Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Common/LtsMultiMonitor/lts_screen_container.h

@@ -0,0 +1,68 @@
+#pragma once
+
+#include "lts_screen_base.h" 
+
+#include <lts_multi_monitor_export.h> 
+
+#include <QWidget>
+#include <QRect>
+
+
+class QHBoxLayout;
+
+
+namespace LtsMultiMonitor
+{
+class LTSMULTIMONITOR_EXPORT LtsScreenContainer : public QWidget
+{
+  Q_OBJECT
+
+public:
+  LtsScreenContainer(QRect screenGeo);
+
+  bool isIrreplaceable() const;
+  bool isEmpty() const;
+  bool hasMainWidget();
+  bool hasSecondaryWidget();
+  void setWidget(QWidget *widget);
+  bool hasWidget(QWidget *widget) const;
+  QWidget *widget() noexcept(false);
+  QWidget *stealWidget() noexcept(false);
+  void switchToTemp(LtsScreenBase::WidgetType widgetType);
+  void finalizeSwitch();
+  void revertSwitch();
+  bool mainAndSecondaryOccupied() const;
+  QIcon mainWindowIcon() const;
+  QIcon secondaryWindowIcon() const;
+  LtsScreenBase::WidgetType activeWidgetType() const;
+  bool isInactiveWidgetOccupied() const;
+
+signals:
+  void check();
+  void signalSetCornerIcons();
+
+private:
+  QHBoxLayout *m_layout { nullptr };
+  QWidget *m_mainWidget { nullptr }; 
+  QWidget *m_secondaryWidget { nullptr }; 
+  QWidget **m_activeWidget { nullptr };
+  QWidget **m_oldActiveWidget { nullptr };
+  bool m_nullSwitchActive { false };
+  QRect m_screenGeo;
+
+  QString geoStr() const;
+  bool tryPutDummyUnmanaged(QWidget *widget);
+  void vanish();
+  void reappear();
+  QWidget *activeWidget() const;
+  QWidget **activeWidgetPtr();
+
+public slots:
+  void toggle();
+
+private slots:
+  
+  void slotChildDestroyed();
+};
+
+}