include/wx/any.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/any.h
   3 // Purpose:     wxAny class
   4 // Author:      Jaakko Salli
   5 // Modified by:
   6 // Created:     07/05/2009
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) wxWidgets team
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_ANY_H_
  13 #define _WX_ANY_H_
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_ANY
  18
  19 #include <new> // for placement new
  20 #include "wx/string.h"
  21 #include "wx/meta/if.h"
  22 #include "wx/typeinfo.h"
  23
  24
  25 // Size of the wxAny value buffer.
  26 enum
  27 {
  28     WX_ANY_VALUE_BUFFER_SIZE = 16
  29 };
  30
  31 union wxAnyValueBuffer
  32 {
  33     union Alignment
  34     {
  35     #if wxHAS_INT64
  36         wxInt64 m_int64;
  37     #endif
  38         long double m_longDouble;
  39         void ( *m_funcPtr )(void);
  40         void ( wxAnyValueBuffer::*m_mFuncPtr )(void);
  41     } m_alignment;
  42
  43     void*   m_ptr;
  44     wxByte  m_buffer[WX_ANY_VALUE_BUFFER_SIZE];
  45 };
  46
  47 //
  48 // wxAnyValueType is base class for value type functionality for C++ data
  49 // types used with wxAny. Usually the default template (wxAnyValueTypeImpl<>)
  50 // will create a satisfactory wxAnyValueType implementation for a data type.
  51 //
  52 class WXDLLIMPEXP_BASE wxAnyValueType
  53 {
  54     WX_DECLARE_ABSTRACT_TYPEINFO(wxAnyValueType)
  55 public:
  56     /**
  57         Default constructor.
  58     */
  59     wxAnyValueType()
  60     {
  61     }
  62
  63     /**
  64         Destructor.
  65     */
  66     virtual ~wxAnyValueType()
  67     {
  68     }
  69
  70     /**
  71         This function is used for internal type matching.
  72     */
  73     virtual bool IsSameType(const wxAnyValueType* otherType) const = 0;
  74
  75     /**
  76         This function is called every time the data in wxAny
  77         buffer needs to be freed.
  78     */
  79     virtual void DeleteValue(wxAnyValueBuffer& buf) const = 0;
  80
  81     /**
  82         Implement this for buffer-to-buffer copy.
  83
  84         @param src
  85             This is the source data buffer.
  86
  87         @param dst
  88             This is the destination data buffer that is in either
  89             uninitialized or freed state.
  90     */
  91     virtual void CopyBuffer(const wxAnyValueBuffer& src,
  92                             wxAnyValueBuffer& dst) const = 0;
  93
  94     /**
  95         Convert value into buffer of different type. Return false if
  96         not possible.
  97     */
  98     virtual bool ConvertValue(const wxAnyValueBuffer& src,
  99                               wxAnyValueType* dstType,
 100                               wxAnyValueBuffer& dst) const = 0;
 101
 102     /**
 103         Use this template function for checking if wxAnyValueType represents
 104         a specific C++ data type.
 105
 106         @remarks This template function does not work on some older compilers
 107                 (such as Visual C++ 6.0). For full compiler ccompatibility
 108                 please use wxANY_VALUE_TYPE_CHECK_TYPE(valueTypePtr, T) macro
 109                 instead.
 110
 111         @see wxAny::CheckType()
 112     */
 113     // FIXME-VC6: remove this hack when VC6 is no longer supported
 114     template <typename T>
 115     bool CheckType(T* reserved = NULL) const;
 116 private:
 117 };
 118
 119
 120 //
 121 // We need to allocate wxAnyValueType instances in heap, and need to use
 122 // scoped ptr to properly deallocate them in dynamic library use cases.
 123 // Here we have a minimal specialized scoped ptr implementation to deal
 124 // with various compiler-specific problems with template class' static
 125 // member variable of template type with explicit constructor which
 126 // is initialized in global scope.
 127 //
 128 class wxAnyValueTypeScopedPtr
 129 {
 130 public:
 131     wxAnyValueTypeScopedPtr(wxAnyValueType* ptr) : m_ptr(ptr) { }
 132     ~wxAnyValueTypeScopedPtr() { delete m_ptr; }
 133     wxAnyValueType* get() const { return m_ptr; }
 134 private:
 135     wxAnyValueType* m_ptr;
 136 };
 137
 138
 139 //
 140 // This method of checking the type is compatible with VC6
 141 #define wxANY_VALUE_TYPE_CHECK_TYPE(valueTypePtr, T) \
 142     wxAnyValueTypeImpl<T>::IsSameClass(valueTypePtr)
 143
 144
 145 /**
 146     Helper macro for defining user value types.
 147
 148     Even though C++ RTTI would be fully available to use, we'd have to to
 149     facilitate sub-type system which allows, for instance, wxAny with
 150     signed short '15' to be treated equal to wxAny with signed long long '15'.
