#pragma once
 
#ifndef T_UNDO_INCLUDED
#define T_UNDO_INCLUDED
 
#include <memory>
 
// TnzCore includes
#include "tsmartpointer.h"
 
// Qt includes
#include <QObject>
#include <QString>
 
#undef DVAPI
#undef DVVAR
#ifdef TNZCORE_EXPORTS
#define DVAPI DV_EXPORT_API
#define DVVAR DV_EXPORT_VAR
#else
#define DVAPI DV_IMPORT_API
#define DVVAR DV_IMPORT_VAR
#endif
 
//************************************************************************
//    TUndo  class
//************************************************************************
 
class DVAPI TUndo {
public:
  bool m_isLastInBlock;
 
public:
  TUndo() {}
  virtual ~TUndo() {}
 
  virtual int getSize() const = 0;
 
  virtual void undo() const = 0;
  virtual void redo() const = 0;
 
  virtual void onAdd() {}
 
  // for history viewer panel
  virtual QString getHistoryString() {
    return QObject::tr("Unidentified Action");
  }
  virtual int getHistoryType() { return 0; }  // HistoryType::Unidentified
 
private:
  // Noncopyable
  TUndo(const TUndo &undo);
  TUndo &operator=(const TUndo &undo);
};
 
//************************************************************************
//    TUndoManager  class
//************************************************************************
 
class DVAPI TUndoManager final : public QObject {
  Q_OBJECT
 
public:
  TUndoManager();
  ~TUndoManager();
 
  static TUndoManager *manager();
 
  void beginBlock();
  void endBlock();
 
  void add(TUndo *undo);
 
  bool undo();
  bool redo();
 
  void reset();
 
  /*!If forward = false remove n elements in the stack before m_imp->m_current;
else if forward = true remove n elements in the stack after m_imp->m_current.
If n = -1 remove all elements before or after m_imp->m_current.*/
 
  void popUndo(int n = -1, bool forward = false);
 
  //! undo() and redo() methods call TUndoManager::manager()->skip() if
  //! they want another undo/redo performed
 
  void skip();
 
  //! Set the size of memory used for undo redo.
  //! \b memorySyze is expressed in MB
  void setUndoMemorySize(int memorySyze);
 
  // for history viewer pane
  int getHistoryCount();
  int getCurrentHistoryIndex();
  TUndo *getUndoItem(int index);
 
Q_SIGNALS:
 
  void historyChanged();
 
  void somethingChanged();
 
private:
  struct TUndoManagerImp;
  std::unique_ptr<TUndoManagerImp> m_imp;
 
private:
  // Noncopyable
  TUndoManager(const TUndoManager &);
  TUndoManager &operator=(const TUndoManager &);
};
 
//************************************************************************
//    TUndoScopedBlock  class
//************************************************************************
 
struct TUndoScopedBlock {
  TUndoScopedBlock() { TUndoManager::manager()->beginBlock(); }
  ~TUndoScopedBlock() { TUndoManager::manager()->endBlock(); }
 
private:
  // Noncopyable
  TUndoScopedBlock(const TUndoScopedBlock &);
  TUndoScopedBlock &operator=(const TUndoScopedBlock &);
};
 
#endif  // T_UNDO_INCLUDED