interface/app.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        app.h
   3 // Purpose:     interface of wxApp
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxApp
  11     @wxheader{app.h}
  12
  13     The @b wxApp class represents the application itself. It is used
  14     to:
  15
  16      set and get application-wide properties;
  17      implement the windowing system message or event loop;
  18      initiate application processing via wxApp::OnInit;
  19      allow default processing of events not handled by other
  20     objects in the application.
  21
  22     You should use the macro IMPLEMENT_APP(appClass) in your application
  23     implementation
  24     file to tell wxWidgets how to create an instance of your application class.
  25
  26     Use DECLARE_APP(appClass) in a header file if you want the wxGetApp function
  27     (which returns
  28     a reference to your application object) to be visible to other files.
  29
  30     @library{wxbase}
  31     @category{appmanagement}
  32
  33     @see @ref overview_wxappoverview "wxApp overview"
  34 */
  35 class wxApp : public wxEvtHandler
  36 {
  37 public:
  38     /**
  39         Constructor. Called implicitly with a definition of a wxApp object.
  40     */
  41     wxApp();
  42
  43     /**
  44         Destructor. Will be called implicitly on program exit if the wxApp
  45         object is created on the stack.
  46     */
  47     ~wxApp();
  48
  49     /**
  50         Creates a wxLog class for the application to use for logging errors. The default
  51         implementation returns a new wxLogGui class.
  52
  53         @see wxLog
  54     */
  55     virtual wxLog* CreateLogTarget();
  56
  57     /**
  58         Creates the wxAppTraits object when GetTraits()
  59         needs it for the first time.
  60
  61         @see wxAppTraits
  62     */
  63     virtual wxAppTraits* CreateTraits();
  64
  65     /**
  66         Dispatches the next event in the windowing system event queue.
  67         This can be used for programming event loops, e.g.
  68
  69         @see Pending()
  70     */
  71     virtual void Dispatch();
  72
  73     /**
  74         Call this to explicitly exit the main message (event) loop.
  75         You should normally exit the main loop (and the application) by deleting
  76         the top window.
  77     */
  78     virtual void ExitMainLoop();
  79
  80     /**
  81         This function is called before processing any event and allows the application
  82         to preempt the processing of some events. If this method returns -1 the event
  83         is processed normally, otherwise either @true or @false should be
  84         returned and the event processing stops immediately considering that the event
  85         had been already processed (for the former return value) or that it is not
  86         going to be processed at all (for the latter one).
  87     */
  88     int FilterEvent(wxEvent& event);
  89
  90     /**
  91         Returns the user-readable application name. The difference between this string
  92         and the one returned by GetAppName() is that this one
  93         is meant to be shown to the user and so should be used for the window titles,
  94         page headers and so on while the other one should be only used internally, e.g.
  95         for the file names or configuration file keys.
  96         By default, returns the same string as GetAppName().
  97
  98         @wxsince{2.9.0}
  99     */
 100     wxString GetAppDisplayName() const;
 101
 102     /**
 103         Returns the application name.
 104
 105         @remarks wxWidgets sets this to a reasonable default before calling
 106                  OnInit(), but the application can reset it at will.
 107
 108         @see GetAppDisplayName()
 109     */
 110     wxString GetAppName() const;
 111
 112     /**
 113         Gets the class name of the application. The class name may be used in a
 114         platform specific
 115         manner to refer to the application.
 116
 117         @see SetClassName()
 118     */
 119     wxString GetClassName() const;
 120
 121     /**
 122         Returns @true if the application will exit when the top-level window is deleted,
 123         @false
 124         otherwise.
 125
 126         @see SetExitOnFrameDelete(), @ref overview_wxappshutdownoverview "wxApp
 127              shutdown overview"
 128     */
 129     bool GetExitOnFrameDelete() const;
 130
 131     /**
 132         Returns the one and only global application object.
 133         Usually @c wxTheApp is usead instead.
 134
 135         @see SetInstance()
 136     */
 137     static wxAppConsole* GetInstance();
 138
 139     /**
 140         Returns a pointer to the top window.
 141
 142         @remarks If the top window hasn't been set using SetTopWindow(),
 143                  this function will find the first top-level window
 144                  (frame or dialog) and return that.
