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_IOSTREAMH
  25 #include <iostream.h>
  26 #else
  27 #include <iostream>
  28 #endif
  29
  30 /*
  31  * wxVariantData stores the actual data in a wxVariant object,
  32  * to allow it to store any type of data.
  33  * Derive from this to provide custom data handling.
  34  *
  35  * TODO: in order to replace wxPropertyValue, we would need
  36  * to consider adding constructors that take pointers to C++ variables,
  37  * or removing that functionality from the wxProperty library.
  38  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  39  * by storing pointers and not just actual values, allowing update of C++ data
  40  * to be handled automatically. Perhaps there's another way of doing this without
  41  * overloading wxVariant with unnecessary functionality.
  42  */
  43
  44 class WXDLLEXPORT wxVariantData: public wxObject
  45 {
  46 DECLARE_ABSTRACT_CLASS(wxVariantData)
  47 public:
  48
  49 // Construction & destruction
  50     wxVariantData() {};
  51
  52 // Override these to provide common functionality
  53     // Copy to data
  54     virtual void Copy(wxVariantData& data) = 0;
  55     virtual bool Eq(wxVariantData& data) const = 0;
  56     virtual bool Write(ostream& str) const = 0;
  57     virtual bool Write(wxString& str) const = 0;
  58     virtual bool Read(istream& str) = 0;
  59     virtual bool Read(wxString& str) = 0;
  60     // What type is it? Return a string name.
  61     virtual wxString GetType() const = 0;
  62 };
  63
  64 /*
  65  * wxVariant can store any kind of data, but has some basic types
  66  * built in.
  67  * NOTE: this eventually should have a reference-counting implementation.
  68  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  69  * this class too much.
  70  */
  71
  72 class WXDLLEXPORT wxVariant: public wxObject
  73 {
  74 DECLARE_DYNAMIC_CLASS(wxVariant)
  75 public:
  76
  77 // Construction & destruction
  78     wxVariant();
  79     wxVariant(double val);
  80     wxVariant(long val);
  81     wxVariant(bool val);
  82     wxVariant(char val);
  83     wxVariant(const wxString& val);
  84     wxVariant(const char* val); // Necessary or VC++ assumes bool!
  85 /* Causes ambiguity
  86     wxVariant(const wxStringList& val);
  87 */
  88     wxVariant(const wxList& val); // List of variants
  89     wxVariant(const wxVariant& variant);
  90     wxVariant(wxVariantData* data); // User-defined data
  91     ~wxVariant();
  92
  93 // Generic operators
  94     // Assignment
  95     void operator= (const wxVariant& variant);
  96
  97     // Assignment using data, e.g.
  98     // myVariant = new wxStringVariantData("hello");
  99     void operator= (wxVariantData* variantData);
 100     bool operator== (const wxVariant& variant) const;
 101     bool operator!= (const wxVariant& variant) const;
 102
 103 // Specific operators
 104     bool operator== (double value) const;
 105     bool operator!= (double value) const;
 106     void operator= (double value) ;
 107     bool operator== (long value) const;
 108     bool operator!= (long value) const;
 109     void operator= (long value) ;
 110     bool operator== (char value) const;
 111     bool operator!= (char value) const;
 112     void operator= (char value) ;
 113     bool operator== (bool value) const;
 114     bool operator!= (bool value) const;
 115     void operator= (bool value) ;
 116     bool operator== (const wxString& value) const;
 117     bool operator!= (const wxString& value) const;
 118     void operator= (const wxString& value) ;
 119     void operator= (const char* value) ; // Necessary or VC++ assumes bool!
 120     bool operator== (const wxStringList& value) const;
 121     bool operator!= (const wxStringList& value) const;
 122     void operator= (const wxStringList& value) ;
 123     bool operator== (const wxList& value) const;
 124     bool operator!= (const wxList& value) const;
 125     void operator= (const wxList& value) ;
 126
 127     // Treat a list variant as an array
 128     wxVariant operator[] (size_t idx) const;
 129     wxVariant& operator[] (size_t idx) ;
 130
 131     // Implicit conversion to a wxString
 132     inline operator wxString () const {  return MakeString(); }
 133     wxString MakeString() const;
 134
 135     // Other implicit conversions
 136     inline operator double () const {  return GetDouble(); }
 137     inline operator long () const {  return GetLong(); }
 138     inline operator bool () const {  return GetBool(); }
 139
 140 // Accessors
 141     // Tests whether there is data
 142     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 143
 144     wxVariantData* GetData() const { return m_data; }
 145     void SetData(wxVariantData* data) ;
 146
 147     // Returns a string representing the type of the variant,
 148     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 149     wxString GetType() const;
 150
 151     bool IsType(const wxString& type) const;
 152
 153     // Return the number of elements in a list
 154     int GetCount() const;
 155
 156 // Value accessors
 157     double GetReal() const ;
 158     inline double GetDouble() const { return GetReal(); };
 159     long GetInteger() const ;
 160     inline long GetLong() const { return GetInteger(); };
 161     char GetChar() const ;
 162     bool GetBool() const ;
 163     wxString GetString() const ;
 164     wxList& GetList() const ;
 165     wxStringList& GetStringList() const ;
 166
 167 // Operations
 168     // Make NULL (i.e. delete the data)
 169     void MakeNull();
 170
 171     // Make empty list
 172     void NullList();
 173
 174     // Append to list
 175     void Append(const wxVariant& value);
 176
 177     // Insert at front of list
 178     void Insert(const wxVariant& value);
 179
 180     // Returns TRUE if the variant is a member of the list
 181     bool Member(const wxVariant& value) const;
 182
 183     // Deletes the nth element of the list
 184     bool Delete(int item);
 185
 186     // Clear list
 187     void ClearList();
 188
 189 // Type conversion
 190     bool Convert(long* value) const;
 191     bool Convert(bool* value) const;
 192     bool Convert(double* value) const;
 193     bool Convert(wxString* value) const;
 194     bool Convert(char* value) const;
 195
 196 // Attributes
 197 protected:
 198     wxVariantData*  m_data;
 199 };
 200
 201 #endif
 202     // _WX_VARIANT_H_