// Purpose: interface of wxSingleInstanceChecker
// Author: wxWidgets team
// RCS-ID: $Id$
-// Licence: wxWindows license
+// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
/**
@code
bool MyApp::OnInit()
{
- const wxString name = wxString::Format("MyApp-%s", wxGetUserId().c_str());
- m_checker = new wxSingleInstanceChecker(name);
+ m_checker = new wxSingleInstanceChecker;
if ( m_checker-IsAnotherRunning() )
{
wxLogError(_("Another program instance is already running, aborting."));
}
@endcode
- Note using wxGetUserId() to construct the name: this allows different user
- to run the application concurrently which is usually the intended goal.
- If you don't use the user name in the wxSingleInstanceChecker name, only
- one user would be able to run the application at a time.
+ Note that by default wxSingleInstanceChecker::CreateDefault() is used to
+ create the checker meaning that it will be initialized differently for
+ different users and thus will allow different users to run the application
+ concurrently which is usually the required behaviour. However if only a
+ single instance of a program should be running system-wide, you need to
+ call Create() with a custom name which does @em not include wxGetUserId().
This class is implemented for Win32 and Unix platforms (supporting @c fcntl()
system call, but almost all of modern Unix systems do) only.
{
public:
/**
- Default ctor, use Create() after it.
+ Default constructor.
+
+ You may call Create() after using it or directly call
+ IsAnotherRunning() in which case CreateDefault() will be implicitly
+ used.
*/
wxSingleInstanceChecker();
/**
- Like Create() but without error checking.
+ Constructor calling Create().
+
+ This constructor does exactly the same thing as Create() but doesn't
+ allow to check for errors.
*/
wxSingleInstanceChecker(const wxString& name,
const wxString& path = wxEmptyString);
/**
Destructor frees the associated resources.
+
Note that it is not virtual, this class is not meant to be used polymorphically.
*/
~wxSingleInstanceChecker();
/**
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
- @ref wxSingleInstanceChecker() "non default ctor" had been used is an error.
+ non default ctor had been used is an error.
@param 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.
- GetAppName() and wxGetUserId() are commonly used to construct
+ wxApp::GetAppName() and wxGetUserId() are commonly used to construct
this parameter.
@param path
The path is optional and is ignored under Win32 and used as the
directory to create the lock file in under Unix
(default is wxGetHomeDir()).
- @return Returns @false if initialization failed, it doesn't mean that
- another instance is running - use IsAnotherRunning() to check
- for it.
+ @return
+ Returns @false if initialization failed, it doesn't mean that
+ another instance is running -- use IsAnotherRunning() to check for
+ it.
@note
- One of possible reasons while Create may fail on Unix is that the lock
+ One of possible reasons while Create() may fail on Unix is that the lock
file used for checking already exists but was not created by the user.
Therefore applications shouldn't treat failure of this function as fatal
condition, because doing so would open them to the possibility of a
const wxString& path = wxEmptyString);
/**
- Returns @true if another copy of this program is already running, @false
- otherwise.
+ Calls Create() with default name.
+
+ This method simply calls Create() with a string composed of
+ wxApp::GetAppName() and wxGetUserId().
+
+ Because this method uses wxApp::GetAppName(), it may only be called
+ after the global application was constructed.
+
+ @since 2.9.1
+ */
+ bool CreateDefault();
+
+ /**
+ Returns @true if another copy of this program is already running and
+ @false otherwise.
+
+ Notice that if the object was created using the default constructor
+ Create() hadn't been called before this method, it will call
+ CreateDefault() automatically.
*/
bool IsAnotherRunning() const;
};