 145
 146         @see SetTopWindow()
 147     */
 148     virtual wxWindow* GetTopWindow() const;
 149
 150     /**
 151         Returns a pointer to the wxAppTraits object for the application.
 152         If you want to customize the wxAppTraits object, you must override the
 153         CreateTraits() function.
 154     */
 155     wxAppTraits* GetTraits();
 156
 157     /**
 158         Returns @true if the application will use the best visual on systems that support
 159         different visuals, @false otherwise.
 160
 161         @see SetUseBestVisual()
 162     */
 163     bool GetUseBestVisual() const;
 164
 165     /**
 166         Returns the user-readable vendor name. The difference between this string
 167         and the one returned by GetVendorName() is that this one
 168         is meant to be shown to the user and so should be used for the window titles,
 169         page headers and so on while the other one should be only used internally, e.g.
 170         for the file names or configuration file keys.
 171         By default, returns the same string as GetVendorName().
 172
 173         @wxsince{2.9.0}
 174     */
 175     wxString GetVendorDisplayName() const;
 176
 177     /**
 178         Returns the application's vendor name.
 179     */
 180     wxString GetVendorName() const;
 181
 182     /**
 183         This function simply invokes the given method @a func of the specified
 184         event handler @a handler with the @a event as parameter. It exists solely
 185         to allow to catch the C++ exceptions which could be thrown by all event
 186         handlers in the application in one place: if you want to do this, override this
 187         function in your wxApp-derived class and add try/catch clause(s) to it.
 188     */
 189     virtual void HandleEvent(wxEvtHandler handler,
 190                              wxEventFunction func,
 191                              wxEvent& event) const;
 192
 193     /**
 194         Returns @true if the application is active, i.e. if one of its windows is
 195         currently in the foreground. If this function returns @false and you need to
 196         attract users attention to the application, you may use
 197         wxTopLevelWindow::RequestUserAttention
 198         to do it.
 199     */
 200     bool IsActive() const;
 201
 202     /**
 203         Returns @true if the main event loop is currently running, i.e. if the
 204         application is inside OnRun().
 205         This can be useful to test whether events can be dispatched. For example,
 206         if this function returns @false, non-blocking sockets cannot be used because
 207         the events from them would never be processed.
 208     */
 209     static bool IsMainLoopRunning();
 210
 211     /**
 212         Mac specific. Called in response of an "open-application" Apple event.
 213         Override this to create a new document in your app.
 214     */
 215     void MacNewFile();
 216
 217     /**
 218         Mac specific. Called in response of an "open-document" Apple event. You need to
 219         override this method in order to open a document file after the
 220         user double clicked on it or if the document file was dropped
 221         on either the running application or the application icon in
 222         Finder.
 223     */
 224     void MacOpenFile(const wxString& fileName);
 225
 226     /**
 227         Mac specific. Called in response of a "get-url" Apple event.
 228     */
 229     void MacOpenURL(const wxString& url);
 230
 231     /**
 232         Mac specific. Called in response of a "print-document" Apple event.
 233     */
 234     void MacPrintFile(const wxString& fileName);
 235
 236     /**
 237         Mac specific. Called in response of a "reopen-application" Apple event.
 238     */
 239     void MacReopenApp();
 240
 241     /**
 242         Called by wxWidgets on creation of the application. Override this if you wish
 243         to provide your own (environment-dependent) main loop.
 244
 245         @returns Returns 0 under X, and the wParam of the WM_QUIT message under
 246                  Windows.
 247     */
 248     virtual int MainLoop();
 249
 250     /**
 251         This function is called when an assert failure occurs, i.e. the condition
 252         specified in wxASSERT() macro evaluated to @false.
 253         It is only called in debug mode (when @c __WXDEBUG__ is defined) as
 254         asserts are not left in the release code at all.