 151     Having sm_instance is important here.
 152
 153     NB: We really need to have wxAnyValueType instances allocated
 154         in heap. They are stored as static template member variables,
 155         and with them we just can't be too careful (eg. not allocating
 156         them in heap broke the type identification in GCC).
 157 */
 158 #define WX_DECLARE_ANY_VALUE_TYPE(CLS) \
 159     friend class wxAny; \
 160     WX_DECLARE_TYPEINFO_INLINE(CLS) \
 161 public: \
 162     static bool IsSameClass(const wxAnyValueType* otherType) \
 163     { \
 164         return wxTypeId(*sm_instance.get()) == wxTypeId(*otherType); \
 165     } \
 166     virtual bool IsSameType(const wxAnyValueType* otherType) const \
 167     { \
 168         return IsSameClass(otherType); \
 169     } \
 170 private: \
 171     static wxAnyValueTypeScopedPtr sm_instance; \
 172 public: \
 173     static wxAnyValueType* GetInstance() \
 174     { \
 175         return sm_instance.get(); \
 176     }
 177
 178
 179 #define WX_IMPLEMENT_ANY_VALUE_TYPE(CLS) \
 180 wxAnyValueTypeScopedPtr CLS::sm_instance(new CLS());
 181
 182
 183 #ifdef __VISUALC6__
 184     // "non dll-interface class 'xxx' used as base interface
 185     #pragma warning (push)
 186     #pragma warning (disable:4275)
 187 #endif
 188
 189 /**
 190     Following are helper classes for the wxAnyValueTypeImplBase.
 191 */
 192 namespace wxPrivate
 193 {
 194
 195 template<typename T>
 196 class wxAnyValueTypeOpsInplace
 197 {
 198 public:
 199     static void DeleteValue(wxAnyValueBuffer& buf)
 200     {
 201         T* value = reinterpret_cast<T*>(&buf.m_buffer[0]);
 202         value->~T();
 203
 204         // Some compiler may given 'unused variable' warnings without this
 205         wxUnusedVar(value);
 206     }
 207
 208     static void SetValue(const T& value,
 209                          wxAnyValueBuffer& buf)
 210     {
 211         // Use placement new
 212         void* const place = buf.m_buffer;
 213         ::new(place) T(value);
 214     }
 215
 216     static const T& GetValue(const wxAnyValueBuffer& buf)
 217     {
 218         // Breaking this code into two lines should supress
 219         // GCC's 'type-punned pointer will break strict-aliasing rules'
 220         // warning.
 221         const T* value = reinterpret_cast<const T*>(&buf.m_buffer[0]);
 222         return *value;
 223     }
 224 };
 225
 226
 227 template<typename T>
 228 class wxAnyValueTypeOpsGeneric
 229 {
 230 public:
 231     template<typename T2>
 232     class DataHolder
 233     {
 234     public:
 235         DataHolder(const T2& value)
 236         {
 237             m_value = value;
 238         }
 239         virtual ~DataHolder() { }
 240
 241         T2   m_value;
 242     private:
 243         wxDECLARE_NO_COPY_CLASS(DataHolder);
 244     };
 245
 246     static void DeleteValue(wxAnyValueBuffer& buf)
 247     {
 248         DataHolder<T>* holder = static_cast<DataHolder<T>*>(buf.m_ptr);
 249         delete holder;
 250     }
 251
 252     static void SetValue(const T& value,
 253                          wxAnyValueBuffer& buf)
 254     {
 255         DataHolder<T>* holder = new DataHolder<T>(value);
 256         buf.m_ptr = holder;
 257     }
 258
 259     static const T& GetValue(const wxAnyValueBuffer& buf)
 260     {
 261         DataHolder<T>* holder = static_cast<DataHolder<T>*>(buf.m_ptr);
 262         return holder->m_value;
 263     }
 264 };
 265
 266 } // namespace wxPrivate
 267
 268
 269 /**
 270     Intermediate template for the generic value type implementation.
 271     We can derive from this same value type for multiple actual types
 272     (for instance, we can have wxAnyValueTypeImplInt for all signed
 273     integer types), and also easily implement specialized templates
 274     with specific dynamic type conversion.
 275 */
 276 template<typename T>
 277 class wxAnyValueTypeImplBase : public wxAnyValueType
 278 {
 279     typedef typename wxIf< sizeof(T) <= WX_ANY_VALUE_BUFFER_SIZE,
 280                            wxPrivate::wxAnyValueTypeOpsInplace<T>,
 281                            wxPrivate::wxAnyValueTypeOpsGeneric<T> >::value
 282             Ops;
 283
 284 public:
 285     wxAnyValueTypeImplBase() : wxAnyValueType() { }
 286     virtual ~wxAnyValueTypeImplBase() { }
 287
 288     virtual void DeleteValue(wxAnyValueBuffer& buf) const
 289     {
 290         Ops::DeleteValue(buf);
 291     }
 292
 293     virtual void CopyBuffer(const wxAnyValueBuffer& src,
 294                             wxAnyValueBuffer& dst) const
 295     {
 296         Ops::SetValue(Ops::GetValue(src), dst);
 297     }
 298
 299     /**
 300         It is important to reimplement this in any specialized template
 301         classes that inherit from wxAnyValueTypeImplBase.
