Merge branch 'settings'

65 files changed, 1371 insertions, 1300 deletions

diff --git a/ChangeLog b/ChangeLog
index 8e8afe5..10a2b28 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Version 0.9.10
+==============
+Release date: March 30th 2016
+Contributors: deva, suhr
+ - Fix the 'no sound from plugin when resampler active' bug.
+ - Fix the 'freeze on tempo change' bug.
+ - Fix backspace in lineedits.
+
 Version 0.9.9
 =============
 Release date: March 24th 2016
diff --git a/drumgizmo/drumgizmoc.cc b/drumgizmo/drumgizmoc.cc
index 24d16e8..e993dc3 100644
--- a/drumgizmo/drumgizmoc.cc
+++ b/drumgizmo/drumgizmoc.cc
@@ -92,36 +92,7 @@ static const char usage_str[] =
     "  dummy:\n"
     "\n";
 
-CliMain::CliMain()
-	: MessageReceiver(MSGRCV_UI)
-{
-	loading = true; // Block by default
-}
-
-CliMain::~CliMain()
-{
-	hug_close();
-}
-
-void CliMain::handleMessage(Message* msg)
-{
-	switch(msg->type())
-	{
-	case Message::LoadStatus:
-		{
-			auto ls = static_cast<LoadStatusMessage*>(msg);
-			if(ls->numer_of_files_loaded == ls->number_of_files)
-			{
-				loading = false;
-			}
-		}
-		break;
-	default:
-		break;
-	}
-}
-
-int CliMain::run(int argc, char* argv[])
+int main(int argc, char* argv[])
 {
 	int c;
 
@@ -372,7 +343,8 @@ int CliMain::run(int argc, char* argv[])
 
 	printf("Using kitfile: %s\n", kitfile.c_str());
 
-	DrumGizmo gizmo(oe.get(), ie.get());
+	Settings settings;
+	DrumGizmo gizmo(settings, oe.get(), ie.get());
 
 	gizmo.setFrameSize(oe->getBufferSize());
 
@@ -382,21 +354,37 @@ int CliMain::run(int argc, char* argv[])
 		return 1;
 	}
 
-	printf("Loading drumkit, this may take a while...");
-	fflush(stdout);
-	loading = true;
-	while(async == false && loading)
+	printf("Loading drumkit, this may take a while:\n");
+
+	if(!async)
 	{
+		while(settings.drumkit_load_status.load() != LoadStatus::Done)
+		{
 #ifdef WIN32
-		SleepEx(500, FALSE);
+			SleepEx(10, FALSE);
 #else
-		usleep(500000);
+			usleep(10000);
 #endif /*WIN32*/
-		handleMessages();
-		printf(".");
-		fflush(stdout);
+
+			int total = settings.number_of_files.load();
+			int loaded =  settings.number_of_files_loaded.load();
+
+			printf("\r%d of %d     ", loaded, total);
+			fflush(stdout);
+
+			if(settings.drumkit_load_status.load() == LoadStatus::Error)
+			{
+				printf("\nLoad error\n");
+				return 1;
+			}
+
+			if(loaded == total)
+			{
+				//break;
+			}
+		}
+		printf("\ndone\n");
 	}
-	printf("done.\n");
 
 	gizmo.setSamplerate(oe->getSamplerate());
 
@@ -411,14 +399,7 @@ int CliMain::run(int argc, char* argv[])
 	printf("Quit.\n");
 	fflush(stdout);
 
-	return 0;
-}
-
-int main(int argc, char* argv[])
-{
-	CliMain cli;
-
-	cli.run(argc, argv);
+	hug_close();
 
 	return 0;
 }
diff --git a/drumgizmo/drumgizmoc.h b/drumgizmo/drumgizmoc.h
index 231aec6..cc2f96c 100644
--- a/drumgizmo/drumgizmoc.h
+++ b/drumgizmo/drumgizmoc.h
@@ -24,21 +24,4 @@
  *  along with DrumGizmo; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
  */
-
 #pragma once
-
-#include "messagereceiver.h"
-
-class CliMain : public MessageReceiver
-{
-public:
-	CliMain();
-	virtual ~CliMain();
-
-	int run(int argc, char* argv[]);
-	void handleMessage(Message* msg);
-
-private:
-	bool loading;
-};
-
diff --git a/drumgizmo/output/jackaudio.cc b/drumgizmo/output/jackaudio.cc
index 7710e14..abd7d4f 100644
--- a/drumgizmo/output/jackaudio.cc
+++ b/drumgizmo/output/jackaudio.cc
@@ -33,7 +33,6 @@ JackAudioOutputEngine::JackAudioOutputEngine(JackClient& client)
 	: AudioOutputEngine{}
 	, client(client)
 	, channels{}
-	, sema{"jackaudio"}
 {
 	client.add(*this);
 }
diff --git a/plugin/Makefile.mingw32.in b/plugin/Makefile.mingw32.in
index 40233b4..8b341c7 100644
--- a/plugin/Makefile.mingw32.in
+++ b/plugin/Makefile.mingw32.in
@@ -19,7 +19,6 @@ DG_SRC = \
 	@top_srcdir@/src/channelmixer.cc \
 	@top_srcdir@/src/chresampler.cc \
 	@top_srcdir@/src/configfile.cc \
-	@top_srcdir@/src/configuration.cc \
 	@top_srcdir@/src/configparser.cc \
 	@top_srcdir@/src/drumgizmo.cc \
 	@top_srcdir@/src/drumkit.cc \
@@ -29,8 +28,6 @@ DG_SRC = \
 	@top_srcdir@/src/instrument.cc \
 	@top_srcdir@/src/instrumentparser.cc \
 	@top_srcdir@/src/memchecker.cc \
-	@top_srcdir@/src/messagehandler.cc \
-	@top_srcdir@/src/messagereceiver.cc \
 	@top_srcdir@/src/midimapparser.cc \
 	@top_srcdir@/src/midimapper.cc \
 	@top_srcdir@/src/mutex.cc \
diff --git a/plugin/drumgizmo_plugin.cc b/plugin/drumgizmo_plugin.cc
index b8f8822..06c2799 100644
--- a/plugin/drumgizmo_plugin.cc
+++ b/plugin/drumgizmo_plugin.cc
@@ -59,7 +59,7 @@ DrumGizmoPlugin::DrumGizmoPlugin()
 {
 	init();
 
-	drumgizmo = std::make_shared<DrumGizmo>(&output, &input);
+	drumgizmo = std::make_shared<DrumGizmo>(settings, &output, &input);
 	resizeWindow(370, 330);
 	drumgizmo->setFreeWheel(true);
 	drumgizmo->setSamplerate(44100);
@@ -143,7 +143,7 @@ bool DrumGizmoPlugin::hasGUI()
 
 void DrumGizmoPlugin::createWindow(void *parent)
 {
-	plugin_gui = std::make_shared<GUI::PluginGUI>(parent);
+	plugin_gui = std::make_shared<GUI::PluginGUI>(settings, parent);
 	resizeWindow(370, 330);
 	onShowWindow();
 }
diff --git a/plugin/drumgizmo_plugin.h b/plugin/drumgizmo_plugin.h
index 28a1b8f..3508c3e 100644
--- a/plugin/drumgizmo_plugin.h
+++ b/plugin/drumgizmo_plugin.h
@@ -154,6 +154,8 @@ private:
 	Output output{*this};
 	const std::vector<float*>* output_samples{nullptr};
 
+	Settings settings;
+
 	std::shared_ptr<GUI::PluginGUI> plugin_gui;
 	std::shared_ptr<DrumGizmo> drumgizmo;
 };
diff --git a/plugingui/Makefile.am b/plugingui/Makefile.am
index 3dee864..4176c07 100644
--- a/plugingui/Makefile.am
+++ b/plugingui/Makefile.am
@@ -16,9 +16,7 @@ plugingui_SOURCES = \
 	$(top_srcdir)/src/configfile.cc \
 	$(top_srcdir)/src/thread.cc \
 	$(top_srcdir)/src/semaphore.cc \
-	$(top_srcdir)/src/mutex.cc \
-	$(top_srcdir)/src/messagehandler.cc \
-	$(top_srcdir)/src/messagereceiver.cc
+	$(top_srcdir)/src/mutex.cc
 
 rcgen_SOURCES = rcgen.cc
 
@@ -46,7 +44,6 @@ EXTRA_DIST = \
 	nativewindow.h \
 	nativewindow_win32.h \
 	nativewindow_x11.h \
-	notifier.h \
 	painter.h \
 	pixelbuffer.h \
 	pluginconfig.h \
diff --git a/plugingui/Makefile.mingw32 b/plugingui/Makefile.mingw32
index 3f52e8a..9820d1a 100644
--- a/plugingui/Makefile.mingw32
+++ b/plugingui/Makefile.mingw32
@@ -2,9 +2,7 @@ DG_SRC = \
 	../src/configfile.cc \
 	../src/thread.cc \
 	../src/semaphore.cc \
-	../src/mutex.cc \
-	../src/messagehandler.cc \
-	../src/messagereceiver.cc
+	../src/mutex.cc
 
 DG_CFLAGS = -I.. -I../include -I../src -DSSE -msse -msse2 -DDISABLE_HUGIN
 
diff --git a/plugingui/button.h b/plugingui/button.h
index 7e3e168..1bfeb2d 100644
--- a/plugingui/button.h
+++ b/plugingui/button.h
@@ -28,9 +28,10 @@
 
 #include <string>
 
+#include <notifier.h>
+
 #include "widget.h"
 #include "painter.h"
-#include "notifier.h"
 #include "font.h"
 
 namespace GUI {
diff --git a/plugingui/checkbox.h b/plugingui/checkbox.h
index 3da5511..5c658a5 100644
--- a/plugingui/checkbox.h
+++ b/plugingui/checkbox.h
@@ -26,9 +26,10 @@
  */
 #pragma once
 
+#include <notifier.h>
+
 #include "widget.h"
 #include "image.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/dgwindow.cc b/plugingui/dgwindow.cc
index 86a985d..c325703 100644
--- a/plugingui/dgwindow.cc
+++ b/plugingui/dgwindow.cc
@@ -30,12 +30,12 @@
 #include "verticalline.h"
 #include "../version.h"
 
-#include "messagehandler.h"
 #include "pluginconfig.h"
 
 namespace GUI {
 
-class LabeledControl : public Widget
+class LabeledControl
+	: public Widget
 {
 public:
 	LabeledControl(Widget* parent, const std::string& name)
@@ -60,7 +60,8 @@ public:
 	Label caption{this};
 };
 
-class File : public Widget
+class File
+	: public Widget
 {
 public:
 	File(Widget* parent)
@@ -83,7 +84,8 @@ public:
 	Button browseButton{this};
 };
 
-class HumanizeControls : public Widget
+class HumanizeControls
+	: public Widget
 {
 public:
 	HumanizeControls(Widget* parent)
@@ -119,11 +121,10 @@ public:
 	Knob falloffKnob{&falloff};
 };
 
-DGWindow::DGWindow(void* native_window, MessageHandler& messageHandler,
-                   Config& config)
+DGWindow::DGWindow(void* native_window, Config& config, Settings& settings)
 	: Window(native_window)
-	, messageHandler(messageHandler)
 	, config(config)
+	, settings(settings)
 {
 
 	int vlineSpacing = 16;
@@ -179,6 +180,7 @@ DGWindow::DGWindow(void* native_window, MessageHandler& messageHandler,
 
 	midimapFileProgress = new ProgressBar(this);
 	midimapFileProgress->resize(width() - 40, 11);
+	midimapFileProgress->setTotal(2);
 	layout.addItem(midimapFileProgress);
 
 	VerticalLine *l2 = new VerticalLine(this);
@@ -207,7 +209,7 @@ DGWindow::DGWindow(void* native_window, MessageHandler& messageHandler,
 	layout.addItem(l3);
 
 	Label *lbl_version = new Label(this);
-	lbl_version->setText(".::. v" VERSION "  .::.  http://www.drumgizmo.org  .::.  LGPLv3 .::.");
+	lbl_version->setText(".::.  v" VERSION "  .::.  http://www.drumgizmo.org  .::.  LGPLv3 .::.");
 	lbl_version->resize(width(), 20);
 	lbl_version->setAlignment(TextAlignment::center);
 	layout.addItem(lbl_version);
@@ -219,6 +221,50 @@ DGWindow::DGWindow(void* native_window, MessageHandler& messageHandler,
 	fileBrowser->hide();
 }
 
+void DGWindow::setDrumKitLoadStatus(LoadStatus load_status)
+{
+	ProgressBarState state = ProgressBarState::Blue;
+	switch(load_status)
+	{
+	case LoadStatus::Idle:
+	case LoadStatus::Loading:
+		state = ProgressBarState::Blue;
+		break;
+	case LoadStatus::Done:
+		state = ProgressBarState::Green;
+		break;
+	case LoadStatus::Error:
+		state = ProgressBarState::Red;
+		break;
+	}
+	drumkitFileProgress->setState(state);
+}
+
+void DGWindow::setMidiMapLoadStatus(LoadStatus load_status)
+{
+	ProgressBarState state = ProgressBarState::Blue;
+	switch(load_status)
+	{
+	case LoadStatus::Idle:
+		midimapFileProgress->setValue(0);
+		break;
+	case LoadStatus::Loading:
+		midimapFileProgress->setValue(1);
+		state = ProgressBarState::Blue;
+		break;
+	case LoadStatus::Done:
+		midimapFileProgress->setValue(2);
+		state = ProgressBarState::Green;
+		break;
+	case LoadStatus::Error:
+		midimapFileProgress->setValue(2);
+		state = ProgressBarState::Red;
+		break;
+	}
+
+	midimapFileProgress->setState(state);
+}
+
 void DGWindow::repaintEvent(RepaintEvent* repaintEvent)
 {
 	if(!visible())
@@ -233,42 +279,42 @@ void DGWindow::repaintEvent(RepaintEvent* repaintEvent)
 
 void DGWindow::attackValueChanged(float value)
 {
-	ChangeSettingMessage *msg =
-		new ChangeSettingMessage(ChangeSettingMessage::velocity_modifier_weight,
-														 value);
+	settings.velocity_modifier_weight.store(value);
 
-	messageHandler.sendMessage(MSGRCV_ENGINE, msg);
-
-#ifdef STANDALONE
+#ifdef STANDALONE // For GUI debugging
 	int i = value * 4;
 	switch(i) {
-	case 0: drumkitFileProgress->setState(ProgressBarState::Off); break;
-	case 1: drumkitFileProgress->setState(ProgressBarState::Blue); break;
-	case 2: drumkitFileProgress->setState(ProgressBarState::Green); break;
-	case 3: drumkitFileProgress->setState(ProgressBarState::Red); break;
-	default: break;
+	case 0:
+		drumkitFileProgress->setState(ProgressBarState::Off);
+		break;
+	case 1:
+		drumkitFileProgress->setState(ProgressBarState::Blue);
+		break;
+	case 2:
+		drumkitFileProgress->setState(ProgressBarState::Green);
+		break;
+	case 3:
+		drumkitFileProgress->setState(ProgressBarState::Red);
+		break;
+	default:
+		break;
 	}
 #endif
 }
 
 void DGWindow::falloffValueChanged(float value)
 {
-	ChangeSettingMessage *msg =
-		new ChangeSettingMessage(ChangeSettingMessage::velocity_modifier_falloff,
-		                         value);
-	messageHandler.sendMessage(MSGRCV_ENGINE, msg);
+	settings.velocity_modifier_falloff.store(value);
 
-#ifdef STANDALONE
-	drumkitFileProgress->setProgress(value);
+#ifdef STANDALONE // For GUI debugging
+	drumkitFileProgress->setTotal(100);
+	drumkitFileProgress->setValue(value * 100);
 #endif
 }
 
 void DGWindow::velocityCheckClick(bool checked)
 {
-	ChangeSettingMessage *msg =
-		new ChangeSettingMessage(ChangeSettingMessage::enable_velocity_modifier,
-		                         checked);
-	messageHandler.sendMessage(MSGRCV_ENGINE, msg);
+	settings.enable_velocity_modifier.store(checked);
 }
 
 void DGWindow::kitBrowseClick()
@@ -318,13 +364,7 @@ void DGWindow::selectKitFile(const std::string& filename)
 	config.lastkit = drumkit;
 	config.save();
 
