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git.saurik.com Git - wxWidgets.git/blob - interface/app.h
1 /////////////////////////////////////////////////////////////////////////////
3 // Purpose: interface of wxApp
4 // Author: wxWidgets team
6 // Licence: wxWindows license
7 /////////////////////////////////////////////////////////////////////////////
13 The wxApp class represents the application itself. It is used to:
15 @li set and get application-wide properties;
16 @li implement the windowing system message or event loop;
17 @li initiate application processing via wxApp::OnInit;
18 @li allow default processing of events not handled by other
19 objects in the application.
21 You should use the macro IMPLEMENT_APP(appClass) in your application
22 implementation file to tell wxWidgets how to create an instance of your
25 Use DECLARE_APP(appClass) in a header file if you want the wxGetApp function
26 (which returns a reference to your application object) to be visible to other
30 @category{appmanagement}
32 @see @ref overview_app
34 class wxApp
: public wxEvtHandler
38 Constructor. Called implicitly with a definition of a wxApp object.
43 Destructor. Will be called implicitly on program exit if the wxApp
44 object is created on the stack.
49 Creates a wxLog class for the application to use for logging errors.
50 The default implementation returns a new wxLogGui class.
54 virtual wxLog
* CreateLogTarget();
57 Creates the wxAppTraits object when GetTraits() needs it for the first time.
61 virtual wxAppTraits
* CreateTraits();
64 Dispatches the next event in the windowing system event queue.
65 This can be used for programming event loops, e.g.
74 virtual void Dispatch();
77 Call this to explicitly exit the main message (event) loop.
78 You should normally exit the main loop (and the application) by deleting
81 virtual void ExitMainLoop();
84 This function is called before processing any event and allows the application
85 to preempt the processing of some events.
87 If this method returns -1 the event is processed normally, otherwise either
88 @true or @false should be returned and the event processing stops immediately
89 considering that the event had been already processed (for the former return
90 value) or that it is not going to be processed at all (for the latter one).
92 int FilterEvent(wxEvent
& event
);
95 Returns the user-readable application name.
97 The difference between this string and the one returned by GetAppName() is that
98 this one is meant to be shown to the user and so should be used for the window
99 titles, page headers and so on while the other one should be only used internally,
100 e.g. for the file names or configuration file keys.
101 By default, returns the same string as GetAppName().
105 wxString
GetAppDisplayName() const;
108 Returns the application name.
110 @remarks wxWidgets sets this to a reasonable default before calling
111 OnInit(), but the application can reset it at will.
113 @see GetAppDisplayName()
115 wxString
GetAppName() const;
118 Gets the class name of the application. The class name may be used in a
119 platform specific manner to refer to the application.
123 wxString
GetClassName() const;
126 Returns @true if the application will exit when the top-level window is
127 deleted, @false otherwise.
129 @see SetExitOnFrameDelete(), @ref overview_app_shutdown
131 bool GetExitOnFrameDelete() const;
134 Returns the one and only global application object.
135 Usually ::wxTheApp is usead instead.
139 static wxAppConsole
* GetInstance();
142 Returns a pointer to the top window.
144 @remarks If the top window hasn't been set using SetTopWindow(),
145 this function will find the first top-level window
146 (frame or dialog) and return that.
150 virtual wxWindow
* GetTopWindow() const;
153 Returns a pointer to the wxAppTraits object for the application.
154 If you want to customize the wxAppTraits object, you must override the
155 CreateTraits() function.
157 wxAppTraits
* GetTraits();
160 Returns @true if the application will use the best visual on systems that support
161 different visuals, @false otherwise.
163 @see SetUseBestVisual()
165 bool GetUseBestVisual() const;
168 Returns the user-readable vendor name. The difference between this string
169 and the one returned by GetVendorName() is that this one is meant to be shown
170 to the user and so should be used for the window titles, page headers and so on
171 while the other one should be only used internally, e.g. for the file names or
172 configuration file keys.
