docs/doxygen/overviews/xrc.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        xrc.h
   3 // Purpose:     topic overview
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10
  11 @page overview_xrc XML Based Resource System (XRC)
  12
  13 Classes: wxXmlResource, wxXmlResourceHandler
  14
  15 The XML-based resource system, known as XRC, allows user interface elements
  16 such as dialogs, menu bars and toolbars, to be stored in text files and loaded
  17 into the application at run-time. XRC files can also be compiled into binary
  18 XRS files or C++ code (the former makes it possible to store all resources in a
  19 single file and the latter is useful when you want to embed the resources into
  20 the executable).
  21
  22 There are several advantages to using XRC resources:
  23
  24 @li Recompiling and linking an application is not necessary if the resources
  25     change.
  26 @li If you use a dialog designer that generates C++ code, it can be hard to
  27     reintegrate this into existing C++ code. Separation of resources and code
  28     is a more elegant solution.
  29 @li You can choose between different alternative resource files at run time, if
  30     necessary.
  31 @li The XRC format uses sizers for flexibility, allowing dialogs to be
  32     resizable and highly portable.
  33 @li The XRC format is a wxWidgets standard, and can be generated or
  34     postprocessed by any program that understands it. As it is basedon the XML
  35     standard, existing XML editors can be used for simple editing purposes.
  36
  37 XRC was written by Vaclav Slavik.
  38
  39 @li @ref overview_xrc_concepts
  40 @li @ref overview_xrc_binaryresourcefiles
  41 @li @ref overview_xrc_embeddedresource
  42 @li @ref overview_xrc_cppsample
  43 @li @ref overview_xrc_sample
  44 @li @ref overview_xrc_cppheader
  45 @li @ref overview_xrc_newresourcehandlers
  46 @li @ref xrc_format
  47
  48 <hr>
  49
  50
  51 @section overview_xrc_concepts XRC Concepts
  52
  53 These are the typical steps for using XRC files in your application.
  54
  55 @li Include the appropriate headers: normally "wx/xrc/xmlres.h" will suffice.
  56 @li If you are going to use XRS files (see
  57     @ref overview_xrc_binaryresourcefiles), install wxFileSystem archive
  58     handler first with wxFileSystem::AddHandler(new wxArchiveFSHandler);
  59 @li Call wxXmlResource::Get()->InitAllHandlers() from your wxApp::OnInit
  60     function, and then call wxXmlResource::Get()->Load("myfile.xrc") to load
  61     the resource file.
  62 @li To create a dialog from a resource, create it using the default
  63     constructor, and then load it. For example:
  64     wxXmlResource::Get()->LoadDialog(dlg, this, "dlg1");
  65 @li Set up event tables as usual but use the XRCID(str) macro to translate from
  66     XRC string names to a suitable integer identifier, for example
  67     <tt>EVT_MENU(XRCID("quit"), MyFrame::OnQuit)</tt>.
  68
  69 To create an XRC file, you can use one of the following methods.
  70
  71 @li Create the file by hand.
  72 @li Use wxDesigner <http://www.roebling.de/>, a commercial dialog designer/RAD
  73     tool.
  74 @li Use DialogBlocks <http://www.anthemion.co.uk/dialogblocks/>, a commercial
  75     dialog editor.
  76 @li Use XRCed <http://xrced.sf.net/>, a wxPython-based dialog editor that you
  77     can find in the wxPython/tools subdirectory of the wxWidgets SVN archive.
  78 @li Use wxGlade <http://wxglade.sf.net/>, a GUI designer written in wxPython.
  79     At the moment it can generate Python, C++ and XRC.
  80
  81 A complete list of third-party tools that write to XRC can be found at
  82 <http://www.wxwidgets.org/wiki/index.php/Tools>.
  83
  84 It is highly recommended that you use a resource editing tool, since it's
  85 fiddly writing XRC files by hand.
  86
  87 You can use wxXmlResource::Load in a number of ways. You can pass an XRC file
  88 (XML-based text resource file) or a zip-compressed file (see
  89 @ref overview_xrc_binaryresourcefiles), with extension ZIP or XRS, containing
  90 other XRC.
  91
  92 You can also use embedded C++ resources (see
  93 @ref overview_xrc_embeddedresource).
  94
  95
  96 @section overview_xrc_binaryresourcefiles Using Binary Resource Files
  97
  98 To compile binary resource files, use the command-line @c wxrc utility. It
  99 takes one or more file parameters (the input XRC files) and the following
 100 switches and options:
 101
 102 @li -h (--help): Show a help message.
