diff --git a/source/backend/CarlaHost.h b/source/backend/CarlaHost.h
index 65d17dde4..5d1e17f54 100644
--- a/source/backend/CarlaHost.h
+++ b/source/backend/CarlaHost.h
@@ -545,6 +545,17 @@ CARLA_EXPORT uint64_t carla_get_current_transport_frame();
 CARLA_EXPORT const CarlaTransportInfo* carla_get_transport_info();
 #endif
 
+/*!
+ * Current number of plugins loaded.
+ */
+CARLA_EXPORT uint32_t carla_get_current_plugin_count();
+
+/*!
+ * Maximum number of loadable plugins allowed.
+ * Returns 0 if engine is not started.
+ */
+CARLA_EXPORT uint32_t carla_get_max_plugin_number();
+
 /*!
  * Add a new plugin.
  * If you don't know the binary type use the BINARY_NATIVE macro.
diff --git a/source/backend/CarlaStandalone.cpp b/source/backend/CarlaStandalone.cpp
index 3a5a24522..b0a0e70da 100644
--- a/source/backend/CarlaStandalone.cpp
+++ b/source/backend/CarlaStandalone.cpp
@@ -1291,6 +1291,24 @@ const CarlaTransportInfo* carla_get_transport_info()
 
 // -------------------------------------------------------------------------------------------------------------------
 
+uint32_t carla_get_current_plugin_count()
+{
+    if (gStandalone.engine != nullptr)
+        return gStandalone.engine->getCurrentPluginCount();
+
+    return 0;
+}
+
+uint32_t carla_get_max_plugin_number()
+{
+    if (gStandalone.engine != nullptr)
+        return gStandalone.engine->getMaxPluginNumber();
+
+    return 0;
+}
+
+// -------------------------------------------------------------------------------------------------------------------
+
 bool carla_add_plugin(BinaryType btype, PluginType ptype, const char* filename, const char* name, const char* label, int64_t uniqueId, const void* extraPtr)
 {
     CARLA_SAFE_ASSERT_RETURN(label != nullptr /*&& label[0] != '\0'*/, false);
diff --git a/source/backend/engine/CarlaEngine.cpp b/source/backend/engine/CarlaEngine.cpp
index 141abd314..3ea479567 100644
--- a/source/backend/engine/CarlaEngine.cpp
+++ b/source/backend/engine/CarlaEngine.cpp
@@ -729,7 +729,7 @@ bool CarlaEngine::replacePlugin(const uint id) noexcept
     carla_debug("CarlaEngine::replacePlugin(%i)", id);
 
     // might use this to reset
-    if (id == pData->curPluginCount || id == pData->maxPluginNumber)
+    if (id == pData->maxPluginNumber)
     {
         pData->nextPluginId = pData->maxPluginNumber;
         return true;
diff --git a/source/carla b/source/carla
index 3ecfdc540..df99b0395 100755
--- a/source/carla
+++ b/source/carla
@@ -79,7 +79,6 @@ class CarlaMultiW(QTabWidget):
 
         parent.ui.act_canvas_show_internal.triggered.connect(self.fPatchbay.slot_canvasShowInternal)
         parent.ui.act_canvas_show_external.triggered.connect(self.fPatchbay.slot_canvasShowExternal)
-        parent.ui.act_canvas_arrange.setEnabled(False) # TODO, later
         parent.ui.act_canvas_arrange.triggered.connect(self.fPatchbay.slot_canvasArrange)
         parent.ui.act_canvas_refresh.triggered.connect(self.fPatchbay.slot_canvasRefresh)
         parent.ui.act_canvas_zoom_fit.triggered.connect(self.fPatchbay.slot_canvasZoomFit)
@@ -89,8 +88,20 @@ class CarlaMultiW(QTabWidget):
         parent.ui.act_canvas_print.triggered.connect(self.fPatchbay.slot_canvasPrint)
         parent.ui.act_canvas_save_image.triggered.connect(self.fPatchbay.slot_canvasSaveImage)
 
+        # TODO, later
+        parent.ui.act_canvas_arrange.setEnabled(False)
+
         parent.ui.act_settings_configure.triggered.connect(self.fPatchbay.slot_configureCarla)
 
+        host.PluginAddedCallback.connect(self.fRack.slot_handlePluginAddedCallback)
+        host.PluginAddedCallback.connect(self.fPatchbay.slot_handlePluginAddedCallback)
+        host.PluginRemovedCallback.connect(self.fRack.slot_handlePluginRemovedCallback)
+        host.PluginRemovedCallback.connect(self.fPatchbay.slot_handlePluginRemovedCallback)
+        host.PluginRenamedCallback.connect(self.fRack.slot_handlePluginRenamedCallback)
+        host.PluginRenamedCallback.connect(self.fPatchbay.slot_handlePluginRenamedCallback)
+        host.PluginUnavailableCallback.connect(self.fRack.slot_handlePluginUnavailableCallback)
+        host.PluginUnavailableCallback.connect(self.fPatchbay.slot_handlePluginUnavailableCallback)
+
         host.ParameterValueChangedCallback.connect(self.fRack.slot_handleParameterValueChangedCallback)
         host.ParameterValueChangedCallback.connect(self.fPatchbay.slot_handleParameterValueChangedCallback)
         host.ParameterDefaultChangedCallback.connect(self.fRack.slot_handleParameterDefaultChangedCallback)
@@ -124,24 +135,16 @@ class CarlaMultiW(QTabWidget):
 
