quicksettings/screenrotation: Don't call rotate in signal handler

This is a workaround for https://invent.kde.org/plasma/plasma-mobile/-/issues/405, where if the caller gets deleted by the screen rotation, the entire shell crashes.

Eventually, we need to implement
https://invent.kde.org/plasma/plasma-mobile/-/issues/406 to reduce the
amount of oddities we have from recreating the quick settings panel
during screen rotation.

quicksettings/screenrotation/screenrotationutil.cpp

@@ -13,6 +13,7 @@
 
 #include <QDebug>
 #include <QOrientationSensor>
+#include <QTimer>
 
 ScreenRotationUtil::ScreenRotationUtil(QObject *parent)
     : QObject{parent}
@@ -57,6 +58,20 @@ bool ScreenRotationUtil::autoScreenRotationEnabled()
 }
 
 void ScreenRotationUtil::setAutoScreenRotationEnabled(bool value)
+{
+    // Don't execute immediately, in case the screen rotation
+    // deletes the caller mid-function call, causing a crash.
+    QTimer::singleShot(0, this, [this, value]() {
+        actuallySetAutoScreenRotationEnabled(value);
+    });
+}
+
+bool ScreenRotationUtil::isAvailable()
+{
+    return m_sensor->connectToBackend();
+}
+
+void ScreenRotationUtil::actuallySetAutoScreenRotationEnabled(bool value)
 {
     if (!m_config) {
         return;
@@ -76,8 +91,3 @@ void ScreenRotationUtil::setAutoScreenRotationEnabled(bool value)
 
     Q_EMIT autoScreenRotationEnabledChanged();
 }
-
-bool ScreenRotationUtil::isAvailable()
-{
-    return m_sensor->connectToBackend();
-}

quicksettings/screenrotation/screenrotationutil.h

@@ -27,6 +27,8 @@ Q_SIGNALS:
     void availableChanged();
 
 private:
+    void actuallySetAutoScreenRotationEnabled(bool value);
+
     KScreen::ConfigPtr m_config;
     QOrientationSensor *m_sensor;