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 #ifdef __GNUG__
  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_TIMEDATE
  25     #include "wx/time.h"
  26     #include "wx/date.h"
  27 #endif // time/date
  28
  29 #include "wx/ioswrap.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 WXDLLEXPORT 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(ostream& str) const = 0;
  59 #endif
  60     virtual bool Write(wxString& str) const = 0;
  61 #if wxUSE_STD_IOSTREAM
  62     virtual bool Read(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 };
  68
  69 /*
  70  * wxVariant can store any kind of data, but has some basic types
  71  * built in.
  72  * NOTE: this eventually should have a reference-counting implementation.
  73  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  74  * this class too much.
  75  */
  76
  77 class WXDLLEXPORT wxVariant: public wxObject
  78 {
  79 DECLARE_DYNAMIC_CLASS(wxVariant)
  80 public:
  81
  82 // Construction & destruction
  83     wxVariant();
  84     wxVariant(double val, const wxString& name = wxEmptyString);
  85     wxVariant(long val, const wxString& name = wxEmptyString);
  86 #ifdef HAVE_BOOL
  87     wxVariant(bool val, const wxString& name = wxEmptyString);
  88 #endif
  89     wxVariant(char val, const wxString& name = wxEmptyString);
  90     wxVariant(const wxString& val, const wxString& name = wxEmptyString);
  91     wxVariant(const wxChar* val, const wxString& name = wxEmptyString); // Necessary or VC++ assumes bool!
  92     wxVariant(const wxStringList& val, const wxString& name = wxEmptyString);
  93     wxVariant(const wxList& val, const wxString& name = wxEmptyString); // List of variants
  94 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
  95 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
  96     wxVariant(const wxTime& val, const wxString& name = wxEmptyString); // Time
  97     wxVariant(const wxDate& val, const wxString& name = wxEmptyString); // Date
  98 #endif
  99     wxVariant(void* ptr, const wxString& name = wxEmptyString); // void* (general purpose)
 100     wxVariant(wxVariantData* data, const wxString& name = wxEmptyString); // User-defined data
 101     wxVariant(const wxVariant& variant);
 102     ~wxVariant();
 103
 104 // Generic operators
 105     // Assignment
 106     void operator= (const wxVariant& variant);
 107
 108     // Assignment using data, e.g.
 109     // myVariant = new wxStringVariantData("hello");
 110     void operator= (wxVariantData* variantData);
 111     bool operator== (const wxVariant& variant) const;
 112     bool operator!= (const wxVariant& variant) const;
 113
 114 // Specific operators
 115     bool operator== (double value) const;
 116     bool operator!= (double value) const;
 117     void operator= (double value) ;
 118     bool operator== (long value) const;
 119     bool operator!= (long value) const;
 120     void operator= (long value) ;
 121     bool operator== (char value) const;
 122     bool operator!= (char value) const;
 123     void operator= (char value) ;
 124 #ifdef HAVE_BOOL
 125     bool operator== (bool value) const;
 126     bool operator!= (bool value) const;
 127     void operator= (bool value) ;
 128 #endif
 129     bool operator== (const wxString& value) const;
 130     bool operator!= (const wxString& value) const;
 131     void operator= (const wxString& value) ;
 132     void operator= (const wxChar* value) ; // Necessary or VC++ assumes bool!
 133     bool operator== (const wxStringList& value) const;
 134     bool operator!= (const wxStringList& value) const;
 135     void operator= (const wxStringList& value) ;
 136     bool operator== (const wxList& value) const;
 137     bool operator!= (const wxList& value) const;
 138     void operator= (const wxList& value) ;
 139 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 140 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 141     bool operator== (const wxTime& value) const;
 142     bool operator!= (const wxTime& value) const;
 143     void operator= (const wxTime& value) ;
 144     bool operator== (const wxDate& value) const;
 145     bool operator!= (const wxDate& value) const;
 146     void operator= (const wxDate& value) ;
 147 #endif
 148     bool operator== (void* value) const;
 149     bool operator!= (void* value) const;
 150     void operator= (void* value) ;
 151
 152     // Treat a list variant as an array
 153     wxVariant operator[] (size_t idx) const;
 154     wxVariant& operator[] (size_t idx) ;
 155
 156     // Implicit conversion to a wxString
 157     inline operator wxString () const {  return MakeString(); }
 158     wxString MakeString() const;
 159
 160     // Other implicit conversions
 161     inline operator double () const {  return GetDouble(); }
 162     inline operator char () const {  return GetChar(); }
 163     inline operator long () const {  return GetLong(); }
 164     inline operator bool () const {  return GetBool(); }
 165 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 166 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 167     inline operator wxTime () const {  return GetTime(); }
 168     inline operator wxDate () const {  return GetDate(); }
 169 #endif
 170     inline operator void* () const {  return GetVoidPtr(); }
 171
 172 // Accessors
 173     // Sets/gets name
 174     inline void SetName(const wxString& name) { m_name = name; }
 175     inline const wxString& GetName() const { return m_name; }
 176
 177     // Tests whether there is data
 178     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 179
 180     wxVariantData* GetData() const { return m_data; }
 181     void SetData(wxVariantData* data) ;
 182
 183     // Returns a string representing the type of the variant,
 184     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 185     wxString GetType() const;
 186
 187     bool IsType(const wxString& type) const;
 188
 189     // Return the number of elements in a list
 190     int GetCount() const;
 191
 192 // Value accessors
 193     double GetReal() const ;
 194     inline double GetDouble() const { return GetReal(); };
 195     long GetInteger() const ;
 196     inline long GetLong() const { return GetInteger(); };
 197     char GetChar() const ;
 198     bool GetBool() const ;
 199     wxString GetString() const ;
 200     wxList& GetList() const ;
 201     wxStringList& GetStringList() const ;
 202
 203 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 204 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 205     wxTime GetTime() const ;
 206     wxDate GetDate() const ;
 207 #endif
 208     void* GetVoidPtr() const ;
 209
 210 // Operations
 211     // Make NULL (i.e. delete the data)
 212     void MakeNull();
 213
 214     // Make empty list
 215     void NullList();
 216
 217     // Append to list
 218     void Append(const wxVariant& value);
 219
 220     // Insert at front of list
 221     void Insert(const wxVariant& value);
 222
 223     // Returns TRUE if the variant is a member of the list
 224     bool Member(const wxVariant& value) const;
 225
 226     // Deletes the nth element of the list
 227     bool Delete(int item);
 228
 229     // Clear list
 230     void ClearList();
 231
 232 // Implementation
 233 protected:
 234 // Type conversion
 235     bool Convert(long* value) const;
 236     bool Convert(bool* value) const;
 237     bool Convert(double* value) const;
 238     bool Convert(wxString* value) const;
 239     bool Convert(char* value) const;
 240 // For some reason, Watcom C++ can't link variant.cpp with time/date classes compiled
 241 #if wxUSE_TIMEDATE && !defined(__WATCOMC__)
 242     bool Convert(wxTime* value) const;
 243     bool Convert(wxDate* value) const;
 244 #endif
 245
 246 // Attributes
 247 protected:
 248     wxVariantData*  m_data;
 249     wxString        m_name;
 250 };
 251
 252 extern wxVariant WXDLLEXPORT wxNullVariant;
 253
 254 #endif
 255     // _WX_VARIANT_H_