     # -----------------------------------------------------------------
 
-    def getPluginCount(self):
-        return self.fRack.getPluginCount()
-
-    # -----------------------------------------------------------------
-
-    def addPlugin(self, pluginId, isProjectLoading):
-        self.fRack.addPlugin(pluginId, isProjectLoading)
-        self.fPatchbay.addPlugin(pluginId, isProjectLoading)
-
-    def removePlugin(self, pluginId):
-        self.fRack.removePlugin(pluginId)
-        self.fPatchbay.removePlugin(pluginId)
+    def fixCanvasPreviewSize(self):
+        self.fPatchbay.resize(self.fRack.size())
+        self.fPatchbay.slot_miniCanvasCheckSize()
 
-    def renamePlugin(self, pluginId, newName):
-        self.fRack.renamePlugin(pluginId, newName)
+    def setUseCustomPaint(self, useCustomPaint):
+        if self.fUseCustomPaint != useCustomPaint:
+            self.fUseCustomPaint = useCustomPaint
+            self.update()
 
-    def disablePlugin(self, pluginId, errorMsg):
-        self.fRack.disablePlugin(pluginId, errorMsg)
+    # -----------------------------------------------------------------
 
     def removeAllPlugins(self):
         self.fRack.removeAllPlugins()
@@ -150,12 +153,12 @@ class CarlaMultiW(QTabWidget):
     # -----------------------------------------------------------------
 
     def engineStarted(self):
-        pass
-        #self.fRack.engineStarted()
-        #self.fPatchbay.engineStarted()
+        self.fRack.engineStarted()
+        self.fPatchbay.engineStarted()
+        self.fParent.engineStarted()
 
     def engineStopped(self):
-        #self.fRack.engineStopped()
+        self.fRack.engineStopped()
         self.fPatchbay.engineStopped()
         self.fParent.engineStopped()
 
@@ -173,7 +176,7 @@ class CarlaMultiW(QTabWidget):
 
     def projectLoadingStarted(self):
         self.fRack.projectLoadingStarted()
-        #self.fPatchbay.projectLoadingStarted()
+        self.fPatchbay.projectLoadingStarted()
 
     def projectLoadingFinished(self):
         self.fRack.projectLoadingFinished()
@@ -182,6 +185,7 @@ class CarlaMultiW(QTabWidget):
     # -----------------------------------------------------------------
 
     def saveSettings(self, settings):
+        self.fRack.saveSettings(settings)
         self.fPatchbay.saveSettings(settings)
 
     def showEditDialog(self, pluginId):
@@ -189,15 +193,6 @@ class CarlaMultiW(QTabWidget):
 
     # -----------------------------------------------------------------
 
-    def fixCanvasPreviewSize(self):
-        self.fPatchbay.resize(self.fRack.size())
-        self.fPatchbay.slot_miniCanvasCheckSize()
-
-    def setUseCustomPaint(self, useCustomPaint):
-        if self.fUseCustomPaint != useCustomPaint:
-            self.fUseCustomPaint = useCustomPaint
-            self.update()
-
     def paintEvent(self, event):
         QTabWidget.paintEvent(self, event)
 
@@ -257,14 +252,17 @@ class CarlaHostW(HostWindow):
 
     # -----------------------------------------------------------------
 
+    def engineChanged(self):
+        self.fInfoText = "Engine running | SampleRate: %g | BufferSize: %i" % (self.host.get_sample_rate(), self.host.get_buffer_size())
+        self.fInfoLabel.setText("%s | %s" % (self.fInfoText, self.fTextTransport))
+
+    def engineStarted(self):
+        self.engineChanged()
+
     def engineStopped(self):
         self.fInfoText = ""
         self.fInfoLabel.setText("Engine stopped")
 
-    #def engineChanged(self):
-        #self.fInfoText = "Engine running | SampleRate: %g | BufferSize: %i" % (gCarla.sampleRate, gCarla.bufferSize)
-        #self.fInfoLabel.setText("%s | %s" % (self.fInfoText, self.fTextTransport))
-
     # -----------------------------------------------------------------
 
     def updateInfoLabelXandSize(self):
diff --git a/source/carla_backend.py b/source/carla_backend.py
index a7f4bad64..521d40a0e 100644
--- a/source/carla_backend.py
+++ b/source/carla_backend.py
@@ -1514,6 +1514,17 @@ class CarlaHostMeta(QObject):
     def get_transport_info(self):
         raise NotImplementedError
 
