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git.saurik.com Git - wxWidgets.git/blob - interface/wx/app.h
1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxApp
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
13 This class is essential for writing console-only or hybrid apps without
14 having to define @c wxUSE_GUI=0.
17 @li set and get application-wide properties (see wxAppConsole::CreateTraits
18 and wxAppConsole::SetXXX functions)
19 @li implement the windowing system message or event loop: events in fact are
20 supported even in console-mode applications (see wxAppConsole::HandleEvent
21 and wxAppConsole::ProcessPendingEvents);
22 @li initiate application processing via wxApp::OnInit;
23 @li allow default processing of events not handled by other
24 objects in the application (see wxAppConsole::FilterEvent)
25 @li implement Apple-specific event handlers (see wxAppConsole::MacXXX functions)
27 You should use the macro IMPLEMENT_APP(appClass) in your application
28 implementation file to tell wxWidgets how to create an instance of your
31 Use DECLARE_APP(appClass) in a header file if you want the ::wxGetApp() function
32 (which returns a reference to your application object) to be visible to other
36 @category{appmanagement}
38 @see @ref overview_app, wxApp, wxAppTraits, wxEventLoopBase
40 class wxAppConsole
: public wxEvtHandler
44 Creates the wxAppTraits object when GetTraits() needs it for the first time.
48 virtual wxAppTraits
* CreateTraits();
55 virtual ~wxAppConsole();
64 Dispatches the next event in the windowing system event queue.
65 Blocks until an event appears if there are none currently
66 (use Pending() if this is not wanted).
68 This can be used for programming event loops, e.g.
75 @return @false if the event loop should stop and @true otherwise.
77 @see Pending(), wxEventLoopBase
79 virtual bool Dispatch();
82 Call this to explicitly exit the main message (event) loop.
83 You should normally exit the main loop (and the application) by deleting
86 virtual void ExitMainLoop();
89 This function is called before processing any event and allows the application
90 to preempt the processing of some events.
92 If this method returns -1 the event is processed normally, otherwise either
93 @true or @false should be returned and the event processing stops immediately
94 considering that the event had been already processed (for the former return
95 value) or that it is not going to be processed at all (for the latter one).
97 virtual int FilterEvent(wxEvent
& event
);
101 This function simply invokes the given method @a func of the specified
102 event handler @a handler with the @a event as parameter. It exists solely
103 to allow to catch the C++ exceptions which could be thrown by all event
104 handlers in the application in one place: if you want to do this, override
105 this function in your wxApp-derived class and add try/catch clause(s) to it.
107 virtual void HandleEvent(wxEvtHandler
* handler
,
108 wxEventFunction func
,
109 wxEvent
& event
) const;
112 Returns @true if called from inside Yield().
114 virtual bool IsYielding() const;
117 Process all pending events; it is necessary to call this function to
118 process posted events.
120 This happens during each event loop iteration in GUI mode but if there is
121 no main loop, it may be also called directly.
123 virtual void ProcessPendingEvents();
126 Called by wxWidgets on creation of the application. Override this if you wish
127 to provide your own (environment-dependent) main loop.
129 @return 0 under X, and the wParam of the WM_QUIT message under Windows.
131 virtual int MainLoop();
134 Returns @true if unprocessed events are in the window system event queue.
138 virtual bool Pending();
141 Yields control to pending messages in the windowing system.
143 This can be useful, for example, when a time-consuming process writes to a
144 text window. Without an occasional yield, the text window will not be updated
145 properly, and on systems with cooperative multitasking, such as Windows 3.1
146 other processes will not respond.
148 Caution should be exercised, however, since yielding may allow the
149 user to perform actions which are not compatible with the current task.
150 Disabling menu items or whole menus during processing can avoid unwanted
151 reentrance of code: see ::wxSafeYield for a better function.
152 You can avoid unwanted reentrancies also using IsYielding().
154 Note that Yield() will not flush the message logs. This is intentional as
155 calling Yield() is usually done to quickly update the screen and popping up
156 a message box dialog may be undesirable. If you do wish to flush the log
157 messages immediately (otherwise it will be done during the next idle loop
158 iteration), call wxLog::FlushActive.
