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 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_VARIANT_H_
  13 #define _WX_VARIANT_H_
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_VARIANT
  18
  19 #include "wx/object.h"
  20 #include "wx/string.h"
  21 #include "wx/arrstr.h"
  22 #include "wx/list.h"
  23 #include "wx/cpp.h"
  24 #include "wx/longlong.h"
  25
  26 #if wxUSE_DATETIME
  27     #include "wx/datetime.h"
  28 #endif // wxUSE_DATETIME
  29
  30 #include "wx/iosfwrap.h"
  31
  32 /*
  33  * wxVariantData stores the actual data in a wxVariant object,
  34  * to allow it to store any type of data.
  35  * Derive from this to provide custom data handling.
  36  *
  37  * NB: When you construct a wxVariantData, it will have refcount
  38  *     of one. Refcount will not be further increased when
  39  *     it is passed to wxVariant. This simulates old common
  40  *     scenario where wxVariant took ownership of wxVariantData
  41  *     passed to it.
  42  *     If you create wxVariantData for other reasons than passing
  43  *     it to wxVariant, technically you are not required to call
  44  *     DecRef() before deleting it.
  45  *
  46  * TODO: in order to replace wxPropertyValue, we would need
  47  * to consider adding constructors that take pointers to C++ variables,
  48  * or removing that functionality from the wxProperty library.
  49  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  50  * by storing pointers and not just actual values, allowing update of C++ data
  51  * to be handled automatically. Perhaps there's another way of doing this without
  52  * overloading wxVariant with unnecessary functionality.
  53  */
  54
  55 class WXDLLIMPEXP_BASE wxVariantData : public wxObjectRefData
  56 {
  57     friend class wxVariant;
  58 public:
  59     wxVariantData() { }
  60
  61     // Override these to provide common functionality
  62     virtual bool Eq(wxVariantData& data) const = 0;
  63
  64 #if wxUSE_STD_IOSTREAM
  65     virtual bool Write(wxSTD ostream& WXUNUSED(str)) const { return false; }
  66 #endif
  67     virtual bool Write(wxString& WXUNUSED(str)) const { return false; }
  68 #if wxUSE_STD_IOSTREAM
  69     virtual bool Read(wxSTD istream& WXUNUSED(str)) { return false; }
  70 #endif
  71     virtual bool Read(wxString& WXUNUSED(str)) { return false; }
  72     // What type is it? Return a string name.
  73     virtual wxString GetType() const = 0;
  74     // If it based on wxObject return the ClassInfo.
  75     virtual wxClassInfo* GetValueClassInfo() { return NULL; }
  76
  77     // Implement this to make wxVariant::UnShare work. Returns
  78     // a copy of the data.
  79     virtual wxVariantData* Clone() const { return NULL; }
  80
  81 protected:
  82     // Protected dtor should make some incompatible code
  83     // break more louder. That is, they should do data->DecRef()
  84     // instead of delete data.
  85     virtual ~wxVariantData() { }
  86 };
  87
  88 /*
  89  * wxVariant can store any kind of data, but has some basic types
  90  * built in.
  91  */
  92
  93 class WXDLLIMPEXP_FWD_BASE wxVariant;
  94
  95 WX_DECLARE_LIST_WITH_DECL(wxVariant, wxVariantList, class WXDLLIMPEXP_BASE);
  96
  97 class WXDLLIMPEXP_BASE wxVariant: public wxObject
  98 {
  99 public:
 100     wxVariant();
 101
 102     wxVariant(const wxVariant& variant);
 103     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString);
 104     virtual ~wxVariant();
 105
 106     // generic assignment
 107     void operator= (const wxVariant& variant);
 108
 109     // Assignment using data, e.g.
 110     // myVariant = new wxStringVariantData("hello");
 111     void operator= (wxVariantData* variantData);
 112
 113     bool operator== (const wxVariant& variant) const;
 114     bool operator!= (const wxVariant& variant) const;
 115
 116     // Sets/gets name
 117     inline void SetName(const wxString& name) { m_name = name; }
 118     inline const wxString& GetName() const { return m_name; }
 119
 120     // Tests whether there is data
 121     bool IsNull() const;
 122
 123     // For compatibility with wxWidgets <= 2.6, this doesn't increase
 124     // reference count.