+    # Current number of plugins loaded.
+    @abstractmethod
+    def get_current_plugin_count(self):
+        raise NotImplementedError
+
+    # Maximum number of loadable plugins allowed.
+    # Returns 0 if engine is not started.
+    @abstractmethod
+    def get_max_plugin_number(self):
+        raise NotImplementedError
+
     # Add a new plugin.
     # If you don't know the binary type use the BINARY_NATIVE macro.
     # @param btype    Binary type
@@ -2035,6 +2046,12 @@ class CarlaHostNull(CarlaHostMeta):
     def get_transport_info(self):
         return PyCarlaTransportInfo
 
+    def get_current_plugin_count(self):
+        return 0
+
+    def get_max_plugin_number(self):
+        return 0
+
     def add_plugin(self, btype, ptype, filename, name, label, uniqueId, extraPtr):
         return False
 
@@ -2311,6 +2328,12 @@ class CarlaHostDLL(CarlaHostMeta):
         self.lib.carla_get_transport_info.argtypes = None
         self.lib.carla_get_transport_info.restype = POINTER(CarlaTransportInfo)
 
+        self.lib.carla_get_current_plugin_count.argtypes = None
+        self.lib.carla_get_current_plugin_count.restype = c_uint32
+
+        self.lib.carla_get_max_plugin_number.argtypes = None
+        self.lib.carla_get_max_plugin_number.restype = c_uint32
+
         self.lib.carla_add_plugin.argtypes = [c_enum, c_enum, c_char_p, c_char_p, c_char_p, c_int64, c_void_p]
         self.lib.carla_add_plugin.restype = c_bool
 
@@ -2579,6 +2602,12 @@ class CarlaHostDLL(CarlaHostMeta):
     def get_transport_info(self):
         return structToDict(self.lib.carla_get_transport_info().contents)
 
+    def get_current_plugin_count(self):
+        return int(self.lib.carla_get_current_plugin_count())
+
+    def get_max_plugin_number(self):
+        return int(self.lib.carla_get_max_plugin_number())
+
     def add_plugin(self, btype, ptype, filename, name, label, uniqueId, extraPtr):
         cfilename = filename.encode("utf-8") if filename else None
         cname     = name.encode("utf-8") if name else None
@@ -2912,6 +2941,12 @@ class CarlaHostPlugin(CarlaHostMeta):
     def get_transport_info(self):
         return self.fTransportInfo
 
+    def get_current_plugin_count(self):
+        return len(self.fPluginsInfo)
+
+    def get_max_plugin_number(self):
+        return 0 # TODO
+
     def add_plugin(self, btype, ptype, filename, name, label, uniqueId, extraPtr):
         return self.sendMsgAndSetError(["add_plugin", btype, ptype, filename, name, label, uniqueId])
 
diff --git a/source/carla_host.py b/source/carla_host.py
index 349be4740..85ef616bf 100644
--- a/source/carla_host.py
+++ b/source/carla_host.py
@@ -62,20 +62,17 @@ class HostWidgetMeta(object):
 
     # --------------------------------------------------------------------------------------------------------
 
-    def getPluginCount(self):
-        raise NotImplementedError
-
-    def addPlugin(self, pluginId, isProjectLoading):
-        raise NotImplementedError
+    #def addPlugin(self, pluginId, isProjectLoading):
+        #raise NotImplementedError
 
-    def removePlugin(self, pluginId):
-        raise NotImplementedError
+    #def removePlugin(self, pluginId):
+        #raise NotImplementedError
 
-    def renamePlugin(self, pluginId, newName):
-        raise NotImplementedError
+    #def renamePlugin(self, pluginId, newName):
+        #raise NotImplementedError
 
-    def disablePlugin(self, pluginId, errorMsg):
-        raise NotImplementedError
+    #def disablePlugin(self, pluginId, errorMsg):
+        #raise NotImplementedError
 
     def removeAllPlugins(self):
         raise NotImplementedError
@@ -256,24 +253,14 @@ class HostWindow(QMainWindow):
         self.SIGUSR1.connect(self.slot_handleSIGUSR1)
         self.SIGTERM.connect(self.slot_handleSIGTERM)
 
-        host.DebugCallback.connect(self.slot_handleDebugCallback)
-
-        host.PluginAddedCallback.connect(self.slot_handlePluginAddedCallback)
-        host.PluginRemovedCallback.connect(self.slot_handlePluginRemovedCallback)
-        host.PluginRenamedCallback.connect(self.slot_handlePluginRenamedCallback)
-        host.PluginUnavailableCallback.connect(self.slot_handlePluginUnavailableCallback)
-
-        # parameter (rack, patchbay)
-        # program, midi-program, ui-state (rack, patchbay)
-        # note on, off (rack, patchbay)
-        # update, reload (rack, patchbay)
-        # patchbay
-
         host.EngineStartedCallback.connect(self.slot_handleEngineStartedCallback)
         host.EngineStoppedCallback.connect(self.slot_handleEngineStoppedCallback)
-
         host.SampleRateChangedCallback.connect(self.slot_handleSampleRateChangedCallback)
 
