docs/latex/wx/variant.tex

   1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2 %% Name:        variant.tex
   3 %% Purpose:     wxVariant docs
   4 %% Author:      wxWidgets Team
   5 %% Modified by:
   6 %% Created:     01/30/2005
   7 %% RCS-ID:      $Id$
   8 %% Copyright:   (c) wxWidgets Team
   9 %% License:     wxWindows license
  10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  11
  12 \section{\class{wxVariant}}\label{wxvariant}
  13
  14 The {\bf wxVariant} class represents a container for any type.
  15 A variant's value can be changed at run time, possibly to a different type of value.
  16
  17 As standard, wxVariant can store values of type bool, wxChar, double, long, string,
  18 string list, time, date, void pointer, list of strings, and list of variants.
  19 However, an application can extend wxVariant's capabilities by deriving from the
  20 class \helpref{wxVariantData}{wxvariantdata} and using the wxVariantData form of
  21 the wxVariant constructor or assignment operator to assign this data to a variant.
  22 Actual values for user-defined types will need to be accessed via the wxVariantData
  23 object, unlike the case for basic data types where convenience functions such as
  24 \helpref{GetLong}{wxvariantgetlong} can be used.
  25
  26 Pointers to any \helpref{wxObject}{wxobject} derived class can also easily be stored
  27 in a wxVariant. wxVariant will then use wxWidgets' built-in RTTI system to set the
  28 type name (returned by \helpref{GetType}{wxvariantgettype}) and to perform
  29 type-safety checks at runtime.
  30
  31 This class is useful for reducing the programming for certain tasks, such as an editor
  32 for different data types, or a remote procedure call protocol.
  33
  34 An optional name member is associated with a wxVariant. This might be used, for example,
  35 in CORBA or OLE automation classes, where named parameters are required.
  36
  37 Note that as of wxWidgets 2.7.1, wxVariant is \helpref{reference counted}{trefcount}.
  38 Additionally, the convenience macros {\bf DECLARE\_VARIANT\_OBJECT} and
  39 {\bf IMPLEMENT\_VARIANT\_OBJECT} were added so that adding (limited) support
  40 for conversion to and from wxVariant can be very easily implemented without modifying
  41 either wxVariant or the class to be stored by wxVariant. Since assignment operators
  42 cannot be declared outside the class, the shift left operators are used like this:
  43
  44 \begin{verbatim}
  45     // in the header file
  46     DECLARE_VARIANT_OBJECT(MyClass)
  47
  48     // in the implementation file
  49     IMPLMENT_VARIANT_OBJECT(MyClass)
  50
  51     // in the user code
  52     wxVariant variant;
  53     MyClass value;
  54     variant << value;
  55
  56     // or
  57     value << variant;
  58 \end{verbatim}
  59
  60 For this to work, MyClass must derive from \helpref{wxObject}{wxobject}, implement
  61 the \helpref{wxWidgets RTTI system}{runtimeclassoverview}
  62 and support the assignment operator and equality operator for itself. Ideally, it
  63 should also be reference counted to make copying operations cheap and fast. This
  64 can be most easily implemented using the reference counting support offered by
  65 \helpref{wxObject}{wxobject} itself. By default, wxWidgets already implements
  66 the shift operator conversion for a few of its drawing related classes:
  67
  68 \begin{verbatim}
  69 IMPLEMENT_VARIANT_OBJECT(wxColour)
  70 IMPLEMENT_VARIANT_OBJECT(wxImage)
  71 IMPLEMENT_VARIANT_OBJECT(wxIcon)
  72 IMPLEMENT_VARIANT_OBJECT(wxBitmap)
  73 \end{verbatim}
  74
  75 Note that as of wxWidgets 2.9.0, wxVariantData no longer inherits from wxObject
  76 and wxVariant no longer uses the type-unsafe wxList class for list
  77 operations but the type-safe wxVariantList class. Also, wxVariantData now
  78 supports the Clone function for implementing the \helpref{wxVariant::Unshare}{wxvariantunshare} function.
