wxApp destructor is virtual [ patch 1283503 ]

[wxWidgets.git] / docs / latex / wx / app.tex

diff --git a/docs/latex/wx/app.tex b/docs/latex/wx/app.tex
index 1137aa6ccdb4beadc1ebbc7bfdb72c04cebd9d4c..b0ad4a45959e6fe11335de284e1b12d31a2013f0 100644 (file)
--- a/docs/latex/wx/app.tex
+++ b/docs/latex/wx/app.tex
@@ -12,7 +12,7 @@ objects in the application.
 \end{itemize}
 
 You should use the macro IMPLEMENT\_APP(appClass) in your application implementation
 \end{itemize}
 
 You should use the macro IMPLEMENT\_APP(appClass) in your application implementation

-file to tell wxWindows how to create an instance of your application class.
+file to tell wxWidgets how to create an instance of your application class.

 
 Use DECLARE\_APP(appClass) in a header file if you want the wxGetApp function (which returns
 a reference to your application object) to be visible to other files.
 
 Use DECLARE\_APP(appClass) in a header file if you want the wxGetApp function (which returns
 a reference to your application object) to be visible to other files.


@@ -33,16 +33,16 @@ a reference to your application object) to be visible to other files.
 \latexignore{\rtfignore{\wxheading{Members}}}
 
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 
 

-\membersection{wxApp::wxApp}
+\membersection{wxApp::wxApp}\label{wxappctor}

 
 

-\func{void}{wxApp}{\void}
+\func{}{wxApp}{\void}

 
 Constructor. Called implicitly with a definition of a wxApp object.
 
 
 
 Constructor. Called implicitly with a definition of a wxApp object.
 
 

-\membersection{wxApp::\destruct{wxApp}}
+\membersection{wxApp::\destruct{wxApp}}\label{wxappdtor}

 
 

-\func{void}{\destruct{wxApp}}{\void}
+\func{virtual}{\destruct{wxApp}}{\void}

 
 Destructor. Will be called implicitly on program exit if the wxApp
 object is created on the stack.
 
 Destructor. Will be called implicitly on program exit if the wxApp
 object is created on the stack.


@@ -57,7 +57,7 @@ Number of command line arguments (after environment-specific processing).
 
 \membersection{wxApp::argv}\label{wxappargv}
 
 
 \membersection{wxApp::argv}\label{wxappargv}
 

-\member{char **}{argv}
+\member{wxChar **}{argv}

 
 Command line arguments (after environment-specific processing).
 
 
 Command line arguments (after environment-specific processing).
 


@@ -76,7 +76,7 @@ implementation returns a new wxLogGui class.
 
 \membersection{wxApp::Dispatch}\label{wxappdispatch}
 
 
 \membersection{wxApp::Dispatch}\label{wxappdispatch}
 

-\func{void}{Dispatch}{\void}
+\func{virtual void}{Dispatch}{\void}

 
 Dispatches the next event in the windowing system event queue.
 
 
 Dispatches the next event in the windowing system event queue.
 


@@ -92,6 +92,15 @@ This can be used for programming event loops, e.g.
 \helpref{wxApp::Pending}{wxapppending}
 
 
 \helpref{wxApp::Pending}{wxapppending}
 
 

+\membersection{wxApp::ExitMainLoop}\label{wxappexitmainloop}
+
+\func{virtual void}{ExitMainLoop}{\void}
+
+Call this to explicitly exit the main message (event) loop.
+You should normally exit the main loop (and the application) by deleting
+the top window.
+
+

 \membersection{wxApp::FilterEvent}\label{wxappfilterevent}
 
 \func{int}{FilterEvent}{\param{wxEvent\& }{event}}
 \membersection{wxApp::FilterEvent}\label{wxappfilterevent}
 
 \func{int}{FilterEvent}{\param{wxEvent\& }{event}}


@@ -112,21 +121,10 @@ Returns the application name.
 
 \wxheading{Remarks}
 
 
 \wxheading{Remarks}
 

-wxWindows sets this to a reasonable default before
+wxWidgets sets this to a reasonable default before

 calling \helpref{wxApp::OnInit}{wxapponinit}, but the application can reset it at will.
 
 
 calling \helpref{wxApp::OnInit}{wxapponinit}, but the application can reset it at will.
 