174 By default, returns the same string as GetVendorName().
178 wxString
GetVendorDisplayName() const;
181 Returns the application's vendor name.
183 wxString
GetVendorName() const;
186 This function simply invokes the given method @a func of the specified
187 event handler @a handler with the @a event as parameter. It exists solely
188 to allow to catch the C++ exceptions which could be thrown by all event
189 handlers in the application in one place: if you want to do this, override
190 this function in your wxApp-derived class and add try/catch clause(s) to it.
192 virtual void HandleEvent(wxEvtHandler handler
,
193 wxEventFunction func
,
194 wxEvent
& event
) const;
197 Returns @true if the application is active, i.e. if one of its windows is
198 currently in the foreground.
200 If this function returns @false and you need to attract users attention to
201 the application, you may use wxTopLevelWindow::RequestUserAttention to do it.
203 bool IsActive() const;
206 Returns @true if the main event loop is currently running, i.e. if the
207 application is inside OnRun().
209 This can be useful to test whether events can be dispatched. For example,
210 if this function returns @false, non-blocking sockets cannot be used because
211 the events from them would never be processed.
213 static bool IsMainLoopRunning();
216 Mac specific. Called in response of an "open-application" Apple event.
217 Override this to create a new document in your app.
222 Mac specific. Called in response of an "open-document" Apple event.
224 You need to override this method in order to open a document file after the
225 user double clicked on it or if the document file was dropped on either the
226 running application or the application icon in Finder.
228 void MacOpenFile(const wxString
& fileName
);
231 Mac specific. Called in response of a "get-url" Apple event.
233 void MacOpenURL(const wxString
& url
);
236 Mac specific. Called in response of a "print-document" Apple event.
238 void MacPrintFile(const wxString
& fileName
);
241 Mac specific. Called in response of a "reopen-application" Apple event.
246 Called by wxWidgets on creation of the application. Override this if you wish
247 to provide your own (environment-dependent) main loop.
249 @returns Returns 0 under X, and the wParam of the WM_QUIT message under
252 virtual int MainLoop();
255 This function is called when an assert failure occurs, i.e. the condition
256 specified in wxASSERT() macro evaluated to @false.
258 It is only called in debug mode (when @c __WXDEBUG__ is defined) as
259 asserts are not left in the release code at all.
260 The base class version shows the default assert failure dialog box proposing to
261 the user to stop the program, continue or ignore all subsequent asserts.
264 the name of the source file where the assert occurred
266 the line number in this file where the assert occurred
268 the name of the function where the assert occurred, may be
269 empty if the compiler doesn't support C99 __FUNCTION__
271 the condition of the failed assert in text form
273 the message specified as argument to wxASSERT_MSG or wxFAIL_MSG, will
274 be @NULL if just wxASSERT or wxFAIL was used
276 void OnAssertFailure(const wxChar file
, int line
,
282 Called when command line parsing fails (i.e. an incorrect command line option
283 was specified by the user). The default behaviour is to show the program usage
284 text and abort the program.
286 Return @true to continue normal execution or @false to return
287 @false from OnInit() thus terminating the program.
291 bool OnCmdLineError(wxCmdLineParser
& parser
);
294 Called when the help option (@c --help) was specified on the command line.
295 The default behaviour is to show the program usage text and abort the program.
297 Return @true to continue normal execution or @false to return
298 @false from OnInit() thus terminating the program.
302 bool OnCmdLineHelp(wxCmdLineParser
& parser
);
305 Called after the command line had been successfully parsed. You may override
306 this method to test for the values of the various parameters which could be
307 set from the command line.
309 Don't forget to call the base class version unless you want to suppress
310 processing of the standard command line options.
311 Return @true to continue normal execution or @false to return @false from
312 OnInit() thus terminating the program.
316 bool OnCmdLineParsed(wxCmdLineParser
& parser
);
319 This function is called if an unhandled exception occurs inside the main
320 application event loop. It can return @true to ignore the exception and to
321 continue running the loop or @false to exit the loop and terminate the
322 program. In the latter case it can also use C++ @c throw keyword to
323 rethrow the current exception.
325 The default behaviour of this function is the latter in all ports except under
326 Windows where a dialog is shown to the user which allows him to choose between
327 the different options. You may override this function in your class to do
328 something more appropriate.