 255         The base class version shows the default assert failure dialog box proposing to
 256         the user to stop the program, continue or ignore all subsequent asserts.
 257
 258         @param file
 259             the name of the source file where the assert occurred
 260         @param line
 261             the line number in this file where the assert occurred
 262         @param func
 263             the name of the function where the assert occurred, may be
 264             empty if the compiler doesn't support C99 __FUNCTION__
 265         @param cond
 266             the condition of the failed assert in text form
 267         @param msg
 268             the message specified as argument to
 269             wxASSERT_MSG or wxFAIL_MSG, will
 270             be @NULL if just wxASSERT or wxFAIL
 271             was used
 272     */
 273     void OnAssertFailure(const wxChar file, int line,
 274                          const wxChar func,
 275                          const wxChar cond,
 276                          const wxChar msg);
 277
 278     /**
 279         Called when command line parsing fails (i.e. an incorrect command line option
 280         was specified by the user). The default behaviour is to show the program usage
 281         text and abort the program.
 282         Return @true to continue normal execution or @false to return
 283         @false from OnInit() thus terminating the program.
 284
 285         @see OnInitCmdLine()
 286     */
 287     bool OnCmdLineError(wxCmdLineParser& parser);
 288
 289     /**
 290         Called when the help option (@c --help) was specified on the command line.
 291         The default behaviour is to show the program usage text and abort the program.
 292         Return @true to continue normal execution or @false to return
 293         @false from OnInit() thus terminating the program.
 294
 295         @see OnInitCmdLine()
 296     */
 297     bool OnCmdLineHelp(wxCmdLineParser& parser);
 298
 299     /**
 300         Called after the command line had been successfully parsed. You may override
 301         this method to test for the values of the various parameters which could be
 302         set from the command line.
 303         Don't forget to call the base class version unless you want to suppress
 304         processing of the standard command line options.
 305         Return @true to continue normal execution or @false to return
 306         @false from OnInit() thus terminating the program.
 307
 308         @see OnInitCmdLine()
 309     */
 310     bool OnCmdLineParsed(wxCmdLineParser& parser);
 311
 312     /**
 313         This function is called if an unhandled exception occurs inside the main
 314         application event loop. It can return @true to ignore the exception and to
 315         continue running the loop or @false to exit the loop and terminate the
 316         program. In the latter case it can also use C++ @c throw keyword to
 317         rethrow the current exception.
 318         The default behaviour of this function is the latter in all ports except under
 319         Windows where a dialog is shown to the user which allows him to choose between
 320         the different options. You may override this function in your class to do
 321         something more appropriate.
 322         Finally note that if the exception is rethrown from here, it can be caught in
 323         OnUnhandledException().
 324     */
 325     virtual bool OnExceptionInMainLoop();
 326
 327     /**
 328         Override this member function for any processing which needs to be
 329         done as the application is about to exit. OnExit is called after
 330         destroying all application windows and controls, but before
 331         wxWidgets cleanup. Note that it is not called at all if
 332         OnInit() failed.
 333         The return value of this function is currently ignored, return the same value
 334         as returned by the base class method if you override it.
 335     */
 336     virtual int OnExit();
 337
 338     /**
 339         This function may be called if something fatal happens: an unhandled
 340         exception under Win32 or a a fatal signal under Unix, for example. However,
 341         this will not happen by default: you have to explicitly call
 342         wxHandleFatalExceptions() to enable this.
 343         Generally speaking, this function should only show a message to the user and
 344         return. You may attempt to save unsaved data but this is not guaranteed to
 345         work and, in fact, probably won't.
 346
 347         @see wxHandleFatalExceptions()
 348     */
 349     void OnFatalException();
 350
 351     /**
 352         This must be provided by the application, and will usually create the
 353         application's main window, optionally calling
 354         SetTopWindow(). You may use
 355         OnExit() to clean up anything initialized here, provided
 356         that the function returns @true.
 357         Notice that if you want to to use the command line processing provided by
 358         wxWidgets you have to call the base class version in the derived class
 359         OnInit().
 360         Return @true to continue processing, @false to exit the application
 361         immediately.
