include/wx/variant.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/variant.h
   3 // Purpose:     wxVariant class, container for any type
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     10/09/98
   7 // Copyright:   (c) Julian Smart
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_VARIANT_H_
  12 #define _WX_VARIANT_H_
  13
  14 #include "wx/defs.h"
  15
  16 #if wxUSE_VARIANT
  17
  18 #include "wx/object.h"
  19 #include "wx/string.h"
  20 #include "wx/arrstr.h"
  21 #include "wx/list.h"
  22 #include "wx/cpp.h"
  23 #include "wx/longlong.h"
  24
  25 #if wxUSE_DATETIME
  26     #include "wx/datetime.h"
  27 #endif // wxUSE_DATETIME
  28
  29 #include "wx/iosfwrap.h"
  30
  31 class wxAny;
  32
  33 /*
  34  * wxVariantData stores the actual data in a wxVariant object,
  35  * to allow it to store any type of data.
  36  * Derive from this to provide custom data handling.
  37  *
  38  * NB: When you construct a wxVariantData, it will have refcount
  39  *     of one. Refcount will not be further increased when
  40  *     it is passed to wxVariant. This simulates old common
  41  *     scenario where wxVariant took ownership of wxVariantData
  42  *     passed to it.
  43  *     If you create wxVariantData for other reasons than passing
  44  *     it to wxVariant, technically you are not required to call
  45  *     DecRef() before deleting it.
  46  *
  47  * TODO: in order to replace wxPropertyValue, we would need
  48  * to consider adding constructors that take pointers to C++ variables,
  49  * or removing that functionality from the wxProperty library.
  50  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  51  * by storing pointers and not just actual values, allowing update of C++ data
  52  * to be handled automatically. Perhaps there's another way of doing this without
  53  * overloading wxVariant with unnecessary functionality.
  54  */
  55
  56 class WXDLLIMPEXP_BASE wxVariantData : public wxObjectRefData
  57 {
  58     friend class wxVariant;
  59 public:
  60     wxVariantData() { }
  61
  62     // Override these to provide common functionality
  63     virtual bool Eq(wxVariantData& data) const = 0;
  64
  65 #if wxUSE_STD_IOSTREAM
  66     virtual bool Write(wxSTD ostream& WXUNUSED(str)) const { return false; }
  67 #endif
  68     virtual bool Write(wxString& WXUNUSED(str)) const { return false; }
  69 #if wxUSE_STD_IOSTREAM
  70     virtual bool Read(wxSTD istream& WXUNUSED(str)) { return false; }
  71 #endif
  72     virtual bool Read(wxString& WXUNUSED(str)) { return false; }
  73     // What type is it? Return a string name.
  74     virtual wxString GetType() const = 0;
  75     // If it based on wxObject return the ClassInfo.
  76     virtual wxClassInfo* GetValueClassInfo() { return NULL; }
  77
  78     // Implement this to make wxVariant::UnShare work. Returns
  79     // a copy of the data.
  80     virtual wxVariantData* Clone() const { return NULL; }
  81
  82 #if wxUSE_ANY
  83     // Converts value to wxAny, if possible. Return true if successful.
  84     virtual bool GetAsAny(wxAny* WXUNUSED(any)) const { return false; }
  85 #endif
  86
  87 protected:
  88     // Protected dtor should make some incompatible code
  89     // break more louder. That is, they should do data->DecRef()
  90     // instead of delete data.
  91     virtual ~wxVariantData() { }
  92 };
  93
  94 /*
  95  * wxVariant can store any kind of data, but has some basic types
  96  * built in.
  97  */
  98
  99 class WXDLLIMPEXP_FWD_BASE wxVariant;
 100
 101 WX_DECLARE_LIST_WITH_DECL(wxVariant, wxVariantList, class WXDLLIMPEXP_BASE);
 102
 103 class WXDLLIMPEXP_BASE wxVariant: public wxObject
 104 {
 105 public:
 106     wxVariant();
 107
 108     wxVariant(const wxVariant& variant);
 109     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString);
 110 #if wxUSE_ANY
 111     wxVariant(const wxAny& any);
 112 #endif
 113     virtual ~wxVariant();
 114
 115     // generic assignment
 116     void operator= (const wxVariant& variant);
 117
 118     // Assignment using data, e.g.