 103 @li -v (--verbose): Show verbose logging information.
 104 @li -c (--cpp-code): Write C++ source rather than a XRS file.
 105 @li -e (--extra-cpp-code): If used together with -c, generates C++ header file
 106     containing class definitions for the windows defined by the XRC file (see
 107     special subsection).
 108 @li -u (--uncompressed): Do not compress XML files (C++ only).
 109 @li -g (--gettext): Output underscore-wrapped strings that poEdit or gettext
 110     can scan. Outputs to stdout, or a file if -o is used.
 111 @li -n (--function) @<name@>: Specify C++ function name (use with -c).
 112 @li -o (--output) @<filename@>: Specify the output file, such as resource.xrs
 113     or resource.cpp.
 114 @li -l (--list-of-handlers) @<filename@>: Output a list of necessary handlers
 115     to this file.
 116
 117 For example:
 118
 119 @code
 120 $ wxrc resource.xrc
 121 $ wxrc resource.xrc -o resource.xrs
 122 $ wxrc resource.xrc -v -c -o resource.cpp
 123 @endcode
 124
 125 @note XRS file is essentially a renamed ZIP archive which means that you can
 126 manipulate it with standard ZIP tools. Note that if you are using XRS files,
 127 you have to initialize the wxFileSystem archive handler first! It is a simple
 128 thing to do:
 129
 130 @code
 131 #include <wx/filesys.h>
 132 #include <wx/fs_arc.h>
 133 ...
 134 wxFileSystem::AddHandler(new wxArchiveFSHandler);
 135 @endcode
 136
 137
 138 @section overview_xrc_embeddedresource Using Embedded Resources
 139
 140 It is sometimes useful to embed resources in the executable itself instead of
 141 loading an external file (e.g. when your app is small and consists only of one
 142 exe file). XRC provides means to convert resources into regular C++ file that
 143 can be compiled and included in the executable.
 144
 145 Use the @c -c switch to @c wxrc utility to produce C++ file with embedded
 146 resources. This file will contain a function called @c InitXmlResource (unless
 147 you override this with a command line switch). Use it to load the resource:
 148
 149 @code
 150 extern void InitXmlResource(); // defined in generated file
 151 ...
 152 wxXmlResource::Get()->InitAllHandlers();
 153 InitXmlResource();
 154 ...
 155 @endcode
 156
 157
 158 @section overview_xrc_cppsample XRC C++ Sample
 159
 160 This is the C++ source file (xrcdemo.cpp) for the XRC sample.
 161
 162 @code
 163 #include "wx/wx.h"
 164 #include "wx/image.h"
 165 #include "wx/xrc/xmlres.h"
 166
 167 // the application icon
 168 #if defined(__WXGTK__) || defined(__WXMOTIF__) || defined(__WXMAC__)
 169     #include "rc/appicon.xpm"
 170 #endif
 171
 172 // ----------------------------------------------------------------------------
 173 // private classes
 174 // ----------------------------------------------------------------------------
 175
 176 // Define a new application type, each program should derive a class from wxApp
 177 class MyApp : public wxApp
 178 {
 179 public:
 180     // override base class virtuals
 181     // ----------------------------
 182
 183     // this one is called on application startup and is a good place for the
 184     // app initialization (doing it here and not in the ctor allows to have an
 185     // error return: if OnInit() returns false, the application terminates)
 186     virtual bool OnInit();
 187 };
 188
 189 // Define a new frame type: this is going to be our main frame
 190 class MyFrame : public wxFrame
 191 {
 192 public:
 193     // ctor(s)
 194     MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size);
 195
 196     // event handlers (these functions should _not_ be virtual)
 197     void OnQuit(wxCommandEvent& event);
 198     void OnAbout(wxCommandEvent& event);
 199     void OnDlg1(wxCommandEvent& event);
 200     void OnDlg2(wxCommandEvent& event);
 201
 202 private:
 203     // any class wishing to process wxWidgets events must use this macro
 204     DECLARE_EVENT_TABLE()
 205 };
 206
 207 // ----------------------------------------------------------------------------
 208 // event tables and other macros for wxWidgets
 209 // ----------------------------------------------------------------------------
 210
 211 BEGIN_EVENT_TABLE(MyFrame, wxFrame)
 212     EVT_MENU(XRCID("menu_quit"),  MyFrame::OnQuit)
 213     EVT_MENU(XRCID("menu_about"), MyFrame::OnAbout)
