include/wx/variant.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/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) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_VARIANT_H_
  13 #define _WX_VARIANT_H_
  14
  15 #include "wx/defs.h"
  16 #include "wx/object.h"
  17 #include "wx/string.h"
  18 #include "wx/arrstr.h"
  19 #include "wx/list.h"
  20
  21 #if wxUSE_DATETIME
  22     #include "wx/datetime.h"
  23 #endif // wxUSE_DATETIME
  24
  25 #if wxUSE_ODBC
  26     #include "wx/db.h"  // will #include sqltypes.h
  27 #endif //ODBC
  28
  29 #include "wx/iosfwrap.h"
  30
  31 /*
  32  * wxVariantData stores the actual data in a wxVariant object,
  33  * to allow it to store any type of data.
  34  * Derive from this to provide custom data handling.
  35  *
  36  * TODO: in order to replace wxPropertyValue, we would need
  37  * to consider adding constructors that take pointers to C++ variables,
  38  * or removing that functionality from the wxProperty library.
  39  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  40  * by storing pointers and not just actual values, allowing update of C++ data
  41  * to be handled automatically. Perhaps there's another way of doing this without
  42  * overloading wxVariant with unnecessary functionality.
  43  */
  44
  45 class WXDLLIMPEXP_BASE wxVariantData: public wxObject
  46 {
  47 DECLARE_ABSTRACT_CLASS(wxVariantData)
  48 public:
  49
  50 // Construction & destruction
  51     wxVariantData() {}
  52
  53 // Override these to provide common functionality
  54     // Copy to data
  55     virtual void Copy(wxVariantData& data) = 0;
  56     virtual bool Eq(wxVariantData& data) const = 0;
  57 #if wxUSE_STD_IOSTREAM
  58     virtual bool Write(wxSTD ostream& str) const = 0;
  59 #endif
  60     virtual bool Write(wxString& str) const = 0;
  61 #if wxUSE_STD_IOSTREAM
  62     virtual bool Read(wxSTD istream& str) = 0;
  63 #endif
  64     virtual bool Read(wxString& str) = 0;
  65     // What type is it? Return a string name.
  66     virtual wxString GetType() const = 0;
  67     // If it based on wxObject return the ClassInfo.
  68     virtual wxClassInfo* GetValueClassInfo() { return NULL; }
  69 };
  70
  71 /*
  72  * wxVariant can store any kind of data, but has some basic types
  73  * built in.
  74  * NOTE: this eventually should have a reference-counting implementation.
  75  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  76  * this class too much.
  77  */
  78
  79 class WXDLLIMPEXP_BASE wxVariant: public wxObject
  80 {
  81 DECLARE_DYNAMIC_CLASS(wxVariant)
  82 public:
  83
  84 // Construction & destruction
  85     wxVariant();
  86     wxVariant(double val, const wxString& name = wxEmptyString);
  87     wxVariant(long val, const wxString& name = wxEmptyString);
  88 #ifdef HAVE_BOOL
  89     wxVariant(bool val, const wxString& name = wxEmptyString);
  90 #endif
  91     wxVariant(char val, const wxString& name = wxEmptyString);
  92     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
  93     wxVariant(const wxChar* val, const wxString& name = wxEmptyString); // Necessary or VC++ assumes bool!