160 Calling Yield() recursively is normally an error and an assert failure is
161 raised in debug build if such situation is detected. However if the
162 @a onlyIfNeeded parameter is @true, the method will just silently
163 return @false instead.
165 bool Yield(bool onlyIfNeeded
= false);
168 Works like Yield() with @e onlyIfNeeded == @true, except that it allows
169 the caller to specify a mask of the ::wxEventCategory values which
170 indicates which events should be processed and which should instead
171 be "delayed" (i.e. processed by the main loop later).
173 Note that this is a safer alternative to Yield() since it ensures that
174 only the events you're interested to are processed; i.e. helps to avoid
175 unwanted reentrancies.
177 bool YieldFor(long eventsToProcess
);
180 Returns @true if the given event category is allowed inside
181 a YieldFor() call (i.e. compares the given category against the
182 last mask passed to YieldFor()).
184 virtual bool IsEventAllowedInsideYield(wxEventCategory cat
) const;
190 Allows external code to modify global ::wxTheApp, but you should really
191 know what you're doing if you call it.
194 Replacement for the global application object.
198 static void SetInstance(wxAppConsole
* app
);
201 Returns the one and only global application object.
202 Usually ::wxTheApp is used instead.
206 static wxAppConsole
* GetInstance();
209 Returns @true if the main event loop is currently running, i.e. if the
210 application is inside OnRun().
212 This can be useful to test whether events can be dispatched. For example,
213 if this function returns @false, non-blocking sockets cannot be used because
214 the events from them would never be processed.
216 static bool IsMainLoopRunning();
220 @name Mac-specific functions
225 Called in response of an "open-application" Apple event.
226 Override this to create a new document in your app.
230 virtual void MacNewFile();
233 Called in response of an "open-document" Apple event.
235 You need to override this method in order to open a document file after the
236 user double clicked on it or if the document file was dropped on either the
237 running application or the application icon in Finder.
241 virtual void MacOpenFile(const wxString
& fileName
);
244 Called in response of a "get-url" Apple event.
248 virtual void MacOpenURL(const wxString
& url
);
251 Called in response of a "print-document" Apple event.
255 virtual void MacPrintFile(const wxString
& fileName
);
258 Called in response of a "reopen-application" Apple event.
262 virtual void MacReopenApp();
268 @name Callbacks for application-wide "events"
273 This function is called when an assert failure occurs, i.e. the condition
274 specified in wxASSERT() macro evaluated to @false.
276 It is only called in debug mode (when @c __WXDEBUG__ is defined) as
277 asserts are not left in the release code at all.
278 The base class version shows the default assert failure dialog box proposing to
279 the user to stop the program, continue or ignore all subsequent asserts.
282 the name of the source file where the assert occurred
284 the line number in this file where the assert occurred
286 the name of the function where the assert occurred, may be
287 empty if the compiler doesn't support C99 __FUNCTION__
289 the condition of the failed assert in text form
291 the message specified as argument to wxASSERT_MSG or wxFAIL_MSG, will
292 be @NULL if just wxASSERT or wxFAIL was used
294 virtual void OnAssertFailure(const wxChar
*file
,
301 Called when command line parsing fails (i.e. an incorrect command line option
302 was specified by the user). The default behaviour is to show the program usage
303 text and abort the program.
305 Return @true to continue normal execution or @false to return
306 @false from OnInit() thus terminating the program.
310 virtual bool OnCmdLineError(wxCmdLineParser
& parser
);
313 Called when the help option (@c --help) was specified on the command line.
314 The default behaviour is to show the program usage text and abort the program.
316 Return @true to continue normal execution or @false to return
317 @false from OnInit() thus terminating the program.
321 virtual bool OnCmdLineHelp(wxCmdLineParser
& parser
);
324 Called after the command line had been successfully parsed. You may override
325 this method to test for the values of the various parameters which could be
326 set from the command line.
328 Don't forget to call the base class version unless you want to suppress
329 processing of the standard command line options.
