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
  17 #if wxUSE_VARIANT
  18
  19 #include "wx/object.h"
  20 #include "wx/string.h"
  21 #include "wx/arrstr.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 WXDLLIMPEXP_BASE 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 WXDLLIMPEXP_BASE 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 #if WXWIN_COMPATIBILITY_2_4
  98     wxDEPRECATED( wxVariant(const wxStringList& val, const wxString& name = wxEmptyString) );
  99 #endif
 100     wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
 101     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
 102     wxVariant(wxObject* ptr, const wxString& name = wxEmptyString); //wxObject
 103     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
 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
 114     wxVariant(const wxVariant& variant);
 115     virtual ~wxVariant();
 116
 117 // Generic operators
 118     // Assignment
 119     void operator= (const wxVariant& variant);
 120
 121 #if wxUSE_DATETIME
 122     bool operator== (const wxDateTime& value) const;
 123     bool operator!= (const wxDateTime& value) const;
 124     void operator= (const wxDateTime& value) ;
 125 #endif // wxUSE_DATETIME
 126
 127     bool operator== (const wxArrayString& value) const;
 128     bool operator!= (const wxArrayString& value) const;
 129     void operator= (const wxArrayString& value) ;
 130 #if wxUSE_ODBC
 131     void operator= (const DATE_STRUCT* value) ;
 132     void operator= (const TIME_STRUCT* value) ;
 133     void operator= (const TIMESTAMP_STRUCT* value) ;
 134 #endif
 135
 136     // Assignment using data, e.g.
 137     // myVariant = new wxStringVariantData("hello");
 138     void operator= (wxVariantData* variantData);
 139     bool operator== (const wxVariant& variant) const;
 140     bool operator!= (const wxVariant& variant) const;
 141
 142 // Specific operators
 143     bool operator== (double value) const;
 144     bool operator!= (double value) const;
 145     void operator= (double value) ;
 146     bool operator== (long value) const;
 147     bool operator!= (long value) const;
 148     void operator= (long value) ;
 149     bool operator== (char value) const;
 150     bool operator!= (char value) const;
 151     void operator= (char value) ;
 152 #ifdef HAVE_BOOL
 153     bool operator== (bool value) const;
 154     bool operator!= (bool value) const;
 155     void operator= (bool value) ;
 156 #endif
 157     bool operator== (const wxString& value) const;
 158     bool operator!= (const wxString& value) const;
 159     void operator= (const wxString& value) ;
 160     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 161 #if WXWIN_COMPATIBILITY_2_4
 162     wxDEPRECATED( bool operator== (const wxStringList& value) const );
 163     wxDEPRECATED( bool operator!= (const wxStringList& value) const );
 164     wxDEPRECATED( void operator= (const wxStringList& value) );
 165 #endif
 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     bool operator== (wxObject* value) const;
 173     bool operator!= (wxObject* value) const;
 174     void operator= (wxObject* value);
 175
 176
 177     // Treat a list variant as an array
 178     wxVariant operator[] (size_t idx) const;
 179     wxVariant& operator[] (size_t idx) ;
 180
 181     // Implicit conversion to a wxString
 182     inline operator wxString () const {  return MakeString(); }
 183     wxString MakeString() const;
 184
 185     // Other implicit conversions
 186     inline operator double () const {  return GetDouble(); }
 187     inline operator char () const {  return GetChar(); }
 188     inline operator long () const {  return GetLong(); }
 189     inline operator bool () const {  return GetBool(); }
 190     inline operator void* () const {  return GetVoidPtr(); }
 191     // No implicit conversion to wxObject, as that would really
 192     //  confuse people between conversion to our contained data
 193     //  and downcasting to see our base type.
 194 #if wxUSE_DATETIME
 195     inline operator wxDateTime () const { return GetDateTime(); }
 196 #endif // wxUSE_DATETIME
 197
 198 // Accessors
 199     // Sets/gets name
 200     inline void SetName(const wxString& name) { m_name = name; }
 201     inline const wxString& GetName() const { return m_name; }
 202
 203     // Tests whether there is data
 204     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 205
 206     wxVariantData* GetData() const { return m_data; }
 207     void SetData(wxVariantData* data) ;
 208
 209     // Returns a string representing the type of the variant,
 210     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 211     wxString GetType() const;
 212
 213     bool IsType(const wxString& type) const;
 214     bool IsValueKindOf(const wxClassInfo* type) const;
 215
 216     // Return the number of elements in a list
 217     size_t GetCount() const;
 218
 219 // Value accessors
 220     double GetReal() const ;
 221     inline double GetDouble() const { return GetReal(); };
 222     long GetInteger() const ;
 223     inline long GetLong() const { return GetInteger(); };
 224     char GetChar() const ;
 225     bool GetBool() const ;
 226     wxString GetString() const ;
 227     wxList& GetList() const ;
 228 #if WXWIN_COMPATIBILITY_2_4
 229     wxDEPRECATED( wxStringList& GetStringList() const );
 230 #endif
 231     void* GetVoidPtr() const;
 232     wxObject* GetWxObjectPtr() const;
 233 #if wxUSE_DATETIME
 234     wxDateTime GetDateTime() const ;
 235 #endif // wxUSE_DATETIME
 236     wxArrayString GetArrayString() const;
 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(size_t 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 #if wxUSE_DATETIME
 269     bool Convert(wxDateTime* value) const;
 270 #endif // wxUSE_DATETIME
 271
 272 // Attributes
 273 protected:
 274     wxVariantData*  m_data;
 275     wxString        m_name;
 276 };
 277
 278 //Since we want type safety wxVariant we need to fetch and dynamic_cast
 279 //in a seemingly safe way so the compiler can check, so we define
 280 //a dynamic_cast /wxDynamicCast analogue.
 281
 282 #define wxGetVariantCast(var,classname) \
 283     ((classname*)(var.IsValueKindOf(&classname::ms_classInfo) ?\
 284                   var.GetWxObjectPtr() : NULL));
 285
 286 extern wxVariant WXDLLIMPEXP_BASE wxNullVariant;
 287
 288 #endif // wxUSE_VARIANT
 289
 290 #endif // _WX_VARIANT_H_