
-               ARDOUR::framecnt_t extra = frames_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
-               uint32_t one_way = max ((ARDOUR::framecnt_t) 0, extra / 2);
+               ARDOUR::samplecnt_t samples_total = mididm->latency();
+               ARDOUR::samplecnt_t extra = samples_total - ARDOUR::AudioEngine::instance()->latency_signal_delay();
+               uint32_t one_way = max ((ARDOUR::samplecnt_t) 0, extra / 2);
                _measure_midi->input_latency = one_way;
                _measure_midi->output_latency = one_way;
+               if (backend->can_change_systemic_latency_when_running ()) {
+                       backend->set_systemic_midi_input_latency (_measure_midi->name, one_way);
+                       backend->set_systemic_midi_output_latency (_measure_midi->name, one_way);
+               }
                notebook.set_current_page (midi_tab);
        } else {
                MTDM* mtdm = ARDOUR::AudioEngine::instance()->mtdm ();
@@ -3052,6 +3028,10 @@ EngineControl::use_latency_button_clicked ()
 
                input_latency_adjustment.set_value (one_way);
                output_latency_adjustment.set_value (one_way);
+               if (backend->can_change_systemic_latency_when_running ()) {
+                       backend->set_systemic_input_latency (one_way);
+                       backend->set_systemic_output_latency (one_way);
+               }
 
                /* back to settings page */
                notebook.set_current_page (0);
@@ -3078,7 +3058,7 @@ EngineControl::engine_running ()
        sample_rate_combo.set_active_text (rate_as_string (backend->sample_rate()));
 
        if (backend->can_set_period_size ()) {
-               set_active_text_if_present (nperiods_combo, nperiods_as_string (backend->period_size()));
+               set_active_text_if_present (nperiods_combo, to_string (backend->period_size()));
        }
 
        connect_disconnect_button.set_label (string_compose (_("Disconnect from %1"), backend->name()));
@@ -3128,7 +3108,15 @@ EngineControl::connect_disconnect_click()
        if (ARDOUR::AudioEngine::instance()->running()) {
                stop_engine ();
        } else {
+               if (!ARDOUR_UI::instance()->the_session ()) {
+                       pop_splash ();
+                       hide ();
+                       ARDOUR::GUIIdle ();
+               }
                start_engine ();
+               if (!ARDOUR_UI::instance()->the_session ()) {
+                       ArdourDialog::on_response (RESPONSE_OK);
+               }
        }
 }