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 };
  71
  72 /*
  73  * wxVariant can store any kind of data, but has some basic types
  74  * built in.
  75  * NOTE: this eventually should have a reference-counting implementation.
  76  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  77  * this class too much.
  78  */
  79
  80 class WXDLLEXPORT wxVariant: public wxObject
  81 {
  82 DECLARE_DYNAMIC_CLASS(wxVariant)
  83 public:
  84
  85 // Construction & destruction
  86     wxVariant();
  87     wxVariant(double val, const wxString& name = wxEmptyString);
  88     wxVariant(long val, const wxString& name = wxEmptyString);
  89 #ifdef HAVE_BOOL
  90     wxVariant(bool val, const wxString& name = wxEmptyString);
  91 #endif
  92     wxVariant(char val, const wxString& name = wxEmptyString);
  93     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
  94     wxVariant(const wxChar* val, const wxString& name = wxEmptyString); // Necessary or VC++ assumes bool!
  95     wxVariant(const wxStringList& val, const wxString& name = wxEmptyString);
  96     wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
  97     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
  98     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
  99 //TODO: Need to document
 100 #if wxUSE_DATETIME
 101     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString); // Date
 102 #endif // wxUSE_DATETIME
 103     wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString); // String array
 104 #if wxUSE_ODBC
 105     wxVariant(const DATE_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 106     wxVariant(const TIME_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 107     wxVariant(const TIMESTAMP_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 108 #endif
 109 //TODO: End of Need to document
 110
 111     wxVariant(const wxVariant& variant);
 112     ~wxVariant();
 113
 114 // Generic operators
 115     // Assignment
 116     void operator= (const wxVariant& variant);
 117
 118 //TODO: Need to document
 119 #if wxUSE_DATETIME
 120     bool operator== (const wxDateTime& value) const;
 121     bool operator!= (const wxDateTime& value) const;
 122     void operator= (const wxDateTime& value) ;
 123 #endif // wxUSE_DATETIME
 124
 125     bool operator== (const wxArrayString& value) const;
 126     bool operator!= (const wxArrayString& value) const;
 127     void operator= (const wxArrayString& value) ;
 128 #if wxUSE_ODBC
 129     void operator= (const DATE_STRUCT* value) ;
 130     void operator= (const TIME_STRUCT* value) ;
 131     void operator= (const TIMESTAMP_STRUCT* value) ;
 132 #endif
 133 //TODO: End of Need to document
 134
 135     // Assignment using data, e.g.
 136     // myVariant = new wxStringVariantData("hello");
 137     void operator= (wxVariantData* variantData);
 138     bool operator== (const wxVariant& variant) const;
 139     bool operator!= (const wxVariant& variant) const;
 140
 141 // Specific operators
 142     bool operator== (double value) const;
 143     bool operator!= (double value) const;
 144     void operator= (double value) ;
 145     bool operator== (long value) const;
 146     bool operator!= (long value) const;
 147     void operator= (long value) ;
 148     bool operator== (char value) const;
 149     bool operator!= (char value) const;
 150     void operator= (char value) ;
 151 #ifdef HAVE_BOOL
 152     bool operator== (bool value) const;
 153     bool operator!= (bool value) const;
 154     void operator= (bool value) ;
 155 #endif
 156     bool operator== (const wxString& value) const;
 157     bool operator!= (const wxString& value) const;
 158     void operator= (const wxString& value) ;
 159     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 160     bool operator== (const wxStringList& value) const;
 161     bool operator!= (const wxStringList& value) const;
 162     void operator= (const wxStringList& value) ;
 163     bool operator== (const wxList& value) const;
 164     bool operator!= (const wxList& value) const;
 165     void operator= (const wxList& value) ;
 166     bool operator== (void* value) const;
 167     bool operator!= (void* value) const;
 168     void operator= (void* value) ;
 169
 170     // Treat a list variant as an array
 171     wxVariant operator[] (size_t idx) const;
 172     wxVariant& operator[] (size_t idx) ;
 173
 174     // Implicit conversion to a wxString
 175     inline operator wxString () const {  return MakeString(); }
 176     wxString MakeString() const;
 177
 178     // Other implicit conversions
 179     inline operator double () const {  return GetDouble(); }
 180     inline operator char () const {  return GetChar(); }
 181     inline operator long () const {  return GetLong(); }
 182     inline operator bool () const {  return GetBool(); }
 183     inline operator void* () const {  return GetVoidPtr(); }
 184 //TODO: Need to document
 185 #if wxUSE_DATETIME
 186     inline operator wxDateTime () const { return GetDateTime(); }
 187 #endif // wxUSE_DATETIME
 188 //TODO: End of Need to document
 189
 190 // Accessors
 191     // Sets/gets name
 192     inline void SetName(const wxString& name) { m_name = name; }
 193     inline const wxString& GetName() const { return m_name; }
 194
 195     // Tests whether there is data
 196     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 197
 198     wxVariantData* GetData() const { return m_data; }
 199     void SetData(wxVariantData* data) ;
 200
 201     // Returns a string representing the type of the variant,
 202     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 203     wxString GetType() const;
 204
 205     bool IsType(const wxString& type) const;
 206
 207     // Return the number of elements in a list
 208     int GetCount() const;
 209
 210 // Value accessors
 211     double GetReal() const ;
 212     inline double GetDouble() const { return GetReal(); };
 213     long GetInteger() const ;
 214     inline long GetLong() const { return GetInteger(); };
 215     char GetChar() const ;
 216     bool GetBool() const ;
 217     wxString GetString() const ;
 218     wxList& GetList() const ;
 219     wxStringList& GetStringList() const ;
 220
 221     void* GetVoidPtr() const ;
 222 //TODO: Need to document
 223 #if wxUSE_DATETIME
 224     wxDateTime GetDateTime() const ;
 225 #endif // wxUSE_DATETIME
 226     wxArrayString GetArrayString() const;
 227 //TODO: End of Need to document
 228
 229 // Operations
 230     // Make NULL (i.e. delete the data)
 231     void MakeNull();
 232
 233     // Make empty list
 234     void NullList();
 235
 236     // Append to list
 237     void Append(const wxVariant& value);
 238
 239     // Insert at front of list
 240     void Insert(const wxVariant& value);
 241
 242     // Returns TRUE if the variant is a member of the list
 243     bool Member(const wxVariant& value) const;
 244
 245     // Deletes the nth element of the list
 246     bool Delete(int item);
 247
 248     // Clear list
 249     void ClearList();
 250
 251 // Implementation
 252 public:
 253 // Type conversion
 254     bool Convert(long* value) const;
 255     bool Convert(bool* value) const;
 256     bool Convert(double* value) const;
 257     bool Convert(wxString* value) const;
 258     bool Convert(char* value) const;
 259 //TODO: Need to document
 260 #if wxUSE_DATETIME
 261     bool Convert(wxDateTime* value) const;
 262 #endif // wxUSE_DATETIME
 263 //TODO: End of Need to document
 264
 265 // Attributes
 266 protected:
 267     wxVariantData*  m_data;
 268     wxString        m_name;
 269 };
 270
 271 extern wxVariant WXDLLEXPORT wxNullVariant;
 272
 273 #endif
 274     // _WX_VARIANT_H_