+        host.PluginAddedCallback.connect(self.slot_handlePluginAddedCallback)
+        host.PluginRemovedCallback.connect(self.slot_handlePluginRemovedCallback)
+
+        host.DebugCallback.connect(self.slot_handleDebugCallback)
         host.InfoCallback.connect(self.slot_handleInfoCallback)
         host.ErrorCallback.connect(self.slot_handleErrorCallback)
         host.QuitCallback.connect(self.slot_handleQuitCallback)
@@ -282,6 +269,7 @@ class HostWindow(QMainWindow):
         # Final setup
 
         self.setProperWindowTitle()
+
         QTimer.singleShot(0, self.slot_engineStart)
 
     # --------------------------------------------------------------------------------------------------------
@@ -299,6 +287,15 @@ class HostWindow(QMainWindow):
     # --------------------------------------------------------------------------------------------------------
     # Called by containers
 
+    def isProjectLoading(self):
+        return self.fIsProjectLoading
+
+    def getSavedSettings(self):
+        return self.fSavedSettings
+
+    def setLoadRDFsNeeded(self):
+        self.fLadspaRdfNeedsUpdate = True
+
     def openSettingsWindow(self, hasCanvas, hasCanvasGL):
         hasEngine = bool(self.fSessionManagerName != "Non Session Manager")
         dialog = CarlaSettingsW(self, self.host, hasCanvas, hasCanvasGL, hasEngine)
@@ -336,6 +333,19 @@ class HostWindow(QMainWindow):
         self.ui.miniCanvasPreview.setViewTheme(canvasBg, canvasBrush, canvasPen)
         self.ui.miniCanvasPreview.init(self.fContainer.scene, canvasWidth, canvasHeight, self.fSavedSettings[CARLA_KEY_CUSTOM_PAINTING])
 
+    # --------------------------------------------------------------------------------------------------------
+    # Called by the signal handler
+
+    @pyqtSlot()
+    def slot_handleSIGUSR1(self):
+        print("Got SIGUSR1 -> Saving project now")
+        self.slot_fileSave()
+
+    @pyqtSlot()
+    def slot_handleSIGTERM(self):
+        print("Got SIGTERM -> Closing now")
+        self.close()
+
     # --------------------------------------------------------------------------------------------------------
     # Internal stuff (files)
 
@@ -382,7 +392,7 @@ class HostWindow(QMainWindow):
 
         newFile = True
 
-        if self.fContainer.getPluginCount() > 0:
+        if self.host.get_current_plugin_count() > 0:
             ask = QMessageBox.question(self, self.tr("Question"), self.tr("There are some plugins loaded, do you want to remove them now?"),
                                                                           QMessageBox.Yes | QMessageBox.No, QMessageBox.No)
             newFile = (ask == QMessageBox.Yes)
@@ -516,7 +526,8 @@ class HostWindow(QMainWindow):
 
     # --------------------------------------------------------------------------------------------------------
 
-    def startEngine(self):
+    @pyqtSlot()
+    def slot_engineStart(self):
         audioDriver = self.setEngineSettings()
 
         if not self.host.engine_init(audioDriver, self.fClientName):
@@ -534,8 +545,9 @@ class HostWindow(QMainWindow):
 
         self.fFirstEngineInit = False
 
-    def stopEngine(self):
-        if self.fContainer.getPluginCount() > 0:
+    @pyqtSlot()
+    def slot_engineStop(self):
+        if self.host.get_current_plugin_count() > 0:
             ask = QMessageBox.question(self, self.tr("Warning"), self.tr("There are still some plugins loaded, you need to remove them to stop the engine.\n"
                                                                          "Do you want to do this now?"),
                                                                          QMessageBox.Yes | QMessageBox.No, QMessageBox.No)
@@ -550,7 +562,10 @@ class HostWindow(QMainWindow):
 
     # --------------------------------------------------------------------------------------------------------
 
-    def handleEngineStarted(self):
+    @pyqtSlot(str)
+    def slot_handleEngineStartedCallback(self, processMode, transportMode, driverName):
+        self.fSampleRate = self.host.get_sample_rate()
+
         check = self.host.is_engine_running()
         self.ui.menu_PluginMacros.setEnabled(check)
         self.ui.menu_Canvas.setEnabled(check)
@@ -572,7 +587,12 @@ class HostWindow(QMainWindow):
             self.refreshTransport(True)
             self.fContainer.engineStarted()
 
-    def handleEngineStopped(self):
+        self.startTimers()
+
+    @pyqtSlot()
+    def slot_handleEngineStoppedCallback(self):
+        self.killTimers()
+
         # just in case
         self.ui.act_plugin_remove_all.setEnabled(False)
         self.fContainer.removeAllPlugins()
@@ -596,62 +616,80 @@ class HostWindow(QMainWindow):
             self.fTextTransport = ""
             self.fContainer.engineStopped()
 
+        self.fSampleRate = 0.0
+
+    @pyqtSlot(float)
+    def slot_handleSampleRateChangedCallback(self, newSampleRate):
+        self.fSampleRate = newSampleRate
+        self.refreshTransport(True)
+
     # --------------------------------------------------------------------------------------------------------
+    # Internal stuff (plugins)
 