330 Return @true to continue normal execution or @false to return @false from
331 OnInit() thus terminating the program.
335 virtual bool OnCmdLineParsed(wxCmdLineParser
& parser
);
338 This function is called if an unhandled exception occurs inside the main
339 application event loop. It can return @true to ignore the exception and to
340 continue running the loop or @false to exit the loop and terminate the
341 program. In the latter case it can also use C++ @c throw keyword to
342 rethrow the current exception.
344 The default behaviour of this function is the latter in all ports except under
345 Windows where a dialog is shown to the user which allows him to choose between
346 the different options. You may override this function in your class to do
347 something more appropriate.
349 Finally note that if the exception is rethrown from here, it can be caught in
350 OnUnhandledException().
352 virtual bool OnExceptionInMainLoop();
355 Override this member function for any processing which needs to be
356 done as the application is about to exit. OnExit is called after
357 destroying all application windows and controls, but before
358 wxWidgets cleanup. Note that it is not called at all if
361 The return value of this function is currently ignored, return the same
362 value as returned by the base class method if you override it.
364 virtual int OnExit();
367 This function may be called if something fatal happens: an unhandled
368 exception under Win32 or a a fatal signal under Unix, for example. However,
369 this will not happen by default: you have to explicitly call
370 wxHandleFatalExceptions() to enable this.
372 Generally speaking, this function should only show a message to the user and
373 return. You may attempt to save unsaved data but this is not guaranteed to
374 work and, in fact, probably won't.
376 @see wxHandleFatalExceptions()
378 virtual void OnFatalException();
381 This must be provided by the application, and will usually create the
382 application's main window, optionally calling SetTopWindow().
384 You may use OnExit() to clean up anything initialized here, provided
385 that the function returns @true.
387 Notice that if you want to to use the command line processing provided by
388 wxWidgets you have to call the base class version in the derived class
391 Return @true to continue processing, @false to exit the application
394 virtual bool OnInit();
397 Called from OnInit() and may be used to initialize the parser with the
398 command line options for this application. The base class versions adds
399 support for a few standard options only.
401 virtual void OnInitCmdLine(wxCmdLineParser
& parser
);
404 This virtual function is where the execution of a program written in wxWidgets
405 starts. The default implementation just enters the main loop and starts
406 handling the events until it terminates, either because ExitMainLoop() has
407 been explicitly called or because the last frame has been deleted and
408 GetExitOnFrameDelete() flag is @true (this is the default).
410 The return value of this function becomes the exit code of the program, so it
411 should return 0 in case of successful termination.
416 This function is called when an unhandled C++ exception occurs inside
417 OnRun() (the exceptions which occur during the program startup and shutdown
418 might not be caught at all). Notice that by now the main event loop has been
419 terminated and the program will exit, if you want to prevent this from happening
420 (i.e. continue running after catching an exception) you need to override
421 OnExceptionInMainLoop().
423 The default implementation shows information about the exception in debug build
424 but does nothing in the release build.
426 virtual void OnUnhandledException();
432 @name Application informations
437 Returns the user-readable application name.
439 The difference between this string and the one returned by GetAppName()
440 is that this one is meant to be shown to the user and so should be used
441 for the window titles, page headers and so on while the other one
442 should be only used internally, e.g. for the file names or
443 configuration file keys. By default, returns the application name as
444 returned by GetAppName() capitalized using wxString::Capitalize().
448 wxString
GetAppDisplayName() const;
451 Returns the application name.
453 @remarks wxWidgets sets this to a reasonable default before calling
454 OnInit(), but the application can reset it at will.
456 @see GetAppDisplayName()
458 wxString
GetAppName() const;
461 Gets the class name of the application. The class name may be used in a
462 platform specific manner to refer to the application.
466 wxString
GetClassName() const;
469 Returns a pointer to the wxAppTraits object for the application.
470 If you want to customize the wxAppTraits object, you must override the
471 CreateTraits() function.
473 wxAppTraits
* GetTraits();
476 Returns the user-readable vendor name. The difference between this string
477 and the one returned by GetVendorName() is that this one is meant to be shown
478 to the user and so should be used for the window titles, page headers and so on
479 while the other one should be only used internally, e.g. for the file names or
480 configuration file keys.