 362     */
 363     bool OnInit();
 364
 365     /**
 366         Called from OnInit() and may be used to initialize the
 367         parser with the command line options for this application. The base class
 368         versions adds support for a few standard options only.
 369     */
 370     void OnInitCmdLine(wxCmdLineParser& parser);
 371
 372     /**
 373         This virtual function is where the execution of a program written in wxWidgets
 374         starts. The default implementation just enters the main loop and starts
 375         handling the events until it terminates, either because
 376         ExitMainLoop() has been explicitly called or because
 377         the last frame has been deleted and
 378         GetExitOnFrameDelete() flag is @true (this
 379         is the default).
 380         The return value of this function becomes the exit code of the program, so it
 381         should return 0 in case of successful termination.
 382     */
 383     virtual int OnRun();
 384
 385     /**
 386         This function is called when an unhandled C++ exception occurs inside
 387         OnRun() (the exceptions which occur during the program
 388         startup and shutdown might not be caught at all). Notice that by now the main
 389         event loop has been terminated and the program will exit, if you want to
 390         prevent this from happening (i.e. continue running after catching an exception)
 391         you need to override OnExceptionInMainLoop().
 392         The default implementation shows information about the exception in debug build
 393         but does nothing in the release build.
 394     */
 395     virtual void OnUnhandledException();
 396
 397     /**
 398         Returns @true if unprocessed events are in the window system event queue.
 399
 400         @see Dispatch()
 401     */
 402     virtual bool Pending();
 403
 404     /**
 405         Windows-only function for processing a message. This function
 406         is called from the main message loop, checking for windows that
 407         may wish to process it. The function returns @true if the message
 408         was processed, @false otherwise. If you use wxWidgets with another class
 409         library with its own message loop, you should make sure that this
 410         function is called to allow wxWidgets to receive messages. For example,
 411         to allow co-existence with the Microsoft Foundation Classes, override
 412         the PreTranslateMessage function:
 413     */
 414     bool ProcessMessage(WXMSG* msg);
 415
 416     /**
 417         Sends idle events to a window and its children.
 418         Please note that this function is internal to wxWidgets and shouldn't be used
 419         by user code.
 420
 421         @remarks These functions poll the top-level windows, and their children,
 422                  for idle event processing. If @true is returned, more
 423                  OnIdle processing is requested by one or more window.
 424
 425         @see wxIdleEvent
 426     */
 427     bool SendIdleEvents(wxWindow* win, wxIdleEvent& event);
 428
 429     /**
 430         Set the application name to be used in the user-visible places such as window
 431         titles. See GetAppDisplayName() for more about
 432         the differences between the display name and name.
 433     */
 434     void SetAppDisplayName(const wxString& name);
 435
 436     /**
 437         Sets the name of the application. This name should be used for file names,
 438         configuration file entries and other internal strings. For the user-visible
 439         strings, such as the window titles, the application display name set by
 440         SetAppDisplayName() is used instead.
 441         By default the application name is set to the name of its executable file.
 442
 443         @see GetAppName()
 444     */
 445     void SetAppName(const wxString& name);
 446
 447     /**
 448         Sets the class name of the application. This may be used in a platform specific
 449         manner to refer to the application.
 450
 451         @see GetClassName()
 452     */
 453     void SetClassName(const wxString& name);
 454
 455     /**
 456         Allows the programmer to specify whether the application will exit when the
 457         top-level frame is deleted.
 458
 459         @param flag
 460             If @true (the default), the application will exit when the top-level frame is
 461             deleted. If @false, the application will continue to run.
 462
 463         @see GetExitOnFrameDelete(), @ref overview_wxappshutdownoverview "wxApp
 464              shutdown overview"
 465     */
 466     void SetExitOnFrameDelete(bool flag);
 467
 468     /**
 469         Allows external code to modify global @c wxTheApp, but you should really
 470         know what you're doing if you call it.