 119     // myVariant = new wxStringVariantData("hello");
 120     void operator= (wxVariantData* variantData);
 121
 122     bool operator== (const wxVariant& variant) const;
 123     bool operator!= (const wxVariant& variant) const;
 124
 125     // Sets/gets name
 126     inline void SetName(const wxString& name) { m_name = name; }
 127     inline const wxString& GetName() const { return m_name; }
 128
 129     // Tests whether there is data
 130     bool IsNull() const;
 131
 132     // For compatibility with wxWidgets <= 2.6, this doesn't increase
 133     // reference count.
 134     wxVariantData* GetData() const
 135     {
 136         return (wxVariantData*) m_refData;
 137     }
 138     void SetData(wxVariantData* data) ;
 139
 140     // make a 'clone' of the object
 141     void Ref(const wxVariant& clone) { wxObject::Ref(clone); }
 142
 143     // ensure that the data is exclusive to this variant, and not shared
 144     bool Unshare();
 145
 146     // Make NULL (i.e. delete the data)
 147     void MakeNull();
 148
 149     // Delete data and name
 150     void Clear();
 151
 152     // Returns a string representing the type of the variant,
 153     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 154     wxString GetType() const;
 155
 156     bool IsType(const wxString& type) const;
 157     bool IsValueKindOf(const wxClassInfo* type) const;
 158
 159     // write contents to a string (e.g. for debugging)
 160     wxString MakeString() const;
 161
 162 #if wxUSE_ANY
 163     wxAny GetAny() const;
 164 #endif
 165
 166     // double
 167     wxVariant(double val, const wxString& name = wxEmptyString);
 168     bool operator== (double value) const;
 169     bool operator!= (double value) const;
 170     void operator= (double value) ;
 171     inline operator double () const {  return GetDouble(); }
 172     inline double GetReal() const { return GetDouble(); }
 173     double GetDouble() const;
 174
 175     // long
 176     wxVariant(long val, const wxString& name = wxEmptyString);
 177     wxVariant(int val, const wxString& name = wxEmptyString);
 178     wxVariant(short val, const wxString& name = wxEmptyString);
 179     bool operator== (long value) const;
 180     bool operator!= (long value) const;
 181     void operator= (long value) ;
 182     inline operator long () const {  return GetLong(); }
 183     inline long GetInteger() const { return GetLong(); }
 184     long GetLong() const;
 185
 186     // bool
 187     wxVariant(bool val, const wxString& name = wxEmptyString);
 188     bool operator== (bool value) const;
 189     bool operator!= (bool value) const;
 190     void operator= (bool value) ;
 191     inline operator bool () const {  return GetBool(); }
 192     bool GetBool() const ;
 193
 194     // wxDateTime
 195 #if wxUSE_DATETIME
 196     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString);
 197     bool operator== (const wxDateTime& value) const;
 198     bool operator!= (const wxDateTime& value) const;
 199     void operator= (const wxDateTime& value) ;
 200     inline operator wxDateTime () const { return GetDateTime(); }
 201     wxDateTime GetDateTime() const;
 202 #endif
 203
 204     // wxString
 205     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
 206     // these overloads are necessary to prevent the compiler from using bool
 207     // version instead of wxString one:
 208     wxVariant(const char* val, const wxString& name = wxEmptyString);
 209     wxVariant(const wchar_t* val, const wxString& name = wxEmptyString);
 210     wxVariant(const wxCStrData& val, const wxString& name = wxEmptyString);
 211     wxVariant(const wxScopedCharBuffer& val, const wxString& name = wxEmptyString);
 212     wxVariant(const wxScopedWCharBuffer& val, const wxString& name = wxEmptyString);
 213
 214     bool operator== (const wxString& value) const;
 215     bool operator!= (const wxString& value) const;