-	drumkitFileProgress->setProgress(0);
-	drumkitFileProgress->setState(ProgressBarState::Blue);
-
-	LoadDrumKitMessage *msg = new LoadDrumKitMessage();
-	msg->drumkitfile = drumkit;
-
-	messageHandler.sendMessage(MSGRCV_ENGINE, msg);
+	settings.drumkit_file.store(drumkit);
 }
 
 void DGWindow::selectMapFile(const std::string& filename)
@@ -337,9 +377,7 @@ void DGWindow::selectMapFile(const std::string& filename)
 	config.lastmidimap = midimap;
 	config.save();
 
-	LoadMidimapMessage *msg = new LoadMidimapMessage();
-	msg->midimapfile = midimap;
-	messageHandler.sendMessage(MSGRCV_ENGINE, msg);
+	settings.midimap_file.store(midimap);
 }
 
 
diff --git a/plugingui/dgwindow.h b/plugingui/dgwindow.h
index 605e87a..72e4679 100644
--- a/plugingui/dgwindow.h
+++ b/plugingui/dgwindow.h
@@ -26,8 +26,9 @@
  */
 #pragma once
 
-#include "window.h"
+#include <settings.h>
 
+#include "window.h"
 #include "label.h"
 #include "lineedit.h"
 #include "checkbox.h"
@@ -37,8 +38,6 @@
 #include "filebrowser.h"
 #include "layout.h"
 
-class MessageHandler;
-
 namespace GUI {
 
 class Config;
@@ -47,7 +46,7 @@ class File;
 
 class DGWindow : public Window {
 public:
-	DGWindow(void* native_window, MessageHandler& messageHandler, Config& config);
+	DGWindow(void* native_window, Config& config, Settings& settings);
 
 	Header* header;
 
@@ -65,6 +64,9 @@ public:
 	Knob* falloffKnob;
 	FileBrowser* fileBrowser;
 
+	void setDrumKitLoadStatus(LoadStatus load_status);
+	void setMidiMapLoadStatus(LoadStatus load_status);
+
 protected:
 	// From Widget:
 	void repaintEvent(RepaintEvent* repaintEvent) override;
@@ -78,13 +80,14 @@ private:
 	void selectKitFile(const std::string& filename);
 	void selectMapFile(const std::string& filename);
 
-	MessageHandler& messageHandler;
 	Config& config;
 
 	VBoxLayout layout{this};
 
 	Image back{":bg.png"};
 	Image logo{":logo.png"};
+
+	Settings& settings;
 };
 
 } // GUI::
diff --git a/plugingui/eventhandler.h b/plugingui/eventhandler.h
index 1fdb1e8..490c515 100644
--- a/plugingui/eventhandler.h
+++ b/plugingui/eventhandler.h
@@ -26,9 +26,10 @@
  */
 #pragma once
 
+#include <notifier.h>
+
 #include "guievent.h"
 #include "nativewindow.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/filebrowser.h b/plugingui/filebrowser.h
index 04b34f6..bc2019f 100644
--- a/plugingui/filebrowser.h
+++ b/plugingui/filebrowser.h
@@ -26,15 +26,15 @@
  */
 #pragma once
 
-#include "widget.h"
+#include <notifier.h>
 
+#include "widget.h"
 #include "button.h"
 #include "listbox.h"
 #include "lineedit.h"
 #include "label.h"
 #include "image.h"
 #include "directory.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/knob.h b/plugingui/knob.h
index 10d91d6..d144184 100644
--- a/plugingui/knob.h
+++ b/plugingui/knob.h
@@ -26,10 +26,11 @@
  */
 #pragma once
 
+#include <notifier.h>
+
 #include "widget.h"
 #include "image.h"
 #include "font.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/layout.h b/plugingui/layout.h
index 55cc93f..49bf75c 100644
--- a/plugingui/layout.h
+++ b/plugingui/layout.h
@@ -29,7 +29,7 @@
 #include <list>
 #include <cstdlib>
 
-#include "notifier.h"
+#include <notifier.h>
 
 namespace GUI {
 
diff --git a/plugingui/listboxbasic.h b/plugingui/listboxbasic.h
index 7953dc3..2ebe845 100644
--- a/plugingui/listboxbasic.h
+++ b/plugingui/listboxbasic.h
@@ -29,11 +29,12 @@
 #include <string.h>
 #include <vector>
 
+#include <notifier.h>
+
 #include "widget.h"
 #include "font.h"
 #include "painter.h"
 #include "scrollbar.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/listboxthin.h b/plugingui/listboxthin.h
index 3139ecc..1617234 100644
--- a/plugingui/listboxthin.h
+++ b/plugingui/listboxthin.h
@@ -29,10 +29,11 @@
 #include <string.h>
 #include <vector>
 
+#include <notifier.h>
+
 #include "widget.h"
 #include "painter.h"
 #include "listboxbasic.h"
-#include "notifier.h"
 
 namespace GUI {
 
diff --git a/plugingui/plugingui.cc b/plugingui/plugingui.cc
index e34c471..2802c44 100644
--- a/plugingui/plugingui.cc
+++ b/plugingui/plugingui.cc
@@ -26,16 +26,17 @@
  */
 #include "plugingui.h"
 
+#include <iostream>
+
 #include <hugin.hpp>
 
 #include "pluginconfig.h"
-#include "messagehandler.h"
 
 namespace GUI {
 
-PluginGUI::PluginGUI(void* native_window)
-	: MessageReceiver(MSGRCV_UI)
-	, native_window(native_window)
+PluginGUI::PluginGUI(Settings& settings, void* native_window)
+	: native_window(native_window)
+	, settings(settings)
 {
 	init();
 }
@@ -44,70 +45,6 @@ PluginGUI::~PluginGUI()
 {
 }
 
-void PluginGUI::handleMessage(Message *msg)
-{
-	Painter p(*window);// Make sure we only redraw buffer once (set refcount to 1)
-
-	switch(msg->type()) {
-	case Message::LoadStatus:
-		{
-			LoadStatusMessage *ls = (LoadStatusMessage*)msg;
-			window->drumkitFileProgress->setProgress((float)ls->numer_of_files_loaded /
-			                              (float)ls->number_of_files);
-			if(ls->numer_of_files_loaded == ls->number_of_files)
-			{
-				window->drumkitFileProgress->setState(ProgressBarState::Green);
-			}
-		}
-		break;
-	case Message::LoadStatusMidimap:
-		{
-			LoadStatusMessageMidimap *ls = (LoadStatusMessageMidimap*)msg;
-			window->midimapFileProgress->setProgress(1);
-			if(ls->success)
-			{
-				window->midimapFileProgress->setState(ProgressBarState::Green);
-			}
-			else
-			{
-				window->midimapFileProgress->setState(ProgressBarState::Red);
-			}
-		}
-		break;
-	case Message::EngineSettingsMessage:
-		{
-			EngineSettingsMessage *settings = (EngineSettingsMessage *)msg;
-			window->lineedit->setText(settings->drumkitfile);
-			if(settings->drumkit_loaded)
-			{
-				window->drumkitFileProgress->setProgress(1);
-				window->drumkitFileProgress->setState(ProgressBarState::Green);
-			}
-			else
-			{
-				window->drumkitFileProgress->setProgress(0);
-				window->drumkitFileProgress->setState(ProgressBarState::Blue);
-			}
-			window->lineedit2->setText(settings->midimapfile);
-			if(settings->midimap_loaded)
-			{
-				window->midimapFileProgress->setProgress(1);
-				window->midimapFileProgress->setState(ProgressBarState::Green);
-			}
-			else
-			{
-				window->midimapFileProgress->setProgress(0);
-				window->midimapFileProgress->setState(ProgressBarState::Blue);
-			}
-			window->velocityCheck->setChecked(settings->enable_velocity_modifier);
-			window->attackKnob->setValue(settings->velocity_modifier_weight);
-			window->falloffKnob->setValue(settings->velocity_modifier_falloff);
-		}
-	default:
-		break;
-	}
-}
-
 bool PluginGUI::processEvents()
 {
 	if(!initialised)
@@ -116,7 +53,12 @@ bool PluginGUI::processEvents()
 	}
 
 	window->eventHandler()->processEvents();
-	handleMessages();
+
+	{
+		Painter p(*window);
+
+		settings_notifier.evaluate();
+	}
 
 	if(closing)
 	{
@@ -135,18 +77,51 @@ void PluginGUI::init()
 	config = new Config();
 	config->load();
 
-	window = new DGWindow(native_window, msghandler, *config);
+	window = new DGWindow(native_window, *config, settings);
+
+
+	CONNECT(this, settings_notifier.drumkit_file,
+	        window->lineedit, &LineEdit::setText);
+	CONNECT(this, settings_notifier.drumkit_load_status,
+	        window, &DGWindow::setDrumKitLoadStatus);
+
+	CONNECT(this, settings_notifier.midimap_file,
+	        window->lineedit2, &LineEdit::setText);
+	CONNECT(this, settings_notifier.midimap_load_status,
+	        window, &DGWindow::setMidiMapLoadStatus);
+
+	CONNECT(this, settings_notifier.enable_velocity_modifier,
+	        window->velocityCheck, &CheckBox::setChecked);
+
+	CONNECT(this, settings_notifier.velocity_modifier_falloff,
+	        window->falloffKnob, &Knob::setValue);
+	CONNECT(this, settings_notifier.velocity_modifier_weight,
+	        window->attackKnob, &Knob::setValue);
+
+
+	// TODO:
+	//CONNECT(this, settings_notifier.enable_velocity_randomiser,
+	//        window->, &CheckBox::setChecked);
+	//CONNECT(this, settings_notifier.velocity_randomiser_weight,
+	//        window->, &Knob::setValue);
+
+	//CONNECT(this, settings_notifier.samplerate,
+	//        window->, &Knob::setValue);
+
+	//CONNECT(this, settings_notifier.enable_resampling,
+	//        window->, &CheckBox::setChecked);
+
+	CONNECT(this, settings_notifier.number_of_files,
+	        window->drumkitFileProgress, &ProgressBar::setTotal);
+
+	CONNECT(this, settings_notifier.number_of_files_loaded,
+	        window->drumkitFileProgress, &ProgressBar::setValue);
 
 	auto eventHandler = window->eventHandler();
 	CONNECT(eventHandler, closeNotifier, this, &PluginGUI::closeEventHandler);
 
 	window->show();
 
-	{ // Request all engine settings
-		EngineSettingsMessage *msg = new EngineSettingsMessage();
-		msghandler.sendMessage(MSGRCV_ENGINE, msg);
-	}
-
 	initialised = true;
 }
 
diff --git a/plugingui/plugingui.h b/plugingui/plugingui.h
index f441696..04b0a29 100644
--- a/plugingui/plugingui.h
+++ b/plugingui/plugingui.h
@@ -26,26 +26,20 @@
  */
 #pragma once
 
+#include <settings.h>
+#include <notifier.h>
+
 #include "dgwindow.h"
 #include "eventhandler.h"
-
 #include "pluginconfig.h"
 
-
-#include "thread.h"
-#include "semaphore.h"
-
-#include "messagereceiver.h"
-#include "notifier.h"
-
 namespace GUI {
 
 class PluginGUI
-	: public MessageReceiver
-	, public Listener
+	: public Listener
 {
 public:
-	PluginGUI(void* native_window = nullptr);
+	PluginGUI(Settings& settings, void* native_window = nullptr);
 	virtual ~PluginGUI();
 
 	//! Process all events and messages in queue
@@ -58,9 +52,6 @@ public:
 	void show();
 	void hide();
 
-
-	void handleMessage(Message* msg);
-
 	DGWindow* window{nullptr};
 	EventHandler* eventhandler{nullptr};
 
@@ -80,11 +71,12 @@ private:
 	volatile bool closing{false};
 	volatile bool initialised{false};
 
-	Semaphore sem{"plugingui"};
-
 	// For the old-style notifier.
 	void (*windowClosedHandler)(void *){nullptr};
 	void *windowClosedPtr{nullptr};
+
+	Settings& settings;
+	SettingsNotifier settings_notifier{settings};
 };
 
 } // GUI::
diff --git a/plugingui/progressbar.cc b/plugingui/progressbar.cc
index 932f17c..8a382f5 100644
--- a/plugingui/progressbar.cc
+++ b/plugingui/progressbar.cc
@@ -26,6 +26,8 @@
  */
 #include "progressbar.h"
 
+#include <iostream>
+
 namespace GUI {
 
 ProgressBar::ProgressBar(Widget *parent)
@@ -46,9 +48,6 @@ ProgressBar::ProgressBar(Widget *parent)
 	bar_green.left    = new Image(":progress_front_green_l.png");
 	bar_green.right   = new Image(":progress_front_green_r.png");
 	bar_green.center  = new Image(":progress_front_green_c.png");
-
-	state = ProgressBarState::Blue;
-	_progress = .5;
 }
 
 ProgressBar::~ProgressBar()
@@ -79,22 +78,31 @@ void ProgressBar::setState(ProgressBarState state)
 	}
 }
 
-float ProgressBar::progress()
+void ProgressBar::setTotal(std::size_t total)
 {
-	return _progress;
+	if(this->total != total)
+	{
+		this->total = total;
+		repaintEvent(nullptr);
+	}
 }
 
-void ProgressBar::setProgress(float progress)
+void ProgressBar::setValue(std::size_t value)
 {
-	_progress = progress;
-	repaintEvent(nullptr);
+	if(this->value != value)
+	{
+		this->value = value;
+		repaintEvent(nullptr);
+	}
 }
 
 void ProgressBar::repaintEvent(RepaintEvent* repaintEvent)
 {
 	Painter p(*this);
 
-	int max = width() * _progress;
+	float progress = (float)value / (float)total;
+
+	int max = width() * progress;
 
 	p.clear();
 
diff --git a/plugingui/progressbar.h b/plugingui/progressbar.h
index d5f6c61..7485e40 100644
--- a/plugingui/progressbar.h
+++ b/plugingui/progressbar.h
@@ -43,11 +43,11 @@ enum class ProgressBarState
 
 class ProgressBar : public Widget {
 public:
-	ProgressBar(Widget *parent);
+	ProgressBar(Widget* parent);
 	~ProgressBar();
 
-	float progress();
-	void setProgress(float progress);
+	void setTotal(std::size_t total);
+	void setValue(std::size_t value);
 
 	void setState(ProgressBarState state);
 
@@ -56,7 +56,7 @@ protected:
 	virtual void repaintEvent(RepaintEvent* repaintEvent) override;
 
 private:
-	ProgressBarState state;
+	ProgressBarState state{ProgressBarState::Blue};
 
 	Painter::Bar bar_bg;
 
@@ -64,7 +64,8 @@ private:
 	Painter::Bar bar_blue;
 	Painter::Bar bar_red;
 
-	float _progress;
+	std::size_t total{0};
+	std::size_t value{0};
 };
 
 } // GUI::
diff --git a/plugingui/testmain.cc b/plugingui/testmain.cc
index 8282bc8..84d813d 100644
--- a/plugingui/testmain.cc
+++ b/plugingui/testmain.cc
@@ -26,15 +26,17 @@
  */
 #include "plugingui.h"
 
+#ifdef WIN32
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
 #include <hugin.hpp>
 
-// Dummy Engine class.
-class Engine : public MessageHandler {
-public:
-	void handleMessage(Message *msg) {}
-};
+#include <notifier.h>
+#include <settings.h>
 
-class TestMain : public GUI::Listener {
+class TestMain : public Listener {
 public:
 	TestMain()
 	{
@@ -62,7 +64,8 @@ public:
 
 	bool running = true;
 
