hide "turn down volume" label for midi-latency measurement
[ardour.git] / gtk2_ardour / engine_dialog.cc
index 51cbdda398c09c303a064bd09edd79e386b76f91..a89ddddb1a9ec7e5ff295ef4c0055bd96922f446 100644 (file)
@@ -1,36 +1,56 @@
+/*
+    Copyright (C) 2010 Paul Davis
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <exception>
 #include <vector>
 #include <cmath>
 #include <fstream>
 #include <map>
 
-#include <glibmm.h>
-#include <gtkmm/messagedialog.h>
-#include "pbd/xml++.h"
+#include <boost/scoped_ptr.hpp>
 
-#ifdef __APPLE__
-#include <CoreAudio/CoreAudio.h>
-#include <CoreFoundation/CFString.h>
-#include <sys/param.h>
-#include <mach-o/dyld.h>
-#else
-#include <alsa/asoundlib.h>
-#endif
+#include <gtkmm/messagedialog.h>
 
-#include "ardour/profile.h"
-#include <jack/jack.h>
+#include "pbd/error.h"
+#include "pbd/xml++.h"
+#include "pbd/unwind.h"
+#include "pbd/failed_constructor.h"
 
+#include <gtkmm/alignment.h>
 #include <gtkmm/stock.h>
+#include <gtkmm/notebook.h>
 #include <gtkmm2ext/utils.h>
 
+#include "ardour/audio_backend.h"
+#include "ardour/audioengine.h"
+#include "ardour/mtdm.h"
+#include "ardour/mididm.h"
+#include "ardour/rc_configuration.h"
+#include "ardour/types.h"
+
 #include "pbd/convert.h"
 #include "pbd/error.h"
-#include "pbd/pathscanner.h"
-
-#ifdef __APPLE
-#include <CFBundle.h>
-#endif
 
+#include "ardour_ui.h"
 #include "engine_dialog.h"
+#include "gui_thread.h"
+#include "utils.h"
 #include "i18n.h"
 
 using namespace std;
@@ -39,1255 +59,2044 @@ using namespace Gtkmm2ext;
 using namespace PBD;
 using namespace Glib;
 
+static const unsigned int midi_tab = 2;
+static const unsigned int latency_tab = 1; /* zero-based, page zero is the main setup page */
+
+static const char* results_markup = X_("<span weight=\"bold\" size=\"larger\">%1</span>");
+
 EngineControl::EngineControl ()
-       : periods_adjustment (2, 2, 16, 1, 2),
-         periods_spinner (periods_adjustment),
-         priority_adjustment (60, 10, 90, 1, 10),
-         priority_spinner (priority_adjustment),
-         ports_adjustment (128, 8, 1024, 1, 16),
-         ports_spinner (ports_adjustment),
-         realtime_button (_("Realtime")),
-         no_memory_lock_button (_("Do not lock memory")),
-         unlock_memory_button (_("Unlock memory")),
-         soft_mode_button (_("No zombies")),
-         monitor_button (_("Provide monitor ports")),
-         force16bit_button (_("Force 16 bit")),
-         hw_monitor_button (_("H/W monitoring")),
-         hw_meter_button (_("H/W metering")),
-         verbose_output_button (_("Verbose output")),
-         start_button (_("Start")),
-         stop_button (_("Stop")),
-#ifdef __APPLE__
-         basic_packer (5, 2),
-         options_packer (4, 2),
-         device_packer (4, 2)
-#else
-         basic_packer (8, 2),
-         options_packer (14, 2),
-         device_packer (6, 2)
-#endif   
+       : ArdourDialog (_("Audio/MIDI Setup"))
+       , basic_packer (9, 4)
+       , input_latency_adjustment (0, 0, 99999, 1)
+       , input_latency (input_latency_adjustment)
+       , output_latency_adjustment (0, 0, 99999, 1)
+       , output_latency (output_latency_adjustment)
+       , input_channels_adjustment (0, 0, 256, 1)
+       , input_channels (input_channels_adjustment)
+       , output_channels_adjustment (0, 0, 256, 1)
+       , output_channels (output_channels_adjustment)
+       , ports_adjustment (128, 8, 1024, 1, 16)
+       , ports_spinner (ports_adjustment)
+       , control_app_button (_("Device Control Panel"))
+       , midi_devices_button (_("Midi Device Setup"))
+       , lm_measure_label (_("Measure"))
+       , lm_use_button (_("Use results"))
+       , lm_back_button (_("Back to settings ... (ignore results)"))
+       , lm_button_audio (_("Calibrate Audio"))
+       , lm_table (12, 3)
+       , have_lm_results (false)
+       , lm_running (false)
+       , midi_back_button (_("Back to settings"))
+       , ignore_changes (0)
+       , _desired_sample_rate (0)
+       , started_at_least_once (false)
 {
        using namespace Notebook_Helpers;
-       Label* label;
        vector<string> strings;
-       int row = 0;
-
-       _used = false;
-
-       strings.push_back (_("8000Hz"));
-       strings.push_back (_("22050Hz"));
-       strings.push_back (_("44100Hz"));
-       strings.push_back (_("48000Hz"));
-       strings.push_back (_("88200Hz"));
-       strings.push_back (_("96000Hz"));
-       strings.push_back (_("192000Hz"));
-       set_popdown_strings (sample_rate_combo, strings);
-       sample_rate_combo.set_active_text ("48000Hz");
-
-       strings.clear ();
-       strings.push_back ("32");
-       strings.push_back ("64");
-       strings.push_back ("128");
-       strings.push_back ("256");
-       strings.push_back ("512");
-       strings.push_back ("1024");
-       strings.push_back ("2048");
-       strings.push_back ("4096");
-       strings.push_back ("8192");
-       set_popdown_strings (period_size_combo, strings);
-       period_size_combo.set_active_text ("1024");
-
-       strings.clear ();
-       strings.push_back (_("None"));
-       strings.push_back (_("Triangular"));
-       strings.push_back (_("Rectangular"));
-       strings.push_back (_("Shaped"));
-       set_popdown_strings (dither_mode_combo, strings);
-       dither_mode_combo.set_active_text (_("None"));
-
-       /* basic parameters */
+       Label* label;
+       AttachOptions xopt = AttachOptions (FILL|EXPAND);
+       int row;
 
-       basic_packer.set_spacings (6);
+       set_name (X_("AudioMIDISetup"));
 
-       strings.clear ();
-#ifdef __APPLE__
-       strings.push_back (X_("CoreAudio"));
-#else
-       strings.push_back (X_("ALSA"));
-       strings.push_back (X_("OSS"));
-       strings.push_back (X_("FFADO"));
-#endif
-       strings.push_back (X_("NetJACK"));
-       strings.push_back (X_("Dummy"));
-       set_popdown_strings (driver_combo, strings);
-       driver_combo.set_active_text (strings.front());
+       /* the backend combo is the one thing that is ALWAYS visible */
 
-       driver_combo.signal_changed().connect (mem_fun (*this, &EngineControl::driver_changed));
-       driver_changed ();
+       vector<const ARDOUR::AudioBackendInfo*> backends = ARDOUR::AudioEngine::instance()->available_backends();
 
-       strings.clear ();
-       strings.push_back (_("Playback/Recording on 1 Device"));
-       strings.push_back (_("Playback/Recording on 2 Devices"));
-       strings.push_back (_("Playback only"));
-       strings.push_back (_("Recording only"));
-       set_popdown_strings (audio_mode_combo, strings);
-       audio_mode_combo.set_active_text (strings.front());
+       if (backends.empty()) {
+               MessageDialog msg (string_compose (_("No audio/MIDI backends detected. %1 cannot run\n\n(This is a build/packaging/system error. It should never happen.)"), PROGRAM_NAME));
+               msg.run ();
+               throw failed_constructor ();
+       }
 
-       audio_mode_combo.signal_changed().connect (mem_fun (*this, &EngineControl::audio_mode_changed));
-       audio_mode_changed ();
+       for (vector<const ARDOUR::AudioBackendInfo*>::const_iterator b = backends.begin(); b != backends.end(); ++b) {
+               strings.push_back ((*b)->name);
+       }
 
-       row = 0;
+       set_popdown_strings (backend_combo, strings);
+       backend_combo.set_active_text (strings.front());
+       backend_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::backend_changed));
 
-       label = manage (new Label (_("Driver")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (driver_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       row++;
+       /* setup basic packing characteristics for the table used on the main
+        * tab of the notebook
+        */
 
-       label = manage (new Label (_("Interface")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (interface_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       row++;
+       basic_packer.set_spacings (6);
+       basic_packer.set_border_width (12);
+       basic_packer.set_homogeneous (false);
 
-       label = manage (new Label (_("Sample Rate")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (sample_rate_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       row++;
+       /* pack it in */
 
-       label = manage (new Label (_("Buffer size")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (period_size_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       row++;
+       basic_hbox.pack_start (basic_packer, false, false);
 
-#ifndef __APPLE__
-       label = manage (new Label (_("Number of buffers")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (periods_spinner, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       periods_spinner.set_value (2);
-       row++;
-#endif
+       /* latency measurement tab */
 
-       label = manage (new Label (_("Approximate latency")));
-       label->set_alignment (0.0, 0.5);
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (latency_label, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       row++;
+       lm_title.set_markup (string_compose ("<span size=\"large\" weight=\"bold\">%1</span>", _("Latency Measurement Tool")));
 
-       sample_rate_combo.signal_changed().connect (mem_fun (*this, &EngineControl::redisplay_latency));
-       periods_adjustment.signal_value_changed().connect (mem_fun (*this, &EngineControl::redisplay_latency));
-       period_size_combo.signal_changed().connect (mem_fun (*this, &EngineControl::redisplay_latency));
-       redisplay_latency();
-       row++;
-       /* no audio mode with CoreAudio, its duplex or nuthin' */
+       row = 0;
+       lm_table.set_row_spacings (12);
+       lm_table.set_col_spacings (6);
+       lm_table.set_homogeneous (false);
 
-#ifndef __APPLE__
-       label = manage (new Label (_("Audio Mode")));
-       basic_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       basic_packer.attach (audio_mode_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
+       lm_table.attach (lm_title, 0, 3, row, row+1, xopt, (AttachOptions) 0);
        row++;
-#endif
-
-       interface_combo.set_size_request (125, -1);
-       input_device_combo.set_size_request (125, -1);
-       output_device_combo.set_size_request (125, -1);
-
-       /*
-
-       if (engine_running()) {
-               start_button.set_sensitive (false);
-       } else {
-               stop_button.set_sensitive (false);
-       }
 
-       start_button.signal_clicked().connect (mem_fun (*this, &EngineControl::start_engine));
-       stop_button.signal_clicked().connect (mem_fun (*this, &EngineControl::start_engine));
-       */
+       lm_preamble.set_width_chars (60);
+       lm_preamble.set_line_wrap (true);
+       lm_preamble.set_markup (_("<span weight=\"bold\">Turn down the volume on your audio equipment to a very low level.</span>"));
 
-       button_box.pack_start (start_button, false, false);
-       button_box.pack_start (stop_button, false, false);
+       lm_table.attach (lm_preamble, 0, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
+       row++;
 
-       // basic_packer.attach (button_box, 0, 2, 8, 9, FILL|EXPAND, (AttachOptions) 0);
+       Gtk::Label* preamble;
+       preamble = manage (new Label);
+       preamble->set_width_chars (60);
+       preamble->set_line_wrap (true);
+       preamble->set_markup (_("Select two channels below and connect them using a cable."));
 
-       /* options */
+       lm_table.attach (*preamble, 0, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
+       row++;
 
-       options_packer.set_spacings (6);
-       row = 0;
+       label = manage (new Label (_("Output channel")));
+       lm_table.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
 
-       options_packer.attach (realtime_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
+       Gtk::Alignment* misc_align = manage (new Alignment (0.0, 0.5));
+       misc_align->add (lm_output_channel_combo);
+       lm_table.attach (*misc_align, 1, 3, row, row+1, xopt, (AttachOptions) 0);
        ++row;
 
-       realtime_button.set_active (true);
-       realtime_button.signal_toggled().connect (mem_fun (*this, &EngineControl::realtime_changed));
-       realtime_changed ();
-
-#if PROVIDE_TOO_MANY_OPTIONS
+       label = manage (new Label (_("Input channel")));
+       lm_table.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
 
-#ifndef __APPLE__
-       label = manage (new Label (_("Realtime Priority")));
-       label->set_alignment (1.0, 0.5);
-       options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       options_packer.attach (priority_spinner, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
+       misc_align = manage (new Alignment (0.0, 0.5));
+       misc_align->add (lm_input_channel_combo);
+       lm_table.attach (*misc_align, 1, 3, row, row+1, FILL, (AttachOptions) 0);
        ++row;
-       priority_spinner.set_value (60);
 