 302     */
 303     static void SetValue(const T& value,
 304                          wxAnyValueBuffer& buf)
 305     {
 306         Ops::SetValue(value, buf);
 307     }
 308
 309     /**
 310         It is important to reimplement this in any specialized template
 311         classes that inherit from wxAnyValueTypeImplBase.
 312     */
 313     static const T& GetValue(const wxAnyValueBuffer& buf)
 314     {
 315         return Ops::GetValue(buf);
 316     }
 317 };
 318
 319
 320 /*
 321     Generic value type template. Note that bulk of the implementation
 322     resides in wxAnyValueTypeImplBase.
 323 */
 324 template<typename T>
 325 class wxAnyValueTypeImpl : public wxAnyValueTypeImplBase<T>
 326 {
 327     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImpl<T>)
 328 public:
 329     wxAnyValueTypeImpl() : wxAnyValueTypeImplBase<T>() { }
 330     virtual ~wxAnyValueTypeImpl() { }
 331
 332     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 333                               wxAnyValueType* dstType,
 334                               wxAnyValueBuffer& dst) const
 335     {
 336         wxUnusedVar(src);
 337         wxUnusedVar(dstType);
 338         wxUnusedVar(dst);
 339         return false;
 340     }
 341 };
 342
 343 template<typename T>
 344 wxAnyValueTypeScopedPtr wxAnyValueTypeImpl<T>::sm_instance = new wxAnyValueTypeImpl<T>();
 345
 346
 347 //
 348 // Helper macro for using same base value type implementation for multiple
 349 // actual C++ data types.
 350 //
 351 #define WX_ANY_DEFINE_SUB_TYPE(T, CLSTYPE) \
 352 template<> \
 353 class wxAnyValueTypeImpl<T> : public wxAnyValueTypeImpl##CLSTYPE \
 354 { \
 355     typedef wxAnyBase##CLSTYPE##Type UseDataType; \
 356 public: \
 357     wxAnyValueTypeImpl() : wxAnyValueTypeImpl##CLSTYPE() { } \
 358     virtual ~wxAnyValueTypeImpl() { } \
 359     static void SetValue(const T& value, wxAnyValueBuffer& buf) \
 360     { \
 361         void* voidPtr = reinterpret_cast<void*>(&buf.m_buffer[0]); \
 362         UseDataType* dptr = reinterpret_cast<UseDataType*>(voidPtr); \
 363         *dptr = static_cast<UseDataType>(value); \
 364     } \
 365     static T GetValue(const wxAnyValueBuffer& buf) \
 366     { \
 367         const void* voidPtr = \
 368             reinterpret_cast<const void*>(&buf.m_buffer[0]); \
 369         const UseDataType* sptr = \
 370             reinterpret_cast<const UseDataType*>(voidPtr); \
 371         return static_cast<T>(*sptr); \
 372     } \
 373 };
 374
 375
 376 //
 377 //  Integer value types
 378 //
 379
 380 #ifdef wxLongLong_t
 381     typedef wxLongLong_t wxAnyBaseIntType;
 382     typedef wxULongLong_t wxAnyBaseUintType;
 383 #else
 384     typedef long wxAnyBaseIntType;
 385     typedef unsigned long wxAnyBaseUintType;
 386 #endif
 387
 388
 389 class WXDLLIMPEXP_BASE wxAnyValueTypeImplInt :
 390     public wxAnyValueTypeImplBase<wxAnyBaseIntType>
 391 {
 392     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImplInt)
 393 public:
 394     wxAnyValueTypeImplInt() :
 395         wxAnyValueTypeImplBase<wxAnyBaseIntType>() { }
 396     virtual ~wxAnyValueTypeImplInt() { }
 397
 398     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 399                               wxAnyValueType* dstType,
 400                               wxAnyValueBuffer& dst) const;
 401 };
 402
 403
 404 class WXDLLIMPEXP_BASE wxAnyValueTypeImplUint :
 405     public wxAnyValueTypeImplBase<wxAnyBaseUintType>
 406 {
 407     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImplUint)
 408 public:
 409     wxAnyValueTypeImplUint() :
 410         wxAnyValueTypeImplBase<wxAnyBaseUintType>() { }
 411     virtual ~wxAnyValueTypeImplUint() { }
 412
 413     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 414                               wxAnyValueType* dstType,
 415                               wxAnyValueBuffer& dst) const;
 416 };
 417
 418
 419 WX_ANY_DEFINE_SUB_TYPE(signed long, Int)
 420 WX_ANY_DEFINE_SUB_TYPE(signed int, Int)
 421 WX_ANY_DEFINE_SUB_TYPE(signed short, Int)
 422 WX_ANY_DEFINE_SUB_TYPE(signed char, Int)