-	GUI::PluginGUI gui;
+	Settings settings;
+	GUI::PluginGUI gui{settings};
 };
 
 int main()
diff --git a/src/Makefile.am b/src/Makefile.am
index a1b1615..4d167af 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -13,7 +13,6 @@ EXTRA_DIST = \
 	channelmixer.h \
 	chresampler.h \
 	configfile.h \
-	configuration.h \
 	configparser.h \
 	cpp11fix.h \
 	drumgizmo.h \
@@ -24,13 +23,11 @@ EXTRA_DIST = \
 	instrument.h \
 	instrumentparser.h \
 	memchecker.h \
-	message.h \
-	messagehandler.h \
-	messagereceiver.h \
 	midimapparser.h \
 	midimapper.h \
 	mutex.h \
 	nolocale.h \
+	notifier.h \
 	path.h \
 	powerlist.h \
 	rangemap.h \
@@ -54,7 +51,6 @@ EXTRA_DIST = \
 	channelmixer.cc \
 	chresampler.cc \
 	configfile.cc \
-	configuration.cc \
 	configparser.cc \
 	drumgizmo.cc \
 	drumkit.cc \
@@ -64,8 +60,6 @@ EXTRA_DIST = \
 	instrument.cc \
 	instrumentparser.cc \
 	memchecker.cc \
-	messagehandler.cc \
-	messagereceiver.cc \
 	midimapparser.cc \
 	midimapper.cc \
 	mutex.cc \
diff --git a/src/Makefile.am.drumgizmo b/src/Makefile.am.drumgizmo
index 8f648d0..6fddded 100644
--- a/src/Makefile.am.drumgizmo
+++ b/src/Makefile.am.drumgizmo
@@ -11,7 +11,6 @@ DRUMGIZMO_SOURCES = \
 	$(top_srcdir)/src/channelmixer.cc \
 	$(top_srcdir)/src/chresampler.cc \
 	$(top_srcdir)/src/configfile.cc \
-	$(top_srcdir)/src/configuration.cc \
 	$(top_srcdir)/src/configparser.cc \
 	$(top_srcdir)/src/drumgizmo.cc \
 	$(top_srcdir)/src/drumkit.cc \
@@ -21,8 +20,6 @@ DRUMGIZMO_SOURCES = \
 	$(top_srcdir)/src/instrument.cc \
 	$(top_srcdir)/src/instrumentparser.cc \
 	$(top_srcdir)/src/memchecker.cc \
-	$(top_srcdir)/src/messagehandler.cc \
-	$(top_srcdir)/src/messagereceiver.cc \
 	$(top_srcdir)/src/midimapparser.cc \
 	$(top_srcdir)/src/midimapper.cc \
 	$(top_srcdir)/src/mutex.cc \
diff --git a/src/atomic.h b/src/atomic.h
new file mode 100644
index 0000000..95a5e9d
--- /dev/null
+++ b/src/atomic.h
@@ -0,0 +1,182 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            atomic.h
+ *
+ *  Wed Mar 23 09:15:05 CET 2016
+ *  Copyright 2016 Christian Glöckner
+ *  cgloeckner@freenet.de
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#pragma once
+
+#include <type_traits>
+#include <atomic>
+
+#include <mutex>
+#include "mutex.h"
+
+template <typename T, typename = void>
+class Atomic;
+
+// use std::atomic if possible
+template <typename T>
+class Atomic<T, typename std::enable_if<std::is_pod<T>::value>::type>
+	: public std::atomic<T>
+{
+public:
+	// inherit methods
+	using std::atomic<T>::atomic;
+	using std::atomic<T>::operator=;
+};
+
+// else work around it using a mutex
+template <typename T>
+class Atomic<T, typename std::enable_if<!std::is_pod<T>::value>::type>
+{
+public:
+	using self_type =
+		Atomic<T, typename std::enable_if<!std::is_pod<T>::value>::type>;
+
+	Atomic()
+		: data{}
+		, mutex{}
+	{
+	}
+
+	Atomic(T data)
+		: data{std::move(data)}
+		, mutex{}
+	{
+	}
+
+	Atomic(self_type const & other)
+		: data{}
+		, mutex{}
+	{
+		std::lock_guard<std::mutex> lock{other.mutex};
+		data = other.data;
+	}
+
+	Atomic(self_type&& other)
+		: data{}
+		, mutex{}
+	{
+		std::lock_guard<std::mutex> lock{other.mutex};
+		std::swap(data, other.data);
+	}
+
+	T operator=(T data)
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		this->data = std::move(data);
+		return this->data;
+	}
+
+	operator T() const
+	{
+		return load();
+	}
+
+	bool is_lock_free() const
+	{
+		return false;
+	}
+
+	void store(T data)
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		this->data = std::move(data);
+	}
+
+	T load() const {
+		std::lock_guard<std::mutex> lock{mutex};
+		return data;
+	}
+
+	T exchange(T data){
+		std::lock_guard<std::mutex> lock{mutex};
+		std::swap(data, this->data);
+		return data;
+	}
+
+	bool operator==(const T& other) const
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		return other == data;
+	}
+
+	bool operator!=(const T& other) const
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		return !(other == data);
+	}
+
+	bool operator==(const Atomic<T>& other) const
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		return other.load() == data;
+	}
+
+	bool operator!=(const Atomic<T>& other) const
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		return !(other.load() == data);
+	}
+
+private:
+	T data;
+	mutable std::mutex mutex;
+};
+
+//! Getter utility class.
+template <typename T> class SettingRef
+{
+public:
+	SettingRef(Atomic<T>& value)
+		: value(value)
+	{
+		// string isn't lock free either
+		assert((std::is_same<T, std::string>::value || value.is_lock_free()));
+	}
+
+	bool hasChanged()
+	{
+		T tmp = cache;
+		cache.exchange(value);
+
+		if(firstAccess)
+		{
+			firstAccess = false;
+			return true;
+		}
+
+		return cache != tmp;
+	}
+
+	T getValue() const
+	{
+		return cache;
+	}
+
+private:
+	bool firstAccess{true};
+	Atomic<T>& value;
+	Atomic<T> cache;
+};
diff --git a/src/audiofile.cc b/src/audiofile.cc
index 58b248b..84329f8 100644
--- a/src/audiofile.cc
+++ b/src/audiofile.cc
@@ -36,8 +36,6 @@
 #include <sndfile.h>
 #include <hugin.hpp>
 
-#include "configuration.h"
-
 AudioFile::AudioFile(const std::string& filename, int filechannel)
 {
 	is_loaded = false;
diff --git a/src/configuration.cc b/src/configuration.cc
deleted file mode 100644
index 72f6e4a..0000000
--- a/src/configuration.cc
+++ /dev/null
@@ -1,38 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            configuration.cc
- *
- *  Sat Oct  8 14:37:14 CEST 2011
- *  Copyright 2011 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#include "configuration.h"
-
-bool Conf::enable_velocity_modifier = true;
-float Conf::velocity_modifier_falloff = 0.5;
-float Conf::velocity_modifier_weight = 0.25;
-
-bool Conf::enable_velocity_randomiser = false;
-float Conf::velocity_randomiser_weight = 0.1;
-
-int Conf::samplerate = 44100;
-
-bool Conf::enable_resampling = true;
diff --git a/src/configuration.h b/src/configuration.h
deleted file mode 100644
index 3adf525..0000000
--- a/src/configuration.h
+++ /dev/null
@@ -1,44 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            configuration.h
- *
- *  Sat Oct  8 14:37:13 CEST 2011
- *  Copyright 2011 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#ifndef __DRUMGIZMO_CONFIGURATION_H__
-#define __DRUMGIZMO_CONFIGURATION_H__
-
-namespace Conf {
-  extern bool enable_velocity_modifier;
-  extern float velocity_modifier_falloff;
-  extern float velocity_modifier_weight;
-
-  extern bool enable_velocity_randomiser;
-  extern float velocity_randomiser_weight;
-
-  extern int samplerate;
-
-  extern bool enable_resampling;
-};
-
-
-#endif/*__DRUMGIZMO_CONFIGURATION_H__*/
diff --git a/src/drumgizmo.cc b/src/drumgizmo.cc
index 853e93d..aa6be23 100644
--- a/src/drumgizmo.cc
+++ b/src/drumgizmo.cc
@@ -38,26 +38,27 @@
 #include <hugin.hpp>
 
 #include <config.h>
+#include <memory>
 
 #include "drumkitparser.h"
 #include "audioinputenginemidi.h"
-#include "configuration.h"
 #include "configparser.h"
 
 #include "nolocale.h"
 
-DrumGizmo::DrumGizmo(AudioOutputEngine *o, AudioInputEngine *i)
-	: MessageReceiver(MSGRCV_ENGINE)
-	, loader()
+DrumGizmo::DrumGizmo(Settings& settings,
+                     AudioOutputEngine *o, AudioInputEngine *i)
+	: loader(settings)
 	, oe(o)
 	, ie(i)
 	, framesize(0)
 	, freewheel(false)
 	, events{}
+	, settings(settings)
 {
 	is_stopping = false;
 	audioCache.init(10000); // start thread
-	
+
 	events.reserve(1000);
 }
 
@@ -68,9 +69,12 @@ DrumGizmo::~DrumGizmo()
 
 bool DrumGizmo::loadkit(std::string file)
 {
+	settings.drumkit_load_status.store(LoadStatus::Idle);
+
 	if(file == "")
 	{
-		return 1;
+		settings.drumkit_load_status.store(LoadStatus::Error);
+		return false;
 	}
 
 	DEBUG(drumgizmo, "loadkit(%s)\n", file.c_str());
@@ -81,27 +85,31 @@ bool DrumGizmo::loadkit(std::string file)
 	// Delete all Channels, Instruments, Samples and AudioFiles.
 	kit.clear();
 
-	DrumKitParser parser(kit);
+	settings.drumkit_load_status.store(LoadStatus::Loading);
+
+	DrumKitParser parser(settings, kit);
 	if(parser.parseFile(file))
 	{
 		ERR(drumgizmo, "Drumkit parser failed: %s\n", file.c_str());
+		settings.drumkit_load_status.store(LoadStatus::Error);
 		return false;
 	}
 
-	// Check if there is enough free RAM to load the drumkit.
-	if(!memchecker.enoughFreeMemory(kit))
-	{
-		printf("WARNING: "
-		       "There doesn't seem to be enough RAM available to load the kit.\n"
-		       "Trying to load it anyway...\n");
-	}
+	// TODO: Re-introduce when the code has been moved to the loader thread.
+	//// Check if there is enough free RAM to load the drumkit.
+	//if(!memchecker.enoughFreeMemory(kit))
+	//{
+	//	printf("WARNING: "
+	//	       "There doesn't seem to be enough RAM available to load the kit.\n"
+	//	       "Trying to load it anyway...\n");
+	//}
 
 	loader.loadKit(&kit);
 
 #ifdef WITH_RESAMPLER
 	for(int i = 0; i < MAX_NUM_CHANNELS; ++i)
 	{
-		resampler[i].setup(kit.getSamplerate(), Conf::samplerate);
+		resampler[i].setup(kit.getSamplerate(), settings.samplerate.load());
 	}
 #endif/*WITH_RESAMPLER*/
 
@@ -125,79 +133,6 @@ bool DrumGizmo::init()
 	return true;
 }
 
-void DrumGizmo::handleMessage(Message *msg)
-{
-	DEBUG(msg, "got message.");
-	switch(msg->type()) {
-	case Message::LoadDrumKit:
-		{
-			DEBUG(msg, "got LoadDrumKitMessage message.");
-			LoadDrumKitMessage *m = (LoadDrumKitMessage*)msg;
-			loadkit(m->drumkitfile);
-			//init(true);
-		}
-		break;
-	case Message::LoadMidimap:
-		DEBUG(msg, "got LoadMidimapMessage message.");
-		if(!ie->isMidiEngine())
-		{
-			break;
-		}
-		{
-			AudioInputEngineMidi *aim = (AudioInputEngineMidi*)ie;
-			LoadMidimapMessage *m = (LoadMidimapMessage*)msg;
-			bool ret = aim->loadMidiMap(m->midimapfile, kit.instruments);
-
-			LoadStatusMessageMidimap *ls = new LoadStatusMessageMidimap();
-			ls->success = ret;
-			msghandler.sendMessage(MSGRCV_UI, ls);
-		}
-		break;
-	case Message::EngineSettingsMessage:
-		{
-			bool mmap_loaded = false;
-			std::string mmapfile;
-			if(ie->isMidiEngine())
-			{
-				AudioInputEngineMidi *aim = (AudioInputEngineMidi*)ie;
-				mmapfile = aim->getMidimapFile();
-				mmap_loaded = aim->isValid();
-			}
-
-			EngineSettingsMessage *msg = new EngineSettingsMessage();
-			msg->midimapfile = mmapfile;
-			msg->midimap_loaded = mmap_loaded;
-			msg->drumkitfile = kit.getFile();
-			msg->drumkit_loaded = loader.isDone();
-			msg->enable_velocity_modifier = Conf::enable_velocity_modifier;
-			msg->velocity_modifier_falloff = Conf::velocity_modifier_falloff;
-			msg->velocity_modifier_weight = Conf::velocity_modifier_weight;
-			msg->enable_velocity_randomiser = Conf::enable_velocity_randomiser;
-			msg->velocity_randomiser_weight = Conf::velocity_randomiser_weight;
-			msghandler.sendMessage(MSGRCV_UI, msg);
-		}
-		break;
-	case Message::ChangeSettingMessage:
-		{
-			ChangeSettingMessage *ch = (ChangeSettingMessage*)msg;
-			switch(ch->name) {
-			case ChangeSettingMessage::enable_velocity_modifier:
-				Conf::enable_velocity_modifier = ch->value;
-				break;
-			case ChangeSettingMessage::velocity_modifier_weight:
-				Conf::velocity_modifier_weight = ch->value;
-				break;
-			case ChangeSettingMessage::velocity_modifier_falloff:
-				Conf::velocity_modifier_falloff = ch->value;
-				break;
-			}
-		}
-		break;
-	default:
-		break;
-	}
-}
-
 void DrumGizmo::setFrameSize(size_t framesize)
 {
 	// If we are resampling override the frame size.
@@ -259,8 +194,31 @@ bool DrumGizmo::run(size_t pos, sample_t *samples, size_t nsamples)
 {
 	setFrameSize(nsamples);
 
-	// Handle engine messages, at most one in each iteration:
-	handleMessages(1);
+	// TODO: Move this to DrumKitLoader thread.
+	if(getter.drumkit_file.hasChanged())
+	{
+		loadkit(getter.drumkit_file.getValue());
+	}
+
+	// TODO: Move this to DrumKitLoader thread.
+	if(getter.midimap_file.hasChanged())
+	{
+		auto ie_midi = dynamic_cast<AudioInputEngineMidi*>(ie);
+		if(ie_midi)
+		{
+			settings.midimap_load_status.store(LoadStatus::Loading);
+			bool ret = ie_midi->loadMidiMap(getter.midimap_file.getValue(),
+			                                kit.instruments);
+			if(ret)
+			{
+				settings.midimap_load_status.store(LoadStatus::Done);
+			}
+			else
+			{
+				settings.midimap_load_status.store(LoadStatus::Error);
+			}
+		}
+	}
 
 	ie->pre();
 	oe->pre(nsamples);
@@ -398,7 +356,7 @@ bool DrumGizmo::run(size_t pos, sample_t *samples, size_t nsamples)
 	// Write audio
 	//
 #ifdef WITH_RESAMPLER
-	if((Conf::enable_resampling == false) ||
+	if((settings.enable_resampling.load() == false) ||
 	   (resampler[0].getRatio() == 1.0)) // No resampling needed
 	{
 #endif
@@ -636,17 +594,17 @@ void DrumGizmo::stop()
 
 int DrumGizmo::samplerate()
 {
-	return Conf::samplerate;
+	return settings.samplerate.load();
 }
 
 void DrumGizmo::setSamplerate(int samplerate)
 {
 	DEBUG(dgeditor, "%s samplerate: %d\n", __PRETTY_FUNCTION__, samplerate);
-	Conf::samplerate = samplerate;
+	settings.samplerate.store(samplerate);
 #ifdef WITH_RESAMPLER
 	for(int i = 0; i < MAX_NUM_CHANNELS; ++i)
 	{
-		resampler[i].setup(kit.getSamplerate(), Conf::samplerate);
+		resampler[i].setup(kit.getSamplerate(), settings.samplerate.load());
 	}
 	if(resampler[0].getRatio() != 1)
 	{
@@ -691,15 +649,15 @@ std::string DrumGizmo::configString()
 		"  <value name=\"drumkitfile\">" + kit.getFile() + "</value>\n"
 		"  <value name=\"midimapfile\">" + mmapfile + "</value>\n"
 		"  <value name=\"enable_velocity_modifier\">" +
-		bool2str(Conf::enable_velocity_modifier) + "</value>\n"
+		bool2str(settings.enable_velocity_modifier.load()) + "</value>\n"
 		"  <value name=\"velocity_modifier_falloff\">" +
-		float2str(Conf::velocity_modifier_falloff) + "</value>\n"
+		float2str(settings.velocity_modifier_falloff.load()) + "</value>\n"
 		"  <value name=\"velocity_modifier_weight\">" +
-		float2str(Conf::velocity_modifier_weight) + "</value>\n"
+		float2str(settings.velocity_modifier_weight.load()) + "</value>\n"
 		"  <value name=\"enable_velocity_randomiser\">" +
-		bool2str(Conf::enable_velocity_randomiser) + "</value>\n"
+		bool2str(settings.enable_velocity_randomiser.load()) + "</value>\n"
 		"  <value name=\"velocity_randomiser_weight\">" +
-		float2str(Conf::velocity_randomiser_weight) + "</value>\n"
+		float2str(settings.velocity_randomiser_weight.load()) + "</value>\n"
 		"</config>";
 }
 