  79 Clone is implemented automatically by IMPLEMENT\_VARIANT\_OBJECT.
  80
  81 Since wxVariantData no longer derives from wxObject, any code that tests the type
  82 of the data using wxDynamicCast will require adjustment. You can use the macro
  83 wxDynamicCastVariantData with the same arguments as wxDynamicCast, to use C++ RTTI
  84 type information instead of wxWidgets RTTI.
  85
  86 \wxheading{Derived from}
  87
  88 \helpref{wxObject}{wxobject}
  89
  90 \wxheading{Include files}
  91
  92 <wx/variant.h>
  93
  94 \wxheading{Library}
  95
  96 \helpref{wxBase}{librarieslist}
  97
  98 \wxheading{See also}
  99
 100 \helpref{wxVariantData}{wxvariantdata}
 101
 102 \latexignore{\rtfignore{\wxheading{Members}}}
 103
 104 \membersection{wxVariant::wxVariant}\label{wxvariantctor}
 105
 106 \func{}{wxVariant}{\void}
 107
 108 Default constructor.
 109
 110 \func{}{wxVariant}{\param{const wxVariant\& }{variant}}
 111
 112 Copy constructor, uses \helpref{reference counting}{trefcount}.
 113
 114 \func{}{wxVariant}{\param{const wxChar*}{ value}, \param{const wxString\& }{name = ``"}}
 115
 116 \func{}{wxVariant}{\param{const wxString\&}{ value}, \param{const wxString\& }{name = ``"}}
 117
 118 Construction from a string value.
 119
 120 \func{}{wxVariant}{\param{wxChar}{ value}, \param{const wxString\& }{name = ``"}}
 121
 122 Construction from a character value.
 123
 124 \func{}{wxVariant}{\param{long}{ value}, \param{const wxString\& }{name = ``"}}
 125
 126 Construction from an integer value. You may need to cast to (long) to
 127 avoid confusion with other constructors (such as the bool constructor).
 128
 129 \func{}{wxVariant}{\param{bool}{ value}, \param{const wxString\& }{name = ``"}}
 130
 131 Construction from a boolean value.
 132
 133 \func{}{wxVariant}{\param{double}{ value}, \param{const wxString\& }{name = ``"}}
 134
 135 Construction from a double-precision floating point value.
 136
 137 \func{}{wxVariant}{\param{const wxVariantList\&}{ value}, \param{const wxString\& }{name = ``"}}
 138
 139 Construction from a list of wxVariant objects. This constructor
 140 copies {\it value}, the application is still responsible for
 141 deleting {\it value} and its contents.
 142
 143 \func{}{wxVariant}{\param{void*}{ value}, \param{const wxString\& }{name = ``"}}
 144
 145 Construction from a void pointer.
 146
 147 \func{}{wxVariant}{\param{wxObject*}{ value}, \param{const wxString\& }{name = ``"}}
 148
 149 Construction from a wxObject pointer.
 150
 151 \func{}{wxVariant}{\param{wxVariantData*}{ data}, \param{const wxString\& }{name = ``"}}
 152
 153 Construction from user-defined data.  The variant holds onto the {\it data} pointer.
 154
 155 \func{}{wxVariant}{\param{wxDateTime\&}{ val}, \param{const wxString\& }{name = ``"}}
 156
 157 Construction from a \helpref{wxDateTime}{wxdatetime}.
 158
 159 \func{}{wxVariant}{\param{wxArrayString\&}{ val}, \param{const wxString\& }{name = ``"}}
 160
 161 Construction from an array of strings.  This constructor copies {\it value} and its contents.
 162
 163 \func{}{wxVariant}{\param{DATE\_STRUCT*}{ val}, \param{const wxString\& }{name = ``"}}