 471
 472         @param app
 473             Replacement for the global application object.
 474
 475         @see GetInstance()
 476     */
 477     static void SetInstance(wxAppConsole* app);
 478
 479     /**
 480         Allows runtime switching of the UI environment theme. Currently implemented for
 481         wxGTK2-only.
 482         Return @true if theme was successfully changed.
 483
 484         @param theme
 485             The name of the new theme or an absolute path to a gtkrc-theme-file
 486     */
 487     bool SetNativeTheme(const wxStringamp;);
 488
 489     /**
 490         Sets the 'top' window. You can call this from within OnInit() to
 491         let wxWidgets know which is the main window. You don't have to set the top
 492         window;
 493         it is only a convenience so that (for example) certain dialogs without parents
 494         can use a
 495         specific window as the top window. If no top window is specified by the
 496         application,
 497         wxWidgets just uses the first frame or dialog in its top-level window list,
 498         when it
 499         needs to use the top window.
 500
 501         @param window
 502             The new top window.
 503
 504         @see GetTopWindow(), OnInit()
 505     */
 506     void SetTopWindow(wxWindow* window);
 507
 508     /**
 509         Allows the programmer to specify whether the application will use the best
 510         visual
 511         on systems that support several visual on the same display. This is typically
 512         the
 513         case under Solaris and IRIX, where the default visual is only 8-bit whereas
 514         certain
 515         applications are supposed to run in TrueColour mode.
 516         If @a forceTrueColour is @true then the application will try to force
 517         using a TrueColour visual and abort the app if none is found.
 518         Note that this function has to be called in the constructor of the @c wxApp
 519         instance and won't have any effect when called later on.
 520         This function currently only has effect under GTK.
 521
 522         @param flag
 523             If @true, the app will use the best visual.
 524     */
 525     void SetUseBestVisual(bool flag, bool forceTrueColour = false);
 526
 527     /**
 528         Set the vendor name to be used in the user-visible places. See
 529         GetVendorDisplayName() for more about
 530         the differences between the display name and name.
 531     */
 532     void SetVendorDisplayName(const wxString& name);
 533
 534     /**
 535         Sets the name of application's vendor. The name will be used
 536         in registry access. A default name is set by
 537         wxWidgets.
 538
 539         @see GetVendorName()
 540     */
 541     void SetVendorName(const wxString& name);
 542
 543     /**
 544         Yields control to pending messages in the windowing system. This can be useful,
 545         for example, when a
 546         time-consuming process writes to a text window. Without an occasional
 547         yield, the text window will not be updated properly, and on systems with
 548         cooperative multitasking, such as Windows 3.1 other processes will not respond.
 549         Caution should be exercised, however, since yielding may allow the
 550         user to perform actions which are not compatible with the current task.
 551         Disabling menu items or whole menus during processing can avoid unwanted
 552         reentrance of code: see ::wxSafeYield for a better
 553         function.
 554         Note that Yield() will not flush the message logs. This is intentional as
 555         calling Yield() is usually done to quickly update the screen and popping up a
 556         message box dialog may be undesirable. If you do wish to flush the log
 557         messages immediately (otherwise it will be done during the next idle loop
 558         iteration), call wxLog::FlushActive.
 559         Calling Yield() recursively is normally an error and an assert failure is
 560         raised in debug build if such situation is detected. However if the
 561         @a onlyIfNeeded parameter is @true, the method will just silently
 562         return @false instead.
 563     */
 564     bool Yield(bool onlyIfNeeded = false);
 565
 566     /**
 567         int argc
 568         Number of command line arguments (after environment-specific processing).
 569     */
 570
 571
 572     /**
 573         wxChar ** argv
 574         Command line arguments (after environment-specific processing).
 575         Under Windows and Linux/Unix, you should parse the command line
 576         arguments and check for files to be opened when starting your
 577         application. Under OS X, you need to override MacOpenFile()
 578         since command line arguments are used differently there.
 579         You may use the wxCmdLineParser to
 580         parse command line arguments.
 581     */
 582 };
 583
 584
 585
 586 // ============================================================================
 587 // Global functions/macros
 588 // ============================================================================
 589
 590 //@{
 591 /**
 592     For all normal, informational messages. They also appear in a message box by
 593     default (but it can be changed).