@@ -711,68 +669,50 @@ bool DrumGizmo::setConfigString(std::string cfg)
 	ConfigParser p;
 	if(p.parseString(cfg))
 	{
-	 ERR(drumgizmo, "Config parse error.\n");
-	 return false;
+		ERR(drumgizmo, "Config parse error.\n");
+		return false;
 	}
 
 	if(p.value("enable_velocity_modifier") != "")
 	{
-		Conf::enable_velocity_modifier =
-			p.value("enable_velocity_modifier") == "true";
+		settings.enable_velocity_modifier.store(p.value("enable_velocity_modifier") == "true");
 	}
 
 	if(p.value("velocity_modifier_falloff") != "")
 	{
-		Conf::velocity_modifier_falloff =
-			str2float(p.value("velocity_modifier_falloff"));
+		settings.velocity_modifier_falloff.store(str2float(p.value("velocity_modifier_falloff")));
 	}
 
 	if(p.value("velocity_modifier_weight") != "")
 	{
-		Conf::velocity_modifier_weight =
-			str2float(p.value("velocity_modifier_weight"));
+		settings.velocity_modifier_weight.store(str2float(p.value("velocity_modifier_weight")));
 	}
 
 	if(p.value("enable_velocity_randomiser") != "")
 	{
-		Conf::enable_velocity_randomiser =
-			p.value("enable_velocity_randomiser") == "true";
+		settings.enable_velocity_randomiser.store(p.value("enable_velocity_randomiser") == "true");
 	}
 
 	if(p.value("velocity_randomiser_weight") != "")
 	{
-		Conf::velocity_randomiser_weight =
-			str2float(p.value("velocity_randomiser_weight"));
+		settings.velocity_randomiser_weight.store(str2float(p.value("velocity_randomiser_weight")));
 	}
 
 	if(p.value("enable_resampling") != "")
 	{
-		Conf::enable_resampling =
-			p.value("enable_resampling") == "true";
+		settings.enable_resampling.store(p.value("enable_resampling") == "true");
 	}
 
 	std::string newkit = p.value("drumkitfile");
-	if(newkit != "" && kit.getFile() != newkit)
+	if(newkit != "")
 	{
-		/*
-		  if(!loadkit(p.values["drumkitfile"]))
-		  {
-		  return false;
-		  }
-		  init(true);
-		*/
-		LoadDrumKitMessage *msg = new LoadDrumKitMessage();
-		msg->drumkitfile = newkit;
-		msghandler.sendMessage(MSGRCV_ENGINE, msg);
+		settings.drumkit_file.store(newkit);
 	}
 
 	std::string newmidimap = p.value("midimapfile");
 	if(newmidimap != "")
 	{
-		//midimapfile = newmidimap;
-		LoadMidimapMessage *msg = new LoadMidimapMessage();
-		msg->midimapfile = newmidimap;
-		msghandler.sendMessage(MSGRCV_ENGINE, msg);
+		settings.midimap_file.store(newmidimap);
 	}
 
 	return true;
diff --git a/src/drumgizmo.h b/src/drumgizmo.h
index 632d5fc..7af5dbb 100644
--- a/src/drumgizmo.h
+++ b/src/drumgizmo.h
@@ -31,34 +31,26 @@
 
 #include "audiooutputengine.h"
 #include "audioinputengine.h"
-
 #include "events.h"
 #include "audiofile.h"
 #include "drumkit.h"
 #include "memchecker.h"
-
 #include "drumkitloader.h"
 #include "audiocache.h"
-
 #include "mutex.h"
-
-#include "message.h"
-
-#include "messagereceiver.h"
-
 #include "chresampler.h"
-
 #include "configfile.h"
+#include "settings.h"
 
 #define MAX_NUM_CHANNELS 64
 #define REFSFILE "refs.conf"
 #define RESAMPLER_INPUT_BUFFER 64
 
 class DrumGizmo
-	: public MessageReceiver
 {
 public:
-	DrumGizmo(AudioOutputEngine *outputengine, AudioInputEngine *inputengine);
+	DrumGizmo(Settings& settings,
+	          AudioOutputEngine *outputengine, AudioInputEngine *inputengine);
 	virtual ~DrumGizmo();
 
 	bool loadkit(std::string kitfile);
@@ -74,8 +66,6 @@ public:
 	std::string configString();
 	bool setConfigString(std::string cfg);
 
-	void handleMessage(Message *msg);
-
 	int samplerate();
 	void setSamplerate(int samplerate);
 
@@ -106,6 +96,8 @@ protected:
 
 	size_t framesize;
 	bool freewheel;
-	
+
 	std::vector<event_t> events;
+	Settings& settings;
+	SettingsGetter getter{settings};
 };
diff --git a/src/drumkit.cc b/src/drumkit.cc
index 1b95c87..f25a6ea 100644
--- a/src/drumkit.cc
+++ b/src/drumkit.cc
@@ -39,12 +39,11 @@ DrumKit::~DrumKit()
 
 void DrumKit::clear()
 {
-	Instruments::iterator i = instruments.begin();
-	while(i != instruments.end())
+	for(auto& instrument : instruments)
 	{
-		delete *i;
-		i++;
+		delete instrument;
 	}
+
 	instruments.clear();
 
 	channels.clear();
@@ -78,20 +77,3 @@ size_t DrumKit::getSamplerate() const
 {
 	return _samplerate;
 }
-
-#ifdef TEST_DRUMKIT
-// Additional dependency files
-// deps:
-// Required cflags (autoconf vars may be used)
-// cflags:
-// Required link options (autoconf vars may be used)
-// libs:
-#include "test.h"
-
-TEST_BEGIN;
-
-// TODO: Put some testcode here (see test.h for usable macros).
-
-TEST_END;
-
-#endif /*TEST_DRUMKIT*/
diff --git a/src/drumkit.h b/src/drumkit.h
index 1ceef3e..e3ae783 100644
--- a/src/drumkit.h
+++ b/src/drumkit.h
@@ -33,11 +33,9 @@
 #include "instrument.h"
 #include "versionstr.h"
 
-class DrumKitParser;
 class DrumKit
 {
 	friend class DrumKitParser;
-
 public:
 	DrumKit();
 	~DrumKit();
diff --git a/src/drumkitloader.cc b/src/drumkitloader.cc
index ff489ea..3a0e096 100644
--- a/src/drumkitloader.cc
+++ b/src/drumkitloader.cc
@@ -26,14 +26,17 @@
  */
 #include "drumkitloader.h"
 
+#include <iostream>
+
 #include <hugin.hpp>
 
 #include "drumkitparser.h"
 #include "drumgizmo.h"
 
-DrumKitLoader::DrumKitLoader()
-	: semaphore("drumkitloader")
-	, framesize(0)
+DrumKitLoader::DrumKitLoader(Settings& settings)
+	: framesize(0)
+	, settings(settings)
+	, getter(settings)
 {
 	run();
 	run_semaphore.wait(); // Wait for the thread to actually start.
@@ -55,7 +58,7 @@ DrumKitLoader::~DrumKitLoader()
 void DrumKitLoader::stop()
 {
 	{
-		MutexAutolock l(mutex);
+		std::lock_guard<std::mutex> guard(mutex);
 		load_queue.clear();
 	}
 
@@ -66,68 +69,48 @@ void DrumKitLoader::stop()
 
 void DrumKitLoader::skip()
 {
-	MutexAutolock l(mutex);
+	std::lock_guard<std::mutex> guard(mutex);
 	load_queue.clear();
 }
 
 void DrumKitLoader::setFrameSize(size_t framesize)
 {
-	DEBUG(loader, "%s pre\n", __PRETTY_FUNCTION__);
-
-	{
-		MutexAutolock l(mutex);
-		this->framesize = framesize;
-		framesize_semaphore.post(); // Signal that the framesize has been set.
-	}
-
-	DEBUG(loader, "%s post\n", __PRETTY_FUNCTION__);
+	std::lock_guard<std::mutex> guard(mutex);
+	this->framesize = framesize;
+	framesize_semaphore.post(); // Signal that the framesize has been set.
 }
 
 bool DrumKitLoader::isDone()
 {
-	MutexAutolock l(mutex);
+	std::lock_guard<std::mutex> guard(mutex);
 	return load_queue.size() == 0;
 }
 
 void DrumKitLoader::loadKit(DrumKit *kit)
 {
-	MutexAutolock l(mutex);
+	std::lock_guard<std::mutex> guard(mutex);
 
 	DEBUG(loader, "Create AudioFile queue from DrumKit\n");
 
-	total_num_audiofiles = 0;// For UI Progress Messages
-
-	{ // Count total number of files that need loading:
-		Instruments::iterator i = kit->instruments.begin();
-		while(i != kit->instruments.end())
-		{
-			Instrument *instr = *i;
-			total_num_audiofiles += instr->audiofiles.size();
-			++i;
-		}
-	}
+	std::size_t total_num_audiofiles = 0;// For UI Progress Messages
 
-	fraction = total_num_audiofiles / 200;
-	if(fraction == 0)
+	// Count total number of files that need loading:
+	for(auto instr : kit->instruments)
 	{
-		fraction = 1;
+		total_num_audiofiles += instr->audiofiles.size();
 	}
 
-	{ // Now actually queue them for loading:
-		Instruments::iterator i = kit->instruments.begin();
-		while(i != kit->instruments.end())
-		{
-			Instrument *instr = *i;
-
-			std::vector<AudioFile*>::iterator af = instr->audiofiles.begin();
-			while(af != instr->audiofiles.end())
-			{
-				AudioFile *audiofile = *af;
-				load_queue.push_back(audiofile);
-				af++;
-			}
+	settings.number_of_files.store(total_num_audiofiles);
 
-			++i;
+	// Now actually queue them for loading:
+	for(auto instr : kit->instruments)
+	{
+		std::vector<AudioFile*>::iterator af = instr->audiofiles.begin();
+		while(af != instr->audiofiles.end())
+		{
+			AudioFile *audiofile = *af;
+			load_queue.push_back(audiofile);
+			af++;
 		}
 	}
 
@@ -151,23 +134,35 @@ void DrumKitLoader::thread_main()
 	{
 		size_t size;
 		{
-			MutexAutolock l(mutex);
+			std::lock_guard<std::mutex> guard(mutex);
 			size = load_queue.size();
 		}
 
 		// Only sleep if queue is empty.
 		if(size == 0)
 		{
-			semaphore.wait();
+			semaphore.wait(std::chrono::milliseconds(1000));
+		}
+
+		if(getter.drumkit_file.hasChanged())
+		{
+			//std::cout << "RELOAD DRUMKIT!" << std::endl;
+		}
+
+		if(getter.midimap_file.hasChanged())
+		{
+			//std::cout << "RELOAD MIDIMAP!" << std::endl;
 		}
 
 		std::string filename;
 		{
-			MutexAutolock l(mutex);
+			std::lock_guard<std::mutex> guard(mutex);
+
 			if(load_queue.size() == 0)
 			{
 				continue;
 			}
+
 			AudioFile *audiofile = load_queue.front();
 			load_queue.pop_front();
 			filename = audiofile->filename;
@@ -183,15 +178,13 @@ void DrumKitLoader::thread_main()
 			audiofile->load(preload_size);
 		}
 
-		loaded++;
+		++loaded;
+
+		settings.number_of_files_loaded.store(loaded);
 
-		if(loaded % fraction == 0 || loaded == total_num_audiofiles)
+		if(settings.number_of_files.load() == loaded)
 		{
-			LoadStatusMessage *ls = new LoadStatusMessage();
-			ls->number_of_files = total_num_audiofiles;
-			ls->numer_of_files_loaded = loaded;
-			ls->current_file = filename;
-			msghandler.sendMessage(MSGRCV_UI, ls);
+			settings.drumkit_load_status.store(LoadStatus::Done);
 		}
 	}
 
diff --git a/src/drumkitloader.h b/src/drumkitloader.h
index 3656839..3fd7ec1 100644
--- a/src/drumkitloader.h
+++ b/src/drumkitloader.h
@@ -28,12 +28,14 @@
 
 #include <string>
 #include <list>
+#include <mutex>
+#include "mutex.h"
 
 #include "thread.h"
 #include "semaphore.h"
-#include "mutex.h"
 
 #include "drumkit.h"
+#include "settings.h"
 
 //! This class is responsible for loading the drumkits in its own thread.
 //! All interaction calls are simply modifying queues and not doing any
@@ -45,7 +47,7 @@ class DrumKitLoader
 {
 public:
 	//! The constrcutor starts the loader thread.
-	DrumKitLoader();
+	DrumKitLoader(Settings& settings);
 
 	//! The destructor signals the thread to stop and waits to merge before
 	//! returning (ie. deleting the object will garantuee that the thread has
@@ -75,11 +77,11 @@ protected:
 	Semaphore run_semaphore;
 	Semaphore semaphore;
 	Semaphore framesize_semaphore;
-	Mutex mutex;
+	std::mutex mutex;
 	volatile bool running{false};
 	std::list<AudioFile*> load_queue;
-	size_t total_num_audiofiles{0};
-	size_t fraction{1};
-	size_t loaded{0};
-	size_t framesize{0};
+	std::size_t loaded{0};
+	std::size_t framesize{0};
+	Settings& settings;
+	SettingsGetter getter;
 };
diff --git a/src/drumkitparser.cc b/src/drumkitparser.cc
index 3ba69c8..048a05b 100644
--- a/src/drumkitparser.cc
+++ b/src/drumkitparser.cc
@@ -34,9 +34,10 @@
 #include "path.h"
 #include "drumgizmo.h"
 
-DrumKitParser::DrumKitParser(DrumKit& kit)
-	: kit(kit)
- 	, refs(REFSFILE)
+DrumKitParser::DrumKitParser(Settings& settings, DrumKit& k)
+	: kit(k)
+	, refs(REFSFILE)
+	, settings(settings)
 {
 }
 
@@ -46,9 +47,9 @@ int DrumKitParser::parseFile(const std::string& filename)
 
 	if(refs.load())
 	{
-		if(filename.size() > 1 && filename[0] == '@')
+		if((filename.size() > 1) && (filename[0] == '@'))
 		{
-			edited_filename	= refs.getValue(filename.substr(1));
+			edited_filename = refs.getValue(filename.substr(1));
 		}
 	}
 	else
@@ -57,9 +58,10 @@ int DrumKitParser::parseFile(const std::string& filename)
 	}
 
 	path = getPath(edited_filename);
-	auto result = SAXParser::parseFile(filename);
+	auto result = SAXParser::parseFile(edited_filename);
 