 164
 165 Construction from a ODBC date value.  Represented internally by a \helpref{wxDateTime}{wxdatetime} value.
 166
 167 \func{}{wxVariant}{\param{TIME\_STRUCT*}{ val}, \param{const wxString\& }{name = ``"}}
 168
 169 Construction from a ODBC time value.  Represented internally by a \helpref{wxDateTime}{wxdatetime} value.
 170
 171 \func{}{wxVariant}{\param{TIMESTAMP\_STRUCT*}{ val}, \param{const wxString\& }{name = ``"}}
 172
 173 Construction from a ODBC timestamp value.  Represented internally by a \helpref{wxDateTime}{wxdatetime} value.
 174
 175 \membersection{wxVariant::\destruct{wxVariant}}\label{wxvariantdtor}
 176
 177 \func{}{\destruct{wxVariant}}{\void}
 178
 179 Destructor.
 180
 181 Note that destructor is protected, so wxVariantData cannot usually
 182 be deleted. Instead, \helpref{DecRef}{wxvariantdatadecref} should be called.
 183 See \helpref{reference-counted object destruction}{refcountdestruct} for more info.
 184
 185
 186 \membersection{wxVariant::Append}\label{wxvariantappend}
 187
 188 \func{void}{Append}{\param{const wxVariant\&}{ value}}
 189
 190 Appends a value to the list.
 191
 192 \membersection{wxVariant::Clear}\label{wxvariantclear}
 193
 194 \func{void}{Clear}{\void}
 195
 196 Makes the variant null by deleting the internal data and
 197 set the name to {\it wxEmptyString}.
 198
 199 \membersection{wxVariant::ClearList}\label{wxvariantclearlist}
 200
 201 \func{void}{ClearList}{\void}
 202
 203 Deletes the contents of the list.
 204
 205
 206 \membersection{wxVariant::Convert}\label{wxvariantconvert}
 207
 208 \constfunc{bool}{Convert}{\param{long*}{ value}}
 209
 210 \constfunc{bool}{Convert}{\param{bool*}{ value}}
 211
 212 \constfunc{bool}{Convert}{\param{double*}{ value}}
 213
 214 \constfunc{bool}{Convert}{\param{wxString*}{ value}}
 215
 216 \constfunc{bool}{Convert}{\param{wxChar*}{ value}}
 217
 218 \constfunc{bool}{Convert}{\param{wxDateTime*}{ value}}
 219
 220 Retrieves and converts the value of this variant to the type that {\it value} is.
 221
 222
 223 \membersection{wxVariant::GetCount}\label{wxvariantgetcount}
 224
 225 \constfunc{size\_t}{GetCount}{\void}
 226
 227 Returns the number of elements in the list.
 228
 229 \membersection{wxVariant::Delete}\label{wxvariantdelete}
 230
 231 \func{bool}{Delete}{\param{size\_t }{item}}
 232
 233 Deletes the zero-based {\it item} from the list.
 234
 235 \membersection{wxVariant::GetArrayString}\label{wxvariantgetarraystring}
 236
 237 \constfunc{wxArrayString}{GetArrayString}{\void}
 238
 239 Returns the string array value.
 240
 241 \membersection{wxVariant::GetBool}\label{wxvariantgetbool}
 242
 243 \constfunc{bool}{GetBool}{\void}
 244
 245 Returns the boolean value.
 246
 247 \membersection{wxVariant::GetChar}\label{wxvariantgetchar}
 248
 249 \constfunc{wxChar}{GetChar}{\void}
 250
 251 Returns the character value.
 252
 253 \membersection{wxVariant::GetData}\label{wxvariantgetdata}
 254
 255 \constfunc{wxVariantData*}{GetData}{\void}
 256
 257 Returns a pointer to the internal variant data. To take ownership
 258 of this data, you must call its \helpref{IncRef}{wxvariantdataincref}
 259 method. When you stop using it, \helpref{DecRef}{wxvariantdatadecref}
 260 must be likewise called.