 216     wxVariant& operator=(const wxString& value);
 217     // these overloads are necessary to prevent the compiler from using bool
 218     // version instead of wxString one:
 219     wxVariant& operator=(const char* value)
 220         { return *this = wxString(value); }
 221     wxVariant& operator=(const wchar_t* value)
 222         { return *this = wxString(value); }
 223     wxVariant& operator=(const wxCStrData& value)
 224         { return *this = value.AsString(); }
 225     template<typename T>
 226     wxVariant& operator=(const wxScopedCharTypeBuffer<T>& value)
 227         { return *this = value.data(); }
 228
 229     inline operator wxString () const {  return MakeString(); }
 230     wxString GetString() const;
 231
 232 #if wxUSE_STD_STRING
 233     wxVariant(const std::string& val, const wxString& name = wxEmptyString);
 234     bool operator==(const std::string& value) const
 235         { return operator==(wxString(value)); }
 236     bool operator!=(const std::string& value) const
 237         { return operator!=(wxString(value)); }
 238     wxVariant& operator=(const std::string& value)
 239         { return operator=(wxString(value)); }
 240     operator std::string() const { return (operator wxString()).ToStdString(); }
 241
 242     wxVariant(const wxStdWideString& val, const wxString& name = wxEmptyString);
 243     bool operator==(const wxStdWideString& value) const
 244         { return operator==(wxString(value)); }
 245     bool operator!=(const wxStdWideString& value) const
 246         { return operator!=(wxString(value)); }
 247     wxVariant& operator=(const wxStdWideString& value)
 248         { return operator=(wxString(value)); }
 249     operator wxStdWideString() const { return (operator wxString()).ToStdWstring(); }
 250 #endif // wxUSE_STD_STRING
 251
 252     // wxUniChar
 253     wxVariant(const wxUniChar& val, const wxString& name = wxEmptyString);
 254     wxVariant(const wxUniCharRef& val, const wxString& name = wxEmptyString);
 255     wxVariant(char val, const wxString& name = wxEmptyString);
 256     wxVariant(wchar_t val, const wxString& name = wxEmptyString);
 257     bool operator==(const wxUniChar& value) const;
 258     bool operator==(const wxUniCharRef& value) const { return *this == wxUniChar(value); }
 259     bool operator==(char value) const { return *this == wxUniChar(value); }
 260     bool operator==(wchar_t value) const { return *this == wxUniChar(value); }
 261     bool operator!=(const wxUniChar& value) const { return !(*this == value); }
 262     bool operator!=(const wxUniCharRef& value) const { return !(*this == value); }
 263     bool operator!=(char value) const { return !(*this == value); }
 264     bool operator!=(wchar_t value) const { return !(*this == value); }
 265     wxVariant& operator=(const wxUniChar& value);
 266     wxVariant& operator=(const wxUniCharRef& value) { return *this = wxUniChar(value); }
 267     wxVariant& operator=(char value) { return *this = wxUniChar(value); }
 268     wxVariant& operator=(wchar_t value) { return *this = wxUniChar(value); }
 269     operator wxUniChar() const { return GetChar(); }
 270     operator char() const { return GetChar(); }
 271     operator wchar_t() const { return GetChar(); }
 272     wxUniChar GetChar() const;
 273
 274     // wxArrayString
 275     wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString);
 276     bool operator== (const wxArrayString& value) const;
 277     bool operator!= (const wxArrayString& value) const;
 278     void operator= (const wxArrayString& value);
 279     operator wxArrayString () const { return GetArrayString(); }
 280     wxArrayString GetArrayString() const;
 281
 282     // void*
 283     wxVariant(void* ptr, const wxString& name = wxEmptyString);
 284     bool operator== (void* value) const;
 285     bool operator!= (void* value) const;
 286     void operator= (void* value);