-	if (result == 0) {
+	if(result == 0)
+	{
 		kit._file = edited_filename;
 	}
 
@@ -101,7 +103,7 @@ void DrumKitParser::startTag(const std::string& name, const attr_t& attr)
 			{
 				ERR(kitparser, "Error parsing version number: %s, using 1.0\n", err);
 				kit._version = VersionStr(1,0,0);
-			} 
+			}
 		}
 		else
 		{
@@ -112,7 +114,7 @@ void DrumKitParser::startTag(const std::string& name, const attr_t& attr)
 
 	if(name == "channels")
 	{
-	
+
 	}
 
 	if(name == "channel")
@@ -140,6 +142,7 @@ void DrumKitParser::startTag(const std::string& name, const attr_t& attr)
 			ERR(kitparser, "Missing name in instrument tag.\n");
 			return;
 		}
+
 		if(attr.find("file") == attr.end())
 		{
 			ERR(kitparser, "Missing file in instrument tag.\n");
@@ -180,12 +183,14 @@ void DrumKitParser::endTag(const std::string& name)
 {
 	if(name == "instrument")
 	{
-		Instrument* i = new Instrument();
-		i->setGroup(instr_group);
-		//    Instrument &i = kit.instruments[kit.instruments.size() - 1];
-		InstrumentParser parser(*i);
+		Instrument* instrument = new Instrument(settings);
+		instrument->setGroup(instr_group);
+
+		InstrumentParser parser(*instrument);
 		parser.parseFile(path + "/" + instr_file);
-		kit.instruments.push_back(i);
+
+		// Transfer ownership to the DrumKit object.
+		kit.instruments.push_back(instrument);
 
 		// Assign kit channel numbers to instruments channels.
 		std::vector<InstrumentChannel*>::iterator ic = parser.channellist.begin();
@@ -206,16 +211,18 @@ void DrumKitParser::endTag(const std::string& name)
 					c->num = kit.channels[cnt].num;
 				}
 			}
+
 			if(c->num == NO_CHANNEL)
 			{
 				ERR(kitparser, "Missing channel '%s' in instrument '%s'\n",
-				      c->name.c_str(), i->getName().c_str());
+				      c->name.c_str(), instrument->getName().c_str());
 			}
-			else {
+			else
+			{
 				/*
-				   DEBUG(kitparser, "Assigned channel '%s' to number %d in instrument '%s'\n",
-				   c->name.c_str(), c->num, i.name().c_str());
-				   */
+				  DEBUG(kitparser, "Assigned channel '%s' to number %d in instrument '%s'\n",
+				  c->name.c_str(), c->num, i.name().c_str());
+				*/
 			}
 			ic++;
 		}
diff --git a/src/drumkitparser.h b/src/drumkitparser.h
index b0c8d8f..0adccb9 100644
--- a/src/drumkitparser.h
+++ b/src/drumkitparser.h
@@ -34,7 +34,7 @@ class DrumKitParser
 	: public SAXParser
 {
 public:
-	DrumKitParser(DrumKit& kit);
+	DrumKitParser(Settings& setting, DrumKit& kit);
 
 	virtual int parseFile(const std::string& filename) override;
 
@@ -52,4 +52,5 @@ private:
 	std::string instr_group;
 
 	ConfigFile refs;
+	Settings& settings;
 };
diff --git a/src/instrument.cc b/src/instrument.cc
index 9f18233..cc052e9 100644
--- a/src/instrument.cc
+++ b/src/instrument.cc
@@ -26,15 +26,12 @@
  */
 #include "instrument.h"
 
-#include <stdlib.h>
-#include <stdio.h>
-
 #include <hugin.hpp>
 
 #include "sample.h"
-#include "configuration.h"
 
-Instrument::Instrument()
+Instrument::Instrument(Settings& settings)
+	: settings(settings)
 {
 	DEBUG(instrument, "new %p\n", this);
 	mod = 1.0;
@@ -45,7 +42,7 @@ Instrument::Instrument()
 
 Instrument::~Instrument()
 {
-	magic = NULL;
+	magic = nullptr;
 
 	DEBUG(instrument, "delete %p\n", this);
 	std::vector<AudioFile*>::iterator i = audiofiles.begin();
@@ -63,16 +60,26 @@ bool Instrument::isValid() const
 
 Sample* Instrument::sample(level_t level, size_t pos)
 {
-	Sample *sample = NULL;
+	// Read out all values from settings.
+	auto enable_velocity_randomiser = settings.enable_velocity_randomiser.load();
+	auto velocity_randomiser_weight = settings.velocity_randomiser_weight.load();
+	auto samplerate = settings.samplerate.load();
+	auto velocity_modifier_falloff = settings.velocity_modifier_falloff.load();
+	auto enable_velocity_modifier = settings.enable_velocity_modifier.load();
+	auto velocity_modifier_weight = settings.velocity_modifier_weight.load();
+
+	Sample *sample = nullptr;
 
-	if(Conf::enable_velocity_modifier == false) {
+	if(enable_velocity_modifier == false)
+	{
 		mod = 1.0;
 		lastpos = 0;
 	}
 
-	if(Conf::enable_velocity_randomiser) {
-		float r = rand.floatInRange(-1.0*Conf::velocity_randomiser_weight,
-					    Conf::velocity_randomiser_weight);
+	if(enable_velocity_randomiser)
+	{
+		float r = rand.floatInRange(-1.0 * velocity_randomiser_weight,
+		                            velocity_randomiser_weight);
 		level += r;
 		if(level > 1.0)
 		{
@@ -84,9 +91,9 @@ Sample* Instrument::sample(level_t level, size_t pos)
 		}
 	}
 
-	if(Conf::enable_velocity_modifier) {
-		mod += (pos - lastpos) /
-			(Conf::samplerate * Conf::velocity_modifier_falloff);
+	if(enable_velocity_modifier)
+	{
+		mod += (pos - lastpos) / (samplerate * velocity_modifier_falloff);
 		if(mod > 1.0)
 		{
 			mod = 1.0;
@@ -98,21 +105,22 @@ Sample* Instrument::sample(level_t level, size_t pos)
 		// Version 2.0
 		sample = powerlist.get(level * mod);
 	}
-	else {
+	else
+	{
 		// Version 1.0
 		std::vector<Sample*> s = samples.get(level * mod);
 		if(s.size() == 0)
 		{
-			return NULL;
+			return nullptr;
 		}
 
 		sample = rand.choose(s);
 	}
 
-	if(Conf::enable_velocity_modifier)
+	if(enable_velocity_modifier)
 	{
 		lastpos = pos;
-		mod *= Conf::velocity_modifier_weight;
+		mod *= velocity_modifier_weight;
 	}
 
 	return sample;
@@ -157,41 +165,3 @@ void Instrument::setGroup(const std::string& g)
 {
 	_group = g;
 }
-
-#ifdef TEST_INSTRUMENT
-// deps: channel.cc sample.cc audiofile.cc
-// cflags: $(SNDFILE_CFLAGS)
-// libs: $(SNDFILE_LIBS)
-#include "test.h"
-
-TEST_BEGIN;
-
-Instrument i("test");
-
-Sample* a = new Sample();
-i.addSample(0.0, 1.0, a);
-
-Sample* b = new Sample();
-i.addSample(0.0, 1.0, b);
-
-Sample* c = new Sample();
-i.addSample(1.5, 1.7, c);
-
-TEST_EQUAL(i.sample(0.0), b, "?");
-TEST_EQUAL(i.sample(0.0), a, "?");
-TEST_EQUAL(i.sample(0.0), b, "?");
-TEST_EQUAL(i.sample(0.0), b, "?");
-TEST_EQUAL(i.sample(0.0), b, "?");
-TEST_EQUAL(i.sample(0.0), b, "?");
-TEST_EQUAL(i.sample(0.0), a, "?");
-TEST_EQUAL(i.sample(0.0), a, "?");
-
-TEST_EQUAL(i.sample(2.0), NULL, "?");
-
-TEST_EQUAL(i.sample(1.6), c, "?");
-TEST_EQUAL(i.sample(1.6), c, "?");
-TEST_EQUAL(i.sample(1.6), c, "?");
-
-TEST_END;
-
-#endif /*TEST_INSTRUMENT*/
diff --git a/src/instrument.h b/src/instrument.h
index de5546b..a531aec 100644
--- a/src/instrument.h
+++ b/src/instrument.h
@@ -36,13 +36,13 @@
 #include "versionstr.h"
 #include "random.h"
 
-class InstrumentParser;
+#include "settings.h"
+
 class Instrument
 {
 	friend class InstrumentParser;
-
 public:
-	Instrument();
+	Instrument(Settings& settings);
 	~Instrument();
 
 	Sample* sample(level_t level, size_t pos);
@@ -78,7 +78,7 @@ private:
 
 	size_t lastpos;
 	float mod;
-
+	Settings& settings;
 	Random rand;
 };
 
diff --git a/src/instrumentparser.cc b/src/instrumentparser.cc
index 268f8f3..1e42cc3 100644
--- a/src/instrumentparser.cc
+++ b/src/instrumentparser.cc
@@ -35,8 +35,8 @@
 
 #include "nolocale.h"
 
-InstrumentParser::InstrumentParser(Instrument& i)
-	: instrument(i)
+InstrumentParser::InstrumentParser(Instrument& instrument)
+	: instrument(instrument)
 {
 
 }
@@ -64,14 +64,15 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 
 		if(attr.find("version") != attr.end())
 		{
-			try {
+			try
+			{
 				instrument.version = VersionStr(attr.at("version"));
 			}
-			catch(const char *err)
+			catch(const char* err)
 			{
 				ERR(instrparser, "Error parsing version number: %s, using 1.0\n", err);
 				instrument.version = VersionStr(1,0,0);
-			} 
+			}
 		}
 		else
 		{
@@ -82,7 +83,6 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 
 	if(name == "samples")
 	{
-
 	}
 
 	if(name == "sample")
@@ -93,10 +93,10 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 			return;
 		}
 
-		float power; 
+		float power;
 		if(attr.find("power") == attr.end())
 		{
-			power = -1; 
+			power = -1;
 		}
 		else
 		{
@@ -105,12 +105,12 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 		}
 
 		// TODO get rid of new or delete it properly
-		s = new Sample(attr.at("name"), power);
+		sample = new Sample(attr.at("name"), power);
 	}
 
 	if(name == "audiofile")
 	{
-		if(s == nullptr)
+		if(sample == nullptr)
 		{
 			ERR(instrparser,"Missing Sample!\n");
 			return;
@@ -139,18 +139,24 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 			}
 		}
 
-		filechannel = filechannel - 1; // 1-based in file, but zero-based internally
-		// TODO do those next two lines correspond with proper deletes? If not fix it.
-		AudioFile *af = new AudioFile(path + "/" + attr.at("file"), filechannel);
-		InstrumentChannel *ch = new InstrumentChannel(attr.at("channel"));
-		channellist.push_back(ch);
-		s->addAudioFile(ch, af);
-		instrument.audiofiles.push_back(af);
+		filechannel = filechannel - 1; // 1-based in file but zero-based internally.
+
+		AudioFile *audio_file =
+			new AudioFile(path + "/" + attr.at("file"), filechannel);
+
+		// TODO: This is not deleted anywhere...
+		InstrumentChannel *instrument_channel =
+			new InstrumentChannel(attr.at("channel"));
+
+		channellist.push_back(instrument_channel);
+		sample->addAudioFile(instrument_channel, audio_file);
+
+		// Transfer audio_file ownership to the instrument.
+		instrument.audiofiles.push_back(audio_file);
 	}
 
 	if(name == "velocities")
 	{
-
 	}
 
 	if(name == "velocity")
@@ -179,19 +185,17 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 			return;
 		}
 
-		Sample* sample = nullptr;
-		std::vector<Sample *>::iterator i = instrument.samplelist.begin();
-		while(i != instrument.samplelist.end())
+		Sample* sample_ref = nullptr;
+		for(auto& sample : instrument.samplelist)
 		{
-			if((*i)->name == attr.at("name"))
+			if(sample->name == attr.at("name"))
 			{
-				sample = *i;
+				sample_ref = sample;
 				break;
 			}
-			i++;
 		}
 
-		if(sample == nullptr)
+		if(sample_ref == nullptr)
 		{
 			ERR(instrparser,"Samplref pointed at non-existing sample.\n");
 			return;
@@ -200,7 +204,7 @@ void InstrumentParser::startTag(const std::string& name, const attr_t& attr)
 		if(instrument.version == VersionStr("1.0"))
 		{
 			// Old "velocity group" algorithm needs this
-			instrument.addSample(lower, upper, sample);
+			instrument.addSample(lower, upper, sample_ref);
 		}
 	}
 }
@@ -209,15 +213,15 @@ void InstrumentParser::endTag(const std::string& name)
 {
 	if(name == "sample")
 	{
-		if(s == nullptr)
+		if(sample == nullptr)
 		{
 			ERR(instrparser,"Missing Sample.\n");
 			return;
 		}
 
-		instrument.samplelist.push_back(s);
+		instrument.samplelist.push_back(sample);
 
-		s = nullptr;
+		sample = nullptr;
 	}
 
 	if(name == "instrument") {
diff --git a/src/instrumentparser.h b/src/instrumentparser.h
index 965694a..6cbaf8a 100644
--- a/src/instrumentparser.h
+++ b/src/instrumentparser.h
@@ -47,7 +47,7 @@ protected:
 
 private:
 	Instrument& instrument;
-	Sample* s{nullptr};
+	Sample* sample{nullptr};
 
 	std::string path;
 