 214     EVT_MENU(XRCID("menu_dlg1"), MyFrame::OnDlg1)
 215     EVT_MENU(XRCID("menu_dlg2"), MyFrame::OnDlg2)
 216 END_EVENT_TABLE()
 217
 218 IMPLEMENT_APP(MyApp)
 219
 220 // ----------------------------------------------------------------------------
 221 // the application class
 222 // ----------------------------------------------------------------------------
 223
 224 // 'Main program' equivalent: the program execution "starts" here
 225 bool MyApp::OnInit()
 226 {
 227     wxImage::AddHandler(new wxGIFHandler);
 228     wxXmlResource::Get()->InitAllHandlers();
 229     wxXmlResource::Get()->Load("rc/resource.xrc");
 230
 231     MyFrame *frame = new MyFrame("XML resources demo",
 232                                  wxPoint(50, 50), wxSize(450, 340));
 233     frame->Show(true);
 234     return true;
 235 }
 236
 237 // ----------------------------------------------------------------------------
 238 // main frame
 239 // ----------------------------------------------------------------------------
 240
 241 // frame constructor
 242 MyFrame::MyFrame(const wxString& title, const wxPoint& pos, const wxSize& size)
 243 : wxFrame((wxFrame *)NULL, -1, title, pos, size)
 244 {
 245     SetIcon(wxICON(appicon));
 246
 247     SetMenuBar(wxXmlResource::Get()->LoadMenuBar("mainmenu"));
 248     SetToolBar(wxXmlResource::Get()->LoadToolBar(this, "toolbar"));
 249 }
 250
 251 // event handlers
 252 void MyFrame::OnQuit(wxCommandEvent& WXUNUSED(event))
 253 {
 254     // true is to force the frame to close
 255     Close(true);
 256 }
 257
 258 void MyFrame::OnAbout(wxCommandEvent& WXUNUSED(event))
 259 {
 260     wxString msg;
 261     msg.Printf( _T("This is the about dialog of XML resources demo.\n")
 262                 _T("Welcome to %s"), wxVERSION_STRING);
 263
 264     wxMessageBox(msg, "About XML resources demo",
 265                  wxOK | wxICON_INFORMATION, this);
 266 }
 267
 268 void MyFrame::OnDlg1(wxCommandEvent& WXUNUSED(event))
 269 {
 270     wxDialog dlg;
 271     wxXmlResource::Get()->LoadDialog(&dlg, this, "dlg1");
 272     dlg.ShowModal();
 273 }
 274
 275 void MyFrame::OnDlg2(wxCommandEvent& WXUNUSED(event))
 276 {
 277     wxDialog dlg;
 278     wxXmlResource::Get()->LoadDialog(&dlg, this, "dlg2");
 279     dlg.ShowModal();
 280 }
 281 @endcode
 282
 283
 284 @section overview_xrc_sample XRC Resource File Sample
 285
 286 This is the XML file (resource.xrc) for the XRC sample.
 287
 288 @code
 289 <?xml version="1.0"?>
 290 <resource version="2.3.0.1">
 291   <object class="wxMenuBar" name="mainmenu">
 292     <style>wxMB_DOCKABLE</style>
 293     <object class="wxMenu" name="menu_file">
 294       <label>_File</label>
 295       <style>wxMENU_TEAROFF</style>
 296       <object class="wxMenuItem" name="menu_about">
 297         <label>_About...</label>
 298         <bitmap>filesave.gif</bitmap>
 299       </object>
 300       <object class="separator"/>
 301       <object class="wxMenuItem" name="menu_dlg1">
 302         <label>Dialog 1</label>
 303       </object>
 304       <object class="wxMenuItem" name="menu_dlg2">
 305         <label>Dialog 2</label>
 306       </object>
 307       <object class="separator"/>
 308       <object class="wxMenuItem" name="menu_quit">
 309         <label>E_xit\tAlt-X</label>
 310       </object>
 311     </object>
 312   </object>
 313   <object class="wxToolBar" name="toolbar">
 314     <style>wxTB_FLAT|wxTB_DOCKABLE</style>
 315     <margins>2,2</margins>
 316     <object class="tool" name="menu_open">
 317       <bitmap>fileopen.gif</bitmap>
 318       <tooltip>Open catalog</tooltip>
 319     </object>
 320     <object class="tool" name="menu_save">
 321       <bitmap>filesave.gif</bitmap>
 322       <tooltip>Save catalog</tooltip>
 323     </object>
 324     <object class="tool" name="menu_update">
 325       <bitmap>update.gif</bitmap>
 326       <tooltip>Update catalog - synchronize it with sources</tooltip>
 327     </object>
 328     <separator/>
 329     <object class="tool" name="menu_quotes">
 330       <bitmap>quotes.gif</bitmap>
 331       <toggle>1</toggle>
 332       <tooltip>Display quotes around the string?</tooltip>
 333     </object>
 334     <object class="separator"/>
 335     <object class="tool" name="menu_fuzzy">
 336       <bitmap>fuzzy.gif</bitmap>