 125     wxVariantData* GetData() const
 126     {
 127         return (wxVariantData*) m_refData;
 128     }
 129     void SetData(wxVariantData* data) ;
 130
 131     // make a 'clone' of the object
 132     void Ref(const wxVariant& clone) { wxObject::Ref(clone); }
 133
 134     // ensure that the data is exclusive to this variant, and not shared
 135     bool Unshare();
 136
 137     // Make NULL (i.e. delete the data)
 138     void MakeNull();
 139
 140     // Delete data and name
 141     void Clear();
 142
 143     // Returns a string representing the type of the variant,
 144     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 145     wxString GetType() const;
 146
 147     bool IsType(const wxString& type) const;
 148     bool IsValueKindOf(const wxClassInfo* type) const;
 149
 150     // write contents to a string (e.g. for debugging)
 151     wxString MakeString() const;
 152
 153     // double
 154     wxVariant(double val, const wxString& name = wxEmptyString);
 155     bool operator== (double value) const;
 156     bool operator!= (double value) const;
 157     void operator= (double value) ;
 158     inline operator double () const {  return GetDouble(); }
 159     inline double GetReal() const { return GetDouble(); }
 160     double GetDouble() const;
 161
 162     // long
 163     wxVariant(long val, const wxString& name = wxEmptyString);
 164     wxVariant(int val, const wxString& name = wxEmptyString);
 165     wxVariant(short val, const wxString& name = wxEmptyString);
 166     bool operator== (long value) const;
 167     bool operator!= (long value) const;
 168     void operator= (long value) ;
 169     inline operator long () const {  return GetLong(); }
 170     inline long GetInteger() const { return GetLong(); }
 171     long GetLong() const;
 172
 173     // bool
 174     wxVariant(bool val, const wxString& name = wxEmptyString);
 175     bool operator== (bool value) const;
 176     bool operator!= (bool value) const;
 177     void operator= (bool value) ;
 178     inline operator bool () const {  return GetBool(); }
 179     bool GetBool() const ;
 180
 181     // wxDateTime
 182 #if wxUSE_DATETIME
 183     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString);
 184     bool operator== (const wxDateTime& value) const;
 185     bool operator!= (const wxDateTime& value) const;
 186     void operator= (const wxDateTime& value) ;
 187     inline operator wxDateTime () const { return GetDateTime(); }
 188     wxDateTime GetDateTime() const;
 189 #endif
 190
 191     // wxString
 192     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
 193     // these overloads are necessary to prevent the compiler from using bool
 194     // version instead of wxString one:
 195     wxVariant(const char* val, const wxString& name = wxEmptyString);
 196     wxVariant(const wchar_t* val, const wxString& name = wxEmptyString);
 197     wxVariant(const wxCStrData& val, const wxString& name = wxEmptyString);
 198     wxVariant(const wxScopedCharBuffer& val, const wxString& name = wxEmptyString);
 199     wxVariant(const wxScopedWCharBuffer& val, const wxString& name = wxEmptyString);
 200
 201     bool operator== (const wxString& value) const;
 202     bool operator!= (const wxString& value) const;
 203     wxVariant& operator=(const wxString& value);
 204     // these overloads are necessary to prevent the compiler from using bool
 205     // version instead of wxString one:
 206     wxVariant& operator=(const char* value)
 207         { return *this = wxString(value); }
 208     wxVariant& operator=(const wchar_t* value)
 209         { return *this = wxString(value); }
 210     wxVariant& operator=(const wxCStrData& value)
 211         { return *this = value.AsString(); }
 212     template<typename T>
 213     wxVariant& operator=(const wxScopedCharTypeBuffer<T>& value)
 214         { return *this = value.data(); }
 215
 216     inline operator wxString () const {  return MakeString(); }
 217     wxString GetString() const;
 218
 219     // wxUniChar
 220     wxVariant(const wxUniChar& val, const wxString& name = wxEmptyString);
 221     wxVariant(const wxUniCharRef& val, const wxString& name = wxEmptyString);
 222     wxVariant(char val, const wxString& name = wxEmptyString);
 223     wxVariant(wchar_t val, const wxString& name = wxEmptyString);
 224     bool operator==(const wxUniChar& value) const;
 225     bool operator==(const wxUniCharRef& value) const { return *this == wxUniChar(value); }