 

-\membersection{wxApp::GetAuto3D}\label{wxappgetauto3d}
-
-\constfunc{bool}{GetAuto3D}{\void}
-
-Returns true if 3D control mode is on, false otherwise.
-
-\wxheading{See also}
-
-\helpref{wxApp::SetAuto3D}{wxappsetauto3d}
-
-

 \membersection{wxApp::GetClassName}\label{wxappgetclassname}
 
 \constfunc{wxString}{GetClassName}{\void}
 \membersection{wxApp::GetClassName}\label{wxappgetclassname}
 
 \constfunc{wxString}{GetClassName}{\void}


@@ -152,6 +150,18 @@ otherwise.
 \helpref{wxApp shutdown overview}{wxappshutdownoverview}
 
 
 \helpref{wxApp shutdown overview}{wxappshutdownoverview}
 
 

+\membersection{wxApp::GetInstance}\label{wxappgetinstance}
+
+\func{static wxAppConsole *}{GetInstance}{\void}
+
+Returns the one and only global application object.
+Usually \texttt{wxTheApp} is usead instead.
+
+\wxheading{See also}
+
+\helpref{wxApp::SetInstance}{wxappsetinstance}
+
+

 \membersection{wxApp::GetTopWindow}\label{wxappgettopwindow}
 
 \constfunc{virtual wxWindow *}{GetTopWindow}{\void}
 \membersection{wxApp::GetTopWindow}\label{wxappgettopwindow}
 
 \constfunc{virtual wxWindow *}{GetTopWindow}{\void}


@@ -187,31 +197,34 @@ different visuals, false otherwise.
 Returns the application's vendor name.
 
 
 Returns the application's vendor name.
 
 

-\membersection{wxApp::ExitMainLoop}\label{wxappexitmainloop}
+\membersection{wxApp::IsActive}\label{wxappisactive}

 
 

-\func{void}{ExitMainLoop}{\void}
+\constfunc{bool}{IsActive}{\void}
+
+Returns \true if the application is active, i.e. if one of its windows is
+currently in the foreground. If this function returns \false and you need to
+attract users attention to the application, you may use 
+\helpref{wxTopLevelWindow::RequestUserAttention}{wxtoplevelwindowrequestuserattention} 
+to do it.

 
 

-Call this to explicitly exit the main message (event) loop.
-You should normally exit the main loop (and the application) by deleting
-the top window.

 
 

+\membersection{wxApp::IsMainLoopRunning}\label{wxappismainlooprunning}

 
 

-\membersection{wxApp::Initialized}\label{wxappinitialized}
+\func{static bool}{IsMainLoopRunning}{\void}

 
 

-\func{bool}{Initialized}{\void}
+Returns \true if the main event loop is currently running, i.e. if the
+application is inside \helpref{OnRun}{wxapponrun}.

 
 

-Returns true if the application has been initialized (i.e. if\rtfsp
-\helpref{wxApp::OnInit}{wxapponinit} has returned successfully).  This can be useful for error
-message routines to determine which method of output is best for the
-current state of the program (some windowing systems may not like
-dialogs to pop up before the main loop has been entered).
+This can be useful to test whether the events can be dispatched. For example,
+if this function returns \false, non-blocking sockets cannot be used because
+the events from them would never be processed.

 
 
 \membersection{wxApp::MainLoop}\label{wxappmainloop}
 
 
 
 \membersection{wxApp::MainLoop}\label{wxappmainloop}
 

-\func{int}{MainLoop}{\void}
+\func{virtual int}{MainLoop}{\void}

 
 

-Called by wxWindows on creation of the application. Override this if you wish
+Called by wxWidgets on creation of the application. Override this if you wish

 to provide your own (environment-dependent) main loop.
 
 \wxheading{Return value}
 to provide your own (environment-dependent) main loop.
 
 \wxheading{Return value}


@@ -269,9 +282,9 @@ the user to stop the program, continue or ignore all subsequent asserts.
 
