include/wx/variant.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        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)
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_VARIANT_H_
  13 #define _WX_VARIANT_H_
  14
  15 #ifdef __GNUG__
  16 #pragma interface "variant.h"
  17 #endif
  18
  19 #include "wx/defs.h"
  20 #include "wx/object.h"
  21 #include "wx/string.h"
  22 #include "wx/list.h"
  23
  24 #if wxUSE_TIMEDATE
  25     #include "wx/time.h"
  26     #include "wx/date.h"
  27 #endif // time/date
  28
  29 #include "wx/datetime.h"
  30
  31 #if wxUSE_ODBC
  32     #include "wx/db.h"  // will #include sqltypes.h
  33 #endif //ODBC
  34
  35 #include "wx/ioswrap.h"
  36
  37 /*
  38  * wxVariantData stores the actual data in a wxVariant object,
  39  * to allow it to store any type of data.
  40  * Derive from this to provide custom data handling.
  41  *
  42  * TODO: in order to replace wxPropertyValue, we would need
  43  * to consider adding constructors that take pointers to C++ variables,
  44  * or removing that functionality from the wxProperty library.
  45  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  46  * by storing pointers and not just actual values, allowing update of C++ data
  47  * to be handled automatically. Perhaps there's another way of doing this without
  48  * overloading wxVariant with unnecessary functionality.
  49  */
  50
  51 class WXDLLEXPORT wxVariantData: public wxObject
  52 {
  53 DECLARE_ABSTRACT_CLASS(wxVariantData)
  54 public:
  55
  56 // Construction & destruction
  57     wxVariantData() {};
  58
  59 // Override these to provide common functionality
  60     // Copy to data
  61     virtual void Copy(wxVariantData& data) = 0;
  62     virtual bool Eq(wxVariantData& data) const = 0;
  63 #if wxUSE_STD_IOSTREAM
  64     virtual bool Write(wxSTD ostream& str) const = 0;
  65 #endif
  66     virtual bool Write(wxString& str) const = 0;
  67 #if wxUSE_STD_IOSTREAM
  68     virtual bool Read(wxSTD istream& str) = 0;
  69 #endif
  70     virtual bool Read(wxString& str) = 0;
  71     // What type is it? Return a string name.
  72     virtual wxString GetType() const = 0;
  73 };
  74
  75 /*
  76  * wxVariant can store any kind of data, but has some basic types
  77  * built in.
  78  * NOTE: this eventually should have a reference-counting implementation.
  79  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  80  * this class too much.
  81  */
  82
  83 class WXDLLEXPORT wxVariant: public wxObject
  84 {
  85 DECLARE_DYNAMIC_CLASS(wxVariant)
  86 public:
  87
  88 // Construction & destruction
  89     wxVariant();
  90     wxVariant(double val, const wxString& name = wxEmptyString);
  91     wxVariant(long val, const wxString& name = wxEmptyString);
  92 #ifdef HAVE_BOOL
  93     wxVariant(bool val, const wxString& name = wxEmptyString);
  94 #endif
  95     wxVariant(char val, const wxString& name = wxEmptyString);
  96     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
  97     wxVariant(const wxChar* val, const wxString& name = wxEmptyString); // Necessary or VC++ assumes bool!
  98     wxVariant(const wxStringList& val, const wxString& name = wxEmptyString);
  99     wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
 100 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 101 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 102     wxVariant(const wxTime& val, const wxString& name = wxEmptyString); // Time
 103     wxVariant(const wxDate& val, const wxString& name = wxEmptyString); // Date
 104 #endif
 105     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
 106     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
 107 //TODO: Need to document
 108     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString); // Date
 109 #if wxUSE_ODBC
 110     wxVariant(const DATE_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 111     wxVariant(const TIME_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 112     wxVariant(const TIMESTAMP_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 113 #endif
 114 //TODO: End of Need to document
 115
 116     wxVariant(const wxVariant& variant);
 117     ~wxVariant();
 118
 119 // Generic operators
 120     // Assignment
 121     void operator= (const wxVariant& variant);
 122
 123 //TODO: Need to document
 124     bool operator== (const wxDateTime& value) const;
 125     bool operator!= (const wxDateTime& value) const;
 126     void operator= (const wxDateTime& value) ;
 127 #if wxUSE_ODBC
 128     void operator= (const DATE_STRUCT* value) ;
 129     void operator= (const TIME_STRUCT* value) ;
 130     void operator= (const TIMESTAMP_STRUCT* value) ;
 131 #endif
 132 //TODO: End of Need to document
 133
 134     // Assignment using data, e.g.