 226     bool operator==(char value) const { return *this == wxUniChar(value); }
 227     bool operator==(wchar_t value) const { return *this == wxUniChar(value); }
 228     bool operator!=(const wxUniChar& value) const { return !(*this == value); }
 229     bool operator!=(const wxUniCharRef& value) const { return !(*this == value); }
 230     bool operator!=(char value) const { return !(*this == value); }
 231     bool operator!=(wchar_t value) const { return !(*this == value); }
 232     wxVariant& operator=(const wxUniChar& value);
 233     wxVariant& operator=(const wxUniCharRef& value) { return *this = wxUniChar(value); }
 234     wxVariant& operator=(char value) { return *this = wxUniChar(value); }
 235     wxVariant& operator=(wchar_t value) { return *this = wxUniChar(value); }
 236     operator wxUniChar() const { return GetChar(); }
 237     operator char() const { return GetChar(); }
 238     operator wchar_t() const { return GetChar(); }
 239     wxUniChar GetChar() const;
 240
 241     // wxArrayString
 242     wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString);
 243     bool operator== (const wxArrayString& value) const;
 244     bool operator!= (const wxArrayString& value) const;
 245     void operator= (const wxArrayString& value);
 246     operator wxArrayString () const { return GetArrayString(); }
 247     wxArrayString GetArrayString() const;
 248
 249     // void*
 250     wxVariant(void* ptr, const wxString& name = wxEmptyString);
 251     bool operator== (void* value) const;
 252     bool operator!= (void* value) const;
 253     void operator= (void* value);
 254     operator void* () const {  return GetVoidPtr(); }
 255     void* GetVoidPtr() const;
 256
 257     // wxObject*
 258     wxVariant(wxObject* ptr, const wxString& name = wxEmptyString);
 259     bool operator== (wxObject* value) const;
 260     bool operator!= (wxObject* value) const;
 261     void operator= (wxObject* value);
 262     wxObject* GetWxObjectPtr() const;
 263
 264 #if wxUSE_LONGLONG
 265     // wxLongLong
 266     wxVariant(wxLongLong, const wxString& name = wxEmptyString);
 267     bool operator==(wxLongLong value) const;
 268     bool operator!=(wxLongLong value) const;
 269     void operator=(wxLongLong value);
 270     operator wxLongLong() const { return GetLongLong(); }
 271     wxLongLong GetLongLong() const;
 272
 273     // wxULongLong
 274     wxVariant(wxULongLong, const wxString& name = wxEmptyString);
 275     bool operator==(wxULongLong value) const;
 276     bool operator!=(wxULongLong value) const;
 277     void operator=(wxULongLong value);
 278     operator wxULongLong() const { return GetULongLong(); }
 279     wxULongLong GetULongLong() const;
 280 #endif
 281
 282     // ------------------------------
 283     // list operations
 284     // ------------------------------
 285
 286     wxVariant(const wxVariantList& val, const wxString& name = wxEmptyString); // List of variants
 287     bool operator== (const wxVariantList& value) const;
 288     bool operator!= (const wxVariantList& value) const;
 289     void operator= (const wxVariantList& value) ;
 290     // Treat a list variant as an array
 291     wxVariant operator[] (size_t idx) const;
 292     wxVariant& operator[] (size_t idx) ;
 293     wxVariantList& GetList() const ;
 294
 295     // Return the number of elements in a list
 296     size_t GetCount() const;
 297
 298     // Make empty list
 299     void NullList();
 300
 301     // Append to list
 302     void Append(const wxVariant& value);
 303
 304     // Insert at front of list
 305     void Insert(const wxVariant& value);
 306
 307     // Returns true if the variant is a member of the list
 308     bool Member(const wxVariant& value) const;
 309
 310     // Deletes the nth element of the list
 311     bool Delete(size_t item);
 312
 313     // Clear list
 314     void ClearList();
 315
 316 public:
 317     // Type conversion
 318     bool Convert(long* value) const;
 319     bool Convert(bool* value) const;
 320     bool Convert(double* value) const;
 321     bool Convert(wxString* value) const;
 322     bool Convert(wxUniChar* value) const;
 323     bool Convert(char* value) const;
 324     bool Convert(wchar_t* value) const;
 325 #if wxUSE_DATETIME
 326     bool Convert(wxDateTime* value) const;
 327 #endif // wxUSE_DATETIME
 328 #if wxUSE_LONGLONG
 329     bool Convert(wxLongLong* value) const;