     @pyqtSlot()
-    def slot_engineStart(self):
-        self.startEngine()
-        #self.handleEngineStarted()
+    def slot_pluginAdd(self, pluginToReplace = -1):
+        dialog = PluginDatabaseW(self, self.host)
 
-    @pyqtSlot()
-    def slot_engineStop(self):
-        self.stopEngine()
-        #self.handleEngineStopped()
+        if not dialog.exec_():
+            return
 
-    # --------------------------------------------------------------------------------------------------------
+        if not self.host.is_engine_running():
+            QMessageBox.warning(self, self.tr("Warning"), self.tr("Cannot add new plugins while engine is stopped"))
+            return
 
-    @pyqtSlot(str)
-    def slot_handleEngineStartedCallback(self, processMode, transportMode, driverName):
-        self.fSampleRate = self.host.get_sample_rate()
-        self.handleEngineStarted()
-        self.startTimers()
+        btype    = dialog.fRetPlugin['build']
+        ptype    = dialog.fRetPlugin['type']
+        filename = dialog.fRetPlugin['filename']
+        label    = dialog.fRetPlugin['label']
+        uniqueId = dialog.fRetPlugin['uniqueId']
+        extraPtr = self.getExtraPtr(dialog.fRetPlugin)
+
+        if pluginToReplace >= 0:
+            if not self.host.replace_plugin(pluginToReplace):
+                CustomMessageBox(self, QMessageBox.Critical, self.tr("Error"), self.tr("Failed to replace plugin"), self.host.get_last_error(), QMessageBox.Ok, QMessageBox.Ok)
+                return
+
+        ok = self.host.add_plugin(btype, ptype, filename, None, label, uniqueId, extraPtr)
+
+        if pluginToReplace >= 0:
+            self.host.replace_plugin(self.host.get_max_plugin_number())
+
+        if not ok:
+            CustomMessageBox(self, QMessageBox.Critical, self.tr("Error"), self.tr("Failed to load plugin"), self.host.get_last_error(), QMessageBox.Ok, QMessageBox.Ok)
 
     @pyqtSlot()
-    def slot_handleEngineStoppedCallback(self):
-        self.killTimers()
-        self.handleEngineStopped()
-        self.fSampleRate = 0.0
+    def slot_pluginRemoveAll(self):
+        self.ui.act_plugin_remove_all.setEnabled(False)
 
-    # --------------------------------------------------------------------------------------------------------
-    # Internal stuff (timers)
+        count = self.host.get_current_plugin_count()
 
-    def startTimers(self):
-        if self.fIdleTimerFast == 0:
-            self.fIdleTimerFast = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL])
+        if count == 0:
+            return
 
-        if self.fIdleTimerSlow == 0:
-            self.fIdleTimerSlow = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL]*4)
+        self.fContainer.projectLoadingStarted()
 
-    def restartTimersIfNeeded(self):
-        if self.fIdleTimerFast != 0:
-            self.killTimer(self.fIdleTimerFast)
-            self.fIdleTimerFast = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL])
+        app = QApplication.instance()
+        for i in range(count):
+            app.processEvents()
+            self.host.remove_plugin(count-i-1)
 
-        if self.fIdleTimerSlow != 0:
-            self.killTimer(self.fIdleTimerSlow)
-            self.fIdleTimerSlow = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL]*4)
+        self.fContainer.projectLoadingFinished()
 
-    def killTimers(self):
-        if self.fIdleTimerFast != 0:
-            self.killTimer(self.fIdleTimerFast)
-            self.fIdleTimerFast = 0
+        #self.fContainer.removeAllPlugins()
+        #self.host.remove_all_plugins()
 
-        if self.fIdleTimerSlow != 0:
-            self.killTimer(self.fIdleTimerSlow)
-            self.fIdleTimerSlow = 0
+    # --------------------------------------------------------------------------------------------------------
 
-    # -----------------------------------------------------------------
-    # Internal stuff (plugins)
+    @pyqtSlot(int, str)
+    def slot_handlePluginAddedCallback(self, pluginId, pluginName):
+        self.ui.act_plugin_remove_all.setEnabled(self.host.get_current_plugin_count() > 0)
+
+    @pyqtSlot(int)
+    def slot_handlePluginRemovedCallback(self, pluginId):
+        self.ui.act_plugin_remove_all.setEnabled(self.host.get_current_plugin_count() > 0)
+
+    # --------------------------------------------------------------------------------------------------------
+    # Internal stuff (plugin data)
 
     def getExtraPtr(self, plugin):
         ptype = plugin['type']
@@ -696,11 +734,35 @@ class HostWindow(QMainWindow):
 
             frLadspa.close()
 
-    # FIXME - put above?
-    def setLoadRDFsNeeded(self):
-        self.fLadspaRdfNeedsUpdate = True
+    # --------------------------------------------------------------------------------------------------------
+    # Internal stuff (timers)
 