330 Finally note that if the exception is rethrown from here, it can be caught in
331 OnUnhandledException().
333 virtual bool OnExceptionInMainLoop();
336 Override this member function for any processing which needs to be
337 done as the application is about to exit. OnExit is called after
338 destroying all application windows and controls, but before
339 wxWidgets cleanup. Note that it is not called at all if
342 The return value of this function is currently ignored, return the same
343 value as returned by the base class method if you override it.
345 virtual int OnExit();
348 This function may be called if something fatal happens: an unhandled
349 exception under Win32 or a a fatal signal under Unix, for example. However,
350 this will not happen by default: you have to explicitly call
351 wxHandleFatalExceptions() to enable this.
353 Generally speaking, this function should only show a message to the user and
354 return. You may attempt to save unsaved data but this is not guaranteed to
355 work and, in fact, probably won't.
357 @see wxHandleFatalExceptions()
359 void OnFatalException();
362 This must be provided by the application, and will usually create the
363 application's main window, optionally calling SetTopWindow().
365 You may use OnExit() to clean up anything initialized here, provided
366 that the function returns @true.
368 Notice that if you want to to use the command line processing provided by
369 wxWidgets you have to call the base class version in the derived class
372 Return @true to continue processing, @false to exit the application
378 Called from OnInit() and may be used to initialize the parser with the
379 command line options for this application. The base class versions adds
380 support for a few standard options only.
382 void OnInitCmdLine(wxCmdLineParser
& parser
);
385 This virtual function is where the execution of a program written in wxWidgets
386 starts. The default implementation just enters the main loop and starts
387 handling the events until it terminates, either because ExitMainLoop() has
388 been explicitly called or because the last frame has been deleted and
389 GetExitOnFrameDelete() flag is @true (this is the default).
391 The return value of this function becomes the exit code of the program, so it
392 should return 0 in case of successful termination.
397 This function is called when an unhandled C++ exception occurs inside
398 OnRun() (the exceptions which occur during the program startup and shutdown
399 might not be caught at all). Notice that by now the main event loop has been
400 terminated and the program will exit, if you want to prevent this from happening
401 (i.e. continue running after catching an exception) you need to override
402 OnExceptionInMainLoop().
404 The default implementation shows information about the exception in debug build
405 but does nothing in the release build.
407 virtual void OnUnhandledException();
410 Returns @true if unprocessed events are in the window system event queue.
414 virtual bool Pending();
417 Windows-only function for processing a message. This function is called
418 from the main message loop, checking for windows that may wish to process it.
420 The function returns @true if the message was processed, @false otherwise.
421 If you use wxWidgets with another class library with its own message loop,
422 you should make sure that this function is called to allow wxWidgets to
423 receive messages. For example, to allow co-existence with the Microsoft
424 Foundation Classes, override the PreTranslateMessage function:
427 // Provide wxWidgets message loop compatibility
428 BOOL CTheApp::PreTranslateMessage(MSG *msg)
430 if (wxTheApp && wxTheApp->ProcessMessage((WXMSW *)msg))
433 return CWinApp::PreTranslateMessage(msg);
437 bool ProcessMessage(WXMSG
* msg
);
440 Sends idle events to a window and its children.
441 Please note that this function is internal to wxWidgets and shouldn't be used
444 @remarks These functions poll the top-level windows, and their children,
445 for idle event processing. If @true is returned, more OnIdle
446 processing is requested by one or more window.
450 bool SendIdleEvents(wxWindow
* win
, wxIdleEvent
& event
);
453 Set the application name to be used in the user-visible places such as window
454 titles. See GetAppDisplayName() for more about the differences between the
455 display name and name.
457 void SetAppDisplayName(const wxString
& name
);
460 Sets the name of the application. This name should be used for file names,
461 configuration file entries and other internal strings. For the user-visible
462 strings, such as the window titles, the application display name set by
463 SetAppDisplayName() is used instead.
465 By default the application name is set to the name of its executable file.
469 void SetAppName(const wxString
& name
);
472 Sets the class name of the application. This may be used in a platform specific
473 manner to refer to the application.
