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 #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
 113     wxVariant(const wxVariant& variant);
 114     ~wxVariant();
 115
 116 // Generic operators
 117     // Assignment
 118     void operator= (const wxVariant& variant);
 119
 120 #if wxUSE_DATETIME
 121     bool operator== (const wxDateTime& value) const;
 122     bool operator!= (const wxDateTime& value) const;
 123     void operator= (const wxDateTime& value) ;
 124 #endif // wxUSE_DATETIME
 125
 126     bool operator== (const wxArrayString& value) const;
 127     bool operator!= (const wxArrayString& value) const;
 128     void operator= (const wxArrayString& value) ;
 129 #if wxUSE_ODBC
 130     void operator= (const DATE_STRUCT* value) ;
 131     void operator= (const TIME_STRUCT* value) ;
 132     void operator= (const TIMESTAMP_STRUCT* value) ;
 133 #endif
 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     // No implicit conversion to wxObject, as that would really
 185     //  confuse people between conversion to our contained data
 186     //  and downcasting to see our base type.
 187 #if wxUSE_DATETIME
 188     inline operator wxDateTime () const { return GetDateTime(); }
 189 #endif // wxUSE_DATETIME
 190
 191 // Accessors
 192     // Sets/gets name
 193     inline void SetName(const wxString& name) { m_name = name; }
 194     inline const wxString& GetName() const { return m_name; }
 195
 196     // Tests whether there is data
 197     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 198
 199     wxVariantData* GetData() const { return m_data; }
 200     void SetData(wxVariantData* data) ;
 201
 202     // Returns a string representing the type of the variant,
 203     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 204     wxString GetType() const;
 205
 206     bool IsType(const wxString& type) const;
 207     bool IsValueKindOf(const wxClassInfo* type) const;
 208
 209     // Return the number of elements in a list
 210     int GetCount() const;
 211
 212 // Value accessors
 213     double GetReal() const ;
 214     inline double GetDouble() const { return GetReal(); };
 215     long GetInteger() const ;
 216     inline long GetLong() const { return GetInteger(); };
 217     char GetChar() const ;
 218     bool GetBool() const ;
 219     wxString GetString() const ;
 220     wxList& GetList() const ;
 221     wxStringList& GetStringList() const ;
 222
 223     void* GetVoidPtr() const ;
 224     wxObject* GetWxObjectPtr()  ;
 225 #if wxUSE_DATETIME
 226     wxDateTime GetDateTime() const ;
 227 #endif // wxUSE_DATETIME
 228     wxArrayString GetArrayString() const;
 229
 230 // Operations
 231     // Make NULL (i.e. delete the data)
 232     void MakeNull();
 233
 234     // Make empty list
 235     void NullList();
 236
 237     // Append to list
 238     void Append(const wxVariant& value);
 239
 240     // Insert at front of list
 241     void Insert(const wxVariant& value);
 242
 243     // Returns true if the variant is a member of the list
 244     bool Member(const wxVariant& value) const;
 245
 246     // Deletes the nth element of the list
 247     bool Delete(int item);
 248
 249     // Clear list
 250     void ClearList();
 251
 252 // Implementation
 253 public:
 254 // Type conversion
 255     bool Convert(long* value) const;
 256     bool Convert(bool* value) const;
 257     bool Convert(double* value) const;
 258     bool Convert(wxString* value) const;
 259     bool Convert(char* value) const;
 260 #if wxUSE_DATETIME
 261     bool Convert(wxDateTime* value) const;
 262 #endif // wxUSE_DATETIME
 263
 264 // Attributes
 265 protected:
 266     wxVariantData*  m_data;
 267     wxString        m_name;
 268 };
 269
 270 //Since we want type safety wxVariant we need to fetch and dynamic_cast
 271 //in a seemingly safe way so the compiler can check, so we define
 272 //a dynamic_cast /wxDynamicCast analogue.
 273
 274 #define wxGetVariantCast(var,classname) \
 275     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
 276                   var.GetWxObjectPtr() : NULL));
 277
 278 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 279
 280 #endif
 281     // _WX_VARIANT_H_