 261
 262 \membersection{wxVariant::GetDateTime}\label{wxvariantgetdatetime}
 263
 264 \constfunc{wxDateTime}{GetDateTime}{\void}
 265
 266 Returns the date value.
 267
 268 \membersection{wxVariant::GetDouble}\label{wxvariantgetdouble}
 269
 270 \constfunc{double}{GetDouble}{\void}
 271
 272 Returns the floating point value.
 273
 274 \membersection{wxVariant::GetList}\label{wxvariantgetlist}
 275
 276 \constfunc{wxVariantList &}{GetList}{\void}
 277
 278 Returns a reference to the wxVariantList class used by
 279 wxVariant if this wxVariant is currently a list of variants.
 280
 281 \membersection{wxVariant::GetLong}\label{wxvariantgetlong}
 282
 283 \constfunc{long}{GetLong}{\void}
 284
 285 Returns the integer value.
 286
 287 \membersection{wxVariant::GetName}\label{wxvariantgetname}
 288
 289 \constfunc{const wxString\&}{GetName}{\void}
 290
 291 Returns a constant reference to the variant name.
 292
 293 \membersection{wxVariant::GetString}\label{wxvariantgetstring}
 294
 295 \constfunc{wxString}{GetString}{\void}
 296
 297 Gets the string value.
 298
 299 \membersection{wxVariant::GetType}\label{wxvariantgettype}
 300
 301 \constfunc{wxString}{GetType}{\void}
 302
 303 Returns the value type as a string. The built-in types are: bool, char, datetime, double, list, long, string, arrstring, void*.
 304
 305 If the variant is null, the value type returned is the string ``null" (not the empty string).
 306
 307 \membersection{wxVariant::GetVoidPtr}\label{wxvariantgetvoidptr}
 308
 309 \constfunc{void*}{GetVoidPtr}{\void}
 310
 311 Gets the void pointer value.
 312
 313 \membersection{wxVariant::GetWxObjectPtr}\label{wxvariantgetwxobjectptr}
 314
 315 \constfunc{wxObject*}{GetWxObjectPtr}{\void}
 316
 317 Gets the wxObject pointer value.
 318
 319 \membersection{wxVariant::Insert}\label{wxvariantinsert}
 320
 321 \func{void}{Insert}{\param{const wxVariant\&}{ value}}
 322
 323 Inserts a value at the front of the list.
 324
 325 \membersection{wxVariant::IsNull}\label{wxvariantisnull}
 326
 327 \constfunc{bool}{IsNull}{\void}
 328
 329 Returns true if there is no data associated with this variant, false if there is data.
 330
 331 \membersection{wxVariant::IsType}\label{wxvariantistype}
 332
 333 \constfunc{bool}{IsType}{\param{const wxString\&}{ type}}
 334
 335 Returns true if {\it type} matches the type of the variant, false otherwise.
 336
 337 \membersection{wxVariant::IsValueKindOf}\label{wxvariantisvaluekindof}
 338
 339 \constfunc{bool}{IsValueKindOf}{\param{const wxClassInfo* type}{ type}}
 340
 341 Returns true if the data is derived from the class described by {\it type}, false otherwise.
 342
 343 \membersection{wxVariant::MakeNull}\label{wxvariantmakenull}
 344
 345 \func{void}{MakeNull}{\void}
 346
 347 Makes the variant null by deleting the internal data.
 348
 349 \membersection{wxVariant::MakeString}\label{wxvariantmakestring}
 350
 351 \constfunc{wxString}{MakeString}{\void}
 352
 353 Makes a string representation of the variant value (for any type).
 354
 355 \membersection{wxVariant::Member}\label{wxvariantmember}
 356
 357 \constfunc{bool}{Member}{\param{const wxVariant\&}{ value}}
 358
 359 Returns true if {\it value} matches an element in the list.
 360
 361 \membersection{wxVariant::NullList}\label{wxvariantnulllist}
 362
 363 \func{void}{NullList}{\void}
 364
 365 Makes an empty list. This differs from a null variant which has no data; a null list
 366 is of type list, but the number of elements in the list is zero.