482 By default, returns the same string as GetVendorName().
486 const wxString
& GetVendorDisplayName() const;
489 Returns the application's vendor name.
491 const wxString
& GetVendorName() const;
494 Set the application name to be used in the user-visible places such as
497 See GetAppDisplayName() for more about the differences between the
498 display name and name.
500 Notice that if this function is called, the name is used as is, without
501 any capitalization as done by default by GetAppDisplayName().
503 void SetAppDisplayName(const wxString
& name
);
506 Sets the name of the application. This name should be used for file names,
507 configuration file entries and other internal strings. For the user-visible
508 strings, such as the window titles, the application display name set by
509 SetAppDisplayName() is used instead.
511 By default the application name is set to the name of its executable file.
515 void SetAppName(const wxString
& name
);
518 Sets the class name of the application. This may be used in a platform specific
519 manner to refer to the application.
523 void SetClassName(const wxString
& name
);
526 Set the vendor name to be used in the user-visible places.
527 See GetVendorDisplayName() for more about the differences between the
528 display name and name.
530 void SetVendorDisplayName(const wxString
& name
);
533 Sets the name of application's vendor. The name will be used
534 in registry access. A default name is set by wxWidgets.
538 void SetVendorName(const wxString
& name
);
544 Number of command line arguments (after environment-specific processing).
549 Command line arguments (after environment-specific processing).
551 Under Windows and Linux/Unix, you should parse the command line
552 arguments and check for files to be opened when starting your
553 application. Under OS X, you need to override MacOpenFile()
554 since command line arguments are used differently there.
556 You may use the wxCmdLineParser to parse command line arguments.
567 The wxApp class represents the application itself when @c wxUSE_GUI=1.
569 In addition to the features provided by wxAppConsole it keeps track of
570 the <em>top window</em> (see SetTopWindow()) and adds support for
571 video modes (see SetVideoMode()).
573 In general, application-wide settings for GUI-only apps are accessible
574 from wxApp (or from wxSystemSettings or wxSystemOptions classes).
577 @category{appmanagement}
579 @see @ref overview_app, wxAppTraits, wxEventLoopBase, wxSystemSettings
581 class wxApp
: public wxAppConsole
585 Constructor. Called implicitly with a definition of a wxApp object.
590 Destructor. Will be called implicitly on program exit if the wxApp
591 object is created on the stack.
596 Get display mode that is used use. This is only used in framebuffer
597 wxWin ports (such as wxMGL or wxDFB).
599 virtual wxVideoMode
GetDisplayMode() const;
602 Returns @true if the application will exit when the top-level frame is deleted.
604 @see SetExitOnFrameDelete()
606 bool GetExitOnFrameDelete() const;
609 Return the layout direction for the current locale or @c wxLayout_Default
612 virtual wxLayoutDirection
GetLayoutDirection() const;
615 Returns @true if the application will use the best visual on systems that support
616 different visuals, @false otherwise.
618 @see SetUseBestVisual()
620 bool GetUseBestVisual() const;
623 Returns a pointer to the top window.
626 If the top window hasn't been set using SetTopWindow(), this function
627 will find the first top-level window (frame or dialog or instance of
628 wxTopLevelWindow) from the internal top level window list and return that.
632 virtual wxWindow
* GetTopWindow() const;
635 Returns @true if the application is active, i.e. if one of its windows is
636 currently in the foreground.
638 If this function returns @false and you need to attract users attention to
639 the application, you may use wxTopLevelWindow::RequestUserAttention to do it.
641 virtual bool IsActive() const;
644 This function is similar to wxYield(), except that it disables the user
645 input to all program windows before calling wxAppConsole::Yield and re-enables it
646 again afterwards. If @a win is not @NULL, this window will remain enabled,
647 allowing the implementation of some limited user interaction.