 \wxheading{Parameters}
 
 
 \wxheading{Parameters}
 

-\docparam{file}{the name of the source file where the assert occured}
+\docparam{file}{the name of the source file where the assert occurred}

 
 

-\docparam{line}{the line number in this file where the assert occured}
+\docparam{line}{the line number in this file where the assert occurred}

 
 \docparam{cond}{the condition of the failed assert in string form}
 
 
 \docparam{cond}{the condition of the failed assert in string form}
 


@@ -331,14 +344,37 @@ Return {\tt true} to continue normal execution or {\tt false} to return
 \helpref{OnInitCmdLine}{wxapponinitcmdline}
 
 
 \helpref{OnInitCmdLine}{wxapponinitcmdline}
 
 

+\membersection{wxApp::OnExceptionInMainLoop}\label{wxapponexceptioninmainloop}
+
+\func{virtual bool}{OnExceptionInMainLoop}{\void}
+
+This function is called if an unhandled exception occurs inside the main
+application event loop. It can return \true to ignore the exception and to
+continue running the loop or \false to exit the loop and terminate the
+program. In the latter case it can also use C++ \texttt{throw} keyword to
+rethrow the current exception.
+
+The default behaviour of this function is the latter in all ports except under
+Windows where a dialog is shown to the user which allows him to choose between
+the different options. You may override this function in your class to do
+something more appropriate.
+
+Finally note that if the exception is rethrown from here, it can be caught in 
+\helpref{OnUnhandledException}{wxapponunhandledexception}.
+
+

 \membersection{wxApp::OnExit}\label{wxapponexit}
 
 \membersection{wxApp::OnExit}\label{wxapponexit}
 

-\func{int}{OnExit}{\void}
+\func{virtual int}{OnExit}{\void}

 
 

-Provide this member function for any processing which needs to be
+Override this member function for any processing which needs to be

 done as the application is about to exit. OnExit is called after
 destroying all application windows and controls, but before
 done as the application is about to exit. OnExit is called after
 destroying all application windows and controls, but before

-wxWindows cleanup.
+wxWidgets cleanup. Note that it is not called at all if 
+\helpref{OnInit}{wxapponinit} failed.
+
+The return value of this function is currently ignored, return the same value
+as returned by the base class method if you override it.

 
 
 \membersection{wxApp::OnFatalException}\label{wxapponfatalexception}
 
 
 \membersection{wxApp::OnFatalException}\label{wxapponfatalexception}


@@ -356,7 +392,7 @@ work and, in fact, probably won't.
 
 \wxheading{See also}
 
 
 \wxheading{See also}
 

-\helpref{wxHandleFatalExcetions}{wxhandlefatalexceptions}
+\helpref{wxHandleFatalExceptions}{wxhandlefatalexceptions}

 
 %% VZ: the wxApp event handler are private and should not be documented here!
 %%
 
 %% VZ: the wxApp event handler are private and should not be documented here!
 %%


@@ -369,11 +405,11 @@ work and, in fact, probably won't.
 %%since this forwards OnIdle events to windows and also performs garbage collection for
 %%windows whose destruction has been delayed.
 %%
 %%since this forwards OnIdle events to windows and also performs garbage collection for
 %%windows whose destruction has been delayed.
 %%

-%%wxWindows' strategy for OnIdle processing is as follows. After pending user interface events for an
-%%application have all been processed, wxWindows sends an OnIdle event to the application object. wxApp::OnIdle itself
+%%wxWidgets' strategy for OnIdle processing is as follows. After pending user interface events for an
+%%application have all been processed, wxWidgets sends an OnIdle event to the application object. wxApp::OnIdle itself

 %%sends an OnIdle event to each application window, allowing windows to do idle processing such as updating
 %%their appearance. If either wxApp::OnIdle or a window OnIdle function requested more time, by
 %%sends an OnIdle event to each application window, allowing windows to do idle processing such as updating
 %%their appearance. If either wxApp::OnIdle or a window OnIdle function requested more time, by

-%%calling \helpref{wxIdleEvent::RequestMore}{wxidleeventrequestmore}, wxWindows will send another OnIdle
+%%calling \helpref{wxIdleEvent::RequestMore}{wxidleeventrequestmore}, wxWidgets will send another OnIdle

 %%event to the application object. This will occur in a loop until either a user event is found to be
 %%pending, or OnIdle requests no more time. Then all pending user events are processed until the system
 %%goes idle again, when OnIdle is called, and so on.
 %%event to the application object. This will occur in a loop until either a user event is found to be
 %%pending, or OnIdle requests no more time. Then all pending user events are processed until the system
 %%goes idle again, when OnIdle is called, and so on.