 287     operator void* () const {  return GetVoidPtr(); }
 288     void* GetVoidPtr() const;
 289
 290     // wxObject*
 291     wxVariant(wxObject* ptr, const wxString& name = wxEmptyString);
 292     bool operator== (wxObject* value) const;
 293     bool operator!= (wxObject* value) const;
 294     void operator= (wxObject* value);
 295     wxObject* GetWxObjectPtr() const;
 296
 297 #if wxUSE_LONGLONG
 298     // wxLongLong
 299     wxVariant(wxLongLong, const wxString& name = wxEmptyString);
 300     bool operator==(wxLongLong value) const;
 301     bool operator!=(wxLongLong value) const;
 302     void operator=(wxLongLong value);
 303     operator wxLongLong() const { return GetLongLong(); }
 304     wxLongLong GetLongLong() const;
 305
 306     // wxULongLong
 307     wxVariant(wxULongLong, const wxString& name = wxEmptyString);
 308     bool operator==(wxULongLong value) const;
 309     bool operator!=(wxULongLong value) const;
 310     void operator=(wxULongLong value);
 311     operator wxULongLong() const { return GetULongLong(); }
 312     wxULongLong GetULongLong() const;
 313 #endif
 314
 315     // ------------------------------
 316     // list operations
 317     // ------------------------------
 318
 319     wxVariant(const wxVariantList& val, const wxString& name = wxEmptyString); // List of variants
 320     bool operator== (const wxVariantList& value) const;
 321     bool operator!= (const wxVariantList& value) const;
 322     void operator= (const wxVariantList& value) ;
 323     // Treat a list variant as an array
 324     wxVariant operator[] (size_t idx) const;
 325     wxVariant& operator[] (size_t idx) ;
 326     wxVariantList& GetList() const ;
 327
 328     // Return the number of elements in a list
 329     size_t GetCount() const;
 330
 331     // Make empty list
 332     void NullList();
 333
 334     // Append to list
 335     void Append(const wxVariant& value);
 336
 337     // Insert at front of list
 338     void Insert(const wxVariant& value);
 339
 340     // Returns true if the variant is a member of the list
 341     bool Member(const wxVariant& value) const;
 342
 343     // Deletes the nth element of the list
 344     bool Delete(size_t item);
 345
 346     // Clear list
 347     void ClearList();
 348
 349 public:
 350     // Type conversion
 351     bool Convert(long* value) const;
 352     bool Convert(bool* value) const;
 353     bool Convert(double* value) const;
 354     bool Convert(wxString* value) const;
 355     bool Convert(wxUniChar* value) const;
 356     bool Convert(char* value) const;
 357     bool Convert(wchar_t* value) const;
 358 #if wxUSE_DATETIME
 359     bool Convert(wxDateTime* value) const;
 360 #endif // wxUSE_DATETIME
 361 #if wxUSE_LONGLONG
 362     bool Convert(wxLongLong* value) const;
 363     bool Convert(wxULongLong* value) const;
 364   #ifdef wxLongLong_t
 365     bool Convert(wxLongLong_t* value) const
 366     {
 367         wxLongLong temp;
 368         if ( !Convert(&temp) )
 369             return false;
 370         *value = temp.GetValue();
 371         return true;
 372     }
 373     bool Convert(wxULongLong_t* value) const
 374     {
 375         wxULongLong temp;
 376         if ( !Convert(&temp) )
 377             return false;
 378         *value = temp.GetValue();
 379         return true;
 380     }
 381   #endif // wxLongLong_t
 382 #endif // wxUSE_LONGLONG
 383
 384 // Attributes
 385 protected:
 386     virtual wxObjectRefData *CreateRefData() const;
 387     virtual wxObjectRefData *CloneRefData(const wxObjectRefData *data) const;
 388
 389     wxString        m_name;
 390
 391 private:
 392     DECLARE_DYNAMIC_CLASS(wxVariant)
 393 };
 394
 395
 396 //
 397 // wxVariant <-> wxAny conversion code
 398 //
 399 #if wxUSE_ANY
 400
 401 #include "wx/any.h"
 402
 403 // In order to convert wxAny to wxVariant, we need to be able to associate
 404 // wxAnyValueType with a wxVariantData factory function.