 594 */
 595 void wxLogMessage(const char* formatString, ... );
 596 void wxVLogMessage(const char* formatString, va_list argPtr);
 597 //@}
 598
 599 //@{
 600 /**
 601     For verbose output. Normally, it is suppressed, but
 602     might be activated if the user wishes to know more details about the program
 603     progress (another, but possibly confusing name for the same function is @b
 604     wxLogInfo).
 605 */
 606 void wxLogVerbose(const char* formatString, ... );
 607 void wxVLogVerbose(const char* formatString, va_list argPtr);
 608 //@}
 609
 610 /**
 611     This is used in headers to create a forward declaration of the
 612     wxGetApp() function implemented by
 613     wxIMPLEMENT_APP(). It creates the declaration
 614     @c className wxGetApp(void).
 615     Example:
 616
 617     @code
 618     wxDECLARE_APP(MyApp)
 619     @endcode
 620 */
 621 #define wxDECLARE_APP()     /* implementation is private */
 622
 623 /**
 624     Exits application after calling wxApp::OnExit.
 625     Should only be used in an emergency: normally the top-level frame
 626     should be deleted (after deleting all other frames) to terminate the
 627     application. See wxCloseEvent and wxApp.
 628 */
 629 void wxExit();
 630
 631 //@{
 632 /**
 633     For warnings - they are also normally shown to the user, but don't interrupt
 634     the program work.
 635 */
 636 void wxLogWarning(const char* formatString, ... );
 637 void wxVLogWarning(const char* formatString, va_list argPtr);
 638 //@}
 639
 640 //@{
 641 /**
 642     Like wxLogError(), but also
 643     terminates the program with the exit code 3. Using @e abort() standard
 644     function also terminates the program with this exit code.
 645 */
 646 void wxLogFatalError(const char* formatString, ... );
 647 void wxVLogFatalError(const char* formatString,
 648                       va_list argPtr);
 649 //@}
 650
 651 /**
 652     If @a doIt is @true, the fatal exceptions (also known as general protection
 653     faults under Windows or segmentation violations in the Unix world) will be
 654     caught and passed to wxApp::OnFatalException.
 655     By default, i.e. before this function is called, they will be handled in the
 656     normal way which usually just means that the application will be terminated.
 657     Calling wxHandleFatalExceptions() with @a doIt equal to @false will restore
 658     this default behaviour.
 659     Notice that this function is only available if
 660     @c wxUSE_ON_FATAL_EXCEPTION is 1 and under Windows platform this
 661     requires a compiler with support for SEH (structured exception handling) which
 662     currently means only Microsoft Visual C++ or a recent Borland C++ version.
 663 */
 664 bool wxHandleFatalExceptions(bool doIt = true);
 665
 666 /**
 667     This is used in the application class implementation file to make the
 668     application class known to
 669     wxWidgets for dynamic construction. You use this instead of
 670     Old form:
 671
 672     @code
 673     MyApp myApp;
 674     @endcode
 675
 676     New form:
 677
 678     @code
 679     IMPLEMENT_APP(MyApp)
 680     @endcode
 681
 682     See also DECLARE_APP().
 683 */
 684 #define IMPLEMENT_APP()     /* implementation is private */
 685
 686 /**
 687     Returns the error code from the last system call. This function uses
 688     @c errno on Unix platforms and @c GetLastError under Win32.
 689
 690     @see wxSysErrorMsg(), wxLogSysError()
 691 */
 692 unsigned long wxSysErrorCode();
 693
 694 /**
 695     In a GUI application, this function posts @a event to the specified @e dest
 696     object using wxEvtHandler::AddPendingEvent.
 697     Otherwise, it dispatches @a event immediately using
 698     wxEvtHandler::ProcessEvent.
 699     See the respective documentation for details (and caveats).
 700 */
 701 void wxPostEvent(wxEvtHandler* dest, wxEvent& event);
 702
 703 //@{
 704 /**
 705     The functions to use for error messages, i.e. the messages that must be shown
 706     to the user. The default processing is to pop up a message box to inform the
 707     user about it.