 423 #ifdef wxLongLong_t
 424 WX_ANY_DEFINE_SUB_TYPE(wxLongLong_t, Int)
 425 #endif
 426
 427 WX_ANY_DEFINE_SUB_TYPE(unsigned long, Uint)
 428 WX_ANY_DEFINE_SUB_TYPE(unsigned int, Uint)
 429 WX_ANY_DEFINE_SUB_TYPE(unsigned short, Uint)
 430 WX_ANY_DEFINE_SUB_TYPE(unsigned char, Uint)
 431 #ifdef wxLongLong_t
 432 WX_ANY_DEFINE_SUB_TYPE(wxULongLong_t, Uint)
 433 #endif
 434
 435
 436 //
 437 // This macro is used in header, but then in source file we must have:
 438 // WX_IMPLEMENT_ANY_VALUE_TYPE(wxAnyValueTypeImpl##TYPENAME)
 439 //
 440 #define _WX_ANY_DEFINE_CONVERTIBLE_TYPE(T, TYPENAME, CONVFUNC, GV) \
 441 class WXDLLIMPEXP_BASE wxAnyValueTypeImpl##TYPENAME : \
 442     public wxAnyValueTypeImplBase<T> \
 443 { \
 444     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImpl##TYPENAME) \
 445 public: \
 446     wxAnyValueTypeImpl##TYPENAME() : \
 447         wxAnyValueTypeImplBase<T>() { } \
 448     virtual ~wxAnyValueTypeImpl##TYPENAME() { } \
 449     virtual bool ConvertValue(const wxAnyValueBuffer& src, \
 450                               wxAnyValueType* dstType, \
 451                               wxAnyValueBuffer& dst) const \
 452     { \
 453         GV value = GetValue(src); \
 454         return CONVFUNC(value, dstType, dst); \
 455     } \
 456 }; \
 457 template<> \
 458 class wxAnyValueTypeImpl<T> : public wxAnyValueTypeImpl##TYPENAME \
 459 { \
 460 public: \
 461     wxAnyValueTypeImpl() : wxAnyValueTypeImpl##TYPENAME() { } \
 462     virtual ~wxAnyValueTypeImpl() { } \
 463 };
 464
 465 #define WX_ANY_DEFINE_CONVERTIBLE_TYPE(T, TYPENAME, CONVFUNC, BT) \
 466 _WX_ANY_DEFINE_CONVERTIBLE_TYPE(T, TYPENAME, CONVFUNC, BT) \
 467
 468 #define WX_ANY_DEFINE_CONVERTIBLE_TYPE_BASE(T, TYPENAME, CONVFUNC) \
 469 _WX_ANY_DEFINE_CONVERTIBLE_TYPE(T, TYPENAME, \
 470                                 CONVFUNC, const T&) \
 471
 472 //
 473 // String value type
 474 //
 475
 476 // Convert wxString to destination wxAny value type
 477 extern WXDLLIMPEXP_BASE bool wxAnyConvertString(const wxString& value,
 478                                                 wxAnyValueType* dstType,
 479                                                 wxAnyValueBuffer& dst);
 480
 481 WX_ANY_DEFINE_CONVERTIBLE_TYPE_BASE(wxString, wxString, wxAnyConvertString)
 482 WX_ANY_DEFINE_CONVERTIBLE_TYPE(const char*, ConstCharPtr,
 483                                wxAnyConvertString, wxString)
 484 WX_ANY_DEFINE_CONVERTIBLE_TYPE(const wchar_t*, ConstWchar_tPtr,
 485                                wxAnyConvertString, wxString)
 486
 487 //
 488 // Bool value type
 489 //
 490 template<>
 491 class WXDLLIMPEXP_BASE wxAnyValueTypeImpl<bool> :
 492     public wxAnyValueTypeImplBase<bool>
 493 {
 494     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImpl<bool>)
 495 public:
 496     wxAnyValueTypeImpl() :
 497         wxAnyValueTypeImplBase<bool>() { }
 498     virtual ~wxAnyValueTypeImpl() { }
 499
 500     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 501                               wxAnyValueType* dstType,
 502                               wxAnyValueBuffer& dst) const;
 503 };
 504
 505 //
 506 // Floating point value type
 507 //
 508 class WXDLLIMPEXP_BASE wxAnyValueTypeImplDouble :
 509     public wxAnyValueTypeImplBase<double>
 510 {
 511     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImplDouble)
 512 public:
 513     wxAnyValueTypeImplDouble() :
 514         wxAnyValueTypeImplBase<double>() { }
 515     virtual ~wxAnyValueTypeImplDouble() { }
 516
 517     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 518                               wxAnyValueType* dstType,
 519                               wxAnyValueBuffer& dst) const;
 520 };
 521
 522 // WX_ANY_DEFINE_SUB_TYPE requires this
 523 typedef double wxAnyBaseDoubleType;
 524
 525 WX_ANY_DEFINE_SUB_TYPE(float, Double)
 526 WX_ANY_DEFINE_SUB_TYPE(double, Double)
 527
 528
 529 //
 530 // Defines a dummy wxAnyValueTypeImpl<> with given export
 531 // declaration. This is needed if a class is used with
 532 // wxAny in both user shared library and application.