-       options_packer.attach (no_memory_lock_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (unlock_memory_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (soft_mode_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (monitor_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (force16bit_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (hw_monitor_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (hw_meter_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       options_packer.attach (verbose_output_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-#else 
-       options_packer.attach (verbose_output_button, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-#endif
+       xopt = AttachOptions(0);
 
-       strings.clear ();
-       strings.push_back (_("Ignore"));
-       strings.push_back ("500 msec");
-       strings.push_back ("1 sec");
-       strings.push_back ("2 sec");
-       strings.push_back ("10 sec");
-       set_popdown_strings (timeout_combo, strings);
-       timeout_combo.set_active_text (strings.front ());
-
-       label = manage (new Label (_("Client timeout")));
-       label->set_alignment (1.0, 0.5);
-       options_packer.attach (timeout_combo, 1, 2, row, row + 1, FILL|EXPAND, AttachOptions(0));
-       options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
+       lm_measure_label.set_padding (10, 10);
+       lm_measure_button.add (lm_measure_label);
+       lm_measure_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::latency_button_clicked));
+       lm_use_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::use_latency_button_clicked));
+       lm_back_button_signal = lm_back_button.signal_clicked().connect (sigc::bind (sigc::mem_fun (notebook, &Gtk::Notebook::set_current_page), 0));
 
-#endif /* PROVIDE_TOO_MANY_OPTIONS */
-       label = manage (new Label (_("Number of ports")));
-       label->set_alignment (1.0, 0.5);
-       options_packer.attach (ports_spinner, 1, 2, row, row + 1, FILL|EXPAND, AttachOptions(0));
-       options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
+       lm_use_button.set_sensitive (false);
 
-#ifndef __APPLE__
-       label = manage (new Label (_("Dither")));       
-       label->set_alignment (1.0, 0.5);
-       options_packer.attach (dither_mode_combo, 1, 2, row, row + 1, FILL|EXPAND, AttachOptions(0));
-       options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-#endif
+       /* Increase the default spacing around the labels of these three
+        * buttons
+        */
 
-       find_jack_servers (server_strings);
+       Gtk::Misc* l;
 
-       if (server_strings.empty()) {
-               fatal << _("No JACK server found anywhere on this system. Please install JACK and restart") << endmsg;
-               /*NOTREACHED*/
+       if ((l = dynamic_cast<Gtk::Misc*>(lm_use_button.get_child())) != 0) {
+               l->set_padding (10, 10);
        }
-       
-       set_popdown_strings (serverpath_combo, server_strings);
-       serverpath_combo.set_active_text (server_strings.front());
 
-       if (server_strings.size() > 1) {
-               label = manage (new Label (_("Server:")));
-               options_packer.attach (*label, 0, 1, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-               label->set_alignment (0.0, 0.5);
-               options_packer.attach (serverpath_combo, 1, 2, row, row + 1, FILL|EXPAND, (AttachOptions) 0);
-               ++row;
+       if ((l = dynamic_cast<Gtk::Misc*>(lm_back_button.get_child())) != 0) {
+               l->set_padding (10, 10);
        }
 
-       /* device settings */
+       preamble = manage (new Label);
+       preamble->set_width_chars (60);
+       preamble->set_line_wrap (true);
+       preamble->set_markup (_("Once the channels are connected, click the \"Measure\" button."));
+       lm_table.attach (*preamble, 0, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
+       row++;
 
-       device_packer.set_spacings (6);
-       row = 0;
+       preamble = manage (new Label);
+       preamble->set_width_chars (60);
+       preamble->set_line_wrap (true);
+       preamble->set_markup (_("When satisfied with the results, click the \"Use results\" button."));
+       lm_table.attach (*preamble, 0, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
 
-#ifndef __APPLE__
-       label = manage (new Label (_("Input device")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (input_device_combo, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       label = manage (new Label (_("Output device")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (output_device_combo, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);   
-       ++row;
-#endif
-       label = manage (new Label (_("Input channels")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (input_channels, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       label = manage (new Label (_("Output channels")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (output_channels, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       label = manage (new Label (_("Hardware input latency (samples)")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (input_latency, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
-       label = manage (new Label (_("Hardware output latency (samples)")));
-       label->set_alignment (1.0, 0.5);
-       device_packer.attach (*label, 0, 1, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       device_packer.attach (output_latency, 1, 2, row, row+1, FILL|EXPAND, (AttachOptions) 0);
-       ++row;
+       ++row; // skip a row in the table
+       ++row; // skip a row in the table
 
-       basic_hbox.pack_start (basic_packer, false, false);
-       options_hbox.pack_start (options_packer, false, false);
+       lm_table.attach (lm_results, 0, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
 
-       device_packer.set_border_width (12);
-       options_packer.set_border_width (12);
-       basic_packer.set_border_width (12);
+       ++row; // skip a row in the table
+       ++row; // skip a row in the table
 
-       notebook.pages().push_back (TabElem (basic_hbox, _("Device")));
-       notebook.pages().push_back (TabElem (options_hbox, _("Options")));
-       notebook.pages().push_back (TabElem (device_packer, _("Advanced")));
-       notebook.set_border_width (12);
+       lm_table.attach (lm_measure_button, 0, 1, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
+       lm_table.attach (lm_use_button, 1, 2, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
+       lm_table.attach (lm_back_button, 2, 3, row, row+1, AttachOptions(FILL|EXPAND), (AttachOptions) 0);
 
-       set_border_width (12);
-       pack_start (notebook);
-}
+       lm_results.set_markup (string_compose (results_markup, _("No measurement results yet")));
 
-EngineControl::~EngineControl ()
-{
+       lm_vbox.set_border_width (12);
+       lm_vbox.pack_start (lm_table, false, false);
 
-}
+       midi_back_button.signal_clicked().connect (sigc::bind (sigc::mem_fun (notebook, &Gtk::Notebook::set_current_page), 0));
 
-void
-EngineControl::build_command_line (vector<string>& cmd)
-{
-       string str;
-       string driver;
-       bool using_oss = false;
-       bool using_alsa = false;
-       bool using_coreaudio = false;
-       bool using_netjack = false;
-       bool using_ffado = false;
-       bool using_dummy = false;
-
-       /* first, path to jackd */
-
-       cmd.push_back (serverpath_combo.get_active_text ());
-       
-       /* now jackd arguments */
-
-       str = timeout_combo.get_active_text ();
-       if (str != _("Ignore")) {
-               double secs = 0;
-               uint32_t msecs;
-               secs = atof (str);
-               msecs = (uint32_t) floor (secs * 1000.0);
-               if (msecs > 0) {
-                       cmd.push_back ("-t");
-                       cmd.push_back (to_string (msecs, std::dec));
-               }
-       }
+       /* pack it all up */
 
-       if (no_memory_lock_button.get_active()) {
-               cmd.push_back ("-m"); /* no munlock */
-       }
-       
-       cmd.push_back ("-p"); /* port max */
-       cmd.push_back (to_string ((uint32_t) floor (ports_spinner.get_value()), std::dec));
+       notebook.pages().push_back (TabElem (basic_vbox, _("Audio")));
+       notebook.pages().push_back (TabElem (lm_vbox, _("Latency")));
+       notebook.pages().push_back (TabElem (midi_vbox, _("MIDI")));
+       notebook.set_border_width (12);
 
-       if (realtime_button.get_active()) {
-               cmd.push_back ("-R");
-               cmd.push_back ("-P");
-               cmd.push_back (to_string ((uint32_t) floor (priority_spinner.get_value()), std::dec));
-       }
+       notebook.set_show_tabs (false);
+       notebook.show_all ();
 
-       if (unlock_memory_button.get_active()) {
-               cmd.push_back ("-u");
-       }
+       notebook.set_name ("SettingsNotebook");
 
-       if (verbose_output_button.get_active()) {
-               cmd.push_back ("-v");
-       }
-       
-       /* now add fixed arguments (not user-selectable) */
+       /* packup the notebook */
 
-       cmd.push_back ("-T"); // temporary */
+       get_vbox()->set_border_width (12);
+       get_vbox()->pack_start (notebook);
 
-       /* next the driver */
+       /* need a special function to print "all available channels" when the
+        * channel counts hit zero.
+        */
 
-       cmd.push_back ("-d");
+       input_channels.signal_output().connect (sigc::bind (sigc::ptr_fun (&EngineControl::print_channel_count), &input_channels));
+       output_channels.signal_output().connect (sigc::bind (sigc::ptr_fun (&EngineControl::print_channel_count), &output_channels));
 
-       driver = driver_combo.get_active_text ();
-       if (driver == X_("ALSA")) {
-               using_alsa = true;
-               cmd.push_back ("alsa");
-       } else if (driver == X_("OSS")) {
-               using_oss = true;
-               cmd.push_back ("oss");
-       } else if (driver == X_("CoreAudio")) {
-               using_coreaudio = true;
-               cmd.push_back ("coreaudio");
-       } else if (driver == X_("NetJACK")) {
-               using_netjack = true;
-               cmd.push_back ("netjack");
-       } else if (driver == X_("FFADO")) {
-               using_ffado = true;
+       midi_devices_button.signal_clicked.connect (mem_fun (*this, &EngineControl::configure_midi_devices));
+       midi_devices_button.set_sensitive (false);
+       midi_devices_button.set_name ("generic button");
+       midi_devices_button.set_can_focus(true);
 
-               /* do this until FFADO becomes the standard */
+       control_app_button.signal_clicked().connect (mem_fun (*this, &EngineControl::control_app_button_clicked));
+       manage_control_app_sensitivity ();
 
-               char* hack = getenv ("ARDOUR_FIREWIRE_DRIVER_NAME");
+       cancel_button = add_button (Gtk::Stock::CANCEL, Gtk::RESPONSE_CANCEL);
+       ok_button = add_button (Gtk::Stock::OK, Gtk::RESPONSE_OK);
+       apply_button = add_button (Gtk::Stock::APPLY, Gtk::RESPONSE_APPLY);
 
-               if (hack) {
-                       cmd.push_back (hack);
-               } else {
-                       cmd.push_back ("freebob");
-               }
+       /* Pick up any existing audio setup configuration, if appropriate */
 
-       } else if ( driver == X_("Dummy")) {
-               using_dummy = true;
-               cmd.push_back ("dummy");
-       }
+       XMLNode* audio_setup = ARDOUR::Config->extra_xml ("AudioMIDISetup");
 
-       /* driver arguments */
+       ARDOUR::AudioEngine::instance()->Running.connect (running_connection, MISSING_INVALIDATOR, boost::bind (&EngineControl::engine_running, this), gui_context());
+       ARDOUR::AudioEngine::instance()->Stopped.connect (stopped_connection, MISSING_INVALIDATOR, boost::bind (&EngineControl::engine_stopped, this), gui_context());
+       ARDOUR::AudioEngine::instance()->Halted.connect (stopped_connection, MISSING_INVALIDATOR, boost::bind (&EngineControl::engine_stopped, this), gui_context());
 
-       if (!using_coreaudio) {
-               str = audio_mode_combo.get_active_text();
-               
-               if (str == _("Playback/Recording on 1 Device")) {
-                       
-                       /* relax */
-                       
-               } else if (str == _("Playback/Recording on 2 Devices")) {
-                       
-                       string input_device = get_device_name (driver, input_device_combo.get_active_text());
-                       string output_device = get_device_name (driver, output_device_combo.get_active_text());
+       {
+               PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
+               backend_changed ();
+       }
+       maybe_display_saved_state();
 
-                       if (input_device.empty() || output_device.empty()) {
-                               cmd.clear ();
-                               return;
-                       }
+       /* Connect to signals */
 
-                       cmd.push_back ("-C");
-                       cmd.push_back (input_device);
-                       cmd.push_back ("-P");
-                       cmd.push_back (output_device);
+       driver_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::driver_changed));
+       sample_rate_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::sample_rate_changed));
+       buffer_size_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::buffer_size_changed));
+       device_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::device_changed));
+       midi_option_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::midi_option_changed));
 
-               } else if (str == _("Playback only")) {
-                       cmd.push_back ("-P");
-               } else if (str == _("Recording only")) {
-                       cmd.push_back ("-C");
-               }
+       input_latency.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::parameter_changed));
+       output_latency.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::parameter_changed));
+       input_channels.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::parameter_changed));
+       output_channels.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::parameter_changed));
 
-               if (! using_dummy ) {
-                       cmd.push_back ("-n");
-                       cmd.push_back (to_string ((uint32_t) floor (periods_spinner.get_value()), std::dec));
-               }
+       if (audio_setup) {
+               set_state (*audio_setup);
        }
 