648 Returns the result of the call to wxAppConsole::Yield.
652 virtual bool SafeYield(wxWindow
*win
, bool onlyIfNeeded
);
655 Works like SafeYield() with @e onlyIfNeeded == @true except that
656 it allows the caller to specify a mask of events to be processed.
658 See wxAppConsole::YieldFor for more info.
660 virtual bool SafeYieldFor(wxWindow
*win
, long eventsToProcess
);
663 Windows-only function for processing a message. This function is called
664 from the main message loop, checking for windows that may wish to process it.
666 The function returns @true if the message was processed, @false otherwise.
667 If you use wxWidgets with another class library with its own message loop,
668 you should make sure that this function is called to allow wxWidgets to
669 receive messages. For example, to allow co-existence with the Microsoft
670 Foundation Classes, override the PreTranslateMessage function:
673 // Provide wxWidgets message loop compatibility
674 BOOL CTheApp::PreTranslateMessage(MSG *msg)
676 if (wxTheApp && wxTheApp->ProcessMessage((WXMSW *)msg))
679 return CWinApp::PreTranslateMessage(msg);
685 bool ProcessMessage(WXMSG
* msg
);
688 Sends idle events to a window and its children.
689 Please note that this function is internal to wxWidgets and shouldn't be used
692 @remarks These functions poll the top-level windows, and their children,
693 for idle event processing. If @true is returned, more OnIdle
694 processing is requested by one or more window.
698 virtual bool SendIdleEvents(wxWindow
* win
, wxIdleEvent
& event
);
701 Set display mode to use. This is only used in framebuffer wxWin
702 ports (such as wxMGL or wxDFB). This method should be called from
705 virtual bool SetDisplayMode(const wxVideoMode
& info
);
708 Allows the programmer to specify whether the application will exit when the
709 top-level frame is deleted.
712 If @true (the default), the application will exit when the top-level frame
713 is deleted. If @false, the application will continue to run.
715 @see GetExitOnFrameDelete(), @ref overview_app_shutdown
717 void SetExitOnFrameDelete(bool flag
);
720 Allows runtime switching of the UI environment theme.
722 Currently implemented for wxGTK2-only.
723 Return @true if theme was successfully changed.
726 The name of the new theme or an absolute path to a gtkrc-theme-file
728 virtual bool SetNativeTheme(const wxString
& theme
);
731 Sets the 'top' window. You can call this from within OnInit() to let wxWidgets
732 know which is the main window. You don't have to set the top window;
733 it is only a convenience so that (for example) certain dialogs without parents
734 can use a specific window as the top window.
736 If no top window is specified by the application, wxWidgets just uses the
737 first frame or dialog (or better, any wxTopLevelWindow) in its top-level
738 window list, when it needs to use the top window.
739 If you previously called SetTopWindow() and now you need to restore this
740 automatic behaviour you can call @code wxApp::SetTopWindow(NULL) @endcode.
745 @see GetTopWindow(), OnInit()
747 void SetTopWindow(wxWindow
* window
);
750 Allows the programmer to specify whether the application will use the best
751 visual on systems that support several visual on the same display. This is typically
752 the case under Solaris and IRIX, where the default visual is only 8-bit whereas
753 certain applications are supposed to run in TrueColour mode.
755 Note that this function has to be called in the constructor of the wxApp
756 instance and won't have any effect when called later on.
757 This function currently only has effect under GTK.
760 If @true, the app will use the best visual.
761 @param forceTrueColour
762 If @true then the application will try to force using a TrueColour
763 visual and abort the app if none is found.
765 void SetUseBestVisual(bool flag
, bool forceTrueColour
= false);
770 // ============================================================================
771 // Global functions/macros
772 // ============================================================================
775 /** @addtogroup group_funcmacro_rtti */
779 This is used in headers to create a forward declaration of the ::wxGetApp()
780 function implemented by IMPLEMENT_APP().
782 It creates the declaration <tt>className& wxGetApp()</tt>.
792 #define DECLARE_APP( className )
795 This is used in the application class implementation file to make the
796 application class known to wxWidgets for dynamic construction.