diff --git a/src/message.h b/src/message.h
deleted file mode 100644
index 71d0da6..0000000
--- a/src/message.h
+++ /dev/null
@@ -1,121 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            message.h
- *
- *  Wed Mar 20 15:50:57 CET 2013
- *  Copyright 2013 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#ifndef __DRUMGIZMO_MESSAGE_H__
-#define __DRUMGIZMO_MESSAGE_H__
-
-#include <string>
-
-class MessageHandler;
-
-class Message {
-public:
-  typedef enum {
-    // Engine -> GUI Messages:
-    LoadStatus, // Signal GUI the current load status.
-    LoadStatusMidimap, // Signal GUI the current load status of the midimap.
-
-    // GUI -> Engine, Engine -> Engine Messages:
-    LoadDrumKit, // Signal engine to load drumkit.
-    LoadMidimap, // Signal engine to load midimap.
-    EngineSettingsMessage, // Request or receive engine settings.
-    ChangeSettingMessage, // Update named setting in engine.
-  } type_t;
-
-  typedef enum {
-    NormalProcessing, // Just add to the queue
-    FilterMultiple, // Ignore top message if it has the same type.
-    // SyncWait, // Block the send call until the message has been handled by the receiver.
-  } processing_mode_t;
-
-  virtual ~Message() {}
-  virtual type_t type() = 0;
-  virtual processing_mode_t processing_mode() { return NormalProcessing; }
-};
-
-class LoadStatusMessage : public Message {
-public:
-  type_t type() { return Message::LoadStatus; }
-  processing_mode_t processing_mode() { return FilterMultiple; }
-  unsigned int number_of_files;
-  unsigned int numer_of_files_loaded;
-  std::string current_file;
-};
-
-class LoadStatusMessageMidimap : public Message {
-public:
-  type_t type() { return Message::LoadStatusMidimap; }
-  bool success;
-};
-
-class LoadDrumKitMessage : public Message {
-public:
-  type_t type() { return Message::LoadDrumKit; }
-  std::string drumkitfile;
-};
-
-class LoadMidimapMessage : public Message {
-public:
-  type_t type() { return Message::LoadMidimap; }
-  std::string midimapfile;
-};
-
-class EngineSettingsMessage : public Message {
-public:
-  type_t type() { return Message::EngineSettingsMessage; }
-  std::string midimapfile;
-  bool midimap_loaded;
-
-  std::string drumkitfile;
-  bool drumkit_loaded;
-
-  float enable_velocity_modifier;
-  float velocity_modifier_falloff;
-  float velocity_modifier_weight;
-  float enable_velocity_randomiser;
-  float velocity_randomiser_weight;
-};
-
-class ChangeSettingMessage : public Message {
-public:
-  typedef enum {
-    enable_velocity_modifier,
-    velocity_modifier_weight,
-    velocity_modifier_falloff,
-  } setting_name_t;
-
-  ChangeSettingMessage(setting_name_t n, float v) {
-    name = n;
-    value = v;
-  }
-
-  type_t type() { return Message::ChangeSettingMessage; }
-
-  setting_name_t name;
-  float value;
-};
-
-#endif/*__DRUMGIZMO_MESSAGE_H__*/
diff --git a/src/messagehandler.cc b/src/messagehandler.cc
deleted file mode 100644
index 7a0c7ea..0000000
--- a/src/messagehandler.cc
+++ /dev/null
@@ -1,89 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            messagehandler.cc
- *
- *  Fri Jun 14 20:30:43 CEST 2013
- *  Copyright 2013 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#include "messagehandler.h"
-
-#include <hugin.hpp>
-
-#include "messagereceiver.h"
-
-// Global messagehandler:
-MessageHandler msghandler;
-
-MessageHandler::MessageHandler()
-{
-}
-
-void MessageHandler::addReceiver(message_receiver_id_t id,
-                                 MessageReceiver *receiver)
-{
-  MutexAutolock l(mutex);
-
-  receivers[id] = receiver;
-}
-
-void MessageHandler::removeReceiver(MessageReceiver *receiver)
-{
-  MutexAutolock l(mutex);
-
-  std::map<message_receiver_id_t, MessageReceiver *>::iterator i =
-    receivers.begin();
-  while(i != receivers.end()) {
-    if(i->second == receiver) {
-      receivers.erase(i);
-      break;
-    }
-    i++;
-  }
-}
-
-bool MessageHandler::sendMessage(message_receiver_id_t id, Message* msg)
-{
-  MutexAutolock l(mutex);
-
-  if(receivers.find(id) == receivers.end()) {
-    //WARN(msghandler, "Could not find id %d\n", id);
-    delete msg;
-    return false;
-  }
-
-  //DEBUG(msghandler, "Sending message to id %d\n", id);
-
-  MessageReceiver *receiver = receivers[id];
-  /* // This code causes sporadic segfaults on windows.
-  if(msg->processing_mode() == Message::FilterMultiple) {
-    Message *pmsg;
-    MutexAutolock lock(receiver->message_mutex); // Make peek/receive atomic.
-    while( (pmsg = receiver->peekMessage()) != NULL) {
-      if(pmsg->type() != msg->type()) break;
-      // Remove all old messages with same type.
-      delete receiver->receiveMessage();
-    }
-  }
-  */
-  receiver->sendMessage(msg);
-  return true;
-}
diff --git a/src/messagehandler.h b/src/messagehandler.h
deleted file mode 100644
index 2b6c40e..0000000
--- a/src/messagehandler.h
+++ /dev/null
@@ -1,66 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            messagehandler.h
- *
- *  Fri Jun 14 20:30:43 CEST 2013
- *  Copyright 2013 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#ifndef __DRUMGIZMO_MESSAGEHANDLER_H__
-#define __DRUMGIZMO_MESSAGEHANDLER_H__
-
-#include <map>
-
-#include "message.h"
-#include "mutex.h"
-
-typedef enum {
-  MSGRCV_ENGINE = 1,
-  MSGRCV_UI = 2,
-  MSGRCV_LOADER = 3,
-} message_receiver_id_t;
-
-class MessageReceiver;
-
-class MessageHandler {
-public:
-  MessageHandler();
-
-  void addReceiver(message_receiver_id_t id, MessageReceiver *receiver);
-  void removeReceiver(MessageReceiver *receiver);
-
-  /**
-   * Send Message to receiver with specified id.
-   * @return Return true if id is registered. Return false if id is not
-   * currently registered.
-   */
-  bool sendMessage(message_receiver_id_t id, Message* msg);
-
-private:
-  std::map<message_receiver_id_t, MessageReceiver *> receivers;
-
-  Mutex mutex;
-};
-
-// Global MessageHandler;
-extern MessageHandler msghandler;
-
-#endif/*__DRUMGIZMO_MESSAGEHANDLER_H__*/
diff --git a/src/messagereceiver.cc b/src/messagereceiver.cc
deleted file mode 100644
index 590c98a..0000000
--- a/src/messagereceiver.cc
+++ /dev/null
@@ -1,78 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            messagereceiver.cc
- *
- *  Sun Jun 16 12:09:06 CEST 2013
- *  Copyright 2013 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#include "messagereceiver.h"
-
-#include <hugin.hpp>
-
-MessageReceiver::MessageReceiver(message_receiver_id_t id)
-{
-  msghandler.addReceiver(id, this);
-}
-
-MessageReceiver::~MessageReceiver()
-{
-  msghandler.removeReceiver(this);
-}
-
-void MessageReceiver::sendMessage(Message *msg)
-{
-  MutexAutolock l(message_mutex);
-
-  message_queue.push_back(msg);
-}
-
-Message *MessageReceiver::receiveMessage()
-{
-  Message *msg = NULL;
-  if(message_queue.size()) {
-    msg = message_queue.front();
-    message_queue.pop_front();
-  }
-  return msg;
-}
-
-Message *MessageReceiver::peekMessage()
-{
-  Message *msg = NULL;
-  if(message_queue.size()) {
-    msg = message_queue.front();
-  }
-  return msg;
-}
-
-void MessageReceiver::handleMessages(size_t max)
-{
-  MutexAutolock l(message_mutex);
-  bool process_all = false;
-  if(max == 0) process_all = true;
-
-  while((process_all || max--) && peekMessage()) {
-    Message *msg = receiveMessage();
-    handleMessage(msg);
-    delete msg;
-  }
-}
diff --git a/src/messagereceiver.h b/src/messagereceiver.h
deleted file mode 100644
index c1a8e60..0000000
--- a/src/messagereceiver.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/***************************************************************************
- *            messagereceiver.h
- *
- *  Sun Jun 16 12:09:06 CEST 2013
- *  Copyright 2013 Bent Bisballe Nyeng
- *  deva@aasimon.org
- ****************************************************************************/
-
-/*
- *  This file is part of DrumGizmo.
- *
- *  DrumGizmo is free software; you can redistribute it and/or modify
- *  it under the terms of the GNU Lesser General Public License as published by
- *  the Free Software Foundation; either version 3 of the License, or
- *  (at your option) any later version.
- *
- *  DrumGizmo 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 Lesser General Public License for more details.
- *
- *  You should have received a copy of the GNU Lesser General Public License
- *  along with DrumGizmo; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
- */
-#ifndef __DRUMGIZMO_MESSAGERECEIVER_H__
-#define __DRUMGIZMO_MESSAGERECEIVER_H__
-
-#include <list>
-
-#include "mutex.h"
-#include "message.h"
-#include "messagehandler.h"
-
-class MessageReceiver {
-  friend class MessageHandler;
-public:
-  MessageReceiver(message_receiver_id_t id);
-  ~MessageReceiver();
-
-  /**
-   * Receive message from the message queue.
-   */
-  Message *receiveMessage();
-
-  /**
-   * Receive message from the message queue without removing it.
-   */
-  Message *peekMessage();
-
-  /**
-   * Add a message to the message queue.
-   */
-  void sendMessage(Message *msg);
-
-  /**
-   * Handle messages from the event queue.
-   * @param max_number_of_events the maximum number of events to be handled in
-   * this call. 0 means all.
-   */
-  void handleMessages(size_t max_number_of_events = 0);
-
-  /**
-   * Handler to be implemented in child classes.
-   * Handles a single event.
-   */
-  virtual void handleMessage(Message *msg) = 0;
-
-private:
-  Mutex message_mutex;
-  std::list<Message *> message_queue;
-};
-
-#endif/*__DRUMGIZMO_MESSAGERECEIVER_H__*/
diff --git a/src/midimapparser.cc b/src/midimapparser.cc
index ec4c10d..cc97280 100644
--- a/src/midimapparser.cc
+++ b/src/midimapparser.cc
@@ -30,7 +30,8 @@ void MidiMapParser::startTag(const std::string& name, const attr_t& attr)
 {
 	if(name == "map")
 	{
-		if(attr.find("note") != attr.end() && attr.find("instr") != attr.end())
+		if((attr.find("note") != attr.end()) &&
+		   (attr.find("instr") != attr.end()))
 		{
 			midimap[std::stoi(attr.at("note"))] = attr.at("instr");
 		}
diff --git a/src/midimapparser.h b/src/midimapparser.h
index 740cb60..8ec76c0 100644
--- a/src/midimapparser.h
+++ b/src/midimapparser.h
@@ -26,8 +26,6 @@
  */
 #pragma once
 
-#include <stdio.h>
-
 #include "saxparser.h"
 #include "midimapper.h"
 
diff --git a/plugingui/notifier.h b/src/notifier.h
index 9e9f6eb..ff59741 100644
--- a/plugingui/notifier.h
+++ b/src/notifier.h
@@ -72,7 +72,7 @@ namespace aux
 };
 
 
-namespace GUI {
+//namespace GUI {
 
 class Listener;
 class NotifierBase {
@@ -158,6 +158,6 @@ private:
 
 };
 
-} // GUI::
+//} // GUI::
 
 #define CONNECT(SRC, SIG, TAR, SLO) (SRC)->SIG.connect(TAR, SLO)
diff --git a/src/path.cc b/src/path.cc
index 43c64f0..c2e7910 100644
--- a/src/path.cc
+++ b/src/path.cc
@@ -35,17 +35,19 @@
 
 std::string getPath(const std::string& file)
 {
-	std::string p;
-#ifndef __MINGW32__
-	char *b = strdup(file.c_str());
-	p = dirname(b);
-	free(b);
-#else
+	std::string path;
+
+#ifdef __MINGW32__
 	char drive[_MAX_DRIVE];
 	char dir[_MAX_DIR];
 	_splitpath(file.c_str(), drive, dir, NULL, NULL);
-	p = std::string(drive) + dir;
+	path = std::string(drive) + dir;
+#else
+	// POSIX
+	char* buffer = strdup(file.c_str());
+	path = dirname(buffer);
+	free(buffer);
 #endif
 
-	return p;
+	return path;
 }
diff --git a/src/path.h b/src/path.h
index 7189cea..50ff842 100644
--- a/src/path.h
+++ b/src/path.h
@@ -28,4 +28,5 @@
 
 #include <string>
 
+//! \returns path component of full filename with path.
 std::string getPath(const std::string& file);
diff --git a/src/sample.cc b/src/sample.cc
index 66fe3c5..ced8a47 100644
--- a/src/sample.cc
+++ b/src/sample.cc
@@ -65,24 +65,3 @@ AudioFile* Sample::getAudioFile(Channel* c)
 
 	return nullptr;
 }
-
-#ifdef TEST_SAMPLE
-// deps: channel.cc audiofile.cc
-// cflags: $(SNDFILE_CFLAGS)
-// libs: $(SNDFILE_LIBS)
-#include "test.h"
-
-TEST_BEGIN;
-
-Sample s;
-InstrumentChannel c;
-InstrumentChannel c2;
-AudioFile a("test");
-
-s.addAudioFile(&c, &a);
-TEST_EQUAL(s.getAudioFile(&c), &a, "?");
-TEST_EQUAL(s.getAudioFile(&c2), nullptr, "?");
-
-TEST_END;
-
-#endif /*TEST_SAMPLE*/
diff --git a/src/sample.h b/src/sample.h
index 5b4f3b5..f00db13 100644
--- a/src/sample.h
+++ b/src/sample.h
@@ -32,34 +32,22 @@
 #include "channel.h"
 #include "audiofile.h"
 
-typedef std::map<Channel*, AudioFile*> AudioFiles;
+using AudioFiles = std::map<Channel*, AudioFile*>;
 
-class InstrumentParser;
-class Sample
-{
+class Sample {
 	friend class InstrumentParser;
 	friend class PowerList;
-
 public:
 	Sample(const std::string& name, float power);
 	~Sample();
 
-	AudioFile* getAudioFile(InstrumentChannel* c);
+	AudioFile* getAudioFile(InstrumentChannel *instrument_channel);
 
 private:
-	void addAudioFile(InstrumentChannel* c, AudioFile* a);
+	void addAudioFile(InstrumentChannel* instrument_channel,
+	                  AudioFile* audio_file);
 
 	std::string name;
 	float power;
 	AudioFiles audiofiles;
 };
-
-/*
- *   <sample name="kick-r-1">
- *    <audiofile channel="Alesis-3" file="samples/1-kick-r-Alesis-3.wav"/>
- *    <audiofile channel="Amb L-3" file="samples/1-kick-r-Amb L-3.wav"/>
- *    <audiofile channel="Amb R-3" file="samples/1-kick-r-Amb R-3.wav"/>
- *    <audiofile channel="Kick L-3" file="samples/1-kick-r-Kick L-3.wav"/>
- *    <audiofile channel="Kick R-3" file="samples/1-kick-r-Kick R-3.wav"/>
- *   </sample>
- */
diff --git a/src/saxparser.cc b/src/saxparser.cc
index e32143d..280e608 100644
--- a/src/saxparser.cc
+++ b/src/saxparser.cc
@@ -26,29 +26,30 @@
  */
 #include "saxparser.h"
 
-#include <string.h>
-#include <hugin.hpp>
 #include <sstream>
 #include <iostream>
 
+#include <hugin.hpp>
+
 SAXParser::SAXParser()
 {
-	p = XML_ParserCreate(nullptr);
-	if(!p) {
+	parser = XML_ParserCreate(nullptr);
+	if(!parser)
+	{
 		ERR(sax, "Couldn't allocate memory for parser\n");
 		// throw Exception(...); TODO
 		return;
 	}
 
-	XML_SetUserData(p, this);
-	XML_UseParserAsHandlerArg(p);
-	XML_SetElementHandler(p, start_hndl, end_hndl);
-	XML_SetCharacterDataHandler(p, character_hndl);
+	XML_SetUserData(parser, this);
+	XML_UseParserAsHandlerArg(parser);
+	XML_SetElementHandler(parser, SAXParser::startHandler, SAXParser::endHandler);
+	XML_SetCharacterDataHandler(parser, SAXParser::characterHandler);
 }
 
 SAXParser::~SAXParser()
 {
-	XML_ParserFree(p);
+	XML_ParserFree(parser);
 }
 
 int SAXParser::parseFile(const std::string& filename)
@@ -60,7 +61,8 @@ int SAXParser::parseFile(const std::string& filename)
 
 	std::ifstream file(filename, std::ifstream::in);
 
-	if(!file.is_open()) {
+	if(!file.is_open())
+	{
 		return 1;
 	}
 
@@ -68,59 +70,63 @@ int SAXParser::parseFile(const std::string& filename)
 	ss << file.rdbuf();
 	std::string str = ss.str();
 
-	parseString(str, filename);
-
-	return 0;
+	return parseString(str, filename);
 }
 
-int SAXParser::parseString(const std::string& str, const std::string& xml_source_name)
+int SAXParser::parseString(const std::string& str,
+                           const std::string& xml_source_name)
 {
 	DEBUG(sax, "parse(buffer %d bytes)\n", (int)str.length());
 
-	if(!XML_Parse(p, str.c_str(), str.length(), true)) {
-		parseError(str, XML_ErrorString(XML_GetErrorCode(p)),
-		           xml_source_name, (int)XML_GetCurrentLineNumber(p));
+	if(!XML_Parse(parser, str.c_str(), str.length(), true))
+	{
+		parseError(str, XML_ErrorString(XML_GetErrorCode(parser)),
+		           xml_source_name, (int)XML_GetCurrentLineNumber(parser));
 		return 1;
 	}
 
 	return 0;
 }
 
-void SAXParser::parseError(const std::string& buf, const std::string& error, const std::string& xml_source_name, std::size_t lineno)
+void SAXParser::parseError(const std::string& buf, const std::string& error,
+                           const std::string& xml_source_name,
+                           std::size_t lineno)
 {
-	std::cerr << "SAXParser error trying to parse from source: " << xml_source_name << "\n";
+	std::cerr << "SAXParser error trying to parse from source: " <<
+		xml_source_name << "\n";
 	std::cerr << "At line " << lineno << ": " << error << "\n";
 	std::cerr << "Buffer " << buf.size() << " bytes: \n[\n";
 	std::cerr << buf;
 	std::cerr << "\n]" << std::endl;
 }
 