@@ -407,7 +443,6 @@ work and, in fact, probably won't.
 %%\helpref{wxWindow::Close}{wxwindowclose},\rtfsp
 %%\helpref{wxWindow::OnCloseWindow}{wxwindowonclosewindow},\rtfsp
 %%\helpref{wxCloseEvent}{wxcloseevent},\rtfsp
 %%\helpref{wxWindow::Close}{wxwindowclose},\rtfsp
 %%\helpref{wxWindow::OnCloseWindow}{wxwindowonclosewindow},\rtfsp
 %%\helpref{wxCloseEvent}{wxcloseevent},\rtfsp

-%%\helpref{wxApp::OnQueryEndSession}{wxapponqueryendsession}

 
 
 \membersection{wxApp::OnInit}\label{wxapponinit}
 
 
 \membersection{wxApp::OnInit}\label{wxapponinit}


@@ -416,13 +451,16 @@ work and, in fact, probably won't.
 
 This must be provided by the application, and will usually create the
 application's main window, optionally calling 
 
 This must be provided by the application, and will usually create the
 application's main window, optionally calling 

-\helpref{wxApp::SetTopWindow}{wxappsettopwindow}.
+\helpref{wxApp::SetTopWindow}{wxappsettopwindow}. You may use 
+\helpref{OnExit}{wxapponexit} to clean up anything initialized here, provided
+that the function returns \true.

 
 Notice that if you want to to use the command line processing provided by
 
 Notice that if you want to to use the command line processing provided by

-wxWindows you have to call the base class version in the derived class
+wxWidgets you have to call the base class version in the derived class

 OnInit().
 
 OnInit().
 

-Return true to continue processing, false to exit the application.
+Return \true to continue processing, \false to exit the application
+immediately.

 
 
 \membersection{wxApp::OnInitCmdLine}\label{wxapponinitcmdline}
 
 
 \membersection{wxApp::OnInitCmdLine}\label{wxapponinitcmdline}


@@ -433,49 +471,11 @@ Called from \helpref{OnInit}{wxapponinit} and may be used to initialize the
 parser with the command line options for this application. The base class
 versions adds support for a few standard options only.
 
 parser with the command line options for this application. The base class
 versions adds support for a few standard options only.
 

-
-\membersection{wxApp::OnQueryEndSession}\label{wxapponqueryendsession}
-
-\func{void}{OnQueryEndSession}{\param{wxCloseEvent\& }{event}}
-
-This is an event handler function called when the operating system or GUI session is
-about to close down. Typically, an application will try to save unsaved documents
-at this point.
-
-If \helpref{wxCloseEvent::CanVeto}{wxcloseeventcanveto} returns true, the application
-is allowed to veto the shutdown by calling \helpref{wxCloseEvent::Veto}{wxcloseeventveto}.
-The application might veto the shutdown after prompting for documents to be saved, and the
-user has cancelled the save.
-
-Use the EVT\_QUERY\_END\_SESSION event table macro to handle query end session events.
-
-You should check whether the application is forcing the deletion of the window
-using \helpref{wxCloseEvent::GetForce}{wxcloseeventgetforce}. If this is true,
-destroy the window using \helpref{wxWindow::Destroy}{wxwindowdestroy}.
-If not, it is up to you whether you respond by destroying the window.
-
-The default handler calls \helpref{wxWindow::Close}{wxwindowclose} on the top-level window,
-and vetoes the shutdown if Close returns false. This will be sufficient for many applications.
-
-\wxheading{Remarks}
-
-Under X, OnQueryEndSession is called in response to the `save session' event.
-
-Under Windows, OnQueryEndSession is called in response to the WM\_QUERYENDSESSION message.
-
-\wxheading{See also}
-
-\helpref{wxWindow::Close}{wxwindowclose},\rtfsp
-\helpref{wxCloseEvent}{wxcloseevent}
-%% GD: OnXXX functions are not documented
-%%\helpref{wxApp::OnEndSession}{wxapponendsession}
-
-

 \membersection{wxApp::OnRun}\label{wxapponrun}
 
 \func{virtual int}{OnRun}{\void}
 
 \membersection{wxApp::OnRun}\label{wxapponrun}
 
 \func{virtual int}{OnRun}{\void}
 

-This virtual function is where the execution of a program written in wxWindows
+This virtual function is where the execution of a program written in wxWidgets

 starts. The default implementation just enters the main loop and starts
 handling the events until it terminates, either because 
 \helpref{ExitMainLoop}{wxappexitmainloop} has been explicitly called or because
 starts. The default implementation just enters the main loop and starts
 handling the events until it terminates, either because 
 \helpref{ExitMainLoop}{wxappexitmainloop} has been explicitly called or because


@@ -483,6 +483,9 @@ the last frame has been deleted and
 \helpref{GetExitOnFrameDelete}{wxappgetexitonframedelete} flag is \true (this
 is the default).
 
