--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/Utilities/SingleApplication.py Mon Dec 28 16:03:33 2009 +0000
@@ -0,0 +1,169 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2004 - 2009 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing the single application server and client.
+"""
+
+from PyQt4.QtCore import SIGNAL
+from PyQt4.QtNetwork import QLocalServer, QLocalSocket
+
+import Utilities
+
+class SingleApplicationServer(QLocalServer):
+ """
+ Class implementing the single application server base class.
+ """
+ def __init__(self, name):
+ """
+ Constructor
+
+ @param name name this server is listening to (string)
+ """
+ QLocalServer.__init__(self)
+
+ res = self.listen(name)
+ if not res:
+ # maybe it crashed last time
+ self.removeServer(name)
+ self.listen(name)
+
+ self.connect(self, SIGNAL("newConnection()"), self.__newConnection)
+
+ self.qsock = None
+
+ def __newConnection(self):
+ """
+ Private slot to handle a new connection.
+ """
+ sock = self.nextPendingConnection()
+
+ # If we already have a connection, refuse this one. It will be closed
+ # automatically.
+ if self.qsock is not None:
+ return
+
+ self.qsock = sock
+
+ self.connect(self.qsock, SIGNAL('readyRead()'), self.__parseLine)
+ self.connect(self.qsock, SIGNAL('disconnected()'), self.__disconnected)
+
+ def __parseLine(self):
+ """
+ Private method to handle data from the client.
+ """
+ while self.qsock and self.qsock.canReadLine():
+ line = unicode(self.qsock.readLine())
+
+## print line ##debug
+
+ eoc = line.find('<') + 1
+
+ boc = line.find('>')
+ if boc >= 0 and eoc > boc:
+ # handle the command sent by the client.
+ cmd = line[boc:eoc]
+ params = line[eoc:-1]
+
+ self.handleCommand(cmd, params)
+
+ def __disconnected(self):
+ """
+ Private method to handle the closure of the socket.
+ """
+ self.qsock = None
+
+ def shutdown(self):
+ """
+ Public method used to shut down the server.
+ """
+ if self.qsock is not None:
+ self.disconnect(self.qsock, SIGNAL('readyRead()'), self.__parseLine)
+ self.disconnect(self.qsock, SIGNAL('disconnected()'), self.__disconnected)
+
+ self.qsock = None
+
+ self.close()
+
+ def handleCommand(self, cmd, params):
+ """
+ Public slot to handle the command sent by the client.
+
+ <b>Note</b>: This method must be overridden by subclasses.
+
+ @param cmd commandstring (string)
+ @param params parameterstring (string)
+ """
+ raise RuntimeError("'handleCommand' must be overridden")
+
+class SingleApplicationClient(object):
+ """
+ Class implementing the single application client base class.
+ """
+ def __init__(self, name):
+ """
+ Constructor
+
+ @param name name of the local server to connect to (string)
+ """
+ self.name = name
+ self.connected = False
+
+ def connect(self):
+ """
+ Public method to connect the single application client to its server.
+
+ @return value indicating success or an error number. Value is one of:
+ <table>
+ <tr><td>0</td><td>No application is running</td></tr>
+ <tr><td>1</td><td>Application is already running</td></tr>
+ </table>
+ """
+ self.sock = QLocalSocket()
+ self.sock.connectToServer(self.name)
+ if self.sock.waitForConnected(10000):
+ self.connected = True
+ return 1
+ else:
+ err = self.sock.error()
+ if err == QLocalSocket.ServerNotFoundError:
+ return 0
+ else:
+ return -err
+
+ def disconnect(self):
+ """
+ Public method to disconnect from the Single Appliocation server.
+ """
+ self.sock.disconnectFromServer()
+ self.connected = False
+
+ def processArgs(self, args):
+ """
+ Public method to process the command line args passed to the UI.
+
+ <b>Note</b>: This method must be overridden by subclasses.
+
+ @param args command line args (list of strings)
+ """
+ raise RuntimeError("'processArgs' must be overridden")
+
+ def sendCommand(self, cmd):
+ """
+ Public method to send the command to the application server.
+
+ @param cmd command to be sent (string)
+ """
+ if self.connected:
+ self.sock.write(cmd)
+ self.sock.flush()
+
+ def errstr(self):
+ """
+ Public method to return a meaningful error string for the last error.
+
+ @return error string for the last error (string)
+ """
+ return self.sock.errorString()