 367
 368 \membersection{wxVariant::SetData}\label{wxvariantsetdata}
 369
 370 \func{void}{SetData}{\param{wxVariantData*}{ data}}
 371
 372 Sets the internal variant data, deleting the existing data if there is any.
 373
 374 \membersection{wxVariant::Unshare}\label{wxvariantunshare}
 375
 376 \func{bool}{Unshare}{\void}
 377
 378 Makes sure that any data associated with this variant is not shared with other
 379 variants. For this to work, \helpref{wxVariantData::Clone}{wxvariantdataclone} must
 380 be implemented for the data types you are working with. Clone is implemented
 381 for all the default data types.
 382
 383 \membersection{wxVariant::operator $=$}\label{wxvariantassignment}
 384
 385 \func{void}{operator $=$}{\param{const wxVariant\& }{value}}
 386
 387 \func{void}{operator $=$}{\param{wxVariantData* }{value}}
 388
 389 \func{void}{operator $=$}{\param{const wxString\& }{value}}
 390
 391 \func{void}{operator $=$}{\param{const wxChar* }{value}}
 392
 393 \func{void}{operator $=$}{\param{wxChar }{value}}
 394
 395 \func{void}{operator $=$}{\param{const long }{value}}
 396
 397 \func{void}{operator $=$}{\param{const bool }{value}}
 398
 399 \func{void}{operator $=$}{\param{const double }{value}}
 400
 401 \func{void}{operator $=$}{\param{void* }{value}}
 402
 403 \func{void}{operator $=$}{\param{wxObject* }{value}}
 404
 405 \func{void}{operator $=$}{\param{const wxVariantList\& }{value}}
 406
 407 \func{void}{operator $=$}{\param{const wxDateTime\& }{value}}
 408
 409 \func{void}{operator $=$}{\param{const wxArrayString\& }{value}}
 410
 411 \func{void}{operator $=$}{\param{const DATE\_STRUCT* }{value}}
 412
 413 \func{void}{operator $=$}{\param{const TIME\_STRUCT* }{value}}
 414
 415 \func{void}{operator $=$}{\param{const TIMESTAMP\_STRUCT* }{value}}
 416
 417 Assignment operators, using \helpref{reference counting}{trefcount} when possible.
 418
 419 \membersection{wxVariant::operator $==$}\label{wxvarianteq}
 420
 421 \constfunc{bool}{operator $==$}{\param{const wxVariant\& }{value}}
 422
 423 \constfunc{bool}{operator $==$}{\param{const wxString\& }{value}}
 424
 425 \constfunc{bool}{operator $==$}{\param{const wxChar* }{value}}
 426
 427 \constfunc{bool}{operator $==$}{\param{wxChar }{value}}
 428
 429 \constfunc{bool}{operator $==$}{\param{const long }{value}}
 430
 431 \constfunc{bool}{operator $==$}{\param{const bool }{value}}
 432
 433 \constfunc{bool}{operator $==$}{\param{const double }{value}}
 434
 435 \constfunc{bool}{operator $==$}{\param{void* }{value}}
 436
 437 \constfunc{bool}{operator $==$}{\param{wxObject* }{value}}
 438
 439 \constfunc{bool}{operator $==$}{\param{const wxVariantList\& }{value}}
 440
 441 \constfunc{bool}{operator $==$}{\param{const wxArrayString\& }{value}}
 442
 443 \constfunc{bool}{operator $==$}{\param{const wxDateTime\& }{value}}
 444
 445 Equality test operators.
 446
 447 \membersection{wxVariant::operator $!=$}\label{wxvariantneq}
 448
 449 \constfunc{bool}{operator $!=$}{\param{const wxVariant\& }{value}}
 450
 451 \constfunc{bool}{operator $!=$}{\param{const wxString\& }{value}}
 452
 453 \constfunc{bool}{operator $!=$}{\param{const wxChar* }{value}}
 454
 455 \constfunc{bool}{operator $!=$}{\param{wxChar }{value}}
 456
