#ifndef TDRAGDROP_INCLUDED
#define TDRAGDROP_INCLUDED

//#include "tw/tw.h"
// #include "tdata.h"

#include "tgeometry.h"

#undef DVAPI
#undef DVVAR
#ifdef TWIN_EXPORTS
#define DVAPI DV_EXPORT_API
#define DVVAR DV_EXPORT_VAR
#else
#define DVAPI DV_IMPORT_API
#define DVVAR DV_IMPORT_VAR
#endif

class TDataObject;
class TData;

//////////////////
// Exceptions
//////////////////

class DVAPI TOutOfMemory
{
};
class DVAPI TInitFailed
{
};
class DVAPI TDragDropExpt
{
};

//////////////////
//TDropSource/////
//////////////////

class DVAPI TDropSource
{

#if defined(__GNUC__)
public:
#endif
	class Imp;
#if defined(__GNUC__)
private:
#endif

	Imp *m_imp;

private:
	// not implemented
	TDropSource(const TDropSource &);
	TDropSource &operator=(const TDropSource &);

public:
	enum DropEffect {
		None = 0,
		Copy,
		Move,
		Link,
		CopyScroll,
		MoveScroll,
		LinkScroll
	};

	TDropSource();
	virtual ~TDropSource();

	bool isValid() const;

	DropEffect doDragDrop(const TDataObject &data);

	// viene chiamata durante il drag su un target passando come
	// argomento il valore ritornato dalla onOver() del target
	//virtual CursorToUse setCursor(DropEffect dropEffect);

	virtual void setCursor(DropEffect dropEffect);
};

//////////////////
//TDropTarget/////
//////////////////
//! \brief Ascoltatore degli eventi per il Drag&Drop
class DVAPI TDragDropListener
{
public:
	class Event
	{
	public:
		const TData *const m_data;
		TPoint m_pos;
		unsigned int m_buttonMask;

		Event(TData *data) : m_data(data), m_buttonMask(0){};
	};

	TDragDropListener(){};
	virtual ~TDragDropListener(){};
	//! Funzione per il drop di un file - ingresso nel pannello
	virtual TDropSource::DropEffect onEnter(const Event &event) = 0;
	//! Funzione per il drop di un file - interno al pannello
	virtual TDropSource::DropEffect onOver(const Event &event) = 0;
	//! Funzione per il drop di un file - rilascio del file
	virtual TDropSource::DropEffect onDrop(const Event &event) = 0;
	//! Funzione per il drop di un file - uscita dal pannello
	virtual void onLeave() = 0;
};

//////////////////
//TDataObject/////
//////////////////

class DVAPI TDataObject
{
public:
	class Imp;
	Imp *m_imp;

	// not implemented
	TDataObject(const TDataObject &);
	TDataObject &operator=(const TDataObject &);

public:
	enum DataType {
		Text,
		File,
		Bitmap
	};

	TDataObject();
	~TDataObject();

	//Costruttore per Text
	TDataObject(const std::string &str);
	TDataObject(const std::wstring &str);
	//Costruttore per File
	TDataObject(const std::vector<std::string> &vStr);
	TDataObject(const std::vector<std::wstring> &vStr);
	//Costruttore per dt_bitmap o eventualmente un tipo proprietario
	TDataObject(DataType dataType, const unsigned char *data, const unsigned int dataLen);

	bool getDataTypes(std::vector<DataType> &dataType) const;

	bool getData(string &str) const;
	bool getData(std::vector<string> &vStr) const;
	bool getData(DataType dataType, unsigned char *&data, unsigned int *dataLen) const;

	//friend class TDropSource::Imp;
	//friend class TDropTarget::Imp;
	friend class TEnumFormatEtc;
};

// void DVAPI uffa(TWidget *w);

//
// Gestione (discutibilissima) del drag&drop "interno" con tipi speciali
//
// nel dropSource:
//   MyType *data = ...
//   TDNDDataHolder<MyType> holder(data);
//   holder.doDragDrop();
//
// nel target
//   if(MyType *data = TDNDDataHolder<MyType>::getCurrentValue())
//     {
//     }

class DVAPI TDNDGenericDataHolder
{
protected:
	TDNDGenericDataHolder() {}
	static TDNDGenericDataHolder *m_holder;

public:
	virtual ~TDNDGenericDataHolder() {}
	static bool isDraggingCustomData() { return m_holder != 0; }
	TDropSource::DropEffect doDragDrop();
};

template <class T>
class TDNDDataHolder : public TDNDGenericDataHolder
{
	T *m_value;
	string m_name;

public:
	TDNDDataHolder(T *value, string name = "") : m_value(value), m_name(name) { m_holder = this; }
	~TDNDDataHolder() { m_holder = 0; }
	T *getValue() const { return m_value; }
	string getName() const { return m_name; }
	static T *getCurrentValue()
	{
		TDNDDataHolder<T> *holder = dynamic_cast<TDNDDataHolder<T> *>(m_holder);
		return holder ? holder->getValue() : 0;
	}
};

#endif