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 #  ifdef _MSC_VER
  29       using namespace std;
  30 #  endif
  31 #endif
  32
  33 /*
  34  * wxVariantData stores the actual data in a wxVariant object,
  35  * to allow it to store any type of data.
  36  * Derive from this to provide custom data handling.
  37  *
  38  * TODO: in order to replace wxPropertyValue, we would need
  39  * to consider adding constructors that take pointers to C++ variables,
  40  * or removing that functionality from the wxProperty library.
  41  * Essentially wxPropertyValue takes on some of the wxValidator functionality
  42  * by storing pointers and not just actual values, allowing update of C++ data
  43  * to be handled automatically. Perhaps there's another way of doing this without
  44  * overloading wxVariant with unnecessary functionality.
  45  */
  46
  47 class WXDLLEXPORT wxVariantData: public wxObject
  48 {
  49 DECLARE_ABSTRACT_CLASS(wxVariantData)
  50 public:
  51
  52 // Construction & destruction
  53     wxVariantData() {};
  54
  55 // Override these to provide common functionality
  56     // Copy to data
  57     virtual void Copy(wxVariantData& data) = 0;
  58     virtual bool Eq(wxVariantData& data) const = 0;
  59     virtual bool Write(ostream& str) const = 0;
  60     virtual bool Write(wxString& str) const = 0;
  61     virtual bool Read(istream& str) = 0;
  62     virtual bool Read(wxString& str) = 0;
  63     // What type is it? Return a string name.
  64     virtual wxString GetType() const = 0;
  65 };
  66
  67 /*
  68  * wxVariant can store any kind of data, but has some basic types
  69  * built in.
  70  * NOTE: this eventually should have a reference-counting implementation.
  71  * PLEASE, if you change it to ref-counting, make sure it doesn't involve bloating
  72  * this class too much.
  73  */
  74
  75 class WXDLLEXPORT wxVariant: public wxObject
  76 {
  77 DECLARE_DYNAMIC_CLASS(wxVariant)
  78 public:
  79
  80 // Construction & destruction
  81     wxVariant();
  82     wxVariant(double val);
  83     wxVariant(long val);
  84     wxVariant(bool val);
  85     wxVariant(char val);
  86     wxVariant(const wxString& val);
  87     wxVariant(const char* val); // Necessary or VC++ assumes bool!
  88 /* Causes ambiguity
  89     wxVariant(const wxStringList& val);
  90 */
  91     wxVariant(const wxList& val); // List of variants
  92     wxVariant(const wxVariant& variant);
  93     wxVariant(wxVariantData* data); // User-defined data
  94     ~wxVariant();
  95
  96 // Generic operators
  97     // Assignment
  98     void operator= (const wxVariant& variant);
  99
 100     // Assignment using data, e.g.
 101     // myVariant = new wxStringVariantData("hello");
 102     void operator= (wxVariantData* variantData);
 103     bool operator== (const wxVariant& variant) const;
 104     bool operator!= (const wxVariant& variant) const;
 105
 106 // Specific operators
 107     bool operator== (double value) const;
 108     bool operator!= (double value) const;
 109     void operator= (double value) ;
 110     bool operator== (long value) const;
 111     bool operator!= (long value) const;
 112     void operator= (long value) ;
 113     bool operator== (char value) const;
 114     bool operator!= (char value) const;
 115     void operator= (char value) ;
 116     bool operator== (bool value) const;
 117     bool operator!= (bool value) const;
 118     void operator= (bool value) ;
 119     bool operator== (const wxString& value) const;
 120     bool operator!= (const wxString& value) const;
 121     void operator= (const wxString& value) ;
 122     void operator= (const char* value) ; // Necessary or VC++ assumes bool!
 123     bool operator== (const wxStringList& value) const;
 124     bool operator!= (const wxStringList& value) const;
 125     void operator= (const wxStringList& value) ;
 126     bool operator== (const wxList& value) const;
 127     bool operator!= (const wxList& value) const;
 128     void operator= (const wxList& value) ;
 129
 130     // Treat a list variant as an array
 131     wxVariant operator[] (size_t idx) const;
 132     wxVariant& operator[] (size_t idx) ;
 133
 134     // Implicit conversion to a wxString
 135     inline operator wxString () const {  return MakeString(); }
 136     wxString MakeString() const;
 137
 138     // Other implicit conversions
 139     inline operator double () const {  return GetDouble(); }
 140     inline operator long () const {  return GetLong(); }
 141     inline operator bool () const {  return GetBool(); }
 142
 143 // Accessors
 144     // Tests whether there is data
 145     inline bool IsNull() const { return (m_data == (wxVariantData*) NULL); }
 146
 147     wxVariantData* GetData() const { return m_data; }
 148     void SetData(wxVariantData* data) ;
 149
 150     // Returns a string representing the type of the variant,
 151     // e.g. "string", "bool", "stringlist", "list", "double", "long"
 152     wxString GetType() const;
 153
 154     bool IsType(const wxString& type) const;
 155
 156     // Return the number of elements in a list
 157     int GetCount() const;
 158
 159 // Value accessors
 160     double GetReal() const ;
 161     inline double GetDouble() const { return GetReal(); };
 162     long GetInteger() const ;
 163     inline long GetLong() const { return GetInteger(); };
 164     char GetChar() const ;
 165     bool GetBool() const ;
 166     wxString GetString() const ;
 167     wxList& GetList() const ;
 168     wxStringList& GetStringList() const ;
 169
 170 // Operations
 171     // Make NULL (i.e. delete the data)
 172     void MakeNull();
 173
 174     // Make empty list
 175     void NullList();
 176
 177     // Append to list
 178     void Append(const wxVariant& value);
 179
 180     // Insert at front of list
 181     void Insert(const wxVariant& value);
 182
 183     // Returns TRUE if the variant is a member of the list
 184     bool Member(const wxVariant& value) const;
 185
 186     // Deletes the nth element of the list
 187     bool Delete(int item);
 188
 189     // Clear list
 190     void ClearList();
 191
 192 // Type conversion
 193     bool Convert(long* value) const;
 194     bool Convert(bool* value) const;
 195     bool Convert(double* value) const;
 196     bool Convert(wxString* value) const;
 197     bool Convert(char* value) const;
 198
 199 // Attributes
 200 protected:
 201     wxVariantData*  m_data;
 202 };
 203
 204 #endif
 205     // _WX_VARIANT_H_