Use separate face controller for appearance config

This is a workaround for the page being totally broken on when opened
again after the dialog was closed for the first time. Using a new controller
works around that.
BUG:424458

applets/systemmonitor/systemmonitor/package/contents/ui/config/ConfigAppearance.qml

@@ -39,10 +39,12 @@ QQC2.Control {
 
     function saveConfig() {
         contentItem.saveConfig();
+        plasmoid.nativeInterface.faceController.reloadConfig()
     }
-    
-    contentItem: plasmoid.nativeInterface.faceController.appearanceConfigUi
-    
+
+    // Workaround for Bug 424458, when reusing the controller/item things break
+    contentItem: plasmoid.nativeInterface.workaroundController(root).appearanceConfigUi
+
     Connections {
         target: contentItem
         function onConfigurationChanged() {

applets/systemmonitor/systemmonitor/systemmonitor.cpp

@@ -77,6 +77,13 @@ KSysGuard::SensorFaceController *SystemMonitor::faceController() const
     return m_sensorFaceController;
 }
 
+KSysGuard::SensorFaceController *SystemMonitor::workaroundController(QQuickItem *context) const
+{
+    KConfigGroup cg = config();
+    return new KSysGuard::SensorFaceController(cg, qmlEngine(context));
+}
+
+
 void SystemMonitor::configChanged()
 {
     if (m_sensorFaceController) {

applets/systemmonitor/systemmonitor/systemmonitor.h

@@ -52,6 +52,9 @@ public:
 
     KSysGuard::SensorFaceController *faceController() const;
 
+    // Workaround for Bug 424458, when reusing the controller/item things break in ConfigAppearance
+    Q_INVOKABLE KSysGuard::SensorFaceController *workaroundController(QQuickItem *context) const;
+
 public Q_SLOTS:
     void configChanged() override;