 708 */
 709 void wxLogError(const char* formatString, ... );
 710 void wxVLogError(const char* formatString, va_list argPtr);
 711 //@}
 712
 713 //@{
 714 /**
 715     As @b wxLogDebug, trace functions only do something in debug build and
 716     expand to nothing in the release one. The reason for making
 717     it a separate function from it is that usually there are a lot of trace
 718     messages, so it might make sense to separate them from other debug messages.
 719     The trace messages also usually can be separated into different categories and
 720     the second and third versions of this function only log the message if the
 721     @a mask which it has is currently enabled in wxLog. This
 722     allows to selectively trace only some operations and not others by changing
 723     the value of the trace mask (possible during the run-time).
 724     For the second function (taking a string mask), the message is logged only if
 725     the mask has been previously enabled by the call to
 726     wxLog::AddTraceMask or by setting
 727     @ref overview_envvars "@c WXTRACE environment variable".
 728     The predefined string trace masks
 729     used by wxWidgets are:
 730      wxTRACE_MemAlloc: trace memory allocation (new/delete)
 731      wxTRACE_Messages: trace window messages/X callbacks
 732      wxTRACE_ResAlloc: trace GDI resource allocation
 733      wxTRACE_RefCount: trace various ref counting operations
 734      wxTRACE_OleCalls: trace OLE method calls (Win32 only)
 735     @b Caveats: since both the mask and the format string are strings,
 736     this might lead to function signature confusion in some cases:
 737     if you intend to call the format string only version of wxLogTrace,
 738     then add a %s format string parameter and then supply a second string parameter
 739     for that %s, the string mask version of wxLogTrace will erroneously get called instead, since you are supplying two string parameters to the function.
 740     In this case you'll unfortunately have to avoid having two leading
 741     string parameters, e.g. by adding a bogus integer (with its %d format string).
 742     The third version of the function only logs the message if all the bits
 743     corresponding to the @a mask are set in the wxLog trace mask which can be
 744     set by wxLog::SetTraceMask. This version is less
 745     flexible than the previous one because it doesn't allow defining the user
 746     trace masks easily - this is why it is deprecated in favour of using string
 747     trace masks.
 748      wxTraceMemAlloc: trace memory allocation (new/delete)
 749      wxTraceMessages: trace window messages/X callbacks
 750      wxTraceResAlloc: trace GDI resource allocation
 751      wxTraceRefCount: trace various ref counting operations
 752      wxTraceOleCalls: trace OLE method calls (Win32 only)
 753 */
 754 void wxLogTrace(const char* formatString, ... );
 755 void wxVLogTrace(const char* formatString, va_list argPtr);
 756 void wxLogTrace(const char* mask, const char* formatString,
 757                 ... );
 758 void wxVLogTrace(const char* mask,
 759                  const char* formatString,
 760                  va_list argPtr);
 761 void wxLogTrace(wxTraceMask mask, const char* formatString,
 762                 ... );
 763 void wxVLogTrace(wxTraceMask mask, const char* formatString,
 764                  va_list argPtr);
 765 //@}
 766
 767 /**
 768     Returns the error message corresponding to the given system error code. If
 769     @a errCode is 0 (default), the last error code (as returned by
 770     wxSysErrorCode()) is used.
 771
 772     @see wxSysErrorCode(), wxLogSysError()
 773 */
 774 const wxChar* wxSysErrorMsg(unsigned long errCode = 0);
 775
 776 /**
 777     This function is for use in console (wxBase) programs only. It must be called
 778     once for each previous successful call to wxInitialize().
 779 */
 780 void wxUninitialize();
 781
 782 //@{
 783 /**
 784     The right functions for debug output. They only do something in debug
 785     mode (when the preprocessor symbol __WXDEBUG__ is defined) and expand to
 786     nothing in release mode (otherwise).