 \helpref{GetExitOnFrameDelete}{wxappgetexitonframedelete} flag is \true (this
 is the default).
 

+The return value of this function becomes the exit code of the program, so it
+should return $0$ in case of successful termination.
+

 
 \membersection{wxApp::OnUnhandledException}\label{wxapponunhandledexception}
 
 
 \membersection{wxApp::OnUnhandledException}\label{wxapponunhandledexception}
 


@@ -503,14 +506,14 @@ try/catch clause around the call to the base class version there.
 Windows-only function for processing a message. This function
 is called from the main message loop, checking for windows that
 may wish to process it. The function returns true if the message
 Windows-only function for processing a message. This function
 is called from the main message loop, checking for windows that
 may wish to process it. The function returns true if the message

-was processed, false otherwise. If you use wxWindows with another class
+was processed, false otherwise. If you use wxWidgets with another class

 library with its own message loop, you should make sure that this
 library with its own message loop, you should make sure that this

-function is called to allow wxWindows to receive messages. For example,
+function is called to allow wxWidgets to receive messages. For example,

 to allow co-existence with the Microsoft Foundation Classes, override
 the PreTranslateMessage function:
 
 \begin{verbatim}
 to allow co-existence with the Microsoft Foundation Classes, override
 the PreTranslateMessage function:
 
 \begin{verbatim}

-// Provide wxWindows message loop compatibility
+// Provide wxWidgets message loop compatibility

 BOOL CTheApp::PreTranslateMessage(MSG *msg)
 {
   if (wxTheApp && wxTheApp->ProcessMessage((WXMSW *)msg))
 BOOL CTheApp::PreTranslateMessage(MSG *msg)
 {
   if (wxTheApp && wxTheApp->ProcessMessage((WXMSW *)msg))


@@ -523,7 +526,7 @@ BOOL CTheApp::PreTranslateMessage(MSG *msg)
 
 \membersection{wxApp::Pending}\label{wxapppending}
 
 
 \membersection{wxApp::Pending}\label{wxapppending}
 

-\func{bool}{Pending}{\void}
+\func{virtual bool}{Pending}{\void}

 
 Returns true if unprocessed events are in the window system event queue.
 
 
 Returns true if unprocessed events are in the window system event queue.
 


@@ -534,14 +537,13 @@ Returns true if unprocessed events are in the window system event queue.
 
 \membersection{wxApp::SendIdleEvents}\label{wxappsendidleevents}
 
 
 \membersection{wxApp::SendIdleEvents}\label{wxappsendidleevents}
 

-\func{bool}{SendIdleEvents}{\void}
-
-Sends idle events to all top-level windows.
-
-\func{bool}{SendIdleEvents}{\param{wxWindow*}{ win}}
+\func{bool}{SendIdleEvents}{\param{wxWindow*}{ win}, \param{wxIdleEvent\& }{event}}

 
 Sends idle events to a window and its children.
 
 
 Sends idle events to a window and its children.
 

+Please note that this function is internal to wxWidgets and shouldn't be used
+by user code.
+

 \wxheading{Remarks}
 
 These functions poll the top-level windows, and their children, for idle event processing.
 \wxheading{Remarks}
 
 These functions poll the top-level windows, and their children, for idle event processing.


@@ -549,8 +551,6 @@ If true is returned, more OnIdle processing is requested by one or more window.
 
 \wxheading{See also}
 
 
 \wxheading{See also}
 

-%% GD: OnXXX functions are not documented
-%%\helpref{wxApp::OnIdle}{wxapponidle}

 \helpref{wxIdleEvent}{wxidleevent}
 
 
 \helpref{wxIdleEvent}{wxidleevent}
 
 


@@ -560,33 +560,13 @@ If true is returned, more OnIdle processing is requested by one or more window.
 
