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(NO_GCC_PRAGMA)
  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/arrstr.h"
  23 #include "wx/list.h"
  24
  25 #if wxUSE_DATETIME
  26     #include "wx/datetime.h"
  27 #endif // wxUSE_DATETIME
  28
  29 #if wxUSE_ODBC
  30     #include "wx/db.h"  // will #include sqltypes.h
  31 #endif //ODBC
  32
  33 #include "wx/iosfwrap.h"
  34
  35 /*
  36  * wxVariantData stores the actual data in a wxVariant object,
  37  * to allow it to store any type of data.
  38  * Derive from this to provide custom data handling.
  39  *
  40  * TODO: in order to replace wxPropertyValue, we would need
  41  * to consider adding constructors that take pointers to C++ variables,
  42  * or removing that functionality from the wxProperty library.
  43  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  44  * by storing pointers and not just actual values, allowing update of C++ data
  45  * to be handled automatically. Perhaps there's another way of doing this without
  46  * overloading wxVariant with unnecessary functionality.
  47  */
  48
  49 class WXDLLIMPEXP_BASE wxVariantData: public wxObject
  50 {
  51 DECLARE_ABSTRACT_CLASS(wxVariantData)
  52 public:
  53
  54 // Construction & destruction
  55     wxVariantData() {};
  56
  57 // Override these to provide common functionality
  58     // Copy to data
  59     virtual void Copy(wxVariantData& data) = 0;
  60     virtual bool Eq(wxVariantData& data) const = 0;
  61 #if wxUSE_STD_IOSTREAM
  62     virtual bool Write(wxSTD ostream& str) const = 0;
  63 #endif
  64     virtual bool Write(wxString& str) const = 0;
  65 #if wxUSE_STD_IOSTREAM
  66     virtual bool Read(wxSTD istream& str) = 0;
  67 #endif
  68     virtual bool Read(wxString& str) = 0;
  69     // What type is it? Return a string name.
  70     virtual wxString GetType() const = 0;
  71     // If it based on wxObject return the ClassInfo.
  72     virtual wxClassInfo* GetValueClassInfo() { return NULL; }
  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 WXDLLIMPEXP_BASE 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     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
 101     wxVariant(wxObject* ptr, const wxString& name = wxEmptyString); //wxObject
 102     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
 103 //TODO: Need to document
 104 #if wxUSE_DATETIME
 105     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString); // Date
 106 #endif // wxUSE_DATETIME
 107     wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString); // String array
 108 #if wxUSE_ODBC
 109     wxVariant(const DATE_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 110     wxVariant(const TIME_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 111     wxVariant(const TIMESTAMP_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 112 #endif
 113 //TODO: End of Need to document
 114
 115     wxVariant(const wxVariant& variant);
 116     ~wxVariant();
 117
 118 // Generic operators
 119     // Assignment
 120     void operator= (const wxVariant& variant);
 121
 122 //TODO: Need to document
 123 #if wxUSE_DATETIME
 124     bool operator== (const wxDateTime& value) const;
 125     bool operator!= (const wxDateTime& value) const;
 126     void operator= (const wxDateTime& value) ;
 127 #endif // wxUSE_DATETIME
 128
 129     bool operator== (const wxArrayString& value) const;
 130     bool operator!= (const wxArrayString& value) const;
 131     void operator= (const wxArrayString& value) ;
 132 #if wxUSE_ODBC
 133     void operator= (const DATE_STRUCT* value) ;
 134     void operator= (const TIME_STRUCT* value) ;
 135     void operator= (const TIMESTAMP_STRUCT* value) ;
 136 #endif
 137 //TODO: End of Need to document
 138
 139     // Assignment using data, e.g.
