Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Common/LtsTimeline/timeline_view_selection_handler.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include "timeline_view.h"
+
+#include <LtsTimeline/ltstimeline_export.h>
+
+#include <QRect>
+
+
+class QMouseEvent;
+class QKeyEvent;
+
+
+namespace LtsTimeline
+{
+
+class TimelineView;
+
+
+class LTSTIMELINE_EXPORT TimelineViewSelectHandler
+{
+  friend class TimelineView;
+
+public:
+  explicit TimelineViewSelectHandler(TimelineView *view);
+  virtual ~TimelineViewSelectHandler();
+
+  virtual void mouseDoubleClickEvent(QMouseEvent *e);
+  virtual void mouseMoveEvent(QMouseEvent *e);
+  virtual void mousePressEvent(QMouseEvent *e);
+  virtual void mouseReleaseEvent(QMouseEvent *e);
+  virtual void keyPressEvent(QKeyEvent *e);
+
+  virtual bool isActive() const;
+  virtual bool isRubberBandActive() const { return m_isRubberBandActive; }
+
+protected:
+  virtual QVector<int> getItemsWithinRubberBand() const;
+
+protected:
+  TimelineView *m_view{nullptr};
+  int m_selectedItemId{-1};
+  QRect m_rubberBand;
+  bool m_isRubberBandActive{false};
+
+};
+
+}