 337       <tooltip>Toggled if selected string is fuzzy translation</tooltip>
 338       <toggle>1</toggle>
 339     </object>
 340   </object>
 341   <object class="wxDialog" name="dlg1">
 342     <object class="wxBoxSizer">
 343       <object class="sizeritem">
 344         <object class="wxBitmapButton">
 345           <bitmap>fuzzy.gif</bitmap>
 346           <focus>fileopen.gif</focus>
 347         </object>
 348       </object>
 349       <object class="sizeritem">
 350         <object class="wxPanel">
 351           <object class="wxStaticText">
 352             <label>fdgdfgdfgdfg</label>
 353           </object>
 354           <style>wxBORDER\_SUNKEN</style>
 355         </object>
 356         <flag>wxALIGN_CENTER</flag>
 357       </object>
 358       <object class="sizeritem">
 359         <object class="wxButton">
 360           <label>Buttonek</label>
 361         </object>
 362         <border>10d</border>
 363         <flag>wxALL</flag>
 364       </object>
 365       <object class="sizeritem">
 366         <object class="wxHtmlWindow">
 367           <htmlcode><h1>Hi,</h1>man</htmlcode>
 368           <size>100,45d</size>
 369         </object>
 370       </object>
 371       <object class="sizeritem">
 372         <object class="wxNotebook">
 373           <object class="notebookpage">
 374             <object class="wxPanel">
 375               <object class="wxBoxSizer">
 376                 <object class="sizeritem">
 377                   <object class="wxHtmlWindow">
 378                     <htmlcode>Hello, we are inside a <u>NOTEBOOK</u>...</htmlcode>
 379                     <size>50,50d</size>
 380                   </object>
 381                   <option>1</option>
 382                 </object>
 383               </object>
 384             </object>
 385             <label>Page</label>
 386           </object>
 387           <object class="notebookpage">
 388             <object class="wxPanel">
 389               <object class="wxBoxSizer">
 390                 <object class="sizeritem">
 391                   <object class="wxHtmlWindow">
 392                     <htmlcode>Hello, we are inside a <u>NOTEBOOK</u>...</htmlcode>
 393                     <size>50,50d</size>
 394                   </object>
 395                 </object>
 396               </object>
 397             </object>
 398             <label>Page 2</label>
 399           </object>
 400           <usenotebooksizer>1</usenotebooksizer>
 401         </object>
 402         <flag>wxEXPAND</flag>
 403       </object>
 404       <orient>wxVERTICAL</orient>
 405     </object>
 406   </object>
 407   <object class="wxDialog" name="dlg2">
 408     <object class="wxBoxSizer">
 409       <orient>wxVERTICAL</orient>
 410       <object class="sizeritem" name="dfgdfg">
 411         <object class="wxTextCtrl">
 412           <size>200,200d</size>
 413           <style>wxTE_MULTILINE|wxBORDER_SUNKEN</style>
 414           <value>Hello, this is an ordinary multiline\n         textctrl....</value>
 415         </object>
 416         <option>1</option>
 417         <flag>wxEXPAND|wxALL</flag>
 418         <border>10</border>
 419       </object>
 420       <object class="sizeritem">
 421         <object class="wxBoxSizer">
 422           <object class="sizeritem">
 423             <object class="wxButton" name="wxID_OK">
 424               <label>Ok</label>
 425               <default>1</default>
 426             </object>
 427           </object>
 428           <object class="sizeritem">
 429             <object class="wxButton" name="wxID_CANCEL">
 430               <label>Cancel</label>
 431             </object>
 432             <border>10</border>
 433             <flag>wxLEFT</flag>
 434           </object>
 435         </object>
 436         <flag>wxLEFT|wxRIGHT|wxBOTTOM|wxALIGN_RIGHT</flag>
 437         <border>10</border>
 438       </object>
 439     </object>
 440     <title>Second testing dialog</title>
 441   </object>
 442 </resource>
 443 @endcode
 444
 445
 446 @section overview_xrc_cppheader C++ header file generation
 447
 448 Using the @c -e switch together with @c -c, a C++ header file is written
 449 containing class definitions for the GUI windows defined in the XRC file. This
 450 code generation can make it easier to use XRC and automate program development.