 533 //
 534 #define wxDECLARE_ANY_TYPE(CLS, DECL) \
 535 template<> \
 536 class DECL wxAnyValueTypeImpl<CLS> : \
 537     public wxAnyValueTypeImplBase<CLS> \
 538 { \
 539     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImpl<CLS>) \
 540 public: \
 541     wxAnyValueTypeImpl() : \
 542         wxAnyValueTypeImplBase<CLS>() { } \
 543     virtual ~wxAnyValueTypeImpl() { } \
 544  \
 545     virtual bool ConvertValue(const wxAnyValueBuffer& src, \
 546                               wxAnyValueType* dstType, \
 547                               wxAnyValueBuffer& dst) const \
 548     { \
 549         wxUnusedVar(src); \
 550         wxUnusedVar(dstType); \
 551         wxUnusedVar(dst); \
 552         return false; \
 553     } \
 554 };
 555
 556
 557 // Make sure some of wx's own types get the right wxAnyValueType export
 558 // (this is needed only for types that are referred to from wxBase.
 559 // currently we may not use any of these types from there, but let's
 560 // use the macro on at least one to make sure it compiles since we can't
 561 // really test it properly in unittests since a separate DLL would
 562 // be needed).
 563 #if wxUSE_DATETIME
 564     #include "wx/datetime.h"
 565     wxDECLARE_ANY_TYPE(wxDateTime, WXDLLIMPEXP_BASE)
 566 #endif
 567
 568 //#include "wx/object.h"
 569 //wxDECLARE_ANY_TYPE(wxObject*, WXDLLIMPEXP_BASE)
 570
 571 //#include "wx/arrstr.h"
 572 //wxDECLARE_ANY_TYPE(wxArrayString, WXDLLIMPEXP_BASE)
 573
 574
 575 #if wxUSE_VARIANT
 576
 577 class WXDLLIMPEXP_FWD_BASE wxAnyToVariantRegistration;
 578
 579 // Because of header inter-dependencies, cannot include this earlier
 580 #include "wx/variant.h"
 581
 582 //
 583 // wxVariantData* data type implementation. For cases when appropriate
 584 // wxAny<->wxVariant conversion code is missing.
 585 //
 586
 587 class WXDLLIMPEXP_BASE wxAnyValueTypeImplVariantData :
 588     public wxAnyValueTypeImplBase<wxVariantData*>
 589 {
 590     WX_DECLARE_ANY_VALUE_TYPE(wxAnyValueTypeImplVariantData)
 591 public:
 592     wxAnyValueTypeImplVariantData() :
 593         wxAnyValueTypeImplBase<wxVariantData*>() { }
 594     virtual ~wxAnyValueTypeImplVariantData() { }
 595
 596     virtual void DeleteValue(wxAnyValueBuffer& buf) const
 597     {
 598         wxVariantData* data = static_cast<wxVariantData*>(buf.m_ptr);
 599         if ( data )
 600             data->DecRef();
 601     }
 602
 603     virtual void CopyBuffer(const wxAnyValueBuffer& src,
 604                             wxAnyValueBuffer& dst) const
 605     {
 606         wxVariantData* data = static_cast<wxVariantData*>(src.m_ptr);
 607         if ( data )
 608             data->IncRef();
 609         dst.m_ptr = data;
 610     }
 611
 612     static void SetValue(wxVariantData* value,
 613                          wxAnyValueBuffer& buf)
 614     {
 615         value->IncRef();
 616         buf.m_ptr = value;
 617     }
 618
 619     static wxVariantData* GetValue(const wxAnyValueBuffer& buf)
 620     {
 621         return static_cast<wxVariantData*>(buf.m_ptr);
 622     }
 623
 624     virtual bool ConvertValue(const wxAnyValueBuffer& src,
 625                               wxAnyValueType* dstType,
 626                               wxAnyValueBuffer& dst) const
 627     {
 628         wxUnusedVar(src);
 629         wxUnusedVar(dstType);
 630         wxUnusedVar(dst);
 631         return false;
 632     }
 633 };
 634
 635 template<>
 636 class wxAnyValueTypeImpl<wxVariantData*> :
 637     public wxAnyValueTypeImplVariantData
 638 {
 639 public:
 640     wxAnyValueTypeImpl() : wxAnyValueTypeImplVariantData() { }
 641     virtual ~wxAnyValueTypeImpl() { }
 642 };
 643
 644 #endif // wxUSE_VARIANT
 645
 646 #ifdef __VISUALC6__
 647     // Re-enable useless VC6 warnings
 648     #pragma warning (pop)
 649 #endif
 650
 651
 652 /*
 653     Let's define a discrete Null value so we don't have to really
 654     ever check if wxAny.m_type pointer is NULL or not. This is an
 655     optimization, mostly. Implementation of this value type is
 656     "hidden" in the source file.
