Set stage icon for monitor depending on output device state, prevent crash when accessing back-end from unloaded component

plugins/MonitorStage/MonitorStage.py

@@ -16,7 +16,8 @@ class MonitorStage(CuraStage):
         # Wait until QML engine is created, otherwise creating the new QML components will fail
         Application.getInstance().engineCreatedSignal.connect(self._setComponents)
 
-        # TODO: connect output device state to icon source
+        # Update the status icon when the output device is changed
+        Application.getInstance().getOutputDeviceManager().activeDeviceChanged.connect(self._setIconSource)
 
     def _setComponents(self):
         self._setMainOverlay()
@@ -34,41 +35,39 @@ class MonitorStage(CuraStage):
 
     def _setIconSource(self):
         if Application.getInstance().getTheme() is not None:
-            self.setIconSource(Application.getInstance().getTheme().getIcon("tab_status_connected"))
+            icon_name = self._getActiveOutputDeviceStatusIcon()
+            self.setIconSource(Application.getInstance().getTheme().getIcon(icon_name))
 
-# property string iconSource:
+    ##  Find the correct status icon depending on the active output device state
-# //            {
+    def _getActiveOutputDeviceStatusIcon(self):
-# //                if (!printerConnected)
+        output_device = Application.getInstance().getOutputDeviceManager().getActiveDevice()
-# //                {
+
-# //                    return UM.Theme.getIcon("tab_status_unknown");
+        if not output_device:
-# //                }
+            return "tab_status_unknown"
-# //                else if (!printerAcceptsCommands)
+
-# //                {
+        if hasattr(output_device, "acceptsCommands") and not output_device.acceptsCommands:
-# //                    return UM.Theme.getIcon("tab_status_unknown");
+            return "tab_status_unknown"
-# //                }
+
-# //
+        if not hasattr(output_device, "printerState") or not hasattr(output_device, "jobState"):
-# //                if (Cura.MachineManager.printerOutputDevices[0].printerState == "maintenance")
+            return "tab_status_unknown"
-# //                {
+
-# //                    return UM.Theme.getIcon("tab_status_busy");
+        # TODO: refactor to use enum instead of hardcoded strings?
-# //                }
+        if output_device.printerState == "maintenance":
-# //
+            return "tab_status_busy"
-# //                switch (Cura.MachineManager.printerOutputDevices[0].jobState)
+
-# //                {
+        if output_device.jobState in ["printing", "pre_print", "pausing", "resuming"]:
-# //                    case "printing":
+            return "tab_status_busy"
-# //                    case "pre_print":
+
-# //                    case "pausing":
+        if output_device.jobState == "wait_cleanup":
-# //                    case "resuming":
+            return "tab_status_finished"
-# //                        return UM.Theme.getIcon("tab_status_busy");
+
-# //                    case "wait_cleanup":
+        if output_device.jobState in ["ready", ""]:
-# //                        return UM.Theme.getIcon("tab_status_finished");
+            return "tab_status_connected"
-# //                    case "ready":
+
-# //                    case "":
+        if output_device.jobState == "paused":
-# //                        return UM.Theme.getIcon("tab_status_connected")
+            return "tab_status_paused"
-# //                    case "paused":
+
-# //                        return UM.Theme.getIcon("tab_status_paused")
+        if output_device.jobState == "error":
-# //                    case "error":
+            return "tab_status_stopped"
-# //                        return UM.Theme.getIcon("tab_status_stopped")
+
-# //                    default:
+        return "tab_status_unknown"
-# //                        return UM.Theme.getIcon("tab_status_unknown")
-# //                }
-# //            }

resources/qml/Cura.qml

@@ -378,7 +378,6 @@ UM.MainWindow
                 z: 1
 
                 source: UM.Controller.activeStage.sidebarComponent
-                asynchronous: true
             }
 
             Loader
@@ -402,7 +401,6 @@ UM.MainWindow
                 }
 
                 source: UM.Controller.activeStage.mainComponent
-                asynchronous: true
             }
 
             UM.MessageStack

resources/qml/SaveButton.qml

@@ -46,7 +46,7 @@ Item {
     }
 
     function sliceOrStopSlicing() {
-        if ([1, 5].indexOf(UM.Backend.state) != -1) {
+        if (backend != "undefined" && [1, 5].indexOf(UM.Backend.state) != -1) {
             backend.forceSlice();
         } else {
             backend.stopSlicing();