 451 The classes can be used as basis for development, freeing the programmer from
 452 dealing with most of the XRC specifics (e.g. @c XRCCTRL).
 453
 454 For each top level window defined in the XRC file a C++ class definition is
 455 generated, containing as class members the named widgets of the window. A
 456 default constructor for each class is also generated. Inside the constructor
 457 all XRC loading is done and all class members representing widgets are
 458 initialized.
 459
 460 A simple example will help understand how the scheme works. Suppose you have a
 461 XRC file defining a top level window @c TestWnd_Base, which subclasses wxFrame
 462 (any other class like @c wxDialog will do also), and has subwidgets wxTextCtrl A
 463 and wxButton B.
 464
 465 The XRC file and corresponding class definition in the header file will be
 466 something like:
 467
 468 @code
 469 <?xml version="1.0"?>
 470 <resource version="2.3.0.1">
 471     <object class="wxFrame" name="TestWnd_Base">
 472         <size>-1,-1</size>
 473         <title>Test</title>
 474         <object class="wxBoxSizer">
 475             <orient>wxHORIZONTAL</orient>
 476             <object class="sizeritem">
 477                 <object class="wxTextCtrl" name="A">
 478                     <label>Test label</label>
 479                 </object>
 480             </object>
 481             <object class="sizeritem">
 482                 <object class="wxButton" name="B">
 483                     <label>Test button</label>
 484                 </object>
 485             </object>
 486         </object>
 487     </object>
 488 </resource>
 489
 490
 491 class TestWnd_Base : public wxFrame
 492 {
 493 protected:
 494     wxTextCtrl* A;
 495     wxButton* B;
 496
 497 private:
 498     void InitWidgetsFromXRC()
 499     {
 500         wxXmlResource::Get()->LoadObject(this, NULL, "TestWnd", "wxFrame");
 501         A = XRCCTRL(*this, "A", wxTextCtrl);
 502         B = XRCCTRL(*this, "B", wxButton);
 503     }
 504 public:
 505     TestWnd::TestWnd()
 506     {
 507         InitWidgetsFromXRC();
 508     }
 509 };
 510 @endcode
 511
 512 The generated window class can be used as basis for the full window class. The
 513 class members which represent widgets may be accessed by name instead of using
 514 @c XRCCTRL every time you wish to reference them (note that they are
 515 @c protected class members), though you must still use @c XRCID to refer to
 516 widget IDs in the event table.
 517
 518 Example:
 519
 520 @code
 521 #include "resource.h"
 522
 523 class TestWnd : public TestWnd_Base
 524 {
 525 public:
 526     TestWnd()
 527     {
 528         // A, B already initialised at this point
 529         A->SetValue("Updated in TestWnd::TestWnd");
 530         B->SetValue("Nice :)");
 531     }
 532     void OnBPressed(wxEvent& event)
 533     {
 534         Close();
 535     }
 536     DECLARE_EVENT_TABLE();
 537 };
 538
 539 BEGIN_EVENT_TABLE(TestWnd,TestWnd_Base)
 540     EVT_BUTTON(XRCID("B"), TestWnd::OnBPressed)
 541 END_EVENT_TABLE()
 542 @endcode
 543
 544 It is also possible to access the wxSizerItem of a sizer that is part of a
 545 resource. This can be done using @c XRCSIZERITEM as shown.
 546
 547 The resource file can have something like this for a sizer item.
 548
 549 @code
 550 <object class="spacer" name="area">
 551   <size>400, 300</size>
 552 </object>
 553 @endcode
 554
 555 The code can then access the sizer item by using @c XRCSIZERITEM and @c XRCID
 556 together.
 557
 558 @code
 559 wxSizerItem* item = XRCSIZERITEM(*this, "area");
 560 @endcode
 561
 562
 563 @section overview_xrc_newresourcehandlers Adding New Resource Handlers
 564
 565 Adding a new resource handler is pretty easy.
 566
 567 Typically, to add an handler for the @c MyControl class, you'll want to create
 568 the @c xh_mycontrol.h and @c xh_mycontrol.cpp files.