 657 */
 658 extern WXDLLIMPEXP_DATA_BASE(wxAnyValueType*) wxAnyNullValueType;
 659
 660
 661 //
 662 // We need to implement custom signed/unsigned int equals operators
 663 // for signed/unsigned (eg. wxAny(128UL) == 128L) comparisons to work.
 664 #define WXANY_IMPLEMENT_INT_EQ_OP(TS, TUS) \
 665 bool operator==(TS value) const \
 666 { \
 667     if ( wxAnyValueTypeImpl<TS>::IsSameClass(m_type) ) \
 668         return (value == static_cast<TS> \
 669                 (wxAnyValueTypeImpl<TS>::GetValue(m_buffer))); \
 670     if ( wxAnyValueTypeImpl<TUS>::IsSameClass(m_type) ) \
 671         return (value == static_cast<TS> \
 672                 (wxAnyValueTypeImpl<TUS>::GetValue(m_buffer))); \
 673     return false; \
 674 } \
 675 bool operator==(TUS value) const \
 676 { \
 677     if ( wxAnyValueTypeImpl<TUS>::IsSameClass(m_type) ) \
 678         return (value == static_cast<TUS> \
 679                 (wxAnyValueTypeImpl<TUS>::GetValue(m_buffer))); \
 680     if ( wxAnyValueTypeImpl<TS>::IsSameClass(m_type) ) \
 681         return (value == static_cast<TUS> \
 682                 (wxAnyValueTypeImpl<TS>::GetValue(m_buffer))); \
 683     return false; \
 684 }
 685
 686
 687 #if wxUSE_VARIANT
 688
 689 // Note that the following functions are implemented outside wxAny class
 690 // so that it can reside entirely in header and lack the export declaration.
 691
 692 // Helper function used to associate wxAnyValueType with a wxVariantData.
 693 extern WXDLLIMPEXP_BASE void
 694 wxPreRegisterAnyToVariant(wxAnyToVariantRegistration* reg);
 695
 696 // This function performs main wxAny to wxVariant conversion duties.
 697 extern WXDLLIMPEXP_BASE bool
 698 wxConvertAnyToVariant(const wxAny& any, wxVariant* variant);
 699
 700 #endif // wxUSE_VARIANT
 701
 702
 703 //
 704 // The wxAny class represents a container for any type. A variant's value
 705 // can be changed at run time, possibly to a different type of value.
 706 //
 707 // As standard, wxAny can store value of almost any type, in a fairly
 708 // optimal manner even.
 709 //
 710 class wxAny
 711 {
 712 public:
 713     /**
 714         Default constructor.
 715     */
 716     wxAny()
 717     {
 718         m_type = wxAnyNullValueType;
 719     }
 720
 721     /**
 722         Destructor.
 723     */
 724     ~wxAny()
 725     {
 726         m_type->DeleteValue(m_buffer);
 727     }
 728
 729     //@{
 730     /**
 731         Various constructors.
 732     */
 733     template<typename T>
 734     wxAny(const T& value)
 735     {
 736         m_type = wxAnyValueTypeImpl<T>::sm_instance.get();
 737         wxAnyValueTypeImpl<T>::SetValue(value, m_buffer);
 738     }
 739
 740     // These two constructors are needed to deal with string literals
 741     wxAny(const char* value)
 742     {
 743         m_type = wxAnyValueTypeImpl<const char*>::sm_instance.get();
 744         wxAnyValueTypeImpl<const char*>::SetValue(value, m_buffer);
 745     }
 746     wxAny(const wchar_t* value)
 747     {
 748         m_type = wxAnyValueTypeImpl<const wchar_t*>::sm_instance.get();
 749         wxAnyValueTypeImpl<const wchar_t*>::SetValue(value, m_buffer);
 750     }
 751
 752     wxAny(const wxAny& any)
 753     {
 754         m_type = wxAnyNullValueType;
 755         AssignAny(any);
 756     }
 757
 758 #if wxUSE_VARIANT
 759     wxAny(const wxVariant& variant)
 760     {
 761         m_type = wxAnyNullValueType;
 762         AssignVariant(variant);
 763     }
 764 #endif
 765
 766     //@}
 767
 768     /**
 769         Use this template function for checking if this wxAny holds
 770         a specific C++ data type.
 771
 772         @remarks This template function does not work on some older compilers
 773                 (such as Visual C++ 6.0). For full compiler ccompatibility
 774                 please use wxANY_CHECK_TYPE(any, T) macro instead.