477 void SetClassName(const wxString
& name
);
480 Allows the programmer to specify whether the application will exit when the
481 top-level frame is deleted.
484 If @true (the default), the application will exit when the top-level frame
485 is deleted. If @false, the application will continue to run.
487 @see GetExitOnFrameDelete(), @ref overview_app_shutdown
489 void SetExitOnFrameDelete(bool flag
);
492 Allows external code to modify global ::wxTheApp, but you should really
493 know what you're doing if you call it.
496 Replacement for the global application object.
500 static void SetInstance(wxAppConsole
* app
);
503 Allows runtime switching of the UI environment theme.
505 Currently implemented for wxGTK2-only.
506 Return @true if theme was successfully changed.
509 The name of the new theme or an absolute path to a gtkrc-theme-file
511 bool SetNativeTheme(const wxString
& theme
);
514 Sets the 'top' window. You can call this from within OnInit() to let wxWidgets
515 know which is the main window. You don't have to set the top window;
516 it is only a convenience so that (for example) certain dialogs without parents
517 can use a specific window as the top window. If no top window is specified by the
518 application, wxWidgets just uses the first frame or dialog in its top-level window
519 list, when it needs to use the top window.
524 @see GetTopWindow(), OnInit()
526 void SetTopWindow(wxWindow
* window
);
529 Allows the programmer to specify whether the application will use the best
530 visual on systems that support several visual on the same display. This is typically
531 the case under Solaris and IRIX, where the default visual is only 8-bit whereas
532 certain applications are supposed to run in TrueColour mode.
534 Note that this function has to be called in the constructor of the wxApp
535 instance and won't have any effect when called later on.
536 This function currently only has effect under GTK.
539 If @true, the app will use the best visual.
540 @param forceTrueColour
541 If @true then the application will try to force using a TrueColour
542 visual and abort the app if none is found.
544 void SetUseBestVisual(bool flag
, bool forceTrueColour
= false);
547 Set the vendor name to be used in the user-visible places.
548 See GetVendorDisplayName() for more about the differences between the
549 display name and name.
551 void SetVendorDisplayName(const wxString
& name
);
554 Sets the name of application's vendor. The name will be used
555 in registry access. A default name is set by wxWidgets.
559 void SetVendorName(const wxString
& name
);
562 Yields control to pending messages in the windowing system.
564 This can be useful, for example, when a time-consuming process writes to a
565 text window. Without an occasional yield, the text window will not be updated
566 properly, and on systems with cooperative multitasking, such as Windows 3.1
567 other processes will not respond.
569 Caution should be exercised, however, since yielding may allow the
570 user to perform actions which are not compatible with the current task.
571 Disabling menu items or whole menus during processing can avoid unwanted
572 reentrance of code: see ::wxSafeYield for a better function.
574 Note that Yield() will not flush the message logs. This is intentional as
575 calling Yield() is usually done to quickly update the screen and popping up
576 a message box dialog may be undesirable. If you do wish to flush the log
577 messages immediately (otherwise it will be done during the next idle loop
578 iteration), call wxLog::FlushActive.
580 Calling Yield() recursively is normally an error and an assert failure is
581 raised in debug build if such situation is detected. However if the
582 @a onlyIfNeeded parameter is @true, the method will just silently
583 return @false instead.
585 bool Yield(bool onlyIfNeeded
= false);
588 Number of command line arguments (after environment-specific processing).
593 Command line arguments (after environment-specific processing).
595 Under Windows and Linux/Unix, you should parse the command line
596 arguments and check for files to be opened when starting your
597 application. Under OS X, you need to override MacOpenFile()
598 since command line arguments are used differently there.
600 You may use the wxCmdLineParser to parse command line arguments.
607 // ============================================================================
608 // Global functions/macros
609 // ============================================================================
612 The global pointer to the singleton wxApp object.
614 @see wxApp::GetInstance()
620 /** @ingroup group_funcmacro_rtti */
624 This is used in headers to create a forward declaration of the wxGetApp()
625 function implemented by IMPLEMENT_APP().