 569
 570 The header needs to contains the @c MyControlXmlHandler class definition:
 571
 572 @code
 573 class MyControlXmlHandler : public wxXmlResourceHandler
 574 {
 575 public:
 576     // Constructor.
 577     MyControlXmlHandler();
 578
 579     // Creates the control and returns a pointer to it.
 580     virtual wxObject *DoCreateResource();
 581
 582     // Returns true if we know how to create a control for the given node.
 583     virtual bool CanHandle(wxXmlNode *node);
 584
 585     // Register with wxWidgets' dynamic class subsystem.
 586     DECLARE_DYNAMIC_CLASS(MyControlXmlHandler)
 587 };
 588 @endcode
 589
 590 The implementation of your custom XML handler will typically look as:
 591
 592 @code
 593 // Register with wxWidgets' dynamic class subsystem.
 594 IMPLEMENT_DYNAMIC_CLASS(MyControlXmlHandler, wxXmlResourceHandler)
 595
 596 MyControlXmlHandler::MyControlXmlHandler()
 597 {
 598     // this call adds support for all wxWindows class styles
 599     // (e.g. wxBORDER_SIMPLE, wxBORDER_SUNKEN, wxWS_EX_* etc etc)
 600     AddWindowStyles();
 601
 602     // if MyControl class supports e.g. MYCONTROL_DEFAULT_STYLE
 603     // you should use:
 604     //     XRC_ADD_STYLE(MYCONTROL_DEFAULT_STYLE);
 605 }
 606
 607 wxObject *MyControlXmlHandler::DoCreateResource()
 608 {
 609     // the following macro will init a pointer named "control"
 610     // with a new instance of the MyControl class, but will NOT
 611     // Create() it!
 612     XRC_MAKE_INSTANCE(control, MyControl)
 613
 614     // this is the point where you'll typically need to do the most
 615     // important changes: here the control is created and initialized.
 616     // You'll want to use the wxXmlResourceHandler's getters to
 617     // do most of your work.
 618     // If e.g. the MyControl::Create function looks like:
 619     //
 620     // bool MyControl::Create(wxWindow *parent, int id,
 621     //                        const wxBitmap &first, const wxPoint &posFirst,
 622     //                        const wxBitmap &second, const wxPoint &posSecond,
 623     //                        const wxString &theTitle, const wxFont &titleFont,
 624     //                        const wxPoint &pos, const wxSize &size,
 625     //                        long style = MYCONTROL_DEFAULT_STYLE,
 626     //                        const wxString &name = wxT("MyControl"));
 627     //
 628     // Then the XRC for your component should look like:
 629     //
 630     //    <object class="MyControl" name="some_name">
 631     //      <first-bitmap>first.xpm</first-bitmap>
 632     //      <second-bitmap>text.xpm</second-bitmap>
 633     //      <first-pos>3,3</first-pos>
 634     //      <second-pos>4,4</second-pos>
 635     //      <the-title>a title</the-title>
 636     //      <title-font>
 637     //        <!-- Standard XRC tags for a font: <size>, <style>, <weight>, etc -->
 638     //      </title-font>
 639     //      <!-- XRC also accepts other usual tags for wxWindow-derived classes:
 640     //           like e.g. <name>, <style>, <size>, <position>, etc -->
 641     //    </object>
 642     //
 643     // And the code to read your custom tags from the XRC file is just:
 644     control->Create(m_parentAsWindow, GetID(),
 645                     GetBitmap(wxT("first-bitmap")),
 646                     GetPosition(wxT("first-pos")),
 647                     GetBitmap(wxT("second-bitmap")),
 648                     GetPosition(wxT("second-pos")),
 649                     GetText(wxT("the-title")),
 650                     GetFont(wxT("title-font")),
 651                     GetPosition(), GetSize(), GetStyle(), GetName());
 652
 653     SetupWindow(control);
 654
 655     return control;
 656 }
 657
 658 bool MyControlXmlHandler::CanHandle(wxXmlNode *node)
 659 {
 660     // this function tells XRC system that this handler can parse
 661     // the <object class="MyControl"> tags
 662     return IsOfClass(node, wxT("MyControl"));
 663 }
 664 @endcode
 665
 666 You may want to check the wxXmlResourceHandler documentation to see how many
 667 built-in getters it contains. It's very easy to retrieve also complex
 668 structures out of XRC files using them.
 669
 670 */
 671