 330     bool Convert(wxULongLong* value) const;
 331 #endif // wxUSE_LONGLONG
 332
 333 // Attributes
 334 protected:
 335     virtual wxObjectRefData *CreateRefData() const;
 336     virtual wxObjectRefData *CloneRefData(const wxObjectRefData *data) const;
 337
 338     wxString        m_name;
 339
 340 private:
 341     DECLARE_DYNAMIC_CLASS(wxVariant)
 342 };
 343
 344 #define DECLARE_VARIANT_OBJECT(classname) \
 345     DECLARE_VARIANT_OBJECT_EXPORTED(classname, wxEMPTY_PARAMETER_VALUE)
 346
 347 #define DECLARE_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
 348 expdecl classname& operator << ( classname &object, const wxVariant &variant ); \
 349 expdecl wxVariant& operator << ( wxVariant &variant, const classname &object );
 350
 351 #define IMPLEMENT_VARIANT_OBJECT(classname) \
 352     IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname, wxEMPTY_PARAMETER_VALUE)
 353
 354 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,expdecl) \
 355 class classname##VariantData: public wxVariantData \
 356 { \
 357 public:\
 358     classname##VariantData() {} \
 359     classname##VariantData( const classname &value ) { m_value = value; } \
 360 \
 361     classname &GetValue() { return m_value; } \
 362 \
 363     virtual bool Eq(wxVariantData& data) const; \
 364 \
 365     virtual wxString GetType() const; \
 366     virtual wxClassInfo* GetValueClassInfo(); \
 367 \
 368     virtual wxVariantData* Clone() const { return new classname##VariantData(m_value); } \
 369 \
 370 protected:\
 371     classname m_value; \
 372 };\
 373 \
 374 wxString classname##VariantData::GetType() const\
 375 {\
 376     return m_value.GetClassInfo()->GetClassName();\
 377 }\
 378 \
 379 wxClassInfo* classname##VariantData::GetValueClassInfo()\
 380 {\
 381     return m_value.GetClassInfo();\
 382 }\
 383 \
 384 expdecl classname& operator << ( classname &value, const wxVariant &variant )\
 385 {\
 386     wxASSERT( variant.GetType() == #classname );\
 387     \
 388     classname##VariantData *data = (classname##VariantData*) variant.GetData();\
 389     value = data->GetValue();\
 390     return value;\
 391 }\
 392 \
 393 expdecl wxVariant& operator << ( wxVariant &variant, const classname &value )\
 394 {\
 395     classname##VariantData *data = new classname##VariantData( value );\
 396     variant.SetData( data );\
 397     return variant;\
 398 }
 399
 400 // implements a wxVariantData-derived class using for the Eq() method the
 401 // operator== which must have been provided by "classname"
 402 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED(classname,expdecl) \
 403 IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,wxEMPTY_PARAMETER_VALUE expdecl) \
 404 \
 405 bool classname##VariantData::Eq(wxVariantData& data) const \
 406 {\
 407     wxASSERT( GetType() == data.GetType() );\
 408 \
 409     classname##VariantData & otherData = (classname##VariantData &) data;\
 410 \
 411     return otherData.m_value == m_value;\
 412 }\
 413
 414
 415 // implements a wxVariantData-derived class using for the Eq() method a shallow
 416 // comparison (through wxObject::IsSameAs function)
 417 #define IMPLEMENT_VARIANT_OBJECT_SHALLOWCMP(classname) \
 418     IMPLEMENT_VARIANT_OBJECT_EXPORTED_SHALLOWCMP(classname, wxEMPTY_PARAMETER_VALUE)
 419 #define IMPLEMENT_VARIANT_OBJECT_EXPORTED_SHALLOWCMP(classname,expdecl) \
 420 IMPLEMENT_VARIANT_OBJECT_EXPORTED_NO_EQ(classname,wxEMPTY_PARAMETER_VALUE expdecl) \
 421 \
 422 bool classname##VariantData::Eq(wxVariantData& data) const \
 423 {\
 424     wxASSERT( GetType() == data.GetType() );\
 425 \
 426     classname##VariantData & otherData = (classname##VariantData &) data;\
 427 \
 428     return (otherData.m_value.IsSameAs(m_value));\
 429 }\
 430
 431
 432 // Since we want type safety wxVariant we need to fetch and dynamic_cast
 433 // in a seemingly safe way so the compiler can check, so we define
 434 // a dynamic_cast /wxDynamicCast analogue.
 435
 436 #define wxGetVariantCast(var,classname) \
 437     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
 438                   var.GetWxObjectPtr() : NULL));
 439
 440 // Replacement for using wxDynamicCast on a wxVariantData object
 441 #define wxDynamicCastVariantData(data, classname) dynamic_cast<classname*>(data)
 442
 443 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 444
 445 #endif // wxUSE_VARIANT
 446
 447 #endif // _WX_VARIANT_H_