 787 */
 788 void wxLogDebug(const char* formatString, ... );
 789 void wxVLogDebug(const char* formatString, va_list argPtr);
 790 //@}
 791
 792 /**
 793     This function doesn't exist in wxWidgets but it is created by using
 794     the IMPLEMENT_APP() macro. Thus, before using it
 795     anywhere but in the same module where this macro is used, you must make it
 796     available using DECLARE_APP().
 797     The advantage of using this function compared to directly using the global
 798     wxTheApp pointer is that the latter is of type @c wxApp * and so wouldn't
 799     allow you to access the functions specific to your application class but not
 800     present in wxApp while wxGetApp() returns the object of the right type.
 801 */
 802 wxAppDerivedClass wxGetApp();
 803
 804 //@{
 805 /**
 806     Messages logged by these functions will appear in the statusbar of the @a frame
 807     or of the top level application window by default (i.e. when using
 808     the second version of the functions).
 809     If the target frame doesn't have a statusbar, the message will be lost.
 810 */
 811 void wxLogStatus(wxFrame* frame, const char* formatString,
 812                  ... );
 813 void wxVLogStatus(wxFrame* frame, const char* formatString,
 814                   va_list argPtr);
 815 void wxLogStatus(const char* formatString, ... );
 816 void wxVLogStatus(const char* formatString, va_list argPtr);
 817 //@}
 818
 819 /**
 820     This function is used in wxBase only and only if you don't create
 821     wxApp object at all. In this case you must call it from your
 822     @c main() function before calling any other wxWidgets functions.
 823     If the function returns @false the initialization could not be performed,
 824     in this case the library cannot be used and
 825     wxUninitialize() shouldn't be called neither.
 826     This function may be called several times but
 827     wxUninitialize() must be called for each successful
 828     call to this function.
 829 */
 830 bool wxInitialize();
 831
 832 /**
 833     This is used in headers to create a forward declaration of the
 834     wxGetApp() function implemented by
 835     IMPLEMENT_APP(). It creates the declaration
 836     @c className wxGetApp(void).
 837     Example:
 838
 839     @code
 840     DECLARE_APP(MyApp)
 841     @endcode
 842 */
 843 #define DECLARE_APP()     /* implementation is private */
 844
 845 /**
 846     Calls wxApp::Yield.
 847     This function is kept only for backwards compatibility. Please use
 848     the wxApp::Yield method instead in any new code.
 849 */
 850 bool wxYield();
 851
 852 //@{
 853 /**
 854     Mostly used by wxWidgets itself, but might be handy for logging errors after
 855     system call (API function) failure. It logs the specified message text as well
 856     as the last system error code (@e errno or @e ::GetLastError() depending
 857     on the platform) and the corresponding error message. The second form
 858     of this function takes the error code explicitly as the first argument.
 859
 860     @see wxSysErrorCode(), wxSysErrorMsg()
 861 */
 862 void wxLogSysError(const char* formatString, ... );
 863 void wxVLogSysError(const char* formatString,
 864                     va_list argPtr);
 865 //@}
 866
 867 //@{
 868 /**
 869     This initializes wxWidgets in a platform-dependent way. Use this if you are not
 870     using the default wxWidgets entry code (e.g. main or WinMain). For example, you
 871     can initialize wxWidgets from an Microsoft Foundation Classes application using
 872     this function.
 873     The following overload of wxEntry is available under all platforms:
 874
 875     (notice that under Windows CE platform, and only there, the type of
 876     @a pCmdLine is @c wchar_t *, otherwise it is @c char *, even in
 877     Unicode build).
 878
 879     @remarks To clean up wxWidgets, call wxApp::OnExit followed by the static
 880              function wxApp::CleanUp. For example, if exiting from
 881              an MFC application that also uses wxWidgets:
 882
 883     @see wxEntryStart()
 884 */
 885 int wxEntry(int& argc, wxChar** argv);
 886 int wxEntry(HINSTANCE hInstance,
 887             HINSTANCE hPrevInstance = NULL,
 888             char* pCmdLine = NULL,
 889             int nCmdShow = SW_SHOWNORMAL);
 890 //@}
 891