-    # -----------------------------------------------------------------
+    def startTimers(self):
+        if self.fIdleTimerFast == 0:
+            self.fIdleTimerFast = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL])
+
+        if self.fIdleTimerSlow == 0:
+            self.fIdleTimerSlow = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL]*4)
+
+    def restartTimersIfNeeded(self):
+        if self.fIdleTimerFast != 0:
+            self.killTimer(self.fIdleTimerFast)
+            self.fIdleTimerFast = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL])
+
+        if self.fIdleTimerSlow != 0:
+            self.killTimer(self.fIdleTimerSlow)
+            self.fIdleTimerSlow = self.startTimer(self.fSavedSettings[CARLA_KEY_MAIN_REFRESH_INTERVAL]*4)
+
+    def killTimers(self):
+        if self.fIdleTimerFast != 0:
+            self.killTimer(self.fIdleTimerFast)
+            self.fIdleTimerFast = 0
+
+        if self.fIdleTimerSlow != 0:
+            self.killTimer(self.fIdleTimerSlow)
+            self.fIdleTimerSlow = 0
+
+    # --------------------------------------------------------------------------------------------------------
     # Internal stuff (transport)
 
     def refreshTransport(self, forced = False):
@@ -708,8 +770,8 @@ class HostWindow(QMainWindow):
             return
 
         timeInfo = self.host.get_transport_info()
-        playing  = bool(timeInfo['playing'])
-        frame    = int(timeInfo['frame'])
+        playing  = timeInfo['playing']
+        frame    = timeInfo['frame']
 
         if playing != self.fLastTransportState or forced:
             if playing:
@@ -741,6 +803,48 @@ class HostWindow(QMainWindow):
         self.ui.act_transport_forwards.setEnabled(enabled)
         self.ui.menu_Transport.setEnabled(enabled)
 
+    @pyqtSlot(bool)
+    def slot_transportPlayPause(self, toggled):
+        if not self.host.is_engine_running():
+            return
+
+        if toggled:
+            self.host.transport_play()
+        else:
+            self.host.transport_pause()
+
+        self.refreshTransport()
+
+    @pyqtSlot()
+    def slot_transportStop(self):
+        if not self.host.is_engine_running():
+            return
+
+        self.host.transport_pause()
+        self.host.transport_relocate(0)
+
+        self.refreshTransport()
+
+    @pyqtSlot()
+    def slot_transportBackwards(self):
+        if not self.host.is_engine_running():
+            return
+
+        newFrame = self.host.get_current_transport_frame() - 100000
+
+        if newFrame < 0:
+            newFrame = 0
+
+        self.host.transport_relocate(newFrame)
+
+    @pyqtSlot()
+    def slot_transportForwards(self):
+        if not self.host.is_engine_running():
+            return
+
+        newFrame = self.host.get_current_transport_frame() + 100000
+        self.host.transport_relocate(newFrame)
+
     # -----------------------------------------------------------------
     # Internal stuff (settings)
 
@@ -818,131 +922,6 @@ class HostWindow(QMainWindow):
     # -----------------------------------------------------------------
     # Internal stuff (gui)
 