-void SAXParser::character_hndl(void* p, const XML_Char* s, int len)
+void SAXParser::characterHandler(void* parser, const XML_Char* cData, int len)
 {
-	SAXParser* parser = (SAXParser*)XML_GetUserData(p);
-	std::string chars(s, len);
-	parser->characterData(chars);
+	SAXParser* sax_parser = (SAXParser*)XML_GetUserData(parser);
+	std::string chars(cData, len);
+	sax_parser->characterData(chars);
 }
 
-void SAXParser::start_hndl(void* p, const char* el, const char** attr)
+void SAXParser::startHandler(void* parser, const char* el, const char** attr)
 {
-	SAXParser* parser = (SAXParser*)XML_GetUserData(p);
+	SAXParser* sax_parser = (SAXParser*)XML_GetUserData(parser);
 
 	// Convert to comfy C++ values...
 	attr_t attributes;
 
-	while(*attr) {
+	while(*attr)
+	{
 		std::string at_name = *attr++;
 		std::string at_value = *attr++;
 
 		attributes.emplace(at_name, at_value);
 	}
 
-	parser->startTag(std::string(el), attributes);
+	sax_parser->startTag(std::string(el), attributes);
 }
 
-void SAXParser::end_hndl(void* p, const char* el)
+void SAXParser::endHandler(void* parser, const char* el)
 {
-	SAXParser* parser = (SAXParser*)XML_GetUserData(p);
-	parser->endTag(std::string(el));
+	SAXParser* sax_parser = (SAXParser*)XML_GetUserData(parser);
+	sax_parser->endTag(std::string(el));
 }
diff --git a/src/saxparser.h b/src/saxparser.h
index 92197d1..4b1a273 100644
--- a/src/saxparser.h
+++ b/src/saxparser.h
@@ -31,7 +31,8 @@
 #include <expat.h>
 #include <fstream>
 
-class SAXParser {
+class SAXParser
+{
 public:
 	SAXParser();
 	virtual ~SAXParser();
@@ -40,7 +41,8 @@ public:
 	virtual int parseFile(const std::string& filename);
 
 	//! Parses all the data in the buffer.
-	virtual int parseString(const std::string& str, const std::string& xml_source_name = "");
+	virtual int parseString(const std::string& str,
+	                        const std::string& xml_source_name = "");
 
 protected:
 	using attr_t = std::unordered_map<std::string, std::string>;
@@ -48,13 +50,16 @@ protected:
 	virtual void characterData(const std::string& data) {}
 	virtual void startTag(const std::string& name, const attr_t& attr) {}
 	virtual void endTag(const std::string& name) {}
-	virtual void parseError(const std::string& buf, const std::string& error, const std::string& xml_source_name, std::size_t lineno);
+	virtual void parseError(const std::string& buf,
+	                        const std::string& error,
+	                        const std::string& xml_source_name,
+	                        std::size_t lineno);
 
 private:
-	XML_Parser p;
+	XML_Parser parser;
 	std::string filename;
 
-	static void character_hndl(void* p, const XML_Char* s, int len);
-	static void start_hndl(void* p, const char* el, const char** attr);
-	static void end_hndl(void* p, const char* el);
+	static void characterHandler(void* parser, const XML_Char* cData, int len);
+	static void startHandler(void* parser, const char* el, const char** attr);
+	static void endHandler(void* parser, const char* el);
 };
diff --git a/src/semaphore.cc b/src/semaphore.cc
index cd29bbf..6172251 100644
--- a/src/semaphore.cc
+++ b/src/semaphore.cc
@@ -27,87 +27,101 @@
 #include "semaphore.h"
 
 #include <hugin.hpp>
-
 #include <limits>
+#include <assert.h>
 
 #ifdef WIN32
 #include <windows.h>
 #else
-// Make sure we don't include /this/ file...
+// Make sure we don't include /this/ files header...
 #include <../include/semaphore.h>
+#include <errno.h>
+#include <stdio.h>
 #endif
 
 struct semaphore_private_t {
 #ifdef WIN32
-  HANDLE semaphore; 
+	HANDLE semaphore;
 #else
-  sem_t semaphore;
+	sem_t semaphore;
 #endif
 };
 
-Semaphore::Semaphore(const char *name)
+Semaphore::Semaphore(std::size_t initial_count)
 {
-  this->name = name;
-  //  DEBUG(semaphore, "Create [%s]\n", name);
-
-  prv = new struct semaphore_private_t();
+	prv = new struct semaphore_private_t();
 
 #ifdef WIN32
-  prv->semaphore = CreateSemaphore(NULL,  // default security attributes
-                                   0, // initial count
-                                   std::numeric_limits<LONG>::max(),
-                                   NULL); // unnamed semaphore
+	prv->semaphore = CreateSemaphore(nullptr,  // default security attributes
+	                                 initial_count,
+	                                 std::numeric_limits<LONG>::max(),
+	                                 nullptr); // unnamed semaphore
 #else
-  sem_init(&prv->semaphore, 0, 0);
+	const int pshared = 0;
+	sem_init(&prv->semaphore, pshared, initial_count);
 #endif
 }
 
 Semaphore::~Semaphore()
 {
-  //  DEBUG(semaphore, "Delete [%s]\n", name);
-
 #ifdef WIN32
-  CloseHandle(prv->semaphore);
+	CloseHandle(prv->semaphore);
 #else
-  sem_destroy(&prv->semaphore);
+	sem_destroy(&prv->semaphore);
 #endif
 
-  delete prv;
+	delete prv;
 }
 
 void Semaphore::post()
 {
-  //  DEBUG(semaphore, "Post [%s]\n", name);
+#ifdef WIN32
+	ReleaseSemaphore(prv->semaphore, 1, NULL);
+#else
+	sem_post(&prv->semaphore);
+#endif
+}
 
+bool Semaphore::wait(const std::chrono::milliseconds& timeout)
+{
 #ifdef WIN32
-  ReleaseSemaphore(prv->semaphore, 1, NULL);
+	DWORD ret = WaitForSingleObject(prv->semaphore, timeout.count());
+	if(ret == WAIT_TIMEOUT)
+	{
+		return false;
+	}
+
+	assert(ret == WAIT_OBJECT_0);
 #else
-  sem_post(&prv->semaphore);
+	struct timespec t = {
+		// Whole seconds:
+		(time_t)(timeout.count() / 1000),
+
+		// Remainder as nanoseconds:
+		(long)((timeout.count() - ((timeout.count() / 1000) * 1000)) * 1000000)
+	};
+
+	int ret = sem_timedwait(&prv->semaphore, &t);
+	if(ret < 0)
+	{
+		if(errno == ETIMEDOUT)
+		{
+			return false;
+		}
+
+		perror("sem_timedwait()");
+		assert(false);
+	}
 #endif
+
+	return true;
 }
 
 void Semaphore::wait()
 {
-  //  DEBUG(semaphore, "Wait [%s]\n", name);
-
 #ifdef WIN32
-  WaitForSingleObject(prv->semaphore, INFINITE);
+	WaitForSingleObject(prv->semaphore, INFINITE);
 #else
-  sem_wait(&prv->semaphore);
+	sem_wait(&prv->semaphore);
 #endif
 }
-
-#ifdef TEST_SEMAPHORE
-//deps:
-//cflags: -I.. $(PTHREAD_CFLAGS)
-//libs: $(PTHREAD_LIBS)
-#include <test.h>
-
-TEST_BEGIN;
-
-// TODO: Put some testcode here (see test.h for usable macros).
-TEST_TRUE(false, "No tests yet!");
-
-TEST_END;
-
-#endif/*TEST_SEMAPHORE*/
diff --git a/src/semaphore.h b/src/semaphore.h
index 4464898..d5995cb 100644
--- a/src/semaphore.h
+++ b/src/semaphore.h
@@ -24,22 +24,26 @@
  *  along with DrumGizmo; if not, write to the Free Software
  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
  */
-#ifndef __PRACRO_SEMAPHORE_H__
-#define __PRACRO_SEMAPHORE_H__
+#pragma once
+
+#include <chrono>
 
 struct semaphore_private_t;
 
-class Semaphore {
+class Semaphore
+{
 public:
-  Semaphore(const char *name = "");
-  ~Semaphore();
+	Semaphore(std::size_t initial_count = 0);
+	~Semaphore();
+
+	void post();
 
-  void post();
-  void wait();
+	//! Lock semaphore with timeout.
+	//! \returns true if the semaphore was locked, false on timeout.
+	bool wait(const std::chrono::milliseconds& timeout);
+
+	void wait();
 
 private:
 	struct semaphore_private_t *prv{nullptr};
-	const char *name{nullptr};
 };
-
-#endif/*__PRACRO_SEMAPHORE_H__*/
diff --git a/src/settings.h b/src/settings.h
index 74c432d..6b4e882 100644
--- a/src/settings.h
+++ b/src/settings.h
@@ -27,52 +27,54 @@
 #pragma once
 
 #include <atomic>
+#include <string>
 #include <cassert>
 
-template <typename T> class SettingRef
-{
-public:
-	SettingRef(std::atomic<T>& value)
-		: value{value}
-		, cache{}
-	{
-		// string isn't lock free either
-		assert((std::is_same<T, std::string>::value || value.is_lock_free()));
-	}
-
-	bool hasChanged()
-	{
-		T tmp = cache;
-		cache.exchange(value);
-		return tmp == cache;
-	}
+#include "atomic.h"
+#include "notifier.h"
 
-	T getValue() const
-	{
-		return cache;
-	}
-
-private:
-	std::atomic<T>& value;
-	std::atomic<T> cache;
+enum class LoadStatus : unsigned int
+{
+	Idle,
+	Loading,
+	Done,
+	Error
 };
 
+//! Engine settings
 struct Settings
 {
-	std::atomic<bool> enable_velocity_modifier;
-	std::atomic<float> velocity_modifier_falloff;
-	std::atomic<float> velocity_modifier_weight;
+	Atomic<std::string> drumkit_file;
+	Atomic<LoadStatus> drumkit_load_status{LoadStatus::Idle};
+
+	Atomic<std::string> midimap_file;
+	Atomic<LoadStatus> midimap_load_status{LoadStatus::Idle};
+
+	Atomic<bool> enable_velocity_modifier{true};
+	Atomic<float> velocity_modifier_falloff{0.5f};
+	Atomic<float> velocity_modifier_weight{0.25f};
 
-	std::atomic<bool> enable_velocity_randomiser;
-	std::atomic<float> velocity_randomiser_weight;
+	Atomic<bool> enable_velocity_randomiser{false};
+	Atomic<float> velocity_randomiser_weight{0.1f};
 
-	std::atomic<int> samplerate;
+	Atomic<double> samplerate{44100.0};
 
-	std::atomic<bool> enable_resampling;
+	Atomic<bool> enable_resampling{true};
+
+	Atomic<std::size_t> number_of_files;
+	Atomic<std::size_t> number_of_files_loaded;
+	Atomic<std::string> current_file;
 };
 
+//! Settings getter class.
 struct SettingsGetter
 {
+	SettingRef<std::string> drumkit_file;
+	SettingRef<LoadStatus> drumkit_load_status;
+
+	SettingRef<std::string> midimap_file;
+	SettingRef<LoadStatus> midimap_load_status;
+
 	SettingRef<bool> enable_velocity_modifier;
 	SettingRef<float> velocity_modifier_falloff;
 	SettingRef<float> velocity_modifier_weight;
@@ -80,48 +82,125 @@ struct SettingsGetter
 	SettingRef<bool> enable_velocity_randomiser;
 	SettingRef<float> velocity_randomiser_weight;
 
-	SettingRef<int> samplerate;
+	SettingRef<double> samplerate;
 
 	SettingRef<bool> enable_resampling;
 
+	SettingRef<std::size_t> number_of_files;
+	SettingRef<std::size_t> number_of_files_loaded;
+	SettingRef<std::string> current_file;
+
 	SettingsGetter(Settings& settings)
-		: enable_velocity_modifier{settings.enable_velocity_modifier}
+		: drumkit_file(settings.drumkit_file)
+		, drumkit_load_status(settings.drumkit_load_status)
+		, midimap_file(settings.midimap_file)
+		, midimap_load_status(settings.midimap_load_status)
+		, enable_velocity_modifier{settings.enable_velocity_modifier}
 		, velocity_modifier_falloff{settings.velocity_modifier_falloff}
 		, velocity_modifier_weight{settings.velocity_modifier_weight}
 		, enable_velocity_randomiser{settings.enable_velocity_randomiser}
 		, velocity_randomiser_weight{settings.velocity_randomiser_weight}
 		, samplerate{settings.samplerate}
 		, enable_resampling{settings.enable_resampling}
+		, number_of_files{settings.number_of_files}
+		, number_of_files_loaded{settings.number_of_files_loaded}
+		, current_file{settings.current_file}
 	{
 	}
 };
 
+//! Settings change notifier class.
+class SettingsNotifier
+{
+public:
+	Notifier<std::string> drumkit_file;
+	Notifier<LoadStatus> drumkit_load_status;
+
+	Notifier<std::string> midimap_file;
+	Notifier<LoadStatus> midimap_load_status;
+
+	Notifier<bool> enable_velocity_modifier;
+	Notifier<float> velocity_modifier_falloff;
+	Notifier<float> velocity_modifier_weight;
+
+	Notifier<bool> enable_velocity_randomiser;
+	Notifier<float> velocity_randomiser_weight;
+
+	Notifier<double> samplerate;
+
+	Notifier<bool> enable_resampling;
+
+	Notifier<std::size_t> number_of_files;
+	Notifier<std::size_t> number_of_files_loaded;
+	Notifier<std::string> current_file;
+
+	void evaluate()
+	{
+#define EVAL(x) if(settings.x.hasChanged()) { x(settings.x.getValue()); }
+
+		EVAL(drumkit_file);
+		EVAL(drumkit_load_status);
+
+		EVAL(midimap_file);
+		EVAL(midimap_load_status);
+
+		EVAL(enable_velocity_modifier);
+		EVAL(velocity_modifier_falloff);
+		EVAL(velocity_modifier_weight);
+
+		EVAL(enable_velocity_randomiser);
+		EVAL(velocity_randomiser_weight);
+
+		EVAL(samplerate);
+
+		EVAL(enable_resampling);
+
+		EVAL(number_of_files);
+		EVAL(number_of_files_loaded);
+		EVAL(current_file);
+	}
+
+	SettingsNotifier(Settings& settings)
+		: settings(settings)
+	{
+	}
+
+private:
+	SettingsGetter settings;
+};
+
 // lovely reminder: NO, GLOCKE. NOOOO!!
 /*
 enum class IntParams {
-    Foo = 0
+	Foo = 0
 };
 
-struct Settings {
-    std::array<std::atomic<int>, 5> ints;
+struct Settings
+{
+	std::array<std::atomic<int>, 5> ints;
 
-    Settings()
-        : ints{} {
-        //get(IntParams::Foo).store(3);
-    }
+	Settings()
+		: ints{}
+	{
+		//get(IntParams::Foo).store(3);
+	}
 
-    std::atomic<int>& get(IntParams param) {
-        return ints[(size_t)param];
-    }
+	std::atomic<int>& get(IntParams param)
+	{
+		return ints[(size_t)param];
+	}
 };
 
-struct SettingsGetter {
-    std::vector<SettingRef<int>> ints;
+struct SettingsGetter
+{
+	std::vector<SettingRef<int>> ints;
 