-       cmd.push_back ("-r");
-       cmd.push_back (to_string (get_rate(), std::dec));
-       
-       cmd.push_back ("-p");
-       cmd.push_back (period_size_combo.get_active_text());
-
-       if (using_alsa) {
-               
-               if (audio_mode_combo.get_active_text() != _("Playback/Recording on 2 Devices")) {
+       notebook.signal_switch_page().connect (sigc::mem_fun (*this, &EngineControl::on_switch_page));
+}
 
-                       string device = get_device_name (driver, interface_combo.get_active_text());
-                       if (device.empty()) {
-                               cmd.clear ();
-                               return;
+void
+EngineControl::on_response (int response_id)
+{
+       ArdourDialog::on_response (response_id);
+
+       switch (response_id) {
+               case RESPONSE_APPLY:
+                       push_state_to_backend (true);
+                       break;
+               case RESPONSE_OK:
+                       push_state_to_backend (true);
+                       hide ();
+                       break;
+               case RESPONSE_DELETE_EVENT:
+                       {
+                               GdkEventButton ev;
+                               ev.type = GDK_BUTTON_PRESS;
+                               ev.button = 1;
+                               on_delete_event ((GdkEventAny*) &ev);
+                               break;
                        }
-
-                       cmd.push_back ("-d");
-                       cmd.push_back (device);
-               } 
-
-               if (hw_meter_button.get_active()) {
-                       cmd.push_back ("-M");
-               }
-               
-               if (hw_monitor_button.get_active()) {
-                       cmd.push_back ("-H");
-               }
-
-               str = dither_mode_combo.get_active_text();
-
-               if (str == _("None")) {
-               } else if (str == _("Triangular")) {
-                       cmd.push_back ("-z triangular");
-               } else if (str == _("Rectangular")) {
-                       cmd.push_back ("-z rectangular");
-               } else if (str == _("Shaped")) {
-                       cmd.push_back ("-z shaped");
-               }
-
-               if (force16bit_button.get_active()) {
-                       cmd.push_back ("-S");
-               }
-               
-               if (soft_mode_button.get_active()) {
-                       cmd.push_back ("-s");
-               }
-
-       } else if (using_coreaudio) {
-
-#ifdef __APPLE__
-               // note: older versions of the CoreAudio JACK backend use -n instead of -d here
-               
-               string device = get_device_name (driver, interface_combo.get_active_text());
-               if (device.empty()) {
-                       cmd.clear ();
-                       return;
-               }
-
-               cmd.push_back ("-d");
-               cmd.push_back (device);
-#endif
-
-       } else if (using_oss) {
-
-       } else if (using_netjack) {
-
+               default:
+                       hide ();
        }
 }
 
-bool
-EngineControl::engine_running ()
+void
+EngineControl::build_notebook ()
 {
-       jack_status_t status;
-       jack_client_t* c = jack_client_open ("ardourprobe", JackNoStartServer, &status);
+       Label* label;
+       AttachOptions xopt = AttachOptions (FILL|EXPAND);
 
-       if (status == 0) {
-               jack_client_close (c);
-               return true;
-       }
-       return false;
-}
+       /* clear the table */
 
-int
-EngineControl::setup_engine ()
-{
-       vector<string> args;
-       std::string cwd = "/tmp";
+       Gtkmm2ext::container_clear (basic_vbox);
+       Gtkmm2ext::container_clear (basic_packer);
 
-       build_command_line (args);
-       
-       if (args.empty()) {
-               return 1; // try again
+       if (control_app_button.get_parent()) {
+               control_app_button.get_parent()->remove (control_app_button);
        }
 
-       Glib::ustring jackdrc_path = Glib::get_home_dir();
-       jackdrc_path += "/.jackdrc";
+       label = manage (left_aligned_label (_("Audio System:")));
+       basic_packer.attach (*label, 0, 1, 0, 1, xopt, (AttachOptions) 0);
+       basic_packer.attach (backend_combo, 1, 2, 0, 1, xopt, (AttachOptions) 0);
 
-       ofstream jackdrc (jackdrc_path.c_str());
-       if (!jackdrc) {
-               error << string_compose (_("cannot open JACK rc file %1 to store parameters"), jackdrc_path) << endmsg;
-               return -1;
-       }
-       cerr << "JACK COMMAND: ";
-       for (vector<string>::iterator i = args.begin(); i != args.end(); ++i) {
-               cerr << (*i) << ' ';
-               jackdrc << (*i) << ' ';
+       lm_button_audio.signal_clicked.connect (sigc::mem_fun (*this, &EngineControl::calibrate_audio_latency));
+       lm_button_audio.set_name ("generic button");
+       lm_button_audio.set_can_focus(true);
+
+       if (_have_control) {
+               build_full_control_notebook ();
+       } else {
+               build_no_control_notebook ();
        }
-       cerr << endl;
-       jackdrc << endl;
-       jackdrc.close ();
 
-       _used = true;
+       basic_vbox.pack_start (basic_hbox, false, false);
 
-       return 0;
-}
+       if (_have_control) {
+               Gtk::HBox* hpacker = manage (new HBox);
+               hpacker->set_border_width (12);
+               hpacker->pack_start (control_app_button, false, false);
+               hpacker->show ();
+               control_app_button.show();
+               basic_vbox.pack_start (*hpacker);
+       }
 
-void
-EngineControl::realtime_changed ()
-{
-#ifndef __APPLE__
-       priority_spinner.set_sensitive (realtime_button.get_active());
-#endif
+       basic_vbox.show_all ();
 }
 
 void
-EngineControl::enumerate_devices (const string& driver)
+EngineControl::build_full_control_notebook ()
 {
-       /* note: case matters for the map keys */
-
-       if (driver == "CoreAudio") {
-#ifdef __APPLE__               
-               devices[driver] = enumerate_coreaudio_devices ();
-#endif
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
 
-#ifndef __APPLE__
-       } else if (driver == "ALSA") {
-               devices[driver] = enumerate_alsa_devices ();
-       } else if (driver == "FFADO") {
-               devices[driver] = enumerate_ffado_devices ();
-       } else if (driver == "OSS") {
-               devices[driver] = enumerate_oss_devices ();
-       } else if (driver == "Dummy") {
-               devices[driver] = enumerate_dummy_devices ();
-       } else if (driver == "NetJACK") {
-               devices[driver] = enumerate_netjack_devices ();
-       }
-#else
-        }
-#endif
-}
+       using namespace Notebook_Helpers;
+       Label* label;
+       vector<string> strings;
+       AttachOptions xopt = AttachOptions (FILL|EXPAND);
+       int row = 1; // row zero == backend combo
 
-#ifdef __APPLE__
-static OSStatus 
-getDeviceUIDFromID( AudioDeviceID id, char *name, size_t nsize)
-{
-       UInt32 size = sizeof(CFStringRef);
-       CFStringRef UI;
-       OSStatus res = AudioDeviceGetProperty(id, 0, false,
-               kAudioDevicePropertyDeviceUID, &size, &UI);
-       if (res == noErr) 
-               CFStringGetCString(UI,name,nsize,CFStringGetSystemEncoding());
-       CFRelease(UI);
-       return res;
-}
+       /* start packing it up */
 
-vector<string>
-EngineControl::enumerate_coreaudio_devices ()
-{
-       vector<string> devs;
-       
-       // Find out how many Core Audio devices are there, if any...
-       // (code snippet gently "borrowed" from St?hane Letz jackdmp;)
-       OSStatus err;
-       Boolean isWritable;
-       size_t outSize = sizeof(isWritable);
-
-       backend_devs.clear ();
-
-       err = AudioHardwareGetPropertyInfo(kAudioHardwarePropertyDevices,
-                                          &outSize, &isWritable);
-       if (err == noErr) {
-               // Calculate the number of device available...
-               int numCoreDevices = outSize / sizeof(AudioDeviceID);
-               // Make space for the devices we are about to get...
-               AudioDeviceID *coreDeviceIDs = new AudioDeviceID [numCoreDevices];
-               err = AudioHardwareGetProperty(kAudioHardwarePropertyDevices,
-                                              &outSize, (void *) coreDeviceIDs);
-               if (err == noErr) {
-                       // Look for the CoreAudio device name...
-                       char coreDeviceName[256];
-                       size_t nameSize;
-
-                       for (int i = 0; i < numCoreDevices; i++) {
-
-                               nameSize = sizeof (coreDeviceName);
-
-                               /* enforce duplex devices only */
-
-                               err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-                                                                0, true, kAudioDevicePropertyStreams,
-                                                                &outSize, &isWritable);
-
-                               if (err != noErr || outSize == 0) {
-                                       continue;
-                               }
+       if (backend->requires_driver_selection()) {
+               label = manage (left_aligned_label (_("Driver:")));
+               basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+               basic_packer.attach (driver_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+               row++;
+       }
 
-                               err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-                                                                0, false, kAudioDevicePropertyStreams,
-                                                                &outSize, &isWritable);
+       label = manage (left_aligned_label (_("Device:")));
+       basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+       basic_packer.attach (device_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+       row++;
 
-                               if (err != noErr || outSize == 0) {
-                                       continue;
-                               }
+       label = manage (left_aligned_label (_("Sample rate:")));
+       basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+       basic_packer.attach (sample_rate_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+       row++;
 
-                               err = AudioDeviceGetPropertyInfo(coreDeviceIDs[i],
-                                                                0, true, kAudioDevicePropertyDeviceName,
-                                                                &outSize, &isWritable);
-                               if (err == noErr) {
-                                       err = AudioDeviceGetProperty(coreDeviceIDs[i],
-                                                                    0, true, kAudioDevicePropertyDeviceName,
-                                                                    &nameSize, (void *) coreDeviceName);
-                                       if (err == noErr) {
-                                               char drivername[128];
-
-                                               // this returns the unique id for the device
-                                               // that must be used on the commandline for jack
-                                               
-                                               if (getDeviceUIDFromID(coreDeviceIDs[i], drivername, sizeof (drivername)) == noErr) {
-                                                       devs.push_back (coreDeviceName);
-                                                       backend_devs.push_back (drivername);
-                                               } 
-                                       }
-                               }
-                       }
-               }
-               delete [] coreDeviceIDs;
-       }
-
-
-       if (devs.size() == 0) {
-               MessageDialog msg (_("\
-You do not have any audio devices capable of\n\
-simultaneous playback and recording.\n\n\
-Please use Applications -> Utilities -> Audio MIDI Setup\n\
-to create an \"aggregrate\" device, or install a suitable\n\
-audio interface.\n\n\
-Please send email to Apple and ask them why new Macs\n\
-have no duplex audio device.\n\n\
-Alternatively, if you really want just playback\n\
-or recording but not both, start JACK before running\n\
-Ardour and choose the relevant device then."
-                                          ), 
-                                  true, Gtk::MESSAGE_ERROR, Gtk::BUTTONS_OK);
-               msg.set_title (_("No suitable audio devices"));
-               msg.set_position (Gtk::WIN_POS_MOUSE);
-               msg.run ();
-               exit (1);
-       }
 
+       label = manage (left_aligned_label (_("Buffer size:")));
+       basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+       basic_packer.attach (buffer_size_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+       buffer_size_duration_label.set_alignment (0.0); /* left-align */
+       basic_packer.attach (buffer_size_duration_label, 2, 3, row, row+1, SHRINK, (AttachOptions) 0);
+       row++;
 
-       return devs;
-}
-#else
-vector<string>
-EngineControl::enumerate_alsa_devices ()
-{
-       vector<string> devs;
+       input_channels.set_name ("InputChannels");
+       input_channels.set_flags (Gtk::CAN_FOCUS);
+       input_channels.set_digits (0);
+       input_channels.set_wrap (false);
+       output_channels.set_editable (true);
 
-       snd_ctl_t *handle;
-       snd_ctl_card_info_t *info;
-       snd_pcm_info_t *pcminfo;
-       snd_ctl_card_info_alloca(&info);
-       snd_pcm_info_alloca(&pcminfo);
-       string devname;
-       int cardnum = -1;
-       int device = -1;
+       label = manage (left_aligned_label (_("Input Channels:")));
+       basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
+       basic_packer.attach (input_channels, 1, 2, row, row+1, xopt, (AttachOptions) 0);
+       ++row;
 
-       backend_devs.clear ();
+       output_channels.set_name ("OutputChannels");
+       output_channels.set_flags (Gtk::CAN_FOCUS);
+       output_channels.set_digits (0);
+       output_channels.set_wrap (false);
+       output_channels.set_editable (true);
 