 405 typedef wxVariantData* (*wxVariantDataFactory)(const wxAny& any);
 406
 407 // Actual Any-to-Variant registration must be postponed to a time when all
 408 // global variables have been initialized. Hence this arrangement.
 409 // wxAnyToVariantRegistration instances are kept in global scope and
 410 // wxAnyValueTypeGlobals in any.cpp will use their data when the time is
 411 // right.
 412 class WXDLLIMPEXP_BASE wxAnyToVariantRegistration
 413 {
 414 public:
 415     wxAnyToVariantRegistration(wxVariantDataFactory factory);
 416     virtual ~wxAnyToVariantRegistration();
 417
 418     virtual wxAnyValueType* GetAssociatedType() = 0;
 419     wxVariantDataFactory GetFactory() const { return m_factory; }
 420 private:
 421     wxVariantDataFactory    m_factory;
 422 };
 423
 424 template<typename T>
 425 class wxAnyToVariantRegistrationImpl : public wxAnyToVariantRegistration
 426 {
 427 public:
 428     wxAnyToVariantRegistrationImpl(wxVariantDataFactory factory)
 429         : wxAnyToVariantRegistration(factory)
 430     {
 431     }
 432
 433     virtual wxAnyValueType* GetAssociatedType()
 434     {
 435         return wxAnyValueTypeImpl<T>::GetInstance();
 436     }
 437 private:
 438 };
 439
 440 #define DECLARE_WXANY_CONVERSION() \
 441 virtual bool GetAsAny(wxAny* any) const; \
 442 static wxVariantData* VariantDataFactory(const wxAny& any);
 443
 444 #define _REGISTER_WXANY_CONVERSION(T, CLASSNAME, FUNC) \
 445 static wxAnyToVariantRegistrationImpl<T> \
 446     gs_##CLASSNAME##AnyToVariantRegistration = \
 447     wxAnyToVariantRegistrationImpl<T>(&FUNC);
 448
 449 #define REGISTER_WXANY_CONVERSION(T, CLASSNAME) \
 450 _REGISTER_WXANY_CONVERSION(T, CLASSNAME, CLASSNAME::VariantDataFactory)
 451
 452 #define IMPLEMENT_TRIVIAL_WXANY_CONVERSION(T, CLASSNAME) \
 453 bool CLASSNAME::GetAsAny(wxAny* any) const \
 454 { \
 455     *any = m_value; \
 456     return true; \
 457 } \
 458 wxVariantData* CLASSNAME::VariantDataFactory(const wxAny& any) \
 459 { \
 460     return new CLASSNAME(wxANY_AS(any, T)); \
 461 } \
 462 REGISTER_WXANY_CONVERSION(T, CLASSNAME)
 463
 464 #else // if !wxUSE_ANY
 465
 466 #define DECLARE_WXANY_CONVERSION()
 467 #define REGISTER_WXANY_CONVERSION(T, CLASSNAME)
 468 #define IMPLEMENT_TRIVIAL_WXANY_CONVERSION(T, CLASSNAME)
 469
 470 #endif // wxUSE_ANY/!wxUSE_ANY
 471
 472
 473 #define DECLARE_VARIANT_OBJECT(classname) \
 474     DECLARE_VARIANT_OBJECT_EXPORTED(classname, wxEMPTY_PARAMETER_VALUE)
 475
 476 #define DECLARE_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
 477 expdecl classname& operator << ( classname &object, const wxVariant &variant ); \
 478 expdecl wxVariant& operator << ( wxVariant &variant, const classname &object );
 479
 480 #define IMPLEMENT_VARIANT_OBJECT(classname) \
 481     IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname, wxEMPTY_PARAMETER_VALUE)
 482
 483 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,expdecl) \
 484 class classname##VariantData: public wxVariantData \
 485 { \
 486 public:\
 487     classname##VariantData() {} \
 488     classname##VariantData( const classname &value ) { m_value = value; } \
 489 \
 490     classname &GetValue() { return m_value; } \
 491 \
 492     virtual bool Eq(wxVariantData& data) const; \
 493 \
 494     virtual wxString GetType() const; \