627 It creates the declaration @a className wxGetApp(void).
637 #define DECLARE_APP( className )
640 This is used in the application class implementation file to make the
641 application class known to wxWidgets for dynamic construction.
653 #define IMPLEMENT_APP( className )
659 /** @ingroup group_funcmacro_appinitterm */
663 This function doesn't exist in wxWidgets but it is created by using
664 the IMPLEMENT_APP() macro.
666 Thus, before using it anywhere but in the same module where this macro is
667 used, you must make it available using DECLARE_APP().
669 The advantage of using this function compared to directly using the global
670 wxTheApp pointer is that the latter is of type wxApp* and so wouldn't
671 allow you to access the functions specific to your application class but not
672 present in wxApp while wxGetApp() returns the object of the right type.
674 wxAppDerivedClass
wxGetApp();
677 If @a doIt is @true, the fatal exceptions (also known as general protection
678 faults under Windows or segmentation violations in the Unix world) will be
679 caught and passed to wxApp::OnFatalException.
681 By default, i.e. before this function is called, they will be handled in the
682 normal way which usually just means that the application will be terminated.
683 Calling wxHandleFatalExceptions() with @a doIt equal to @false will restore
684 this default behaviour.
686 Notice that this function is only available if @c wxUSE_ON_FATAL_EXCEPTION is 1
687 and under Windows platform this requires a compiler with support for SEH
688 (structured exception handling) which currently means only Microsoft Visual C++
689 or a recent Borland C++ version.
691 bool wxHandleFatalExceptions(bool doIt
= true);
695 This function is used in wxBase only and only if you don't create
696 wxApp object at all. In this case you must call it from your
697 @c main() function before calling any other wxWidgets functions.
699 If the function returns @false the initialization could not be performed,
700 in this case the library cannot be used and wxUninitialize() shouldn't be
703 This function may be called several times but wxUninitialize() must be
704 called for each successful call to this function.
709 This function is for use in console (wxBase) programs only. It must be called
710 once for each previous successful call to wxInitialize().
712 void wxUninitialize();
718 This function is kept only for backwards compatibility. Please use
719 the wxApp::Yield method instead in any new code.
724 This function is similar to wxYield, except that it disables the user input to
725 all program windows before calling wxYield and re-enables it again
726 afterwards. If @a win is not @NULL, this window will remain enabled,
727 allowing the implementation of some limited user interaction.
728 Returns the result of the call to ::wxYield.
730 bool wxSafeYield(wxWindow
* win
= NULL
, bool onlyIfNeeded
= false);
733 This function initializes wxWidgets in a platform-dependent way. Use this if you
734 are not using the default wxWidgets entry code (e.g. main or WinMain).
736 For example, you can initialize wxWidgets from an Microsoft Foundation Classes
737 (MFC) application using this function.
739 @note This overload of wxEntry is available under all platforms.
743 int wxEntry(int& argc
, wxChar
** argv
);
746 See wxEntry(int&,wxChar**) for more info about this function.
748 Notice that under Windows CE platform, and only there, the type of @a pCmdLine
749 is @c wchar_t *, otherwise it is @c char *, even in Unicode build.
751 @remarks To clean up wxWidgets, call wxApp::OnExit followed by the static
752 function wxApp::CleanUp. For example, if exiting from an MFC application
753 that also uses wxWidgets:
755 int CTheApp::ExitInstance()
757 // OnExit isn't called by CleanUp so must be called explicitly.
761 return CWinApp::ExitInstance();
766 int wxEntry(HINSTANCE hInstance
,
767 HINSTANCE hPrevInstance
= NULL
,
768 char* pCmdLine
= NULL
,
769 int nCmdShow
= SW_SHOWNORMAL
);
775 /** @ingroup group_funcmacro_procctrl */
779 Exits application after calling wxApp::OnExit.
781 Should only be used in an emergency: normally the top-level frame
782 should be deleted (after deleting all other frames) to terminate the
783 application. See wxCloseEvent and wxApp.