-       while (snd_card_next (&cardnum) >= 0 && cardnum >= 0) {
+       label = manage (left_aligned_label (_("Output Channels:")));
+       basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
+       basic_packer.attach (output_channels, 1, 2, row, row+1, xopt, (AttachOptions) 0);
+       ++row;
 
-               devname = "hw:";
-               devname += to_string (cardnum, std::dec);
+       input_latency.set_name ("InputLatency");
+       input_latency.set_flags (Gtk::CAN_FOCUS);
+       input_latency.set_digits (0);
+       input_latency.set_wrap (false);
+       input_latency.set_editable (true);
+
+       label = manage (left_aligned_label (_("Hardware input latency:")));
+       basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
+       basic_packer.attach (input_latency, 1, 2, row, row+1, xopt, (AttachOptions) 0);
+       label = manage (left_aligned_label (_("samples")));
+       basic_packer.attach (*label, 2, 3, row, row+1, SHRINK, (AttachOptions) 0);
+       ++row;
 
-               if (snd_ctl_open (&handle, devname.c_str(), 0) >= 0 && snd_ctl_card_info (handle, info) >= 0) {
+       output_latency.set_name ("OutputLatency");
+       output_latency.set_flags (Gtk::CAN_FOCUS);
+       output_latency.set_digits (0);
+       output_latency.set_wrap (false);
+       output_latency.set_editable (true);
 
-                       while (snd_ctl_pcm_next_device (handle, &device) >= 0 && device >= 0) {
+       label = manage (left_aligned_label (_("Hardware output latency:")));
+       basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
+       basic_packer.attach (output_latency, 1, 2, row, row+1, xopt, (AttachOptions) 0);
+       label = manage (left_aligned_label (_("samples")));
+       basic_packer.attach (*label, 2, 3, row, row+1, SHRINK, (AttachOptions) 0);
 
-                               bool have_playback = false;
-                               bool have_capture = false;
+       /* button spans 2 rows */
 
-                               /* find duplex devices only */
+       basic_packer.attach (lm_button_audio, 3, 4, row-1, row+1, xopt, xopt);
+       ++row;
 
-                               snd_pcm_info_set_device (pcminfo, device);
-                               snd_pcm_info_set_subdevice (pcminfo, 0);
-                               snd_pcm_info_set_stream (pcminfo, SND_PCM_STREAM_CAPTURE);
+       label = manage (left_aligned_label (_("MIDI System")));
+       basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+       basic_packer.attach (midi_option_combo, 1, 2, row, row + 1, SHRINK, (AttachOptions) 0);
+       basic_packer.attach (midi_devices_button, 3, 4, row, row+1, xopt, xopt);
+       row++;
+}
 
-                               if (snd_ctl_pcm_info (handle, pcminfo) >= 0) {
-                                       have_capture = true;
-                               }
+void
+EngineControl::build_no_control_notebook ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
 
-                               snd_pcm_info_set_device (pcminfo, device);
-                               snd_pcm_info_set_subdevice (pcminfo, 0);
-                               snd_pcm_info_set_stream (pcminfo, SND_PCM_STREAM_PLAYBACK);
+       using namespace Notebook_Helpers;
+       Label* label;
+       vector<string> strings;
+       AttachOptions xopt = AttachOptions (FILL|EXPAND);
+       int row = 1; // row zero == backend combo
+       const string msg = string_compose (_("The %1 audio backend was configured and started externally.\nThis limits your control over it."), backend->name());
 
-                               if (snd_ctl_pcm_info (handle, pcminfo) >= 0) {
-                                       have_playback = true;
-                               }
+       label = manage (new Label);
+       label->set_markup (string_compose ("<span weight=\"bold\" foreground=\"red\">%1</span>", msg));
+       basic_packer.attach (*label, 0, 2, row, row + 1, xopt, (AttachOptions) 0);
+       row++;
 
-                               if (have_capture && have_playback) {
-                                       devs.push_back (snd_pcm_info_get_name (pcminfo));
-                                       devname += ',';
-                                       devname += to_string (device, std::dec);
-                                       backend_devs.push_back (devname);
-                               }
-                       }
+       if (backend->can_change_sample_rate_when_running()) {
+               label = manage (left_aligned_label (_("Sample rate:")));
+               basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+               basic_packer.attach (sample_rate_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+               row++;
+       }
 
-                       snd_ctl_close(handle);
-               }
+       if (backend->can_change_buffer_size_when_running()) {
+               label = manage (left_aligned_label (_("Buffer size:")));
+               basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
+               basic_packer.attach (buffer_size_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
+               buffer_size_duration_label.set_alignment (0.0); /* left-align */
+               basic_packer.attach (buffer_size_duration_label, 2, 3, row, row+1, xopt, (AttachOptions) 0);
+               row++;
        }
 
-       return devs;
-}
+       connect_disconnect_button.signal_clicked().connect (sigc::mem_fun (*this, &EngineControl::connect_disconnect_click));
 
-vector<string>
-EngineControl::enumerate_ffado_devices ()
-{
-       vector<string> devs;
-       backend_devs.clear ();
-       return devs;
+       basic_packer.attach (connect_disconnect_button, 0, 2, row, row+1, FILL, AttachOptions (0));
+       row++;
 }
 
-vector<string>
-EngineControl::enumerate_freebob_devices ()
-{
-       vector<string> devs;
-       return devs;
-}
-vector<string>
-EngineControl::enumerate_oss_devices ()
-{
-       vector<string> devs;
-       return devs;
-}
-vector<string>
-EngineControl::enumerate_dummy_devices ()
+EngineControl::~EngineControl ()
 {
-       vector<string> devs;
-       return devs;
+       ignore_changes = true;
 }
-vector<string>
-EngineControl::enumerate_netjack_devices ()
+
+void
+EngineControl::disable_latency_tab ()
 {
-       vector<string> devs;
-       return devs;
+       vector<string> empty;
+       set_popdown_strings (lm_output_channel_combo, empty);
+       set_popdown_strings (lm_input_channel_combo, empty);
+       lm_measure_button.set_sensitive (false);
+       lm_use_button.set_sensitive (false);
 }
-#endif
 
 void
-EngineControl::driver_changed ()
+EngineControl::enable_latency_tab ()
 {
-       string driver = driver_combo.get_active_text();
-       string::size_type maxlen = 0;
-       int maxindex = -1;
-       int n = 0;
+       vector<string> outputs;
+       vector<string> inputs;
 
-       enumerate_devices (driver);
+       ARDOUR::DataType const type = _measure_midi ? ARDOUR::DataType::MIDI : ARDOUR::DataType::AUDIO;
+       ARDOUR::AudioEngine::instance()->get_physical_outputs (type, outputs);
+       ARDOUR::AudioEngine::instance()->get_physical_inputs (type, inputs);
 
-       vector<string>& strings = devices[driver];
+       if (_measure_midi) {
+               lm_preamble.set_markup (_(""));
+       } else {
+               lm_preamble.set_markup (_("<span weight=\"bold\">Turn down the volume on your audio equipment to a very low level.</span>"));
+       }
 
-       if (strings.empty() && driver != "FFADO" && driver != "Dummy") {
-               error << string_compose (_("No devices found for driver \"%1\""), driver) << endmsg;
+       if (inputs.empty() || outputs.empty()) {
+               MessageDialog msg (_("Your selected audio configuration is playback- or capture-only.\n\nLatency calibration requires playback and capture"));
+               lm_measure_button.set_sensitive (false);
+               notebook.set_current_page (0);
+               msg.run ();
                return;
        }
-       
-       for (vector<string>::iterator i = strings.begin(); i != strings.end(); ++i, ++n) {
-               if ((*i).length() > maxlen) {
-                       maxlen = (*i).length();
-                       maxindex = n;
-               }
+
+       if (!outputs.empty()) {
+               set_popdown_strings (lm_output_channel_combo, outputs);
+               lm_output_channel_combo.set_active_text (outputs.front());
+               lm_output_channel_combo.set_sensitive (true);
+       } else {
+               lm_output_channel_combo.set_sensitive (false);
        }
 
-       set_popdown_strings (interface_combo, strings);
-       set_popdown_strings (input_device_combo, strings);
-       set_popdown_strings (output_device_combo, strings);
-
-       if (!strings.empty()) {
-               interface_combo.set_active_text (strings.front());
-               input_device_combo.set_active_text (strings.front());
-               output_device_combo.set_active_text (strings.front());
-       } 
-       
-       if (driver == "ALSA") {
-               soft_mode_button.set_sensitive (true);
-               force16bit_button.set_sensitive (true);
-               hw_monitor_button.set_sensitive (true);
-               hw_meter_button.set_sensitive (true);
-               monitor_button.set_sensitive (true);
+       if (!inputs.empty()) {
+               set_popdown_strings (lm_input_channel_combo, inputs);
+               lm_input_channel_combo.set_active_text (inputs.front());
+               lm_input_channel_combo.set_sensitive (true);
        } else {
-               soft_mode_button.set_sensitive (false);
-               force16bit_button.set_sensitive (false);
-               hw_monitor_button.set_sensitive (false);
-               hw_meter_button.set_sensitive (false);
-               monitor_button.set_sensitive (false);
+               lm_input_channel_combo.set_sensitive (false);
        }
+
+       lm_measure_button.set_sensitive (true);
 }
 
-uint32_t
-EngineControl::get_rate ()
+void
+EngineControl::setup_midi_tab_for_backend ()
 {
-       return atoi (sample_rate_combo.get_active_text ());
+       string backend = backend_combo.get_active_text ();
+
+       Gtkmm2ext::container_clear (midi_vbox);
+
+       midi_vbox.set_border_width (12);
+       midi_device_table.set_border_width (12);
+
+       if (backend == "JACK") {
+               setup_midi_tab_for_jack ();
+       }
+
+       midi_vbox.pack_start (midi_device_table, true, true);
+       midi_vbox.pack_start (midi_back_button, false, false);
+       midi_vbox.show_all ();
 }
 
 void
-EngineControl::redisplay_latency ()
+EngineControl::setup_midi_tab_for_jack ()
 {
-       uint32_t rate = get_rate();
-#ifdef __APPLE_
-       float periods = 2;
-#else
-       float periods = periods_adjustment.get_value();
-#endif
-       float period_size = atof (period_size_combo.get_active_text());
+}
 
-       char buf[32];
-       snprintf (buf, sizeof(buf), "%.1fmsec", (periods * period_size) / (rate/1000.0));
+void
+EngineControl::midi_latency_adjustment_changed (Gtk::Adjustment *a, MidiDeviceSettings device, bool for_input) {
+       if (for_input) {
+               device->input_latency = a->get_value();
+       } else {
+               device->output_latency = a->get_value();
+       }
+}
 
-       latency_label.set_text (buf);
+void
+EngineControl::midi_device_enabled_toggled (ArdourButton *b, MidiDeviceSettings device) {
+       b->set_active (!b->get_active());
+       device->enabled = b->get_active();
+       refresh_midi_display(device->name);
 }
 
