wxWidgets/include/wx/variant.h
Vadim Zeitlin a3ab1c1801 renamed IsRefTo() to IsSameAs() (do complain if this is not more clear) and
changed its signature to take a const reference instead of a pointer which
simplifies the code and makes it safer as well


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42776 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
2006-10-30 22:03:53 +00:00

427 lines
13 KiB
C++

/////////////////////////////////////////////////////////////////////////////
// Name: wx/variant.h
// Purpose: wxVariant class, container for any type
// Author: Julian Smart
// Modified by:
// Created: 10/09/98
// RCS-ID: $Id$
// Copyright: (c) Julian Smart
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_VARIANT_H_
#define _WX_VARIANT_H_
#include "wx/defs.h"
#if wxUSE_VARIANT
#include "wx/object.h"
#include "wx/string.h"
#include "wx/arrstr.h"
#include "wx/list.h"
#if wxUSE_DATETIME
#include "wx/datetime.h"
#endif // wxUSE_DATETIME
#if wxUSE_ODBC
#include "wx/db.h" // will #include sqltypes.h
#endif //ODBC
#include "wx/iosfwrap.h"
/*
* wxVariantData stores the actual data in a wxVariant object,
* to allow it to store any type of data.
* Derive from this to provide custom data handling.
*
* NB: To prevent addition of extra vtbl pointer to wxVariantData,
* we don't multiple-inherit from wxObjectRefData. Instead,
* we simply replicate the wxObject ref-counting scheme.
*
* NB: When you construct a wxVariantData, it will have refcount
* of one. Refcount will not be further increased when
* it is passed to wxVariant. This simulates old common
* scenario where wxVariant took ownership of wxVariantData
* passed to it.
* If you create wxVariantData for other reasons than passing
* it to wxVariant, technically you are not required to call
* DecRef() before deleting it.
*
* TODO: in order to replace wxPropertyValue, we would need
* to consider adding constructors that take pointers to C++ variables,
* or removing that functionality from the wxProperty library.
* Essentially wxPropertyValue takes on some of the wxValidator functionality
* by storing pointers and not just actual values, allowing update of C++ data
* to be handled automatically. Perhaps there's another way of doing this without
* overloading wxVariant with unnecessary functionality.
*/
class WXDLLIMPEXP_BASE wxVariantData: public wxObject
{
friend class wxVariant;
public:
wxVariantData()
: wxObject(), m_count(1)
{ }
// Override these to provide common functionality
virtual bool Eq(wxVariantData& data) const = 0;
#if wxUSE_STD_IOSTREAM
virtual bool Write(wxSTD ostream& WXUNUSED(str)) const { return false; }
#endif
virtual bool Write(wxString& WXUNUSED(str)) const { return false; }
#if wxUSE_STD_IOSTREAM
virtual bool Read(wxSTD istream& WXUNUSED(str)) { return false; }
#endif
virtual bool Read(wxString& WXUNUSED(str)) { return false; }
// What type is it? Return a string name.
virtual wxString GetType() const = 0;
// If it based on wxObject return the ClassInfo.
virtual wxClassInfo* GetValueClassInfo() { return NULL; }
void IncRef() { m_count++; }
void DecRef()
{
if ( --m_count == 0 )
delete this;
}
int GetRefCount() const { return m_count; }
protected:
// Protected dtor should make some incompatible code
// break more louder. That is, they should do data->DecRef()
// instead of delete data.
virtual ~wxVariantData() { }
private:
int m_count;
private:
DECLARE_ABSTRACT_CLASS(wxVariantData)
};
/*
* wxVariant can store any kind of data, but has some basic types
* built in.
*/
class WXDLLIMPEXP_BASE wxVariant: public wxObject
{
public:
wxVariant();
wxVariant(const wxVariant& variant);
wxVariant(wxVariantData* data, const wxString& name = wxEmptyString);
virtual ~wxVariant();
// generic assignment
void operator= (const wxVariant& variant);
// Assignment using data, e.g.