 Sets the name of the application. The name may be used in dialogs
 (for example by the document/view framework). A default name is set by
 
 Sets the name of the application. The name may be used in dialogs
 (for example by the document/view framework). A default name is set by

-wxWindows.
+wxWidgets.

 
 \wxheading{See also}
 
 \helpref{wxApp::GetAppName}{wxappgetappname}
 
 
 
 \wxheading{See also}
 
 \helpref{wxApp::GetAppName}{wxappgetappname}
 
 

-\membersection{wxApp::SetAuto3D}\label{wxappsetauto3d}
-
-\func{void}{SetAuto3D}{\param{const bool}{ auto3D}}
-
-Switches automatic 3D controls on or off.
-
-\wxheading{Parameters}
-
-\docparam{auto3D}{If true, all controls will be created with 3D appearances unless
-overridden for a control or dialog. The default is true}
-
-\wxheading{Remarks}
-
-This has an effect on Windows only.
-
-\wxheading{See also}
-
-\helpref{wxApp::GetAuto3D}{wxappgetauto3d}
-
-

 \membersection{wxApp::SetClassName}\label{wxappsetclassname}
 
 \func{void}{SetClassName}{\param{const wxString\& }{name}}
 \membersection{wxApp::SetClassName}\label{wxappsetclassname}
 
 \func{void}{SetClassName}{\param{const wxString\& }{name}}


@@ -617,15 +597,31 @@ deleted. If false, the application will continue to run.}
 \helpref{wxApp shutdown overview}{wxappshutdownoverview}
 
 
 \helpref{wxApp shutdown overview}{wxappshutdownoverview}
 
 

+\membersection{wxApp::SetInstance}\label{wxappsetinstance}
+
+\func{static void}{SetInstance}{\param{wxAppConsole* }{app}}
+
+Allows external code to modify global \texttt{wxTheApp}, but you should really
+know what you're doing if you call it.
+
+\wxheading{Parameters}
+
+\docparam{app}{Replacement for the global application object.}
+
+\wxheading{See also}
+
+\helpref{wxApp::GetInstance}{wxappgetinstance}
+
+

 \membersection{wxApp::SetTopWindow}\label{wxappsettopwindow}
 
 \func{void}{SetTopWindow}{\param{wxWindow* }{window}}
 
 Sets the `top' window. You can call this from within \helpref{wxApp::OnInit}{wxapponinit} to
 \membersection{wxApp::SetTopWindow}\label{wxappsettopwindow}
 
 \func{void}{SetTopWindow}{\param{wxWindow* }{window}}
 
 Sets the `top' window. You can call this from within \helpref{wxApp::OnInit}{wxapponinit} to

-let wxWindows know which is the main window. You don't have to set the top window;
+let wxWidgets know which is the main window. You don't have to set the top window;

 it is only a convenience so that (for example) certain dialogs without parents can use a
 specific window as the top window. If no top window is specified by the application,
 it is only a convenience so that (for example) certain dialogs without parents can use a
 specific window as the top window. If no top window is specified by the application,

-wxWindows just uses the first frame or dialog in its top-level window list, when it
+wxWidgets just uses the first frame or dialog in its top-level window list, when it

 needs to use the top window.
 
 \wxheading{Parameters}
 needs to use the top window.
 
 \wxheading{Parameters}


@@ -644,7 +640,7 @@ needs to use the top window.
 
 Sets the name of application's vendor. The name will be used
 in registry access. A default name is set by
 
 Sets the name of application's vendor. The name will be used
 in registry access. A default name is set by

-wxWindows.
+wxWidgets.

 
 \wxheading{See also}
 
 
 \wxheading{See also}
 


@@ -703,7 +699,7 @@ messages immediately (otherwise it will be done during the next idle loop
 iteration), call \helpref{wxLog::FlushActive}{wxlogflushactive}.
 
 Calling Yield() recursively is normally an error and an assert failure is
 iteration), call \helpref{wxLog::FlushActive}{wxlogflushactive}.
 
 Calling Yield() recursively is normally an error and an assert failure is

-raised in debug build if such situation is detected. However if the the 
+raised in debug build if such situation is detected. However if the 

 {\it onlyIfNeeded} parameter is {\tt true}, the method will just silently
 return {\tt false} instead.
 
 {\it onlyIfNeeded} parameter is {\tt true}, the method will just silently
 return {\tt false} instead.