 457 \constfunc{bool}{operator $!=$}{\param{const long }{value}}
 458
 459 \constfunc{bool}{operator $!=$}{\param{const bool }{value}}
 460
 461 \constfunc{bool}{operator $!=$}{\param{const double }{value}}
 462
 463 \constfunc{bool}{operator $!=$}{\param{void* }{value}}
 464
 465 \constfunc{bool}{operator $!=$}{\param{wxObject* }{value}}
 466
 467 \constfunc{bool}{operator $!=$}{\param{const wxVariantList\& }{value}}
 468
 469 \constfunc{bool}{operator $!=$}{\param{const wxArrayString\& }{value}}
 470
 471 \constfunc{bool}{operator $!=$}{\param{const wxDateTime\& }{value}}
 472
 473 Inequality test operators.
 474
 475 \membersection{wxVariant::operator $[]$}\label{wxvariantarray}
 476
 477 \constfunc{wxVariant}{operator $[]$}{\param{size\_t }{idx}}
 478
 479 Returns the value at {\it idx} (zero-based).
 480
 481 \func{wxVariant\&}{operator $[]$}{\param{size\_t }{idx}}
 482
 483 Returns a reference to the value at {\it idx} (zero-based). This can be used
 484 to change the value at this index.
 485
 486 \membersection{wxVariant::operator wxChar}\label{wxvariantchar}
 487
 488 \constfunc{char}{operator wxChar}{\void}
 489
 490 Operator for implicit conversion to a wxChar, using \helpref{wxVariant::GetChar}{wxvariantgetchar}.
 491
 492 \membersection{wxVariant::operator double}\label{wxvariantdouble}
 493
 494 \constfunc{double}{operator double}{\void}
 495
 496 Operator for implicit conversion to a double, using \helpref{wxVariant::GetDouble}{wxvariantgetdouble}.
 497
 498 \constfunc{long}{operator long}{\void}
 499
 500 Operator for implicit conversion to a long, using \helpref{wxVariant::GetLong}{wxvariantgetlong}.
 501
 502 \membersection{wxVariant::operator wxString}\label{wxvariantwxstring}
 503
 504 \constfunc{wxString}{operator wxString}{\void}
 505
 506 Operator for implicit conversion to a string, using \helpref{wxVariant::MakeString}{wxvariantmakestring}.
 507
 508 \membersection{wxVariant::operator void*}\label{wxvariantvoid}
 509
 510 \constfunc{void*}{operator void*}{\void}
 511
 512 Operator for implicit conversion to a pointer to a void, using \helpref{wxVariant::GetVoidPtr}{wxvariantgetvoidptr}.
 513
 514 \membersection{wxVariant::operator wxDateTime}\label{wxvariantdatetime}
 515
 516 \constfunc{void*}{operator wxDateTime}{\void}
 517
 518 Operator for implicit conversion to a pointer to a \helpref{wxDateTime}{wxdatetime}, using \helpref{wxVariant::GetDateTime}{wxvariantgetdatetime}.
 519
 520
 521
 522 %% wxVariantData
 523
 524
 525 \section{\class{wxVariantData}}\label{wxvariantdata}
 526
 527 The {\bf wxVariantData} class is used to implement a new type for \helpref{wxVariant}{wxvariant}.
 528 Derive from wxVariantData, and override the pure virtual functions.
 529
 530 wxVariantData is \helpref{reference counted}{refcount}, but you don't normally have to care about this,
 531 as wxVariant manages the count automatically. However, in case your application needs to take
 532 ownership of wxVariantData, be aware that the object is created with reference count of 1,
 533 and passing it to wxVariant will not increase this. In other words, \helpref{IncRef}{wxvariantdataincref}
 534 needs to be called only if you both take ownership of wxVariantData and pass it to a wxVariant.