  94 #if WXWIN_COMPATIBILITY_2_4
  95     wxDEPRECATED( wxVariant(const wxStringList& val, const wxString& name = wxEmptyString) );
  96 #endif
  97     wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
  98     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
  99     wxVariant(wxObject* ptr, const wxString& name = wxEmptyString); //wxObject
 100     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
 101 #if wxUSE_DATETIME
 102     wxVariant(const wxDateTime& val, const wxString& name = wxEmptyString); // Date
 103 #endif // wxUSE_DATETIME
 104     wxVariant(const wxArrayString& val, const wxString& name = wxEmptyString); // String array
 105 #if wxUSE_ODBC
 106     wxVariant(const DATE_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 107     wxVariant(const TIME_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 108     wxVariant(const TIMESTAMP_STRUCT* valptr, const wxString& name = wxEmptyString); // DateTime
 109 #endif
 110
 111     wxVariant(const wxVariant& variant);
 112     virtual ~wxVariant();
 113
 114 // Generic operators
 115     // Assignment
 116     void operator= (const wxVariant& variant);
 117
 118 #if wxUSE_DATETIME
 119     bool operator== (const wxDateTime& value) const;
 120     bool operator!= (const wxDateTime& value) const;
 121     void operator= (const wxDateTime& value) ;
 122 #endif // wxUSE_DATETIME
 123
 124     bool operator== (const wxArrayString& value) const;
 125     bool operator!= (const wxArrayString& value) const;
 126     void operator= (const wxArrayString& 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
 133     // Assignment using data, e.g.
 134     // myVariant = new wxStringVariantData("hello");
 135     void operator= (wxVariantData* variantData);
 136     bool operator== (const wxVariant& variant) const;
 137     bool operator!= (const wxVariant& variant) const;
 138
 139 // Specific operators
 140     bool operator== (double value) const;
 141     bool operator!= (double value) const;
 142     void operator= (double value) ;
 143     bool operator== (long value) const;
 144     bool operator!= (long value) const;
 145     void operator= (long value) ;
 146     bool operator== (char value) const;
 147     bool operator!= (char value) const;
 148     void operator= (char value) ;
 149 #ifdef HAVE_BOOL
 150     bool operator== (bool value) const;
 151     bool operator!= (bool value) const;
 152     void operator= (bool value) ;
 153 #endif
 154     bool operator== (const wxString& value) const;
 155     bool operator!= (const wxString& value) const;
 156     void operator= (const wxString& value) ;
 157     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 158 #if WXWIN_COMPATIBILITY_2_4
 159     wxDEPRECATED( bool operator== (const wxStringList& value) const );
 160     wxDEPRECATED( bool operator!= (const wxStringList& value) const );
 161     wxDEPRECATED( void operator= (const wxStringList& value) );
 162 #endif
 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     size_t 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 #if WXWIN_COMPATIBILITY_2_4
 222     wxDEPRECATED( wxStringList& GetStringList() const );
 223 #endif
 224     void* GetVoidPtr() const ;
 225     wxObject* GetWxObjectPtr()  ;
 226 #if wxUSE_DATETIME
 227     wxDateTime GetDateTime() const ;
 228 #endif // wxUSE_DATETIME
 229     wxArrayString GetArrayString() const;
 230
 231 // Operations
 232     // Make NULL (i.e. delete the data)
 233     void MakeNull();
 234
 235     // Make empty list
 236     void NullList();
 237
 238     // Append to list
 239     void Append(const wxVariant& value);
 240
 241     // Insert at front of list
 242     void Insert(const wxVariant& value);
 243
 244     // Returns true if the variant is a member of the list
 245     bool Member(const wxVariant& value) const;
 246
 247     // Deletes the nth element of the list
 248     bool Delete(size_t item);
 249
 250     // Clear list
 251     void ClearList();
 252
 253 // Implementation
 254 public:
 255 // Type conversion
 256     bool Convert(long* value) const;
 257     bool Convert(bool* value) const;
 258     bool Convert(double* value) const;
 259     bool Convert(wxString* value) const;
 260     bool Convert(char* value) const;
 261 #if wxUSE_DATETIME
 262     bool Convert(wxDateTime* value) const;
 263 #endif // wxUSE_DATETIME
 264
 265 // Attributes
 266 protected:
 267     wxVariantData*  m_data;
 268     wxString        m_name;
 269 };
 270
 271 //Since we want type safety wxVariant we need to fetch and dynamic_cast
 272 //in a seemingly safe way so the compiler can check, so we define
 273 //a dynamic_cast /wxDynamicCast analogue.
 274
 275 #define wxGetVariantCast(var,classname) \
 276     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
 277                   var.GetWxObjectPtr() : NULL));
 278
 279 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 280
 281 #endif
 282     // _WX_VARIANT_H_