 void
-EngineControl::audio_mode_changed ()
+EngineControl::refresh_midi_display (std::string focus)
 {
-       Glib::ustring str = audio_mode_combo.get_active_text();
-
-       if (str == _("Playback/Recording on 1 Device")) {
-               input_device_combo.set_sensitive (false);
-               output_device_combo.set_sensitive (false);
-       } else if (str == _("Playback/Recording on 2 Devices")) {
-               input_device_combo.set_sensitive (true);
-               output_device_combo.set_sensitive (true);
-       } else if (str == _("Playback only")) {
-               output_device_combo.set_sensitive (true);
-       } else if (str == _("Recording only")) {
-               input_device_combo.set_sensitive (true);
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+
+       int row  = 0;
+       AttachOptions xopt = AttachOptions (FILL|EXPAND);
+       Gtk::Label* l;
+
+       Gtkmm2ext::container_clear (midi_device_table);
+
+       midi_device_table.set_spacings (6);
+
+       l = manage (new Label);
+       l->set_markup (string_compose ("<span size=\"large\" weight=\"bold\">%1</span>", _("MIDI Devices")));
+       midi_device_table.attach (*l, 0, 4, row, row + 1, xopt, AttachOptions (0));
+       l->set_alignment (0.5, 0.5);
+       row++;
+       l->show ();
+
+       l = manage (new Label (_("Device"))); l->show (); l->set_alignment (0.5, 0.5);
+       midi_device_table.attach (*l, 0, 1, row, row + 2, xopt, AttachOptions (0));
+       l = manage (new Label (_("Hardware Latencies"))); l->show (); l->set_alignment (0.5, 0.5);
+       midi_device_table.attach (*l, 1, 3, row, row + 1, xopt, AttachOptions (0));
+       row++;
+       l = manage (new Label (_("Input"))); l->show (); l->set_alignment (0.5, 0.5);
+       midi_device_table.attach (*l, 1, 2, row, row + 1, xopt, AttachOptions (0));
+       l = manage (new Label (_("Output"))); l->show (); l->set_alignment (0.5, 0.5);
+       midi_device_table.attach (*l, 2, 3, row, row + 1, xopt, AttachOptions (0));
+       row++;
+
+       for (vector<MidiDeviceSettings>::const_iterator p = _midi_devices.begin(); p != _midi_devices.end(); ++p) {
+               ArdourButton *m;
+               Gtk::Button* b;
+               Gtk::Adjustment *a;
+               Gtk::SpinButton *s;
+               bool enabled = (*p)->enabled;
+
+               m = manage (new ArdourButton ((*p)->name, ArdourButton::led_default_elements));
+               m->set_name ("midi device");
+               m->set_can_focus (Gtk::CAN_FOCUS);
+               m->add_events (Gdk::BUTTON_RELEASE_MASK);
+               m->set_active (enabled);
+               m->signal_clicked.connect (sigc::bind (sigc::mem_fun (*this, &EngineControl::midi_device_enabled_toggled), m, *p));
+               midi_device_table.attach (*m, 0, 1, row, row + 1, xopt, AttachOptions (0)); m->show ();
+               if ((*p)->name == focus) {
+                       m->grab_focus();
+               }
+
+               a = manage (new Gtk::Adjustment (0, 0, 99999, 1));
+               s = manage (new Gtk::SpinButton (*a));
+               a->set_value ((*p)->input_latency);
+               s->signal_value_changed().connect (sigc::bind (sigc::mem_fun (*this, &EngineControl::midi_latency_adjustment_changed), a, *p, true));
+               s->set_sensitive (_can_set_midi_latencies && enabled);
+               midi_device_table.attach (*s, 1, 2, row, row + 1, xopt, AttachOptions (0)); s->show ();
+
+               a = manage (new Gtk::Adjustment (0, 0, 99999, 1));
+               s = manage (new Gtk::SpinButton (*a));
+               a->set_value ((*p)->output_latency);
+               s->signal_value_changed().connect (sigc::bind (sigc::mem_fun (*this, &EngineControl::midi_latency_adjustment_changed), a, *p, false));
+               s->set_sensitive (_can_set_midi_latencies && enabled);
+               midi_device_table.attach (*s, 2, 3, row, row + 1, xopt, AttachOptions (0)); s->show ();
+
+               b = manage (new Button (_("Calibrate")));
+               b->signal_clicked().connect (sigc::bind (sigc::mem_fun (*this, &EngineControl::calibrate_midi_latency), *p));
+               b->set_sensitive (_can_set_midi_latencies && enabled);
+               midi_device_table.attach (*b, 3, 4, row, row + 1, xopt, AttachOptions (0)); b->show ();
+
+               row++;
        }
 }
 
-static bool jack_server_filter(const string& str, void */*arg*/)
+void
+EngineControl::update_sensitivity ()
 {
-   return str == "jackd" || str == "jackdmp";
 }
 
 void
-EngineControl::find_jack_servers (vector<string>& strings)
+EngineControl::backend_changed ()
 {
-#ifdef __APPLE__
-       /* this magic lets us finds the path to the OSX bundle, and then
-          we infer JACK's location from there
-       */
-       
-       char execpath[MAXPATHLEN+1];
-       uint32_t pathsz = sizeof (execpath);
-
-       _NSGetExecutablePath (execpath, &pathsz);
-       
-       string path (Glib::path_get_dirname (execpath));
-       path += "/jackd";
-
-       if (Glib::file_test (path, FILE_TEST_EXISTS)) {
-               strings.push_back (path);
-       } 
-
-       if (getenv ("ARDOUR_WITH_JACK")) {
-               /* no other options - only use the JACK we supply */
-               if (strings.empty()) {
-                       fatal << _("JACK appears to be missing from the Ardour bundle") << endmsg;
-                       /*NOTREACHED*/
-               }
+       string backend_name = backend_combo.get_active_text();
+       boost::shared_ptr<ARDOUR::AudioBackend> backend;
+
+       if (!(backend = ARDOUR::AudioEngine::instance()->set_backend (backend_name, "ardour", ""))) {
+               /* eh? setting the backend failed... how ? */
                return;
        }
-#else
-       string path;
-#endif
-       
-       PathScanner scanner;
-       vector<string *> *jack_servers;
-       std::map<string,int> un;
-       char *p;
-       bool need_minimal_path = false;
 
-       p = getenv ("PATH");
+       _have_control = ARDOUR::AudioEngine::instance()->setup_required ();
 
-       if (p && *p) {
-               path = p;
-       } else {
-               need_minimal_path = true;
-       }
+       build_notebook ();
+       setup_midi_tab_for_backend ();
+       _midi_devices.clear();
 
-#ifdef __APPLE__
-       // many mac users don't have PATH set up to include
-       // likely installed locations of JACK
-       need_minimal_path = true;
-#endif
+       if (backend->requires_driver_selection()) {
+               vector<string> drivers = backend->enumerate_drivers();
+               driver_combo.set_sensitive (true);
 
-       if (need_minimal_path) {
-               if (path.empty()) {
-                       path = "/usr/bin:/bin:/usr/local/bin:/opt/local/bin";
-               } else {
-                       path += ":/usr/local/bin:/opt/local/bin";
+               if (!drivers.empty()) {
+                       {
+                               PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
+                               set_popdown_strings (driver_combo, drivers);
+                               driver_combo.set_active_text (drivers.front());
+                       }
+
+                       driver_changed ();
                }
+
+       } else {
+               driver_combo.set_sensitive (false);
+               /* this will change the device text which will cause a call to
+                * device changed which will set up parameters
+                */
+               list_devices ();
        }
 
-#ifdef __APPLE__
-       // push it back into the environment so that auto-started JACK can find it.
-       // XXX why can't we just expect OS X users to have PATH set correctly? we can't ...
-       setenv ("PATH", path.c_str(), 1);
-#endif
+       vector<string> midi_options = backend->enumerate_midi_options();
 
-       jack_servers = scanner (path, jack_server_filter, 0, false, true);
-       
-       vector<string *>::iterator iter;
-       
-       for (iter = jack_servers->begin(); iter != jack_servers->end(); iter++) {
-               string p = **iter;
-               
-               if (un[p]++ == 0) {
-                       strings.push_back(p);
+       if (midi_options.size() == 1) {
+               /* only contains the "none" option */
+               midi_option_combo.set_sensitive (false);
+       } else {
+               if (_have_control) {
+                       set_popdown_strings (midi_option_combo, midi_options);
+                       midi_option_combo.set_active_text (midi_options.front());
+                       midi_option_combo.set_sensitive (true);
+               } else {
+                       midi_option_combo.set_sensitive (false);
                }
        }
-}
 
+       midi_option_changed();
 
-string
-EngineControl::get_device_name (const string& driver, const string& human_readable)
-{
-       vector<string>::iterator n;
-       vector<string>::iterator i;
+       started_at_least_once = false;
 
-       if (human_readable.empty()) {
-               /* this can happen if the user's .ardourrc file has a device name from
-                  another computer system in it
-               */
-               MessageDialog msg (_("You need to choose an audio device first."));
-               msg.run ();
-               return string();
+       if (!ignore_changes) {
+               maybe_display_saved_state ();
        }
+}
 
-       if (backend_devs.empty()) {
-               return human_readable;
-       }
-       
-       for (i = devices[driver].begin(), n = backend_devs.begin(); i != devices[driver].end(); ++i, ++n) {
-               if (human_readable == (*i)) {
-                       return (*n);
-               }
-       }
-       
-       if (i == devices[driver].end()) {
-               warning << string_compose (_("Audio device \"%1\" not known on this computer."), human_readable) << endmsg;
+bool
+EngineControl::print_channel_count (Gtk::SpinButton* sb)
+{
+       uint32_t cnt = (uint32_t) sb->get_value();
+       if (cnt == 0) {
+               sb->set_text (_("all available channels"));
+       } else {
+               char buf[32];
+               snprintf (buf, sizeof (buf), "%d", cnt);
+               sb->set_text (buf);
        }
-
-       return string();
+       return true;
 }
 
-XMLNode&
-EngineControl::get_state ()
+void
+EngineControl::list_devices ()
 {
-       XMLNode* root = new XMLNode ("AudioSetup");
-       XMLNode* child;
-       Glib::ustring path;
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
 
-       child = new XMLNode ("periods");
-       child->add_property ("val", to_string (periods_adjustment.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       /* now fill out devices, mark sample rates, buffer sizes insensitive */
 
-       child = new XMLNode ("priority");
-       child->add_property ("val", to_string (priority_adjustment.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       vector<ARDOUR::AudioBackend::DeviceStatus> all_devices = backend->enumerate_devices ();
 
-       child = new XMLNode ("ports");
-       child->add_property ("val", to_string (ports_adjustment.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       /* NOTE: Ardour currently does not display the "available" field of the
+        * returned devices.
+        *
+        * Doing so would require a different GUI widget than the combo
+        * box/popdown that we currently use, since it has no way to list
+        * items that are not selectable. Something more like a popup menu,
+        * which could have unselectable items, would be appropriate.
+        */
 
-       child = new XMLNode ("inchannels");
-       child->add_property ("val", to_string (input_channels.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       vector<string> available_devices;
 
-       child = new XMLNode ("outchannels");
-       child->add_property ("val", to_string (output_channels.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       for (vector<ARDOUR::AudioBackend::DeviceStatus>::const_iterator i = all_devices.begin(); i != all_devices.end(); ++i) {
+               available_devices.push_back (i->name);
+       }
 
-       child = new XMLNode ("inlatency");
-       child->add_property ("val", to_string (input_latency.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+       if (!available_devices.empty()) {
 
-       child = new XMLNode ("outlatency");
-       child->add_property ("val", to_string (output_latency.get_value(), std::dec));
-       root->add_child_nocopy (*child);
+               update_sensitivity ();
 
-       child = new XMLNode ("realtime");
-       child->add_property ("val", to_string (realtime_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+               {
+                       PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
+                       set_popdown_strings (device_combo, available_devices);
+                       device_combo.set_active_text (available_devices.front());
+               }
 
-       child = new XMLNode ("nomemorylock");
-       child->add_property ("val", to_string (no_memory_lock_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+               device_changed ();
 
-       child = new XMLNode ("unlockmemory");
-       child->add_property ("val", to_string (unlock_memory_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+               ok_button->set_sensitive (true);
+               apply_button->set_sensitive (true);
 