-    @pyqtSlot()
-    def slot_pluginAdd(self, pluginToReplace = -1):
-        dialog = PluginDatabaseW(self, self.host)
-
-        if not dialog.exec_():
-            return
-
-        if not self.host.is_engine_running():
-            QMessageBox.warning(self, self.tr("Warning"), self.tr("Cannot add new plugins while engine is stopped"))
-            return
-
-        btype    = dialog.fRetPlugin['build']
-        ptype    = dialog.fRetPlugin['type']
-        filename = dialog.fRetPlugin['filename']
-        label    = dialog.fRetPlugin['label']
-        uniqueId = dialog.fRetPlugin['uniqueId']
-        extraPtr = self.getExtraPtr(dialog.fRetPlugin)
-
-        if pluginToReplace >= 0:
-            if not self.host.replace_plugin(pluginToReplace):
-                CustomMessageBox(self, QMessageBox.Critical, self.tr("Error"), self.tr("Failed to replace plugin"), self.host.get_last_error(), QMessageBox.Ok, QMessageBox.Ok)
-                return
-
-        ok = self.host.add_plugin(btype, ptype, filename, None, label, uniqueId, extraPtr)
-
-        if pluginToReplace >= 0:
-            self.host.replace_plugin(self.fContainer.getPluginCount())
-
-        if not ok:
-            CustomMessageBox(self, QMessageBox.Critical, self.tr("Error"), self.tr("Failed to load plugin"), self.host.get_last_error(), QMessageBox.Ok, QMessageBox.Ok)
-
-    @pyqtSlot()
-    def slot_pluginRemoveAll(self):
-        self.ui.act_plugin_remove_all.setEnabled(False)
-
-        count = self.fContainer.getPluginCount()
-
-        if count == 0:
-            return
-
-        self.fContainer.projectLoadingStarted()
-
-        app = QApplication.instance()
-        for i in range(count):
-            app.processEvents()
-            self.host.remove_plugin(count-i-1)
-
-        self.fContainer.projectLoadingFinished()
-
-        #self.fContainer.removeAllPlugins()
-        #self.host.remove_all_plugins()
-
-    # -----------------------------------------------------------------
-
-    # TODO clear this, move them into containers
-    @pyqtSlot(int, str)
-    def slot_handlePluginAddedCallback(self, pluginId, pluginName):
-        self.fContainer.addPlugin(pluginId, self.fIsProjectLoading)
-
-        # FIXME ask host directly for plugin count
-        if self.fContainer.getPluginCount() == 1:
-            self.ui.act_plugin_remove_all.setEnabled(True)
-
-    @pyqtSlot(int)
-    def slot_handlePluginRemovedCallback(self, pluginId):
-        self.fContainer.removePlugin(pluginId)
-
-        # FIXME ask host directly for plugin count
-        if self.fContainer.getPluginCount() == 0:
-            self.ui.act_plugin_remove_all.setEnabled(False)
-
-    @pyqtSlot(int, str)
-    def slot_handlePluginRenamedCallback(self, pluginId, newName):
-        self.fContainer.renamePlugin(pluginId, newName)
-
-    @pyqtSlot(int, str)
-    def slot_handlePluginUnavailableCallback(self, pluginId, errorMsg):
-        self.fContainer.disablePlugin(pluginId, errorMsg)
-
-    # -----------------------------------------------------------------
-
-    @pyqtSlot(bool)
-    def slot_transportPlayPause(self, toggled):
-        if not self.host.is_engine_running():
-            return
-
-        if toggled:
-            self.host.transport_play()
-        else:
-            self.host.transport_pause()
-
-        self.refreshTransport()
-
-    @pyqtSlot()
-    def slot_transportStop(self):
-        if not self.host.is_engine_running():
-            return
-
-        self.host.transport_pause()
-        self.host.transport_relocate(0)
-
-        self.refreshTransport()
-
-    @pyqtSlot()
-    def slot_transportBackwards(self):
-        if not self.host.is_engine_running():
-            return
-
-        newFrame = self.host.get_current_transport_frame() - 100000
-
-        if newFrame < 0:
-            newFrame = 0
-
-        self.host.transport_relocate(newFrame)
-
-    @pyqtSlot()
-    def slot_transportForwards(self):
-        if not self.host.is_engine_running():
-            return
-
-        newFrame = self.host.get_current_transport_frame() + 100000
-        self.host.transport_relocate(newFrame)
-
-    # -----------------------------------------------------------------
-
     @pyqtSlot()
     def slot_aboutCarla(self):
         CarlaAboutW(self, self.host).exec_()
@@ -1008,16 +987,6 @@ class HostWindow(QMainWindow):
     @pyqtSlot(int, int, int, float, str)
     def slot_handleDebugCallback(self, pluginId, value1, value2, value3, valueStr):
         print("DEBUG:", pluginId, value1, value2, value3, valueStr)
-        #self.ui.pte_log.appendPlainText(valueStr.replace("", "DEBUG: ").replace("", "ERROR: ").replace("", "").replace("\n", ""))
-
-    # -----------------------------------------------------------------
-
-    @pyqtSlot(float)
-    def slot_handleSampleRateChangedCallback(self, newSampleRate):
-        self.fSampleRate = newSampleRate
-        self.refreshTransport(True)
-
-    # -----------------------------------------------------------------
 
     @pyqtSlot(str)
     def slot_handleInfoCallback(self, info):
@@ -1029,19 +998,7 @@ class HostWindow(QMainWindow):
 
     @pyqtSlot()
     def slot_handleQuitCallback(self):
-        pass
-
-    # -----------------------------------------------------------------
-
-    @pyqtSlot()
-    def slot_handleSIGUSR1(self):
-        print("Got SIGUSR1 -> Saving project now")
-        self.slot_fileSave()
-
-    @pyqtSlot()
-    def slot_handleSIGTERM(self):
-        print("Got SIGTERM -> Closing now")
-        self.close()
+        pass # TODO
 
     # -----------------------------------------------------------------
 
@@ -1082,7 +1039,7 @@ class HostWindow(QMainWindow):
         elif self.host.is_engine_running():
             self.host.set_engine_about_to_close()
 
-            count = self.fContainer.getPluginCount()
+            count = self.host.get_current_plugin_count()
 
             if count > 0:
                 # simulate project loading, to disable container
@@ -1099,7 +1056,7 @@ class HostWindow(QMainWindow):
                 #self.fContainer.removeAllPlugins()
                 #self.host.remove_all_plugins()
 
-            self.stopEngine()
+            self.slot_engineStop()
 
         QMainWindow.closeEvent(self, event)
 
diff --git a/source/carla_patchbay.py b/source/carla_patchbay.py
index 6a1338080..ecdb995c6 100644
--- a/source/carla_patchbay.py
+++ b/source/carla_patchbay.py
@@ -231,6 +231,10 @@ class CarlaPatchbayW(QFrame, PluginEditParentMeta):
 
         parent.ui.act_settings_configure.triggered.connect(self.slot_configureCarla)
 