 775
 776         @see wxAnyValueType::CheckType()
 777     */
 778     // FIXME-VC6: remove this hack when VC6 is no longer supported
 779     template <typename T>
 780     bool CheckType(T* = NULL) const
 781     {
 782         return m_type->CheckType<T>();
 783     }
 784
 785     /**
 786         Returns the value type as wxAnyValueType instance.
 787
 788         @remarks You cannot reliably test whether two wxAnys are of
 789                  same value type by simply comparing return values
 790                  of wxAny::GetType(). Instead, use wxAny::HasSameType().
 791
 792         @see HasSameType()
 793     */
 794     const wxAnyValueType* GetType() const
 795     {
 796         return m_type;
 797     }
 798
 799     /**
 800         Returns @true if this and another wxAny have the same
 801         value type.
 802     */
 803     bool HasSameType(const wxAny& other) const
 804     {
 805         return GetType()->IsSameType(other.GetType());
 806     }
 807
 808     /**
 809         Tests if wxAny is null (that is, whether there is data).
 810     */
 811     bool IsNull() const
 812     {
 813         return (m_type == wxAnyNullValueType);
 814     }
 815
 816     /**
 817         Makes wxAny null (that is, clears it).
 818     */
 819     void MakeNull()
 820     {
 821         m_type->DeleteValue(m_buffer);
 822         m_type = wxAnyNullValueType;
 823     }
 824
 825     //@{
 826     /**
 827         Assignment operators.
 828     */
 829     template<typename T>
 830     wxAny& operator=(const T &value)
 831     {
 832         m_type->DeleteValue(m_buffer);
 833         m_type = wxAnyValueTypeImpl<T>::sm_instance.get();
 834         wxAnyValueTypeImpl<T>::SetValue(value, m_buffer);
 835         return *this;
 836     }
 837
 838     wxAny& operator=(const wxAny &any)
 839     {
 840         if (this != &any)
 841             AssignAny(any);
 842         return *this;
 843     }
 844
 845 #if wxUSE_VARIANT
 846     wxAny& operator=(const wxVariant &variant)
 847     {
 848         AssignVariant(variant);
 849         return *this;
 850     }
 851 #endif
 852
 853     // These two operators are needed to deal with string literals
 854     wxAny& operator=(const char* value)
 855     {
 856         Assign(value);
 857         return *this;
 858     }
 859     wxAny& operator=(const wchar_t* value)
 860     {
 861         Assign(value);
 862         return *this;
 863     }
 864
 865     //@{
 866     /**
 867         Equality operators.
 868     */
 869     bool operator==(const wxString& value) const
 870     {
 871         wxString value2;
 872         if ( !GetAs(&value2) )
 873             return false;
 874         return value == value2;
 875     }
 876
 877     bool operator==(const char* value) const
 878         { return (*this) == wxString(value); }
 879     bool operator==(const wchar_t* value) const
 880         { return (*this) == wxString(value); }
 881
 882     //
 883     // We need to implement custom signed/unsigned int equals operators
 884     // for signed/unsigned (eg. wxAny(128UL) == 128L) comparisons to work.
 885     WXANY_IMPLEMENT_INT_EQ_OP(signed char, unsigned char)
 886     WXANY_IMPLEMENT_INT_EQ_OP(signed short, unsigned short)
 887     WXANY_IMPLEMENT_INT_EQ_OP(signed int, unsigned int)
 888     WXANY_IMPLEMENT_INT_EQ_OP(signed long, unsigned long)
 889 #ifdef wxLongLong_t
 890     WXANY_IMPLEMENT_INT_EQ_OP(wxLongLong_t, wxULongLong_t)
 891 #endif
 892
 893     bool operator==(float value) const
 894     {
 895         if ( !wxAnyValueTypeImpl<float>::IsSameClass(m_type) )
 896             return false;
 897
 898         return value ==
 899             static_cast<float>
 900                 (wxAnyValueTypeImpl<float>::GetValue(m_buffer));
 901     }
 902
 903     bool operator==(double value) const
 904     {
 905         if ( !wxAnyValueTypeImpl<double>::IsSameClass(m_type) )
 906             return false;
 907
 908         return value ==
 909             static_cast<double>
 910                 (wxAnyValueTypeImpl<double>::GetValue(m_buffer));
 911     }
 912
 913     bool operator==(bool value) const
 914     {
 915         if ( !wxAnyValueTypeImpl<bool>::IsSameClass(m_type) )
 916             return false;
 917
 918         return value == (wxAnyValueTypeImpl<bool>::GetValue(m_buffer));
 919     }
 920
 921     //@}
 922
 923     //@{
 924     /**
 925         Inequality operators (implement as template).
 926     */
 927     template<typename T>
 928     bool operator!=(const T& value) const
 929         { return !((*this) == value); }
 930     //@}
 931
 932     /**
 933         This template function converts wxAny into given type. In most cases
 934         no type conversion is performed, so if the type is incorrect an
 935         assertion failure will occur.