-       child = new XMLNode ("softmode");
-       child->add_property ("val", to_string (soft_mode_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+       } else {
+               device_combo.clear();
+               sample_rate_combo.set_sensitive (false);
+               buffer_size_combo.set_sensitive (false);
+               input_latency.set_sensitive (false);
+               output_latency.set_sensitive (false);
+               input_channels.set_sensitive (false);
+               output_channels.set_sensitive (false);
+               if (_have_control) {
+                       ok_button->set_sensitive (false);
+                       apply_button->set_sensitive (false);
+               } else {
+                       ok_button->set_sensitive (true);
+                       apply_button->set_sensitive (true);
+               }
+       }
+}
+
+void
+EngineControl::driver_changed ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+
+       backend->set_driver (driver_combo.get_active_text());
+       list_devices ();
+
+       if (!ignore_changes) {
+               maybe_display_saved_state ();
+       }
+}
+
+void
+EngineControl::device_changed ()
+{
+
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+       string device_name = device_combo.get_active_text ();
+       vector<string> s;
+
+       {
+               PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
+
+               /* don't allow programmatic change to combos to cause a
+                  recursive call to this method.
+                */
+
+               /* sample rates */
+
+               string desired;
+
+               vector<float> sr;
+
+               if (_have_control) {
+                       sr = backend->available_sample_rates (device_name);
+               } else {
+
+                       sr.push_back (8000.0f);
+                       sr.push_back (16000.0f);
+                       sr.push_back (32000.0f);
+                       sr.push_back (44100.0f);
+                       sr.push_back (48000.0f);
+                       sr.push_back (88200.0f);
+                       sr.push_back (96000.0f);
+                       sr.push_back (192000.0f);
+                       sr.push_back (384000.0f);
+               }
+
+               for (vector<float>::const_iterator x = sr.begin(); x != sr.end(); ++x) {
+                       s.push_back (rate_as_string (*x));
+                       if (*x == _desired_sample_rate) {
+                               desired = s.back();
+                       }
+               }
+
+               if (!s.empty()) {
+                       sample_rate_combo.set_sensitive (true);
+                       set_popdown_strings (sample_rate_combo, s);
+
+                       if (desired.empty()) {
+                               sample_rate_combo.set_active_text (rate_as_string (backend->default_sample_rate()));
+                       } else {
+                               sample_rate_combo.set_active_text (desired);
+                       }
+
+               } else {
+                       sample_rate_combo.set_sensitive (false);
+               }
+
+               /* buffer sizes */
+
+               vector<uint32_t> bs;
+
+               if (_have_control) {
+                       bs = backend->available_buffer_sizes (device_name);
+               } else if (backend->can_change_buffer_size_when_running()) {
+                       bs.push_back (8);
+                       bs.push_back (16);
+                       bs.push_back (32);
+                       bs.push_back (64);
+                       bs.push_back (128);
+                       bs.push_back (256);
+                       bs.push_back (512);
+                       bs.push_back (1024);
+                       bs.push_back (2048);
+                       bs.push_back (4096);
+                       bs.push_back (8192);
+               }
+               s.clear ();
+               for (vector<uint32_t>::const_iterator x = bs.begin(); x != bs.end(); ++x) {
+                       s.push_back (bufsize_as_string (*x));
+               }
+
+               if (!s.empty()) {
+                       buffer_size_combo.set_sensitive (true);
+                       set_popdown_strings (buffer_size_combo, s);
+
+                       buffer_size_combo.set_active_text (bufsize_as_string (backend->default_buffer_size()));
+                       show_buffer_duration ();
+               } else {
+                       buffer_size_combo.set_sensitive (false);
+               }
+
+               /* XXX theoretically need to set min + max channel counts here
+               */
+
+               manage_control_app_sensitivity ();
+       }
+
+       /* pick up any saved state for this device */
+
+       if (!ignore_changes) {
+               maybe_display_saved_state ();
+       }
+}
+
+string
+EngineControl::bufsize_as_string (uint32_t sz)
+{
+       /* Translators: "samples" is always plural here, so no
+          need for plural+singular forms.
+        */
+       char buf[32];
+       snprintf (buf, sizeof (buf), _("%u samples"), sz);
+       return buf;
+}
+
+void
+EngineControl::sample_rate_changed ()
+{
+       /* reset the strings for buffer size to show the correct msec value
+          (reflecting the new sample rate).
+        */
+
+       show_buffer_duration ();
+       if (!ignore_changes) {
+               save_state ();
+       }
+
+}
+
+void
+EngineControl::buffer_size_changed ()
+{
+       show_buffer_duration ();
+       if (!ignore_changes) {
+               save_state ();
+       }
+}
+
+void
+EngineControl::show_buffer_duration ()
+{
+
+       /* buffer sizes  - convert from just samples to samples + msecs for
+        * the displayed string
+        */
+
+       string bs_text = buffer_size_combo.get_active_text ();
+       uint32_t samples = atoi (bs_text); /* will ignore trailing text */
+       uint32_t rate = get_rate();
+
+       /* Translators: "msecs" is ALWAYS plural here, so we do not
+          need singular form as well.
+        */
+       /* Developers: note the hard-coding of a double buffered model
+          in the (2 * samples) computation of latency. we always start
+          the audiobackend in this configuration.
+        */
+       char buf[32];
+       snprintf (buf, sizeof (buf), _("(%.1f msecs)"), (2 * samples) / (rate/1000.0));
+       buffer_size_duration_label.set_text (buf);
+}
+
+void
+EngineControl::midi_option_changed ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+
+       backend->set_midi_option (get_midi_option());
+
+       vector<ARDOUR::AudioBackend::DeviceStatus> midi_devices = backend->enumerate_midi_devices();
+
+       //_midi_devices.clear(); // TODO merge with state-saved settings..
+       _can_set_midi_latencies = backend->can_set_systemic_midi_latencies();
+       std::vector<MidiDeviceSettings> new_devices;
+
+       for (vector<ARDOUR::AudioBackend::DeviceStatus>::const_iterator i = midi_devices.begin(); i != midi_devices.end(); ++i) {
+               MidiDeviceSettings mds = find_midi_device (i->name);
+               if (i->available && !mds) {
+                       uint32_t input_latency = 0;
+                       uint32_t output_latency = 0;
+                       if (_can_set_midi_latencies) {
+                               input_latency = backend->systemic_midi_input_latency (i->name);
+                               output_latency = backend->systemic_midi_output_latency (i->name);
+                       }
+                       bool enabled = backend->midi_device_enabled (i->name);
+                       MidiDeviceSettings ptr (new MidiDeviceSetting (i->name, enabled, input_latency, output_latency));
+                       new_devices.push_back (ptr);
+               } else if (i->available) {
+                       new_devices.push_back (mds);
+               }
+       }
+       _midi_devices = new_devices;
+
+       if (_midi_devices.empty()) {
+               midi_devices_button.set_sensitive (false);
+       } else {
+               midi_devices_button.set_sensitive (true);
+       }
+
+       if (!ignore_changes) {
+               save_state ();
+       }
+}
+
+void
+EngineControl::parameter_changed ()
+{
+       if (!ignore_changes) {
+               save_state ();
+       }
+}
+
+EngineControl::State
+EngineControl::get_matching_state (
+               const string& backend,
+               const string& driver,
+               const string& device)
+{
+       for (StateList::iterator i = states.begin(); i != states.end(); ++i) {
+               if ((*i)->backend == backend &&
+                               (*i)->driver == driver &&
+                               (*i)->device == device) {
+                       return (*i);
+               }
+       }
+       return State();
+}
+
+EngineControl::State
+EngineControl::get_saved_state_for_currently_displayed_backend_and_device ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+
+       if (backend) {
+               return get_matching_state (backend_combo.get_active_text(),
+                               (backend->requires_driver_selection() ? (std::string) driver_combo.get_active_text() : string()),
+                               device_combo.get_active_text());
+       }
 
-       child = new XMLNode ("force16bit");
-       child->add_property ("val", to_string (force16bit_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
 
-       child = new XMLNode ("hwmonitor");
-       child->add_property ("val", to_string (hw_monitor_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+       return get_matching_state (backend_combo.get_active_text(),
+                       string(),
+                       device_combo.get_active_text());
+}
 
-       child = new XMLNode ("hwmeter");
-       child->add_property ("val", to_string (hw_meter_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+EngineControl::State
+EngineControl::save_state ()
+{
+       if (!_have_control) {
+               return State();
+       }
+       State state (new StateStruct);
+       store_state (state);
+
+       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;
+               }
+       }
 
-       child = new XMLNode ("verbose");
-       child->add_property ("val", to_string (verbose_output_button.get_active(), std::dec));
-       root->add_child_nocopy (*child);
+       states.push_back (state);
 
-       child = new XMLNode ("samplerate");
-       child->add_property ("val", sample_rate_combo.get_active_text());
-       root->add_child_nocopy (*child);
+       return state;
+}
 
-       child = new XMLNode ("periodsize");
-       child->add_property ("val", period_size_combo.get_active_text());
-       root->add_child_nocopy (*child);
+void
+EngineControl::store_state (State state)
+{
+       state->backend = get_backend ();
+       state->driver = get_driver ();
+       state->device = get_device_name ();
+       state->sample_rate = get_rate ();
+       state->buffer_size = get_buffer_size ();
+       state->input_latency = get_input_latency ();
+       state->output_latency = get_output_latency ();
+       state->input_channels = get_input_channels ();
+       state->output_channels = get_output_channels ();
+       state->midi_option = get_midi_option ();
+       state->midi_devices = _midi_devices;
+}
 
-       child = new XMLNode ("serverpath");
-       child->add_property ("val", serverpath_combo.get_active_text());
-       root->add_child_nocopy (*child);
+void
+EngineControl::maybe_display_saved_state ()
+{
+       if (!_have_control) {
+               return;
+       }
 
-       child = new XMLNode ("driver");
-       child->add_property ("val", driver_combo.get_active_text());
-       root->add_child_nocopy (*child);
+       State state = get_saved_state_for_currently_displayed_backend_and_device ();
 
-       child = new XMLNode ("interface");
-       child->add_property ("val", interface_combo.get_active_text());
-       root->add_child_nocopy (*child);
+       if (state) {
+               PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
 
-       child = new XMLNode ("timeout");
-       child->add_property ("val", timeout_combo.get_active_text());
-       root->add_child_nocopy (*child);
+               if (!_desired_sample_rate) {
+                       sample_rate_combo.set_active_text (rate_as_string (state->sample_rate));
+               }
+               buffer_size_combo.set_active_text (bufsize_as_string (state->buffer_size));
+               /* call this explicitly because we're ignoring changes to
+                  the controls at this point.
+                */
+               show_buffer_duration ();
+               input_latency.set_value (state->input_latency);
+               output_latency.set_value (state->output_latency);
+
+               if (!state->midi_option.empty()) {
+                       midi_option_combo.set_active_text (state->midi_option);
+                       _midi_devices = state->midi_devices;
+               }
+       }
+}
 
-       child = new XMLNode ("dither");
-       child->add_property ("val", dither_mode_combo.get_active_text());
-       root->add_child_nocopy (*child);
+XMLNode&
+EngineControl::get_state ()
+{
+       XMLNode* root = new XMLNode ("AudioMIDISetup");
+       std::string path;
+
+       if (!states.empty()) {
+               XMLNode* state_nodes = new XMLNode ("EngineStates");
+
+               for (StateList::const_iterator i = states.begin(); i != states.end(); ++i) {
+
+                       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 ("sample-rate", (*i)->sample_rate);
+                       node->add_property ("buffer-size", (*i)->buffer_size);
+                       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 ("midi-option", (*i)->midi_option);
+
+                       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_devices->add_child_nocopy (*midi_device_stuff);
+                       }
+                       node->add_child_nocopy (*midi_devices);
 
-       child = new XMLNode ("audiomode");
-       child->add_property ("val", audio_mode_combo.get_active_text());
-       root->add_child_nocopy (*child);
+                       state_nodes->add_child_nocopy (*node);
+               }
 
-       child = new XMLNode ("inputdevice");
-       child->add_property ("val", input_device_combo.get_active_text());
-       root->add_child_nocopy (*child);
+               root->add_child_nocopy (*state_nodes);
+       }
 
-       child = new XMLNode ("outputdevice");
-       child->add_property ("val", output_device_combo.get_active_text());
-       root->add_child_nocopy (*child);
-       
        return *root;
 }
 
 void
 EngineControl::set_state (const XMLNode& root)
 {
-       XMLNodeList          clist;
-       XMLNodeConstIterator citer;
+       XMLNodeList          clist, cclist;
+       XMLNodeConstIterator citer, cciter;
        XMLNode* child;
+       XMLNode* grandchild;
        XMLProperty* prop = NULL;
-       bool using_dummy = false;
-       
-       int val;
-       string strval;
-       
-       if ( (child = root.child ("driver"))){
-               prop = child->property("val");
-               if (prop && (prop->value() == "Dummy") ) {
-                       using_dummy = true;
-               }
+
+       if (root.name() != "AudioMIDISetup") {
+               return;
        }
-       
+
        clist = root.children();
 
+       states.clear ();
+
        for (citer = clist.begin(); citer != clist.end(); ++citer) {
-               if ( prop && (prop->value() == "FFADO" ))
-                               continue;
+
                child = *citer;
 
-               prop = child->property ("val");
+               if (child->name() != "EngineStates") {
+                       continue;
+               }
+
+               cclist = child->children();
+
+               for (cciter = cclist.begin(); cciter != cclist.end(); ++cciter) {
+                       State state (new StateStruct);
 
-               if (!prop || prop->value().empty()) {
+                       grandchild = *cciter;
 
-                       if ( using_dummy && ( child->name() == "interface" || child->name() == "inputdevice" || child->name() == "outputdevice" ))
+                       if (grandchild->name() != "State") {
                                continue;
-                       error << string_compose (_("AudioSetup value for %1 is missing data"), child->name()) << endmsg;
-                       continue;
-               }
-               
-               strval = prop->value();
-
-               /* adjustments/spinners */
-
-               if (child->name() == "periods") {
-                       val = atoi (strval);
-                       periods_adjustment.set_value(val);
-               } else if (child->name() == "priority") {
-                       val = atoi (strval);
-                       priority_adjustment.set_value(val);
-               } else if (child->name() == "ports") {
-                       val = atoi (strval);
-                       ports_adjustment.set_value(val);
-               } else if (child->name() == "inchannels") {
-                       val = atoi (strval);
-                       input_channels.set_value(val);
-               } else if (child->name() == "outchannels") {
-                       val = atoi (strval);
-                       output_channels.set_value(val);
-               } else if (child->name() == "inlatency") {
-                       val = atoi (strval);
-                       input_latency.set_value(val);
-               } else if (child->name() == "outlatency") {
-                       val = atoi (strval);
-                       output_latency.set_value(val);
+                       }
+
+                       if ((prop = grandchild->property ("backend")) == 0) {
+                               continue;
+                       }
+                       state->backend = prop->value ();
+
+                       if ((prop = grandchild->property ("driver")) == 0) {
+                               continue;
+                       }
+                       state->driver = prop->value ();
+
+                       if ((prop = grandchild->property ("device")) == 0) {
+                               continue;
+                       }
+                       state->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 ("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 ("midi-option")) == 0) {
+                               continue;
+                       }
+                       state->midi_option = prop->value ();
+
+                       state->midi_devices.clear();
+                       XMLNode* midinode;
+                       if ((midinode = 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
+                                                ) {
+                                               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 ())
+                                                               ));
+                                       state->midi_devices.push_back (ptr);
+                               }
+                       }
+
+#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);
                }
+       }
 