 535 Also note that the destructor is protected, so you can never explicitly delete a wxVariantData
 536 instance. Instead, \helpref{DecRef}{wxvariantdatadecref} will delete the object automatically
 537 when the reference count reaches zero.
 538
 539 \wxheading{Include files}
 540
 541 <wx/variant.h>
 542
 543 \wxheading{Derived from}
 544
 545 No base class
 546
 547 \wxheading{Library}
 548
 549 \helpref{wxBase}{librarieslist}
 550
 551 \wxheading{See also}
 552
 553 \helpref{wxVariant}{wxvariant}
 554
 555 \latexignore{\rtfignore{\wxheading{Members}}}
 556
 557 \membersection{wxVariantData::wxVariantData}\label{wxvariantdatactor}
 558
 559 \func{}{wxVariantData}{\void}
 560
 561 Default constructor.
 562
 563 \membersection{wxVariantData::Clone}\label{wxvariantdataclone}
 564
 565 \constfunc{wxVariantData*}{Clone}{\void}
 566
 567 This function can be overridden to clone the data.
 568 Implement Clone if you wish \helpref{wxVariant::Unshare}{wxvariantunshare} to work
 569 for your data. This function is implemented for all built-in data types.
 570
 571 \membersection{wxVariantData::DecRef}\label{wxvariantdatadecref}
 572
 573 \func{void}{DecRef}{\void}
 574
 575 Decreases reference count. If the count reaches zero, the object is
 576 automatically deleted.
 577
 578 Note that destructor of wxVariantData is protected, so delete
 579 cannot be used as normal. Instead, \helpref{DecRef}{wxvariantdatadecref} should be called.
 580
 581
 582 \membersection{wxVariantData::Eq}\label{wxvariantdataeq}
 583
 584 \constfunc{bool}{Eq}{\param{wxVariantData\&}{ data}}
 585
 586 Returns true if this object is equal to {\it data}.
 587
 588 \membersection{wxVariantData::GetType}\label{wxvariantdatagettype}
 589
 590 \constfunc{wxString}{GetType}{\void}
 591
 592 Returns the string type of the data.
 593
 594 \membersection{wxVariantData::GetValueClassInfo}\label{wxvariantdatagetvalueclassinfo}
 595
 596 \constfunc{wxClassInfo*}{GetValueClassInfo}{\void}
 597
 598 If the data is a wxObject returns a pointer to the objects wxClassInfo structure, if
 599 the data isn't a wxObject the method returns NULL.
 600
 601 \membersection{wxVariantData::IncRef}\label{wxvariantdataincref}
 602
 603 \func{void}{IncRef}{\void}
 604
 605 Increases reference count. Note that initially wxVariantData has reference count of 1.
 606
 607 \membersection{wxVariantData::Read}\label{wxvariantdataread}
 608
 609 \func{bool}{Read}{\param{ostream\&}{ stream}}
 610
 611 \func{bool}{Read}{\param{wxString\&}{ string}}
 612
 613 Reads the data from {\it stream} or {\it string}.
 614
 615 \membersection{wxVariantData::Write}\label{wxvariantdatawrite}
 616
 617 \constfunc{bool}{Write}{\param{ostream\&}{ stream}}
 618
 619 \constfunc{bool}{Write}{\param{wxString\&}{ string}}
 620
 621 Writes the data to {\it stream} or {\it string}.
 622
 623
 624 \membersection{wxGetVariantCast}\label{wxgetvariantcast}
 625
 626 \func{classname *}{wxGetVariantCast}{wxVariant\&, classname}
 627
 628 This macro returns the data stored in {\it variant} cast to the type {\it classname *} if
 629 the data is of this type (the check is done during the run-time) or
 630 {\tt NULL} otherwise.
 631
 632
 633 \wxheading{See also}
 634
 635 \helpref{RTTI overview}{runtimeclassoverview}\\
 636 \helpref{wxDynamicCast}{wxdynamiccast}
 637