 936
 937         @remarks For conveniency, conversion is done when T is wxString. This
 938                  is useful when a string literal (which are treated as
 939                  const char* and const wchar_t*) has been assigned to wxAny.
 940
 941                  This template function may not work properly with Visual C++
 942                  6. For full compiler compatibility, please use
 943                  wxANY_AS(any, T) macro instead.
 944     */
 945     // FIXME-VC6: remove this hack when VC6 is no longer supported
 946     template<typename T>
 947     T As(T* = NULL) const
 948     {
 949         if ( !wxAnyValueTypeImpl<T>::IsSameClass(m_type) )
 950         {
 951             wxFAIL_MSG("Incorrect or non-convertible data type");
 952         }
 953
 954         return static_cast<T>(wxAnyValueTypeImpl<T>::GetValue(m_buffer));
 955     }
 956
 957     // Allow easy conversion from 'const char *' etc. to wxString
 958     // FIXME-VC6: remove this hack when VC6 is no longer supported
 959     //template<>
 960     wxString As(wxString*) const
 961     {
 962         wxString value;
 963         if ( !GetAs(&value) )
 964         {
 965             wxFAIL_MSG("Incorrect or non-convertible data type");
 966         }
 967         return value;
 968     }
 969
 970     /**
 971         Template function that etrieves and converts the value of this
 972         variant to the type that T* value is.
 973
 974         @return Returns @true if conversion was succesfull.
 975     */
 976     template<typename T>
 977     bool GetAs(T* value) const
 978     {
 979         if ( !wxAnyValueTypeImpl<T>::IsSameClass(m_type) )
 980         {
 981             wxAnyValueType* otherType =
 982                 wxAnyValueTypeImpl<T>::sm_instance.get();
 983             wxAnyValueBuffer temp_buf;
 984
 985             if ( !m_type->ConvertValue(m_buffer, otherType, temp_buf) )
 986                 return false;
 987
 988             *value =
 989                 static_cast<T>(wxAnyValueTypeImpl<T>::GetValue(temp_buf));
 990             otherType->DeleteValue(temp_buf);
 991
 992             return true;
 993         }
 994         *value = static_cast<T>(wxAnyValueTypeImpl<T>::GetValue(m_buffer));
 995         return true;
 996     }
 997
 998 #if wxUSE_VARIANT
 999     // GetAs() wxVariant specialization
1000     bool GetAs(wxVariant* value) const
1001     {
1002         return wxConvertAnyToVariant(*this, value);
1003     }
1004 #endif
1005
1006 private:
1007     // Assignment functions
1008     void AssignAny(const wxAny& any)
1009     {
1010         // Must delete value - CopyBuffer() never does that
1011         m_type->DeleteValue(m_buffer);
1012
1013         wxAnyValueType* newType = any.m_type;
1014
1015         if ( !newType->IsSameType(m_type) )
1016             m_type = newType;
1017
1018         newType->CopyBuffer(any.m_buffer, m_buffer);
1019     }
1020
1021 #if wxUSE_VARIANT
1022     void AssignVariant(const wxVariant& variant)
1023     {
1024         wxVariantData* data = variant.GetData();
1025
1026         if ( data && data->GetAsAny(this) )
1027             return;
1028
1029         m_type->DeleteValue(m_buffer);
1030
1031         if ( variant.IsNull() )
1032         {
1033             // Init as Null
1034             m_type = wxAnyNullValueType;
1035         }
1036         else
1037         {
1038             // If everything else fails, wrap the whole wxVariantData
1039             m_type = wxAnyValueTypeImpl<wxVariantData*>::sm_instance.get();
1040             wxAnyValueTypeImpl<wxVariantData*>::SetValue(data, m_buffer);
1041         }
1042     }
1043 #endif
1044
1045     template<typename T>
1046     void Assign(const T &value)
1047     {
1048         m_type->DeleteValue(m_buffer);
1049         m_type = wxAnyValueTypeImpl<T>::sm_instance.get();
1050         wxAnyValueTypeImpl<T>::SetValue(value, m_buffer);
1051     }
1052
1053     // Data
1054     wxAnyValueBuffer    m_buffer;
1055     wxAnyValueType*     m_type;
1056 };
1057
1058
1059 //
1060 // This method of checking the type is compatible with VC6
1061 #define wxANY_CHECK_TYPE(any, T) \
1062     wxANY_VALUE_TYPE_CHECK_TYPE((any).GetType(), T)
1063
1064
1065 //
1066 // This method of getting the value is compatible with VC6
1067 #define wxANY_AS(any, T) \
1068     (any).As(static_cast<T*>(NULL))
1069
1070
1071 template<typename T>
1072 inline bool wxAnyValueType::CheckType(T* reserved) const
1073 {
1074     wxUnusedVar(reserved);
1075     return wxAnyValueTypeImpl<T>::IsSameClass(this);
1076 }
1077
1078
1079
1080 #endif // wxUSE_ANY
1081
1082 #endif // _WX_ANY_H_