808 #define IMPLEMENT_APP( className )
815 The global pointer to the singleton wxApp object.
817 @see wxApp::GetInstance()
823 /** @addtogroup group_funcmacro_appinitterm */
827 This function doesn't exist in wxWidgets but it is created by using the
828 IMPLEMENT_APP() macro.
830 Thus, before using it anywhere but in the same module where this macro is
831 used, you must make it available using DECLARE_APP().
833 The advantage of using this function compared to directly using the global
834 ::wxTheApp pointer is that the latter is of type wxApp* and so wouldn't
835 allow you to access the functions specific to your application class but
836 not present in wxApp while wxGetApp() returns the object of the right type.
840 wxAppDerivedClass
& wxGetApp();
843 If @a doIt is @true, the fatal exceptions (also known as general protection
844 faults under Windows or segmentation violations in the Unix world) will be
845 caught and passed to wxApp::OnFatalException.
847 By default, i.e. before this function is called, they will be handled in
848 the normal way which usually just means that the application will be
849 terminated. Calling wxHandleFatalExceptions() with @a doIt equal to @false
850 will restore this default behaviour.
852 Notice that this function is only available if @c wxUSE_ON_FATAL_EXCEPTION
853 is 1 and under Windows platform this requires a compiler with support for
854 SEH (structured exception handling) which currently means only Microsoft
855 Visual C++ or a recent Borland C++ version.
859 bool wxHandleFatalExceptions(bool doIt
= true);
862 This function is used in wxBase only and only if you don't create
863 wxApp object at all. In this case you must call it from your
864 @c main() function before calling any other wxWidgets functions.
866 If the function returns @false the initialization could not be performed,
867 in this case the library cannot be used and wxUninitialize() shouldn't be
870 This function may be called several times but wxUninitialize() must be
871 called for each successful call to this function.
878 This function is for use in console (wxBase) programs only. It must be called
879 once for each previous successful call to wxInitialize().
883 void wxUninitialize();
886 This function wakes up the (internal and platform dependent) idle system,
887 i.e. it will force the system to send an idle event even if the system
888 currently @e is idle and thus would not send any idle event until after
889 some other event would get sent. This is also useful for sending events
890 between two threads and is used by the corresponding functions
891 wxPostEvent() and wxEvtHandler::AddPendingEvent().
898 Calls wxAppConsole::Yield.
901 This function is kept only for backwards compatibility. Please use
902 the wxAppConsole::Yield method instead in any new code.
909 Calls wxApp::SafeYield.
913 bool wxSafeYield(wxWindow
* win
= NULL
, bool onlyIfNeeded
= false);
916 This function initializes wxWidgets in a platform-dependent way. Use this if you
917 are not using the default wxWidgets entry code (e.g. main or WinMain).
919 For example, you can initialize wxWidgets from an Microsoft Foundation Classes
920 (MFC) application using this function.
922 @note This overload of wxEntry is available under all platforms.
928 int wxEntry(int& argc
, wxChar
** argv
);
931 See wxEntry(int&,wxChar**) for more info about this function.
933 Notice that under Windows CE platform, and only there, the type of @a pCmdLine
934 is @c wchar_t *, otherwise it is @c char *, even in Unicode build.
936 @remarks To clean up wxWidgets, call wxApp::OnExit followed by the static
937 function wxApp::CleanUp. For example, if exiting from an MFC application
938 that also uses wxWidgets:
940 int CTheApp::ExitInstance()
942 // OnExit isn't called by CleanUp so must be called explicitly.
946 return CWinApp::ExitInstance();
952 int wxEntry(HINSTANCE hInstance
,
953 HINSTANCE hPrevInstance
= NULL
,
954 char* pCmdLine
= NULL
,
955 int nCmdShow
= SW_SHOWNORMAL
);
961 /** @addtogroup group_funcmacro_procctrl */
965 Exits application after calling wxApp::OnExit.
967 Should only be used in an emergency: normally the top-level frame
968 should be deleted (after deleting all other frames) to terminate the
969 application. See wxCloseEvent and wxApp.