// myVariant = new wxStringVariantData("hello");
void operator= (wxVariantData* variantData);
bool operator== (const wxVariant& variant) const;
bool operator!= (const wxVariant& variant) const;
// Sets/gets name
inline void SetName(const wxString& name) { m_name = name; }
inline const wxString& GetName() const { return m_name; }
// Tests whether there is data
bool IsNull() const;
// For compatibility with wxWidgets <= 2.6, this doesn't increase
// reference count.
wxVariantData* GetData() const { return m_data; }
void SetData(wxVariantData* data) ;
// make a 'clone' of the object
void Ref(const wxVariant& clone);
// destroy a reference
void UnRef();
// Make NULL (i.e. delete the data)
void MakeNull();
// Delete data and name
void Clear();
// Returns a string representing the type of the variant,
// e.g. "string", "bool", "stringlist", "list", "double", "long"
wxString GetType() const;
bool IsType(const wxString& type) const;
bool IsValueKindOf(const wxClassInfo* type) const;
// write contents to a string (e.g. for debugging)
wxString MakeString() const;
// double
wxVariant(double val, const wxString& name = wxEmptyString);
bool operator== (double value) const;
bool operator!= (double value) const;
void operator= (double value) ;
inline operator double () const { return GetDouble(); }
inline double GetReal() const { return GetDouble(); }
double GetDouble() const;
// long
wxVariant(long val, const wxString& name = wxEmptyString);
wxVariant(int val, const wxString& name = wxEmptyString);
wxVariant(short val, const wxString& name = wxEmptyString);
bool operator== (long value) const;
bool operator!= (long value) const;
void operator= (long value) ;
inline operator long () const { return GetLong(); }
inline long GetInteger() const { return GetLong(); }
long GetLong() const;
// bool
#ifdef HAVE_BOOL
wxVariant(bool val, const wxString& name = wxEmptyString);
bool operator== (bool value) const;
bool operator!= (bool value) const;
void operator= (bool value) ;
inline operator bool () const { return GetBool(); }
bool GetBool() const ;
#endif
// wxDateTime
#if wxUSE_DATETIME
wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString);
#if wxUSE_ODBC
wxVariant(const DATE_STRUCT* valptr, const wxString& name = wxEmptyString);
wxVariant(const TIME_STRUCT* valptr, const wxString& name = wxEmptyString);
wxVariant(const TIMESTAMP_STRUCT* valptr, const wxString& name = wxEmptyString);
#endif
bool operator== (const wxDateTime& value) const;
bool operator!= (const wxDateTime& value) const;
void operator= (const wxDateTime& value) ;
#if wxUSE_ODBC
void operator= (const DATE_STRUCT* value) ;
void operator= (const TIME_STRUCT* value) ;
void operator= (const TIMESTAMP_STRUCT* value) ;
#endif
inline operator wxDateTime () const { return GetDateTime(); }
wxDateTime GetDateTime() const;
#endif
// wxString
wxVariant(const wxString& val, const wxString& name = wxEmptyString);
wxVariant(const wxChar* val, const wxString& name = wxEmptyString); // Necessary or VC++ assumes bool!
bool operator== (const wxString& value) const;
bool operator!= (const wxString& value) const;
void operator= (const wxString& value) ;
void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
inline operator wxString () const { return MakeString(); }
wxString GetString() const;
// wxChar
wxVariant(wxChar val, const wxString& name = wxEmptyString);
bool operator== (wxChar value) const;
bool operator!= (wxChar value) const;
void operator= (wxChar value) ;
inline operator wxChar () const { return GetChar(); }
wxChar GetChar() const ;
// wxArrayString
wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString);
bool operator== (const wxArrayString& value) const;
bool operator!= (const wxArrayString& value) const;
void operator= (const wxArrayString& value);
inline operator wxArrayString () const { return GetArrayString(); }
wxArrayString GetArrayString() const;
// void*
wxVariant(void* ptr, const wxString& name = wxEmptyString);
bool operator== (void* value) const;
bool operator!= (void* value) const;
void operator= (void* value);
inline operator void* () const { return GetVoidPtr(); }
void* GetVoidPtr() const;
// wxObject*
wxVariant(wxObject* ptr, const wxString& name = wxEmptyString);
bool operator== (wxObject* value) const;
bool operator!= (wxObject* value) const;
void operator= (wxObject* value);
wxObject* GetWxObjectPtr() const;
#if WXWIN_COMPATIBILITY_2_4
wxDEPRECATED( wxVariant(const wxStringList& val, const wxString& name = wxEmptyString) );
wxDEPRECATED( bool operator== (const wxStringList& value) const );
wxDEPRECATED( bool operator!= (const wxStringList& value) const );