-               /* buttons */
-
-               else if (child->name() == "realtime") {
-                       val = atoi (strval);
-                       realtime_button.set_active(val);
-               } else if (child->name() == "nomemorylock") {
-                       val = atoi (strval);
-                       no_memory_lock_button.set_active(val);
-               } else if (child->name() == "unlockmemory") {
-                       val = atoi (strval);
-                       unlock_memory_button.set_active(val);
-               } else if (child->name() == "softmode") {
-                       val = atoi (strval);
-                       soft_mode_button.set_active(val);
-               } else if (child->name() == "force16bit") {
-                       val = atoi (strval);
-                       force16bit_button.set_active(val);
-               } else if (child->name() == "hwmonitor") {
-                       val = atoi (strval);
-                       hw_monitor_button.set_active(val);
-               } else if (child->name() == "hwmeter") {
-                       val = atoi (strval);
-                       hw_meter_button.set_active(val);
-               } else if (child->name() == "verbose") {
-                       val = atoi (strval);
-                       verbose_output_button.set_active(val);
+       /* now see if there was an active state and switch the setup to it */
+
+       for (StateList::const_iterator i = states.begin(); i != states.end(); ++i) {
+
+               if ((*i)->active) {
+                       ignore_changes++;
+                       backend_combo.set_active_text ((*i)->backend);
+                       driver_combo.set_active_text ((*i)->driver);
+                       device_combo.set_active_text ((*i)->device);
+                       sample_rate_combo.set_active_text (rate_as_string ((*i)->sample_rate));
+                       buffer_size_combo.set_active_text (bufsize_as_string ((*i)->buffer_size));
+                       input_latency.set_value ((*i)->input_latency);
+                       output_latency.set_value ((*i)->output_latency);
+                       midi_option_combo.set_active_text ((*i)->midi_option);
+                       ignore_changes--;
+                       break;
                }
+       }
+}
 