-    SettingsGetter(Settings& parent) {
-        for (auto& atomic: parent.ints) {
-            ints.emplace_back(atomic);
-        }
-    }
+	SettingsGetter(Settings& parent)
+	{
+		for(auto& atomic: parent.ints)
+		{
+			ints.emplace_back(atomic);
+		}
+	}
 };
 */
diff --git a/src/syncedsettings.h b/src/syncedsettings.h
new file mode 100644
index 0000000..0fe5efd
--- /dev/null
+++ b/src/syncedsettings.h
@@ -0,0 +1,106 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            syncedsettings.h
+ *
+ *  Thu Mar 31 09:23:27 CEST 2016
+ *  Copyright 2016 Christian Glöckner
+ *  cgloeckner@freenet.de
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#pragma once
+
+#include <mutex>
+
+template <typename T> class Group;
+
+template <typename T> class Accessor
+{
+private:
+	std::lock_guard<std::mutex> lock;
+
+public:
+	Accessor(Group<T>& parent)
+		: lock{parent.mutex}
+		, data(parent.data)
+	{
+	}
+
+	T& data;
+};
+
+template <typename T> class Group
+{
+private:
+	friend class Accessor<T>;
+
+	mutable std::mutex mutex;
+	T data;
+
+public:
+	Group()
+		: mutex{}
+		, data{}
+	{
+	}
+
+	Group(Group<T> const& other)
+		: mutex{}
+		, data{}
+	{
+		std::lock_guard<std::mutex> lock{other.mutex};
+		data = other.data;
+	}
+
+	Group(Group<T>&& other)
+		: mutex{}
+		, data{}
+	{
+		std::lock_guard<std::mutex> lock{other.mutex};
+		std::swap(data, other.data);
+	}
+
+	Group<T>& operator=(const Group<T>& other)
+	{
+		if (*this != &other)
+		{
+			std::lock_guard<std::mutex> lock{mutex};
+			std::lock_guard<std::mutex> lock2{other.mutex};
+			data = other.data;
+		}
+		return *this;
+	}
+	
+	Group<T>& operator=(Group<T>&& other)
+	{
+		if (*this != &other)
+		{
+			std::lock_guard<std::mutex> lock{mutex};
+			std::lock_guard<std::mutex> lock2{other.mutex};
+			std::swap(data, other.data);
+		}
+		return *this;
+	}
+
+	operator T() const
+	{
+		std::lock_guard<std::mutex> lock{mutex};
+		return data;
+	}
+};
diff --git a/test/Makefile.am b/test/Makefile.am
index ccb21e6..3633ad8 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -3,7 +3,7 @@ include $(top_srcdir)/src/Makefile.am.drumgizmo
 
 TESTS = resource engine gui resampler lv2 configfile audiocache \
 	audiocachefile audiocacheidmanager audiocacheeventhandler \
-	memchecker random
+	memchecker random atomictest syncedsettingstest
 
 check_PROGRAMS = $(TESTS)
 
@@ -29,7 +29,6 @@ audiocache_SOURCES = \
 	$(top_srcdir)/src/thread.cc \
 	$(top_srcdir)/src/mutex.cc \
 	$(top_srcdir)/src/semaphore.cc \
-	$(top_srcdir)/src/configuration.cc \
 	$(top_srcdir)/src/audiofile.cc \
 	test.cc \
 	audiocachetest.cc
@@ -43,7 +42,6 @@ audiocachefile_SOURCES = \
 	$(top_srcdir)/src/thread.cc \
 	$(top_srcdir)/src/mutex.cc \
 	$(top_srcdir)/src/semaphore.cc \
-	$(top_srcdir)/src/configuration.cc \
 	$(top_srcdir)/src/audiofile.cc \
 	test.cc \
 	audiocachefiletest.cc
@@ -138,5 +136,15 @@ random_SOURCES = \
 	test.cc \
 	randomtest.cc
 
+atomictest_CXXFLAGS = -DOUTPUT=\"atomictest\" $(CPPUNIT_CFLAGS) \
+	-I$(top_srcdir)/src -I$(top_srcdir)/hugin
+atomictest_LDFLAGS = $(CPPUNIT_LIBS)
+atomictest_SOURCES = atomictest.cc test.cc
+
+syncedsettingstest_CXXFLAGS = -DOUTPUT=\"syncedsettingstest\" $(CPPUNIT_CFLAGS) \
+	-I$(top_srcdir)/src -I$(top_srcdir)/hugin
+syncedsettingstest_LDFLAGS = $(CPPUNIT_LIBS)
+syncedsettingstest_SOURCES = syncedsettings.cc test.cc
+
 EXTRA_DIST = \
 	lv2_test_host.h
diff --git a/test/atomictest.cc b/test/atomictest.cc
new file mode 100644
index 0000000..1718b33
--- /dev/null
+++ b/test/atomictest.cc
@@ -0,0 +1,135 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            atomic.cc
+ *
+ *  Wed Mar 23 09:17:12 CET 2016
+ *  Copyright 2016 Christian Glöckner
+ *  cgloeckner@freenet.de
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <atomic.h>
+
+class AtomicTest
+	: public CppUnit::TestFixture {
+		
+	CPPUNIT_TEST_SUITE(AtomicTest);
+	CPPUNIT_TEST(podAtomicsUseStandardImpl);
+	CPPUNIT_TEST(nonPodAtomicsUseOwnImpl);
+	CPPUNIT_TEST(podAtomicCanBeDefaultInitialized);
+	CPPUNIT_TEST(nonPodAtomicCanBeDefaultInitialized);
+	CPPUNIT_TEST(podAtomicCanBeValueInitialized);
+	CPPUNIT_TEST(nonPodAtomicCanBeValueInitialized);
+	CPPUNIT_TEST(podAtomicCanBeValueAssigned);
+	CPPUNIT_TEST(nonPodAtomicCanBeValueAssigned);
+	CPPUNIT_TEST(podAtomicsAreLockFree);
+	CPPUNIT_TEST_SUITE_END();
+	
+	public:
+		void setUp() {}
+		void tearDown() {}
+		
+		void podAtomicsUseStandardImpl() {
+			CPPUNIT_ASSERT(isUsingStandardImpl<bool>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<unsigned short int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<short int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<unsigned int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<unsigned long int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<long int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<unsigned long long int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<long long int>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<float>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<double>());
+			CPPUNIT_ASSERT(isUsingStandardImpl<long double>());
+		}
+		
+		void nonPodAtomicsUseOwnImpl() {
+			CPPUNIT_ASSERT(!isUsingStandardImpl<std::string>());
+		}
+		
+		void podAtomicCanBeDefaultInitialized() {
+			Atomic<int> i;
+			// note: i is initialized with garbage
+		}
+		
+		void nonPodAtomicCanBeDefaultInitialized() {
+			Atomic<std::string> s;
+			CPPUNIT_ASSERT_EQUAL(s.load(), std::string{});
+		}
+		
+		void podAtomicCanBeValueInitialized() {
+			Atomic<int> i{5};
+			CPPUNIT_ASSERT_EQUAL(i.load(), 5);
+		}
+		
+		void nonPodAtomicCanBeValueInitialized() {
+			Atomic<std::string> s{"hello world"};
+			CPPUNIT_ASSERT_EQUAL(s.load(), std::string{"hello world"});
+		}
+		
+		void podAtomicCanBeValueAssigned() {
+			Atomic<int> i;
+			i = 5;
+			CPPUNIT_ASSERT_EQUAL(i.load(), 5);
+		}
+		
+		void nonPodAtomicCanBeValueAssigned() {
+			Atomic<std::string> s;
+			s = "hello world";
+			CPPUNIT_ASSERT_EQUAL(s.load(), std::string{"hello world"});
+		}
+		
+		void podAtomicsAreLockFree() {
+			CPPUNIT_ASSERT(isLockFree<bool>());
+			CPPUNIT_ASSERT(isLockFree<unsigned short int>());
+			CPPUNIT_ASSERT(isLockFree<short int>());
+			CPPUNIT_ASSERT(isLockFree<unsigned int>());
+			CPPUNIT_ASSERT(isLockFree<int>());
+			CPPUNIT_ASSERT(isLockFree<unsigned long int>());
+			CPPUNIT_ASSERT(isLockFree<long int>());
+			CPPUNIT_ASSERT(isLockFree<unsigned long long int>());
+			CPPUNIT_ASSERT(isLockFree<long long int>());
+			CPPUNIT_ASSERT(isLockFree<float>());
+			CPPUNIT_ASSERT(isLockFree<double>());
+			
+			// compile error: undefined reference to `__atomic_is_lock_free'
+			//CPPUNIT_ASSERT(isLockFree<long double>());
+		}
+		
+		// todo: further testing
+		
+	private:
+		template <typename T>
+		bool isUsingStandardImpl() {
+			return std::is_base_of<std::atomic<T>, Atomic<T>>::value;
+		}
+		
+		template <typename T>
+		bool isLockFree() {
+			Atomic<T> a;
+			return a.is_lock_free();
+		}
+};
+
+// Registers the fixture into the 'registry'
+CPPUNIT_TEST_SUITE_REGISTRATION(AtomicTest);
+
diff --git a/test/engine.cc b/test/engine.cc
index 86f4f4d..89c0158 100644
--- a/test/engine.cc
+++ b/test/engine.cc
@@ -40,9 +40,10 @@ public:
 	void tearDown() {}
 
   void loading() {
+	  Settings settings;
     AudioOutputEngine *oe = NULL;
     AudioInputEngine *ie = NULL;
-    DrumGizmo dg(oe, ie);
+    DrumGizmo dg(settings, oe, ie);
     dg.setFrameSize(100);
 
     // Switch kits emmidiately with giving the loader time to work:
diff --git a/test/memcheckertest.cc b/test/memcheckertest.cc
index 90bd254..e312ca7 100644
--- a/test/memcheckertest.cc
+++ b/test/memcheckertest.cc
@@ -52,6 +52,7 @@ class MemCheckerTest
 	CPPUNIT_TEST(check_free_ram);
 	CPPUNIT_TEST_SUITE_END();
 private:
+	Settings settings;
 	DrumKit kit;
 
 	const std::string small_kit_path = "kit/small_kit.xml";
@@ -70,7 +71,7 @@ public:
 	void small_drumkit()
 	{
 		// load the small kit
-		DrumKitParser parser(kit);
+		DrumKitParser parser(settings, kit);
 		CPPUNIT_ASSERT(!parser.parseFile(small_kit_path));
 
 		// check if the memchecker thinks it fits into memory
@@ -80,7 +81,7 @@ public:
 	void huge_drumkit()
 	{
 		// load the huge kit
-		DrumKitParser parser(kit);
+		DrumKitParser parser(settings, kit);
 		CPPUNIT_ASSERT(!parser.parseFile(huge_kit_path));
 
 		// check if the memchecker thinks it doesn't fit into memory
@@ -94,7 +95,7 @@ public:
 		CPPUNIT_ASSERT_EQUAL(bytes_per_channel, calcBytesPerChannel(audiofile));
 
 		// load the huge kit
-		DrumKitParser parser(kit);
+		DrumKitParser parser(settings, kit);
 		CPPUNIT_ASSERT(!parser.parseFile(huge_kit_path));
 
 		// check if the protected method of the memchecker reports the correct size
diff --git a/test/syncedsettings.cc b/test/syncedsettings.cc
new file mode 100644
index 0000000..62bd8c6
--- /dev/null
+++ b/test/syncedsettings.cc
@@ -0,0 +1,203 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            syncedsettings.cc
+ *
+ *  Wed Mar 31 09:32:12 CET 2016
+ *  Copyright 2016 Christian Glöckner
+ *  cgloeckner@freenet.de
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo 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 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo 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 DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include <cppunit/extensions/HelperMacros.h>
+
+#include <syncedsettings.h>
+
+class SyncedSettingsTest
+	: public CppUnit::TestFixture {
+		
+	CPPUNIT_TEST_SUITE(SyncedSettingsTest);
+	CPPUNIT_TEST(groupCanBeDefaultInitialized);
+	CPPUNIT_TEST(groupDataCanBeCopied);
+	
+	CPPUNIT_TEST(accessorCanGetFields);
+	CPPUNIT_TEST(accessorCanSetFields);
+	
+	CPPUNIT_TEST(groupHasCopyCtor);
+	CPPUNIT_TEST(groupHasMoveCtor);
+	CPPUNIT_TEST(groupHasCopyAssignOp);
+	CPPUNIT_TEST(groupHasMoveAssignOp);
+	
+	CPPUNIT_TEST(mimicRealUse);
+	CPPUNIT_TEST_SUITE_END();
+	
+	private:
+		struct TestData {
+			float foo;
+			bool bar;
+			std::string msg;
+		};
+	
+	public:
+		void setUp() {}
+		void tearDown() {}
+		
+		void groupCanBeDefaultInitialized() {
+			Group<TestData> data;
+		}
+		
+		void groupDataCanBeCopied() {
+			Group<TestData> data;
+			(TestData)data; // copies
+		}
+		
+		void accessorCanSetFields() {
+			Group<TestData> data;
+			{
+				Accessor<TestData> a{data};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			TestData copy = data;
+			CPPUNIT_ASSERT_EQUAL(copy.foo, 3.f);
+			CPPUNIT_ASSERT_EQUAL(copy.bar, false);
+			CPPUNIT_ASSERT_EQUAL(copy.msg, std::string{"hello"});
+		}
+		
+		void accessorCanGetFields() {
+			Group<TestData> data;
+			{
+				Accessor<TestData> a{data};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			// now read
+			{
+				Accessor<TestData> a{data};
+				CPPUNIT_ASSERT_EQUAL(a.data.foo, 3.f);
+				CPPUNIT_ASSERT_EQUAL(a.data.bar, false);
+				CPPUNIT_ASSERT_EQUAL(a.data.msg, std::string{"hello"});
+			}
+		}
+		
+		void groupHasCopyCtor() {
+			Group<TestData> tmp;
+			{
+				Accessor<TestData> a{tmp};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			Group<TestData> data{tmp};
+			TestData copy = data;
+			CPPUNIT_ASSERT_EQUAL(copy.foo, 3.f);
+			CPPUNIT_ASSERT_EQUAL(copy.bar, false);
+			CPPUNIT_ASSERT_EQUAL(copy.msg, std::string{"hello"});
+		}
+		
+		void groupHasMoveCtor() {
+			Group<TestData> tmp;
+			{
+				Accessor<TestData> a{tmp};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			Group<TestData> data{std::move(tmp)};
+			TestData copy = data;
+			CPPUNIT_ASSERT_EQUAL(copy.foo, 3.f);
+			CPPUNIT_ASSERT_EQUAL(copy.bar, false);
+			CPPUNIT_ASSERT_EQUAL(copy.msg, std::string{"hello"});
+		}
+		
+		void groupHasCopyAssignOp() {
+			Group<TestData> tmp;
+			{
+				Accessor<TestData> a{tmp};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			Group<TestData> data = tmp;
+			TestData copy = data;
+			CPPUNIT_ASSERT_EQUAL(copy.foo, 3.f);
+			CPPUNIT_ASSERT_EQUAL(copy.bar, false);
+			CPPUNIT_ASSERT_EQUAL(copy.msg, std::string{"hello"});
+		}
+		
+		void groupHasMoveAssignOp() {
+			Group<TestData> tmp;
+			{
+				Accessor<TestData> a{tmp};
+				a.data.foo = 3.f;
+				a.data.bar = false;
+				a.data.msg = "hello";
+			}
+			Group<TestData> data = std::move(tmp);
+			TestData copy = data;
+			CPPUNIT_ASSERT_EQUAL(copy.foo, 3.f);
+			CPPUNIT_ASSERT_EQUAL(copy.bar, false);
+			CPPUNIT_ASSERT_EQUAL(copy.msg, std::string{"hello"});
+		}
+		
+		void mimicRealUse() {
+			struct Settings {
+				struct Foo {
+					float a{5};
+					float b{3};
+					bool enabled{true};
+				};
+				struct Bar {
+					std::string label{"empty"};
+					float bla{0.f};
+				};
+				
+				Group<Foo> foo;
+				Group<Bar> bar;
+			};
+			
+			Settings s;
+			
+			// set bar settings
+			{
+				Accessor<Settings::Bar> tmp{s.bar};
+				tmp.data.label = "hello world";
+				tmp.data.bla = 3.14f;
+			}
+			
+			// read foo settings
+			{
+				Accessor<Settings::Foo> tmp{s.foo};
+				if (tmp.data.enabled) {
+					// do some while locked
+				}
+			}
+			// or:
+			Settings::Foo copy = s.foo;
+			if (copy.enabled) {
+				// do some stuff without locking
+			}
+			CPPUNIT_ASSERT(copy.enabled);
+		}
+};
+
+// Registers the fixture into the 'registry'
+CPPUNIT_TEST_SUITE_REGISTRATION(SyncedSettingsTest);
+