 495     virtual wxClassInfo* GetValueClassInfo(); \
 496 \
 497     virtual wxVariantData* Clone() const { return new classname##VariantData(m_value); } \
 498 \
 499     DECLARE_WXANY_CONVERSION() \
 500 protected:\
 501     classname m_value; \
 502 };\
 503 \
 504 wxString classname##VariantData::GetType() const\
 505 {\
 506     return m_value.GetClassInfo()->GetClassName();\
 507 }\
 508 \
 509 wxClassInfo* classname##VariantData::GetValueClassInfo()\
 510 {\
 511     return m_value.GetClassInfo();\
 512 }\
 513 \
 514 expdecl classname& operator << ( classname &value, const wxVariant &variant )\
 515 {\
 516     wxASSERT( variant.GetType() == #classname );\
 517     \
 518     classname##VariantData *data = (classname##VariantData*) variant.GetData();\
 519     value = data->GetValue();\
 520     return value;\
 521 }\
 522 \
 523 expdecl wxVariant& operator << ( wxVariant &variant, const classname &value )\
 524 {\
 525     classname##VariantData *data = new classname##VariantData( value );\
 526     variant.SetData( data );\
 527     return variant;\
 528 } \
 529 IMPLEMENT_TRIVIAL_WXANY_CONVERSION(classname, classname##VariantData)
 530
 531 // implements a wxVariantData-derived class using for the Eq() method the
 532 // operator== which must have been provided by "classname"
 533 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
 534 IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,wxEMPTY_PARAMETER_VALUE expdecl) \
 535 \
 536 bool classname##VariantData::Eq(wxVariantData& data) const \
 537 {\
 538     wxASSERT( GetType() == data.GetType() );\
 539 \
 540     classname##VariantData & otherData = (classname##VariantData &) data;\
 541 \
 542     return otherData.m_value == m_value;\
 543 }\
 544
 545
 546 // implements a wxVariantData-derived class using for the Eq() method a shallow
 547 // comparison (through wxObject::IsSameAs function)
 548 #define IMPLEMENT_VARIANT_OBJECT_SHALLOWCMP(classname) \
 549     IMPLEMENT_VARIANT_OBJECT_EXPORTED_SHALLOWCMP(classname, wxEMPTY_PARAMETER_VALUE)
 550 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED_SHALLOWCMP(classname,expdecl) \
 551 IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,wxEMPTY_PARAMETER_VALUE expdecl) \
 552 \
 553 bool classname##VariantData::Eq(wxVariantData& data) const \
 554 {\
 555     wxASSERT( GetType() == data.GetType() );\
 556 \
 557     classname##VariantData & otherData = (classname##VariantData &) data;\
 558 \
 559     return (otherData.m_value.IsSameAs(m_value));\
 560 }\
 561
 562
 563 // Since we want type safety wxVariant we need to fetch and dynamic_cast
 564 // in a seemingly safe way so the compiler can check, so we define
 565 // a dynamic_cast /wxDynamicCast analogue.
 566
 567 #define wxGetVariantCast(var,classname) \
 568     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
 569                   var.GetWxObjectPtr() : NULL));
 570
 571 // Replacement for using wxDynamicCast on a wxVariantData object
 572 #ifndef wxNO_RTTI
 573     #define wxDynamicCastVariantData(data, classname) dynamic_cast<classname*>(data)
 574 #endif
 575
 576 #define wxStaticCastVariantData(data, classname) static_cast<classname*>(data)
 577
 578 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 579
 580 #endif // wxUSE_VARIANT
 581
 582 #endif // _WX_VARIANT_H_