+        host.PluginAddedCallback.connect(self.slot_handlePluginAddedCallback)
+        host.PluginRemovedCallback.connect(self.slot_handlePluginRemovedCallback)
+        host.PluginRenamedCallback.connect(self.slot_handlePluginRenamedCallback)
+        host.PluginUnavailableCallback.connect(self.slot_handlePluginUnavailableCallback)
         host.ParameterValueChangedCallback.connect(self.slot_handleParameterValueChangedCallback)
         host.ParameterDefaultChangedCallback.connect(self.slot_handleParameterDefaultChangedCallback)
         host.ParameterMidiChannelChangedCallback.connect(self.slot_handleParameterMidiChannelChangedCallback)
@@ -677,6 +681,24 @@ class CarlaPatchbayW(QFrame, PluginEditParentMeta):
 
     # -----------------------------------------------------------------
 
+    @pyqtSlot(int, str)
+    def slot_handlePluginAddedCallback(self, pluginId, pluginName):
+        self.addPlugin(pluginId, self.fParent.isProjectLoading())
+
+    @pyqtSlot(int)
+    def slot_handlePluginRemovedCallback(self, pluginId):
+        self.removePlugin(pluginId)
+
+    @pyqtSlot(int, str)
+    def slot_handlePluginRenamedCallback(self, pluginId, newName):
+        self.renamePlugin(pluginId, newName)
+
+    @pyqtSlot(int, str)
+    def slot_handlePluginUnavailableCallback(self, pluginId, errorMsg):
+        self.disablePlugin(pluginId, errorMsg)
+
+    # -----------------------------------------------------------------
+
     @pyqtSlot(int, int, float)
     def slot_handleParameterValueChangedCallback(self, pluginId, index, value):
         if pluginId >= self.fPluginCount:
@@ -911,7 +933,7 @@ class CarlaPatchbayW(QFrame, PluginEditParentMeta):
         if pluginId < 0:
             return
         if pluginId >= self.fPluginCount:
-            print("sorry, can't map this plugin to canvas client", pluginId, self.getPluginCount())
+            print("sorry, can't map this plugin to canvas client", pluginId, self.fPluginCount)
             return
 
         patchcanvas.setGroupAsPlugin(clientId, pluginId, bool(self.host.get_plugin_info(pluginId)['hints'] & PLUGIN_HAS_CUSTOM_UI))
diff --git a/source/carla_rack.py b/source/carla_rack.py
index 2e3fc62b4..3977e4d6b 100644
--- a/source/carla_rack.py
+++ b/source/carla_rack.py
@@ -84,6 +84,7 @@ class CarlaRackList(QListWidget):
         if False:
             # kdevelop likes this :)
             host = CarlaHostMeta()
+            self.host = host
 
         # -------------------------------------------------------------
 
@@ -210,6 +211,7 @@ class CarlaRackW(QFrame):
         if False:
             # kdevelop likes this :)
             host = CarlaHostMeta()
+            self.host = host
 
         # -------------------------------------------------------------
 
@@ -305,6 +307,10 @@ class CarlaRackW(QFrame):
 
         parent.ui.act_settings_configure.triggered.connect(self.slot_configureCarla)
 
+        host.PluginAddedCallback.connect(self.slot_handlePluginAddedCallback)
+        host.PluginRemovedCallback.connect(self.slot_handlePluginRemovedCallback)
+        host.PluginRenamedCallback.connect(self.slot_handlePluginRenamedCallback)
+        host.PluginUnavailableCallback.connect(self.slot_handlePluginUnavailableCallback)
         host.ParameterValueChangedCallback.connect(self.slot_handleParameterValueChangedCallback)
         host.ParameterDefaultChangedCallback.connect(self.slot_handleParameterDefaultChangedCallback)
         host.ParameterMidiChannelChangedCallback.connect(self.slot_handleParameterMidiChannelChangedCallback)
@@ -323,11 +329,6 @@ class CarlaRackW(QFrame):
 
     # -----------------------------------------------------------------
 
-    def getPluginCount(self):
-        return self.fPluginCount
-
-    # -----------------------------------------------------------------
-
     def addPlugin(self, pluginId, isProjectLoading):
         pitem = CarlaRackItem(self.fRack, pluginId)
 
@@ -542,6 +543,24 @@ class CarlaRackW(QFrame):
 
     # -----------------------------------------------------------------
 
+    @pyqtSlot(int, str)
+    def slot_handlePluginAddedCallback(self, pluginId, pluginName):
+        self.addPlugin(pluginId, self.fParent.isProjectLoading())
+
+    @pyqtSlot(int)
+    def slot_handlePluginRemovedCallback(self, pluginId):
+        self.removePlugin(pluginId)
+
+    @pyqtSlot(int, str)
+    def slot_handlePluginRenamedCallback(self, pluginId, newName):
+        self.renamePlugin(pluginId, newName)
+
+    @pyqtSlot(int, str)
+    def slot_handlePluginUnavailableCallback(self, pluginId, errorMsg):
+        self.disablePlugin(pluginId, errorMsg)
+
+    # -----------------------------------------------------------------
+
     @pyqtSlot(int, int, float)
     def slot_handleParameterValueChangedCallback(self, pluginId, index, value):
         if pluginId >= self.fPluginCount: