Qt Single Instance solution for pyside QT 4.7

It is said that QT originally had such a thing as qtsolution, and later updates were not timely.

No corresponding QT 4.7 version.

Google found that there was an antidote on the pyside official website.

Http://developer.qt.nokia.com/forums/viewthread/5733

The following is a general solution description.

// Try to connect to your server
M_socket = qlocalsocket ()
M_socket.connecttoserver (qapp. applicationname (), qiodevice. readonly)

// If this fail is because the app is not running then create the server, then in the next time the connect will work
M_server = qlocalserver ()
M_server = qlocalserver. Listen (qapp. applicationname ())

Try a full version later.

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Let's take a closer look at the last line of the page. someone already has a solution.

Http://www.dallagnese.fr/en/computers-it/recette-python-qt4-qsingleapplication-pyside/

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 """ 
The MIT license

Copyright 2011 Thomas Dall 'agnese <thomas.dallagnese@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
Of this software and associated documentation files (the "software"), to deal
In the software without restriction, including without limitation the rights
To use, copy, modify, merge, publish, distribute, sublicense, and/or decrypt
Copies of the software, and to permit persons to whom the software is
Furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be supported in
All copies or substantial portions of the software.

The software is provided "as is", without warranty of any kind, express or
Implied, including but not limited to the warranties of merchantability,
Fitness for a particle purpose and noninfringement. In no event shall
Authors or copyright holders be liable for any claim, damages or other
Liability, whether in an action of contract, tort or otherwise, arising from,
Out of or in connection with the software or the use or other dealings in
The software.

 """  
 _ Author __     =     "  Thomas Dall 'agnese  "  
  _ Email __     =     "  Thomas.dallagnese@gmail.com  "  
  _ Version __    =     "  1.0  "  
  _ URL __     =     "  Http://www.dallagnese.fr  "  

  From  Pyside. qtgui Import  Qmessagebox, qapplication
  From  Pyside. qtcore  Import  Qiodevice, qtimer, qcoreapplication
  From  Pyside. qtnetwork  Import  Qlocalserver, qlocalsocket
  Import  Sys

  Class  Qsingleapplication (qapplication ):
  Def Singlestart (self, mainwindow ):
Self. mainwindow  =  Mainwindow
  #  Socket  
  Self. m_socket  =  Qlocalsocket ()
Self. m_socket.connected.connect (self. connecttoexistingapp)
Self. m_socket.error.connect (self. startapplication)
Self. m_socket.connecttoserver (self. applicationname (), qiodevice. writeonly)
  Def  Connecttoexistingapp (Self ):
  If Len (SYS. argv)  >  1     And  SYS. argv [  1  ]  Is     Not  None:
Self. m_socket.write (SYS. argv [  1  ])
Self. m_socket.byteswritten.connect (self. Quit)
  Else :
Qmessagebox. Warning (none, self. tr (  "  Already running  "  ), Self. tr (  "  The program is already running.  "  ))
  #  Quit application in 250 MS  
  Qtimer. singleshot (  250  , Self. Quit)
 Def  Startapplication (Self ):
Self. m_server  =  Qlocalserver ()
  If  Self. m_server.listen (self. applicationname ()):
Self. m_server.newconnection.connect (self. getnewconnection)
Self. mainwindow. Show ()
  Else  :
Qmessagebox. Critical (none, self. tr (  "  Error  "  ), Self. tr (  " Error listening the socket.  "  ))
  Def  Getnewconnection (Self ):
Self. new_socket  =  Self. m_server.nextpendingconnection ()
Self. new_socket.readyread.connect (self. readsocket)
  Def  Readsocket (Self ):
F  =  Self. new_socket.readline ()
Self. mainwindow. getargsfromotherinstance (STR (f ))
Self. mainwindow. activatewindow ()
Self. mainwindow. Show ()

 If     _ Name __     =     '  _ Main __  '  :
  From  Pyside. qtgui  Import  Qmainwindow, qlabel
  Class  Dallagnesewindow (qmainwindow ):
  Def    _ Init __  (Self ):
Qmainwindow.  _ Init __  (Self)
Self. setwindowtitle (  "  Qsingleapplication demo  "  )
Labeltext  =     " <B> dallagnese. fr recipe </B> <br/> \
Allows you to start your program only once. <br/> \
Parameters of later cballs can be handled by this application.  "  
Self. setcentralwidget (qlabel (labeltext ))
  Def  Getargsfromotherinstance (self, argS ):
Qmessagebox. Information (self, self. tr (  "  Received ARGs from another instance  "  ), ArgS)
App  = Qsingleapplication (SYS. argv)
App. setapplicationname (  "  Dallagnese. fr recipe 01  "  )
Mywindow  =  Dallagnesewindow ()
App. singlestart (mywindow)
Sys.exit(app.exe C _())