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
  28
  29 #if wxUSE_IOSTREAMH
  30 #include <iostream.h>
  31 #else
  32 #include <iostream>
  33 #  ifdef _MSC_VER
  34       using namespace std;
  35 #  endif
  36 #endif
  37
  38 /*
  39  * wxVariantData stores the actual data in a wxVariant object,
  40  * to allow it to store any type of data.
  41  * Derive from this to provide custom data handling.
  42  *
  43  * TODO: in order to replace wxPropertyValue, we would need
  44  * to consider adding constructors that take pointers to C++ variables,
  45  * or removing that functionality from the wxProperty library.
  46  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  47  * by storing pointers and not just actual values, allowing update of C++ data
  48  * to be handled automatically. Perhaps there's another way of doing this without
  49  * overloading wxVariant with unnecessary functionality.
  50  */
  51
  52 class WXDLLEXPORT wxVariantData: public wxObject
  53 {
  54 DECLARE_ABSTRACT_CLASS(wxVariantData)
  55 public:
  56
  57 // Construction & destruction
  58     wxVariantData() {};
  59
  60 // Override these to provide common functionality
  61     // Copy to data
  62     virtual void Copy(wxVariantData& data) = 0;
  63     virtual bool Eq(wxVariantData& data) const = 0;
  64     virtual bool Write(ostream& str) const = 0;
  65     virtual bool Write(wxString& str) const = 0;
  66     virtual bool Read(istream& str) = 0;
  67     virtual bool Read(wxString& str) = 0;
  68     // What type is it? Return a string name.
  69     virtual wxString GetType() const = 0;
  70 };
  71
  72 /*
  73  * wxVariant can store any kind of data, but has some basic types
  74  * built in.
  75  * NOTE: this eventually should have a reference-counting implementation.
  76  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  77  * this class too much.
  78  */
  79
  80 class WXDLLEXPORT wxVariant: public wxObject
  81 {
  82 DECLARE_DYNAMIC_CLASS(wxVariant)
  83 public:
  84
  85 // Construction & destruction
  86     wxVariant();
  87     wxVariant(double val, const wxString& name = g_szNul);
  88     wxVariant(long val, const wxString& name = g_szNul);
  89     wxVariant(bool val, const wxString& name = g_szNul);
  90     wxVariant(char val, const wxString& name = g_szNul);
  91     wxVariant(const wxString& val, const wxString& name = g_szNul);
  92     wxVariant(const char* val, const wxString& name = g_szNul); // Necessary or VC++ assumes bool!
  93     wxVariant(const wxStringList& val, const wxString& name = g_szNul);
  94     wxVariant(const wxList& val, const wxString& name = g_szNul); // List of variants
  95 #if wxUSE_TIMEDATE
  96     wxVariant(const wxTime& val, const wxString& name = g_szNul); // Time
  97     wxVariant(const wxDate& val, const wxString& name = g_szNul); // Date
  98 #endif
  99     wxVariant(void* ptr, const wxString& name = g_szNul); // void* (general purpose)
 100     wxVariant(wxVariantData* data, const wxString& name = g_szNul); // 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     bool operator== (bool value) const;
 125     bool operator!= (bool value) const;
 126     void operator= (bool value) ;
 127     bool operator== (const wxString& value) const;
 128     bool operator!= (const wxString& value) const;
 129     void operator= (const wxString& value) ;
 130     void operator= (const char* value) ; // Necessary or VC++ assumes bool!
 131     bool operator== (const wxStringList& value) const;
 132     bool operator!= (const wxStringList& value) const;
 133     void operator= (const wxStringList& value) ;
 134     bool operator== (const wxList& value) const;
 135     bool operator!= (const wxList& value) const;
 136     void operator= (const wxList& value) ;
 137 #if wxUSE_TIMEDATE
 138     bool operator== (const wxTime& value) const;
 139     bool operator!= (const wxTime& value) const;
 140     void operator= (const wxTime& value) ;
 141     bool operator== (const wxDate& value) const;
 142     bool operator!= (const wxDate& value) const;
 143     void operator= (const wxDate& value) ;
 144 #endif
 145     bool operator== (void* value) const;
 146     bool operator!= (void* value) const;
 147     void operator= (void* value) ;
 148
 149     // Treat a list variant as an array
 150     wxVariant operator[] (size_t idx) const;
 151     wxVariant& operator[] (size_t idx) ;
 152
 153     // Implicit conversion to a wxString
 154     inline operator wxString () const {  return MakeString(); }
 155     wxString MakeString() const;
 156
 157     // Other implicit conversions
 158     inline operator double () const {  return GetDouble(); }
 159     inline operator char () const {  return GetChar(); }
 160     inline operator long () const {  return GetLong(); }
 161     inline operator bool () const {  return GetBool(); }
 162 #if wxUSE_TIMEDATE
 163     inline operator wxTime () const {  return GetTime(); }
 164     inline operator wxDate () const {  return GetDate(); }
 165 #endif
 166     inline operator void* () const {  return GetVoidPtr(); }
 167
 168 // Accessors
 169     // Sets/gets name
 170     inline void SetName(const wxString& name) { m_name = name; }
 171     inline const wxString& GetName() const { return m_name; }
 172
 173     // Tests whether there is data
 174     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 175
 176     wxVariantData* GetData() const { return m_data; }
 177     void SetData(wxVariantData* data) ;
 178
 179     // Returns a string representing the type of the variant,
 180     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 181     wxString GetType() const;
 182
 183     bool IsType(const wxString& type) const;
 184
 185     // Return the number of elements in a list
 186     int GetCount() const;
 187
 188 // Value accessors
 189     double GetReal() const ;
 190     inline double GetDouble() const { return GetReal(); };
 191     long GetInteger() const ;
 192     inline long GetLong() const { return GetInteger(); };
 193     char GetChar() const ;
 194     bool GetBool() const ;
 195     wxString GetString() const ;
 196     wxList& GetList() const ;
 197     wxStringList& GetStringList() const ;
 198 #if wxUSE_TIMEDATE
 199     wxTime GetTime() const ;
 200     wxDate GetDate() const ;
 201 #endif
 202     void* GetVoidPtr() const ;
 203
 204 // Operations
 205     // Make NULL (i.e. delete the data)
 206     void MakeNull();
 207
 208     // Make empty list
 209     void NullList();
 210
 211     // Append to list
 212     void Append(const wxVariant& value);
 213
 214     // Insert at front of list
 215     void Insert(const wxVariant& value);
 216
 217     // Returns TRUE if the variant is a member of the list
 218     bool Member(const wxVariant& value) const;
 219
 220     // Deletes the nth element of the list
 221     bool Delete(int item);
 222
 223     // Clear list
 224     void ClearList();
 225
 226 // Implementation
 227 protected:
 228 // Type conversion
 229     bool Convert(long* value) const;
 230     bool Convert(bool* value) const;
 231     bool Convert(double* value) const;
 232     bool Convert(wxString* value) const;
 233     bool Convert(char* value) const;
 234 #if wxUSE_TIMEDATE
 235     bool Convert(wxTime* value) const;
 236     bool Convert(wxDate* value) const;
 237 #endif
 238
 239 // Attributes
 240 protected:
 241     wxVariantData*  m_data;
 242     wxString        m_name;
 243 };
 244
 245 extern wxVariant WXDLLEXPORT wxNullVariant;
 246
 247 #endif
 248     // _WX_VARIANT_H_