wxWidgets/docs/latex/wx/snglinst.tex
2002-04-02 10:26:50 +00:00

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%% Name: snglinst.tex
%% Purpose: wxSingleInstanceChecker documentation
%% Author: Vadim Zeitlin
%% Modified by:
%% Created: 08.06.01
%% RCS-ID: $Id$
%% Copyright: (c) 2001 Vadim Zeitlin
%% License: wxWindows license
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{\class{wxSingleInstanceChecker}}\label{wxsingleinstancechecker}
wxSingleInstanceChecker class allows to check that only a single instance of a
program is running. To do it, you should create an object of this class. As
long as this object is alive, calls to
\helpref{IsAnotherRunning()}{wxsingleinstancecheckerisanotherrunning} from
other processes will return {\tt TRUE}.
As the object should have the life span as big as possible, it makes sense to
create it either as a global or in \helpref{wxApp::OnInit}{wxapponinit}. For
example:
\begin{verbatim}
bool MyApp::OnInit()
{
m_checker = new wxSingleInstanceChecker(GetAppName());
if ( m_checker->IsAnotherRunning() )
{
wxLogError(_("Another program instance is already running, aborting."));
return FALSE;
}
... more initializations ...
return TRUE;
}
int MyApp::OnExit()
{
delete m_checker;
return 0;
}
\end{verbatim}
This class is implemented for Win32 and Unix platforms supporting {\tt fcntl()}
system call only.
\wxheading{Derived from}
No base class
\wxheading{Include files}
<wx/snglinst.h>
\latexignore{\rtfignore{\wxheading{Members}}}
\membersection{wxSingleInstanceChecker::wxSingleInstanceChecker}\label{wxsingleinstancecheckerctor}
\func{}{wxSingleInstanceChecker}{\void}
Default ctor, use \helpref{Create()}{wxsingleinstancecheckercreate} after it.
\membersection{wxSingleInstanceChecker::wxSingleInstanceChecker}\label{wxsingleinstancecheckerwxsingleinstancechecker}
\func{}{wxSingleInstanceChecker}{\param{const wxString\& }{name}, \param{const wxString\& }{path = wxEmptyString}}
Like \helpref{Create()}{wxsingleinstancecheckercreate} but without
error checking.
\membersection{wxSingleInstanceChecker::Create}\label{wxsingleinstancecheckercreate}
\func{bool}{Create}{\param{const wxString\& }{name}, \param{const wxString\& }{path = wxEmptyString}}
Initialize the object if it had been created using the default constructor.
Note that you can't call Create() more than once, so calling it if the
\helpref{non default ctor}{wxsingleinstancecheckerwxsingleinstancechecker}
had been used is an error.
\wxheading{Parameters}
\docparam{name}{must be given and be as unique as possible. It is used as the
mutex name under Win32 and the lock file name under Unix.
\helpref{GetAppName()}{wxappgetappname} may be a good value for this parameter}
\docparam{path}{is optional and is ignored under Win32 and used as the directory to
create the lock file in under Unix (default is
\helpref{wxGetHomeDir()}{wxgethomedir})}
\wxheading{Return value}
Returns {\tt FALSE} if initialization failed, it doesn't mean that another
instance is running - use
\helpref{IsAnotherRunning()}{wxsingleinstancecheckerisanotherrunning} to check
for it.
\membersection{wxSingleInstanceChecker::IsAnotherRunning}\label{wxsingleinstancecheckerisanotherrunning}
\constfunc{bool}{IsAnotherRunning}{\void}
Returns {\tt TRUE} if another copy of this program is already running, {\tt
FALSE} otherwise.
\membersection{wxSingleInstanceChecker::\destruct{wxSingleInstanceChecker}}\label{wxsingleinstancecheckerdtor}
\func{}{\destruct{wxSingleInstanceChecker}}{\void}
Destructor frees the associated resources.
Note that it is not virtual, this class is not meant to be used polymorphically