 140     // myVariant = new wxStringVariantData("hello");
 141     void operator= (wxVariantData* variantData);
 142     bool operator== (const wxVariant& variant) const;
 143     bool operator!= (const wxVariant& variant) const;
 144
 145 // Specific operators
 146     bool operator== (double value) const;
 147     bool operator!= (double value) const;
 148     void operator= (double value) ;
 149     bool operator== (long value) const;
 150     bool operator!= (long value) const;
 151     void operator= (long value) ;
 152     bool operator== (char value) const;
 153     bool operator!= (char value) const;
 154     void operator= (char value) ;
 155 #ifdef HAVE_BOOL
 156     bool operator== (bool value) const;
 157     bool operator!= (bool value) const;
 158     void operator= (bool value) ;
 159 #endif
 160     bool operator== (const wxString& value) const;
 161     bool operator!= (const wxString& value) const;
 162     void operator= (const wxString& value) ;
 163     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 164     bool operator== (const wxStringList& value) const;
 165     bool operator!= (const wxStringList& value) const;
 166     void operator= (const wxStringList& value) ;
 167     bool operator== (const wxList& value) const;
 168     bool operator!= (const wxList& value) const;
 169     void operator= (const wxList& value) ;
 170     bool operator== (void* value) const;
 171     bool operator!= (void* value) const;
 172     void operator= (void* value) ;
 173
 174     // Treat a list variant as an array
 175     wxVariant operator[] (size_t idx) const;
 176     wxVariant& operator[] (size_t idx) ;
 177
 178     // Implicit conversion to a wxString
 179     inline operator wxString () const {  return MakeString(); }
 180     wxString MakeString() const;
 181
 182     // Other implicit conversions
 183     inline operator double () const {  return GetDouble(); }
 184     inline operator char () const {  return GetChar(); }
 185     inline operator long () const {  return GetLong(); }
 186     inline operator bool () const {  return GetBool(); }
 187     inline operator void* () const {  return GetVoidPtr(); }
 188     // No implicit conversion to wxObject, as that would really
 189     //  confuse people between conversion to our contained data
 190     //  and downcasting to see our base type.
 191 //TODO: Need to document
 192 #if wxUSE_DATETIME
 193     inline operator wxDateTime () const { return GetDateTime(); }
 194 #endif // wxUSE_DATETIME
 195 //TODO: End of Need to document
 196
 197 // Accessors
 198     // Sets/gets name
 199     inline void SetName(const wxString& name) { m_name = name; }
 200     inline const wxString& GetName() const { return m_name; }
 201
 202     // Tests whether there is data
 203     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 204
 205     wxVariantData* GetData() const { return m_data; }
 206     void SetData(wxVariantData* data) ;
 207
 208     // Returns a string representing the type of the variant,
 209     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 210     wxString GetType() const;
 211
 212     bool IsType(const wxString& type) const;
 213     bool IsValueKindOf(const wxClassInfo* type) const;
 214
 215     // Return the number of elements in a list
 216     int GetCount() const;
 217
 218 // Value accessors
 219     double GetReal() const ;
 220     inline double GetDouble() const { return GetReal(); };
 221     long GetInteger() const ;
 222     inline long GetLong() const { return GetInteger(); };
 223     char GetChar() const ;
 224     bool GetBool() const ;
 225     wxString GetString() const ;
 226     wxList& GetList() const ;
 227     wxStringList& GetStringList() const ;
 228
 229     void* GetVoidPtr() const ;
 230     wxObject* GetWxObjectPtr()  ;
 231 //TODO: Need to document
 232 #if wxUSE_DATETIME
 233     wxDateTime GetDateTime() const ;
 234 #endif // wxUSE_DATETIME
 235     wxArrayString GetArrayString() const;
 236 //TODO: End of Need to document
 237
 238 // Operations
 239     // Make NULL (i.e. delete the data)
 240     void MakeNull();
 241
 242     // Make empty list
 243     void NullList();
 244
 245     // Append to list
 246     void Append(const wxVariant& value);
 247
 248     // Insert at front of list
 249     void Insert(const wxVariant& value);
 250
 251     // Returns TRUE if the variant is a member of the list
 252     bool Member(const wxVariant& value) const;
 253
 254     // Deletes the nth element of the list
 255     bool Delete(int item);
 256
 257     // Clear list
 258     void ClearList();
 259
 260 // Implementation
 261 public:
 262 // Type conversion
 263     bool Convert(long* value) const;
 264     bool Convert(bool* value) const;
 265     bool Convert(double* value) const;
 266     bool Convert(wxString* value) const;
 267     bool Convert(char* value) const;
 268 //TODO: Need to document
 269 #if wxUSE_DATETIME
 270     bool Convert(wxDateTime* value) const;
 271 #endif // wxUSE_DATETIME
 272 //TODO: End of Need to document
 273
 274 // Attributes
 275 protected:
 276     wxVariantData*  m_data;
 277     wxString        m_name;
 278 };
 279
 280 //Since we want type safety wxVariant we need to fetch and dynamic_cast
 281 //in a seemingly safe way so the compiler can check, so we define
 282 //a dynamic_cast /wxDynamicCast analogue.
 283
 284 #define wxGetVariantCast(var,classname) \
 285         ((classname*)(var.IsValueKindOf(&classname::sm_class##classname) ?\
 286                       var.GetWxObjectPtr() : NULL));
 287
 288 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 289
 290 #endif
 291     // _WX_VARIANT_H_