 135     // myVariant = new wxStringVariantData("hello");
 136     void operator= (wxVariantData* variantData);
 137     bool operator== (const wxVariant& variant) const;
 138     bool operator!= (const wxVariant& variant) const;
 139
 140 // Specific operators
 141     bool operator== (double value) const;
 142     bool operator!= (double value) const;
 143     void operator= (double value) ;
 144     bool operator== (long value) const;
 145     bool operator!= (long value) const;
 146     void operator= (long value) ;
 147     bool operator== (char value) const;
 148     bool operator!= (char value) const;
 149     void operator= (char value) ;
 150 #ifdef HAVE_BOOL
 151     bool operator== (bool value) const;
 152     bool operator!= (bool value) const;
 153     void operator= (bool value) ;
 154 #endif
 155     bool operator== (const wxString& value) const;
 156     bool operator!= (const wxString& value) const;
 157     void operator= (const wxString& value) ;
 158     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 159     bool operator== (const wxStringList& value) const;
 160     bool operator!= (const wxStringList& value) const;
 161     void operator= (const wxStringList& value) ;
 162     bool operator== (const wxList& value) const;
 163     bool operator!= (const wxList& value) const;
 164     void operator= (const wxList& value) ;
 165 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 166 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 167     bool operator== (const wxTime& value) const;
 168     bool operator!= (const wxTime& value) const;
 169     void operator= (const wxTime& value) ;
 170     bool operator== (const wxDate& value) const;
 171     bool operator!= (const wxDate& value) const;
 172     void operator= (const wxDate& value) ;
 173 #endif
 174     bool operator== (void* value) const;
 175     bool operator!= (void* value) const;
 176     void operator= (void* value) ;
 177
 178     // Treat a list variant as an array
 179     wxVariant operator[] (size_t idx) const;
 180     wxVariant& operator[] (size_t idx) ;
 181
 182     // Implicit conversion to a wxString
 183     inline operator wxString () const {  return MakeString(); }
 184     wxString MakeString() const;
 185
 186     // Other implicit conversions
 187     inline operator double () const {  return GetDouble(); }
 188     inline operator char () const {  return GetChar(); }
 189     inline operator long () const {  return GetLong(); }
 190     inline operator bool () const {  return GetBool(); }
 191 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 192 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 193     inline operator wxTime () const {  return GetTime(); }
 194     inline operator wxDate () const {  return GetDate(); }
 195 #endif
 196     inline operator void* () const {  return GetVoidPtr(); }
 197 //TODO: Need to document
 198     inline operator wxDateTime () const { return GetDateTime(); }
 199 //TODO: End of Need to document
 200
 201 // Accessors
 202     // Sets/gets name
 203     inline void SetName(const wxString& name) { m_name = name; }
 204     inline const wxString& GetName() const { return m_name; }
 205
 206     // Tests whether there is data
 207     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 208
 209     wxVariantData* GetData() const { return m_data; }
 210     void SetData(wxVariantData* data) ;
 211
 212     // Returns a string representing the type of the variant,
 213     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 214     wxString GetType() const;
 215
 216     bool IsType(const wxString& type) const;
 217
 218     // Return the number of elements in a list
 219     int GetCount() const;
 220
 221 // Value accessors
 222     double GetReal() const ;
 223     inline double GetDouble() const { return GetReal(); };
 224     long GetInteger() const ;
 225     inline long GetLong() const { return GetInteger(); };
 226     char GetChar() const ;
 227     bool GetBool() const ;
 228     wxString GetString() const ;
 229     wxList& GetList() const ;
 230     wxStringList& GetStringList() const ;
 231
 232 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 233 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 234     wxTime GetTime() const ;
 235     wxDate GetDate() const ;
 236 #endif
 237     void* GetVoidPtr() const ;
 238 //TODO: Need to document
 239     wxDateTime GetDateTime() const ;
 240 //TODO: End of Need to document
 241
 242 // Operations
 243     // Make NULL (i.e. delete the data)
 244     void MakeNull();
 245
 246     // Make empty list
 247     void NullList();
 248
 249     // Append to list
 250     void Append(const wxVariant& value);
 251
 252     // Insert at front of list
 253     void Insert(const wxVariant& value);
 254
 255     // Returns TRUE if the variant is a member of the list
 256     bool Member(const wxVariant& value) const;
 257
 258     // Deletes the nth element of the list
 259     bool Delete(int item);
 260
 261     // Clear list
 262     void ClearList();
 263
 264 // Implementation
 265 protected:
 266 // Type conversion
 267     bool Convert(long* value) const;
 268     bool Convert(bool* value) const;
 269     bool Convert(double* value) const;
 270     bool Convert(wxString* value) const;
 271     bool Convert(char* value) const;
 272 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 273 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 274     bool Convert(wxTime* value) const;
 275     bool Convert(wxDate* value) const;
 276 #endif
 277 //TODO: Need to document
 278     bool Convert(wxDateTime* value) const;
 279 //TODO: End of Need to document
 280
 281 // Attributes
 282 protected:
 283     wxVariantData*  m_data;
 284     wxString        m_name;
 285 };
 286
 287 extern wxVariant WXDLLEXPORT wxNullVariant;
 288
 289 #endif
 290     // _WX_VARIANT_H_