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