wxDEPRECATED( void operator= (const wxStringList& value) );
wxDEPRECATED( wxStringList& GetStringList() const );
#endif
// ------------------------------
// list operations
// ------------------------------
wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
bool operator== (const wxList& value) const;
bool operator!= (const wxList& value) const;
void operator= (const wxList& value) ;
// Treat a list variant as an array
wxVariant operator[] (size_t idx) const;
wxVariant& operator[] (size_t idx) ;
wxList& GetList() const ;
// Return the number of elements in a list
size_t GetCount() const;
// Make empty list
void NullList();
// Append to list
void Append(const wxVariant& value);
// Insert at front of list
void Insert(const wxVariant& value);
// Returns true if the variant is a member of the list
bool Member(const wxVariant& value) const;
// Deletes the nth element of the list
bool Delete(size_t item);
// Clear list
void ClearList();
public:
// Type conversion
bool Convert(long* value) const;
bool Convert(bool* value) const;
bool Convert(double* value) const;
bool Convert(wxString* value) const;
bool Convert(wxChar* value) const;
#if wxUSE_DATETIME
bool Convert(wxDateTime* value) const;
#endif // wxUSE_DATETIME
// Attributes
protected:
wxVariantData* m_data;
wxString m_name;
private:
DECLARE_DYNAMIC_CLASS(wxVariant)
};
/* Fake macro parameter value */
#ifdef EMPTY_PARAMETER_VALUE
#undef EMPTY_PARAMETER_VALUE
#endif
#define EMPTY_PARAMETER_VALUE
#define DECLARE_VARIANT_OBJECT(classname) \
DECLARE_VARIANT_OBJECT_EXPORTED(classname,EMPTY_PARAMETER_VALUE)
#define DECLARE_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
expdecl classname& operator << ( classname &object, const wxVariant &variant ); \
expdecl wxVariant& operator << ( wxVariant &variant, const classname &object );
#define IMPLEMENT_VARIANT_OBJECT(classname) \
IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname,EMPTY_PARAMETER_VALUE)
#define IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,expdecl) \
class classname##VariantData: public wxVariantData \
{ \
public:\
classname##VariantData() {} \
classname##VariantData( const classname &value ) { m_value = value; } \
\
classname &GetValue() { return m_value; } \
\
virtual bool Eq(wxVariantData& data) const; \
\
virtual wxString GetType() const; \
virtual wxClassInfo* GetValueClassInfo(); \
\
protected:\
classname m_value; \
\
private: \
DECLARE_CLASS(classname##VariantData) \
};\
\
IMPLEMENT_CLASS(classname##VariantData, wxVariantData)\
\
wxString classname##VariantData::GetType() const\
{\
return m_value.GetClassInfo()->GetClassName();\
}\
\
wxClassInfo* classname##VariantData::GetValueClassInfo()\
{\
return m_value.GetClassInfo();\
}\
\
expdecl classname& operator << ( classname &value, const wxVariant &variant )\
{\
wxASSERT( wxIsKindOf( variant.GetData(), classname##VariantData ) );\
\
classname##VariantData *data = (classname##VariantData*) variant.GetData();\
value = data->GetValue();\
return value;\
}\
\
expdecl wxVariant& operator << ( wxVariant &variant, const classname &value )\
{\
classname##VariantData *data = new classname##VariantData( value );\
variant.SetData( data );\
return variant;\
}
// implements a wxVariantData-derived class using for the Eq() method the operator==
// which must have been provided by "classname"
#define IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,expdecl) \
\
bool classname##VariantData::Eq(wxVariantData& data) const \
{\
wxASSERT( wxIsKindOf((&data), classname##VariantData) );\
\
classname##VariantData & otherData = (classname##VariantData &) data;\
\
return otherData.m_value == m_value;\
}\
// implements a wxVariantData-derived class using for the Eq() method a shallow
// comparison (through wxObject::IsSameAs function)
#define IMPLEMENT_VARIANT_OBJECT_EXPORTED_SHALLOWCMP(classname,expdecl) \
IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,expdecl) \
\
bool classname##VariantData::Eq(wxVariantData& data) const \
{\
wxASSERT( wxIsKindOf((&data), classname##VariantData) );\
\
classname##VariantData & otherData = (classname##VariantData &) data;\
\
return (otherData.m_value.IsSameAs(m_value));\
}\
// Since we want type safety wxVariant we need to fetch and dynamic_cast
// in a seemingly safe way so the compiler can check, so we define
// a dynamic_cast /wxDynamicCast analogue.
#define wxGetVariantCast(var,classname) \
((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
var.GetWxObjectPtr() : NULL));
extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
#endif // wxUSE_VARIANT
#endif // _WX_VARIANT_H_