-               /* combos */
-
-               else if (child->name() == "samplerate") {
-                       sample_rate_combo.set_active_text(strval);
-               } else if (child->name() == "periodsize") {
-                       period_size_combo.set_active_text(strval);
-               } else if (child->name() == "serverpath") {
-                       /* do not allow us to use a server path that doesn't
-                          exist on this system. this handles cases where
-                          the user has an RC file listing a serverpath
-                          from some other machine.
-                       */
-                       vector<string>::iterator x;
-                       for (x = server_strings.begin(); x != server_strings.end(); ++x) {
-                               if (*x == strval) {
-                                       break;
+int
+EngineControl::push_state_to_backend (bool start)
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+
+       if (!backend) {
+               return 0;
+       }
+
+       /* figure out what is going to change */
+
+       bool restart_required = false;
+       bool was_running = ARDOUR::AudioEngine::instance()->running();
+       bool change_driver = false;
+       bool change_device = false;
+       bool change_rate = false;
+       bool change_bufsize = false;
+       bool change_latency = false;
+       bool change_channels = false;
+       bool change_midi = false;
+
+       uint32_t ochan = get_output_channels ();
+       uint32_t ichan = get_input_channels ();
+
+       if (_have_control) {
+
+               if (started_at_least_once) {
+
+                       /* we can control the backend */
+
+                       if (backend->requires_driver_selection()) {
+                               if (get_driver() != backend->driver_name()) {
+                                       change_driver = true;
                                }
                        }
-                       if (x != server_strings.end()) {
-                               serverpath_combo.set_active_text (strval);
-                       } else {
-                               warning << string_compose (_("configuration files contain a JACK server path that doesn't exist (%1)"),
-                                                            strval)
-                                       << endmsg;
+
+                       if (get_device_name() != backend->device_name()) {
+                               change_device = true;
+                       }
+
+                       if (get_rate() != backend->sample_rate()) {
+                               change_rate = true;
+                       }
+
+                       if (get_buffer_size() != backend->buffer_size()) {
+                               change_bufsize = true;
+                       }
+
+                       if (get_midi_option() != backend->midi_option()) {
+                               change_midi = true;
+                       }
+
+                       /* zero-requested channels means "all available" */
+
+                       if (ichan == 0) {
+                               ichan = backend->input_channels();
+                       }
+
+                       if (ochan == 0) {
+                               ochan = backend->output_channels();
+                       }
+
+                       if (ichan != backend->input_channels()) {
+                               change_channels = true;
+                       }
+
+                       if (ochan != backend->output_channels()) {
+                               change_channels = true;
+                       }
+
+                       if (get_input_latency() != backend->systemic_input_latency() ||
+                                       get_output_latency() != backend->systemic_output_latency()) {
+                               change_latency = true;
+                       }
+               } else {
+                       /* backend never started, so we have to force a group
+                          of settings.
+                        */
+                       change_device = true;
+                       if (backend->requires_driver_selection()) {
+                               change_driver = true;
+                       }
+                       change_rate = true;
+                       change_bufsize = true;
+                       change_channels = true;
+                       change_latency = true;
+                       change_midi = true;
+               }
+
+       } else {
+
+               /* we have no control over the backend, meaning that we can
+                * only possibly change sample rate and buffer size.
+                */
+
+
+               if (get_rate() != backend->sample_rate()) {
+                       change_bufsize = true;
+               }
+
+               if (get_buffer_size() != backend->buffer_size()) {
+                       change_bufsize = true;
+               }
+       }
+
+       if (!_have_control) {
+
+               /* We do not have control over the backend, so the best we can
+                * do is try to change the sample rate and/or bufsize and get
+                * out of here.
+                */
+
+               if (change_rate && !backend->can_change_sample_rate_when_running()) {
+                       return 1;
+               }
+
+               if (change_bufsize && !backend->can_change_buffer_size_when_running()) {
+                       return 1;
+               }
+
+               if (change_rate) {
+                       backend->set_sample_rate (get_rate());
+               }
+
+               if (change_bufsize) {
+                       backend->set_buffer_size (get_buffer_size());
+               }
+
+               if (start) {
+                       if (ARDOUR::AudioEngine::instance()->start ()) {
+                               error << string_compose (_("Could not start backend engine %1"), backend->name()) << endmsg;
+                               return -1;
                        }
-               } else if (child->name() == "driver") {
-                       driver_combo.set_active_text(strval);
-               } else if (child->name() == "interface") {
-                       interface_combo.set_active_text(strval);
-               } else if (child->name() == "timeout") {
-                       timeout_combo.set_active_text(strval);
-               } else if (child->name() == "dither") {
-                       dither_mode_combo.set_active_text(strval);
-               } else if (child->name() == "audiomode") {
-                       audio_mode_combo.set_active_text(strval);
-               } else if (child->name() == "inputdevice") {
-                       input_device_combo.set_active_text(strval);
-               } else if (child->name() == "outputdevice") {
-                       output_device_combo.set_active_text(strval);
                }
+
+               post_push ();
+
+               return 0;
+       }
+
+       /* determine if we need to stop the backend before changing parameters */
+
+       if (change_driver || change_device || change_channels || change_latency ||
+                       (change_rate && !backend->can_change_sample_rate_when_running()) ||
+                       change_midi ||
+                       (change_bufsize && !backend->can_change_buffer_size_when_running())) {
+               restart_required = true;
+       } else {
+               restart_required = false;
        }
+
+       if (was_running) {
+
+               if (!change_driver && !change_device && !change_channels && !change_latency && !change_midi) {
+                       /* no changes in any parameters that absolutely require a
+                        * restart, so check those that might be changeable without a
+                        * restart
+                        */
+
+                       if (change_rate && !backend->can_change_sample_rate_when_running()) {
+                               /* can't do this while running ... */
+                               restart_required = true;
+                       }
+
+                       if (change_bufsize && !backend->can_change_buffer_size_when_running()) {
+                               /* can't do this while running ... */
+                               restart_required = true;
+                       }
+               }
+       }
+
+       if (was_running) {
+               if (restart_required) {
+                       if (ARDOUR_UI::instance()->disconnect_from_engine ()) {
+                               return -1;
+                       }
+               }
+       }
+
+
+       if (change_driver && backend->set_driver (get_driver())) {
+               error << string_compose (_("Cannot set driver to %1"), get_driver()) << endmsg;
+               return -1;
+       }
+       if (change_device && backend->set_device_name (get_device_name())) {
+               error << string_compose (_("Cannot set device name to %1"), get_device_name()) << endmsg;
+               return -1;
+       }
+       if (change_rate && backend->set_sample_rate (get_rate())) {
+               error << string_compose (_("Cannot set sample rate to %1"), get_rate()) << endmsg;
+               return -1;
+       }
+       if (change_bufsize && backend->set_buffer_size (get_buffer_size())) {
+               error << string_compose (_("Cannot set buffer size to %1"), get_buffer_size()) << endmsg;
+               return -1;
+       }
+
+       if (change_channels || get_input_channels() == 0 || get_output_channels() == 0) {
+               if (backend->set_input_channels (get_input_channels())) {
+                       error << string_compose (_("Cannot set input channels to %1"), get_input_channels()) << endmsg;
+                       return -1;
+               }
+               if (backend->set_output_channels (get_output_channels())) {
+                       error << string_compose (_("Cannot set output channels to %1"), get_output_channels()) << endmsg;
+                       return -1;
+               }
+       }
+       if (change_latency) {
+               if (backend->set_systemic_input_latency (get_input_latency())) {
+                       error << string_compose (_("Cannot set input latency to %1"), get_input_latency()) << endmsg;
+                       return -1;
+               }
+               if (backend->set_systemic_output_latency (get_output_latency())) {
+                       error << string_compose (_("Cannot set output latency to %1"), get_output_latency()) << endmsg;
+                       return -1;
+               }
+       }
+
+       if (change_midi) {
+               backend->set_midi_option (get_midi_option());
+       }
+
+       if (1 /* TODO */) {
+               for (vector<MidiDeviceSettings>::const_iterator p = _midi_devices.begin(); p != _midi_devices.end(); ++p) {
+                       if (_measure_midi) {
+                               if (*p == _measure_midi) {
+                                       backend->set_midi_device_enabled ((*p)->name, true);
+                               } else {
+                                       backend->set_midi_device_enabled ((*p)->name, false);
+                               }
+                               continue;
+                       }
+                       backend->set_midi_device_enabled ((*p)->name, (*p)->enabled);
+                       if (backend->can_set_systemic_midi_latencies()) {
+                               backend->set_systemic_midi_input_latency ((*p)->name, (*p)->input_latency);
+                               backend->set_systemic_midi_output_latency ((*p)->name, (*p)->output_latency);
+                       }
+               }
+       }
+
+       if (start || (was_running && restart_required)) {
+               if (ARDOUR_UI::instance()->reconnect_to_engine()) {
+                       return -1;
+               }
+       }
+
+       post_push ();
+
+       return 0;
+}
+
+void
+EngineControl::post_push ()
+{
+       /* get a pointer to the current state object, creating one if
+        * necessary
+        */
+
+       if (_have_control) {
+               State state = get_saved_state_for_currently_displayed_backend_and_device ();
+
+               if (!state) {
+                       state = save_state ();
+                       assert (state);
+               }
+
+               /* all off */
+
+               for (StateList::iterator i = states.begin(); i != states.end(); ++i) {
+                       (*i)->active = false;
+               }
+
+               /* mark this one active (to be used next time the dialog is
+                * shown)
+                */
+
+               state->active = true;
+
+               manage_control_app_sensitivity ();
+       }
+
+       /* schedule a redisplay of MIDI ports */
+       //Glib::signal_timeout().connect (sigc::bind_return (sigc::mem_fun (*this, &EngineControl::refresh_midi_display), false), 1000);
+}
+
+
+float
+EngineControl::get_rate () const
+{
+       float r = atof (sample_rate_combo.get_active_text ());
+       /* the string may have been translated with an abbreviation for
+        * thousands, so use a crude heuristic to fix this.
+        */
+       if (r < 1000.0) {
+               r *= 1000.0;
+       }
+       return r;
+}
+
+
+uint32_t
+EngineControl::get_buffer_size () const
+{
+       string txt = buffer_size_combo.get_active_text ();
+       uint32_t samples;
+
+       if (sscanf (txt.c_str(), "%d", &samples) != 1) {
+               throw exception ();
+       }
+
+       return samples;
+}
+
+string
+EngineControl::get_midi_option () const
+{
+       return midi_option_combo.get_active_text();
+}
+
+uint32_t
+EngineControl::get_input_channels() const
+{
+       return (uint32_t) input_channels_adjustment.get_value();
+}
+
+uint32_t
+EngineControl::get_output_channels() const
+{
+       return (uint32_t) output_channels_adjustment.get_value();
+}
+
+uint32_t
+EngineControl::get_input_latency() const
+{
+       return (uint32_t) input_latency_adjustment.get_value();
+}
+
+uint32_t
+EngineControl::get_output_latency() const
+{
+       return (uint32_t) output_latency_adjustment.get_value();
+}
+
+string
+EngineControl::get_backend () const
+{
+       return backend_combo.get_active_text ();
+}
+
+string
+EngineControl::get_driver () const
+{
+       if (driver_combo.get_sensitive() && driver_combo.get_parent()) {
+               return driver_combo.get_active_text ();
+       } else {
+               return "";
+       }
+}
+
+string
+EngineControl::get_device_name () const
+{
+       return device_combo.get_active_text ();
+}
+
+void
+EngineControl::control_app_button_clicked ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+
+       if (!backend) {
+               return;
+       }
+
+       backend->launch_control_app ();
+}
+
+void
+EngineControl::manage_control_app_sensitivity ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+
+       if (!backend) {
+               return;
+       }
+
+       string appname = backend->control_app_name();
+
+       if (appname.empty()) {
+               control_app_button.set_sensitive (false);
+       } else {
+               control_app_button.set_sensitive (true);
+       }
+}
+
+void
+EngineControl::set_desired_sample_rate (uint32_t sr)
+{
+       _desired_sample_rate = sr;
+       device_changed ();
+}
+
+void
+EngineControl::on_switch_page (GtkNotebookPage*, guint page_num)
+{
+       if (page_num == 0) {
+               cancel_button->set_sensitive (true);
+               ok_button->set_sensitive (true);
+               apply_button->set_sensitive (true);
+               _measure_midi.reset();
+       } else {
+               cancel_button->set_sensitive (false);
+               ok_button->set_sensitive (false);
+               apply_button->set_sensitive (false);
+       }
+
+       if (page_num == midi_tab) {
+               /* MIDI tab */
+               refresh_midi_display ();
+       }
+
+       if (page_num == latency_tab) {
+               /* latency tab */
+
+               if (ARDOUR::AudioEngine::instance()->running()) {
+                       // TODO - mark as 'stopped for latency
+                       ARDOUR_UI::instance()->disconnect_from_engine ();
+               }
+
+               {
+                       PBD::Unwinder<uint32_t> protect_ignore_changes (ignore_changes, ignore_changes + 1);
+
+                       /* save any existing latency values */
+
+                       uint32_t il = (uint32_t) input_latency.get_value ();
+                       uint32_t ol = (uint32_t) input_latency.get_value ();
+
+                       /* reset to zero so that our new test instance
+                          will be clean of any existing latency measures.
+
+                          NB. this should really be done by the backend
+                          when stated for latency measurement.
+                       */
+
+                       input_latency.set_value (0);
+                       output_latency.set_value (0);
+
+                       push_state_to_backend (false);
+
+                       /* reset control */
+
+                       input_latency.set_value (il);
+                       output_latency.set_value (ol);
+
+               }
+               // This should be done in push_state_to_backend()
+               if (ARDOUR::AudioEngine::instance()->prepare_for_latency_measurement()) {
+                       disable_latency_tab ();
+               }
+
+               enable_latency_tab ();
+
+       } else {
+               if (lm_running) {
+                       end_latency_detection ();
+                       ARDOUR::AudioEngine::instance()->stop_latency_detection();
+               }
+       }
+}
+
+/* latency measurement */
+
+bool
+EngineControl::check_audio_latency_measurement ()
+{
+       MTDM* mtdm = ARDOUR::AudioEngine::instance()->mtdm ();
+
+       if (mtdm->resolve () < 0) {
+               lm_results.set_markup (string_compose (results_markup, _("No signal detected ")));
+               return true;
+       }
+
+       if (mtdm->err () > 0.3) {
+               mtdm->invert ();
+               mtdm->resolve ();
+       }
+
+       char buf[256];
+       ARDOUR::framecnt_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")));
+               ARDOUR::AudioEngine::instance()->stop_latency_detection ();
+               return false;
+       }
+
+       int frames_total = mtdm->del();
+       int extra = frames_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,
+                       _("Systemic latency: "),
+                       extra, extra * 1000.0f/sample_rate);
+
+       bool solid = true;
+
+       if (mtdm->err () > 0.2) {
+               strcat (buf, " ");
+               strcat (buf, _("(signal detection error)"));
+               solid = false;
+       }
+
+       if (mtdm->inv ()) {
+               strcat (buf, " ");
+               strcat (buf, _("(inverted - bad wiring)"));
+               solid = false;
+       }
+
+       if (solid) {
+               end_latency_detection ();
+               lm_use_button.set_sensitive (true);
+               have_lm_results = true;
+       }
+
+       lm_results.set_markup (string_compose (results_markup, buf));
+
+       return true;
+}
+
+bool
+EngineControl::check_midi_latency_measurement ()
+{
+       ARDOUR::MIDIDM* mididm = ARDOUR::AudioEngine::instance()->mididm ();
+
+       if (!mididm->have_signal () || mididm->latency () == 0) {
+               lm_results.set_markup (string_compose (results_markup, _("No signal detected ")));
+               return true;
+       }
+
+       char buf[256];
+       ARDOUR::framecnt_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")));
+               ARDOUR::AudioEngine::instance()->stop_latency_detection ();
+               return false;
+       }
+
+       ARDOUR::framecnt_t frames_total = mididm->latency();
+       ARDOUR::framecnt_t extra = frames_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 (),
+                       _("Systemic latency: "),
+                       extra, extra * 1000.0f / sample_rate);
+
+       bool solid = true;
+
+       if (!mididm->ok ()) {
+               strcat (buf, " ");
+               strcat (buf, _("(averaging)"));
+               solid = false;
+       }
+
+       if (mididm->deviation () > 50.0) {
+               strcat (buf, " ");
+               strcat (buf, _("(too large jitter)"));
+               solid = false;
+       } else if (mididm->deviation () > 10.0) {
+               strcat (buf, " ");
+               strcat (buf, _("(large jitter)"));
+       }
+
+       if (solid) {
+               end_latency_detection ();
+               lm_use_button.set_sensitive (true);
+               have_lm_results = true;
+               return false;
+       } else if (mididm->processed () > 400) {
+               have_lm_results = false;
+               end_latency_detection ();
+               lm_results.set_markup (string_compose (results_markup, _("Timeout - large MIDI jitter.")));
+               return false;
+       }
+
+       lm_results.set_markup (string_compose (results_markup, buf));
+
+       return true;
+}
+
+void
+EngineControl::start_latency_detection ()
+{
+       ARDOUR::AudioEngine::instance()->set_latency_input_port (lm_input_channel_combo.get_active_text());
+       ARDOUR::AudioEngine::instance()->set_latency_output_port (lm_output_channel_combo.get_active_text());
+
+       if (ARDOUR::AudioEngine::instance()->start_latency_detection (_measure_midi ? true : false) == 0) {
+               lm_results.set_markup (string_compose (results_markup, _("Detecting ...")));
+               if (_measure_midi) {
+                       latency_timeout = Glib::signal_timeout().connect (mem_fun (*this, &EngineControl::check_midi_latency_measurement), 100);
+               } else {
+                       latency_timeout = Glib::signal_timeout().connect (mem_fun (*this, &EngineControl::check_audio_latency_measurement), 100);
+               }
+               lm_measure_label.set_text (_("Cancel"));
+               have_lm_results = false;
+               lm_use_button.set_sensitive (false);
+               lm_input_channel_combo.set_sensitive (false);
+               lm_output_channel_combo.set_sensitive (false);
+               lm_running = true;
+       }
+
+       lm_back_button_signal.disconnect();
+       if (_measure_midi) {
+               lm_back_button_signal = lm_back_button.signal_clicked().connect (sigc::bind (sigc::mem_fun (notebook, &Gtk::Notebook::set_current_page), midi_tab));
+       } else {
+               lm_back_button_signal = lm_back_button.signal_clicked().connect (sigc::bind (sigc::mem_fun (notebook, &Gtk::Notebook::set_current_page), 0));
+       }
+}
+
+void
+EngineControl::end_latency_detection ()
+{
+       latency_timeout.disconnect ();
+       ARDOUR::AudioEngine::instance()->stop_latency_detection ();
+       lm_measure_label.set_text (_("Measure"));
+       if (!have_lm_results) {
+               lm_results.set_markup (string_compose (results_markup, _("No measurement results yet")));
+       } else {
+               lm_use_button.set_sensitive (false);
+       }
+       lm_input_channel_combo.set_sensitive (true);
+       lm_output_channel_combo.set_sensitive (true);
+       lm_running = false;
+}
+
+void
+EngineControl::latency_button_clicked ()
+{
+       if (!lm_running) {
+               start_latency_detection ();
+       } else {
+               end_latency_detection ();
+       }
+}
+
+void
+EngineControl::use_latency_button_clicked ()
+{
+       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);
+               _measure_midi->input_latency = one_way;
+               _measure_midi->output_latency = one_way;
+               notebook.set_current_page (midi_tab);
+       } else {
+               MTDM* mtdm = ARDOUR::AudioEngine::instance()->mtdm ();
+
+               if (!mtdm) {
+                       return;
+               }
+
+               double one_way = rint ((mtdm->del() - ARDOUR::AudioEngine::instance()->latency_signal_delay()) / 2.0);
+               one_way = std::max (0., one_way);
+
+               input_latency_adjustment.set_value (one_way);
+               output_latency_adjustment.set_value (one_way);
+
+               /* back to settings page */
+               notebook.set_current_page (0);
+}
+       }
+
+
+bool
+EngineControl::on_delete_event (GdkEventAny* ev)
+{
+       if (notebook.get_current_page() == 2) {
+               /* currently on latency tab - be sure to clean up */
+               end_latency_detection ();
+       }
+       return ArdourDialog::on_delete_event (ev);
+}
+
+void
+EngineControl::engine_running ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+
+       buffer_size_combo.set_active_text (bufsize_as_string (backend->buffer_size()));
+       sample_rate_combo.set_active_text (rate_as_string (backend->sample_rate()));
+
+       buffer_size_combo.set_sensitive (true);
+       sample_rate_combo.set_sensitive (true);
+
+       connect_disconnect_button.set_label (string_compose (_("Disconnect from %1"), backend->name()));
+
+       started_at_least_once = true;
+}
+
+void
+EngineControl::engine_stopped ()
+{
+       boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
+       assert (backend);
+
+       buffer_size_combo.set_sensitive (false);
+       connect_disconnect_button.set_label (string_compose (_("Connect to %1"), backend->name()));
+
+       sample_rate_combo.set_sensitive (true);
+       buffer_size_combo.set_sensitive (true);
+}
+
+void
+EngineControl::connect_disconnect_click()
+{
+       if (ARDOUR::AudioEngine::instance()->running()) {
+               ARDOUR_UI::instance()->disconnect_from_engine ();
+       } else {
+               ARDOUR_UI::instance()->reconnect_to_engine ();
+       }
+}
+
+void
+EngineControl::calibrate_audio_latency ()
+{
+       _measure_midi.reset ();
+       have_lm_results = false;
+       lm_use_button.set_sensitive (false);
+       lm_results.set_markup (string_compose (results_markup, _("No measurement results yet")));
+       notebook.set_current_page (latency_tab);
+}
+
+void
+EngineControl::calibrate_midi_latency (MidiDeviceSettings s)
+{
+       _measure_midi = s;
+       have_lm_results = false;
+       lm_use_button.set_sensitive (false);
+       lm_results.set_markup (string_compose (results_markup, _("No measurement results yet")));
+       notebook.set_current_page (latency_tab);
+}
+
+void
+EngineControl::configure_midi_devices ()
+{
+       notebook.set_current_page (midi_tab);
 }