Mercurial Repositories > eric / file comparison
comparison: Utilities/SingleApplication.py
Utilities/SingleApplication.py
- changeset 2087
- 795992a5c561
- parent 2085
- b4c1f0b6dac2
- child 2088
- 73a2ca4ac409
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| 2085:b4c1f0b6dac2 | 2087:795992a5c561 |
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| 1 # -*- coding: utf-8 -*- | |
| 2 | |
| 3 # Copyright (c) 2004 - 2012 Detlev Offenbach <detlev@die-offenbachs.de> | |
| 4 # | |
| 5 | |
| 6 """ | |
| 7 Module implementing the single application server and client. | |
| 8 """ | |
| 9 | |
| 10 from PyQt4.QtNetwork import QLocalServer, QLocalSocket | |
| 11 | |
| 12 | |
| 13 class SingleApplicationServer(QLocalServer): | |
| 14 """ | |
| 15 Class implementing the single application server base class. | |
| 16 """ | |
| 17 def __init__(self, name): | |
| 18 """ | |
| 19 Constructor | |
| 20 | |
| 21 @param name name this server is listening to (string) | |
| 22 """ | |
| 23 super().__init__() | |
| 24 | |
| 25 res = self.listen(name) | |
| 26 if not res: | |
| 27 # maybe it crashed last time | |
| 28 self.removeServer(name) | |
| 29 self.listen(name) | |
| 30 | |
| 31 self.newConnection[()].connect(self.__newConnection) | |
| 32 | |
| 33 self.qsock = None | |
| 34 | |
| 35 def __newConnection(self): | |
| 36 """ | |
| 37 Private slot to handle a new connection. | |
| 38 """ | |
| 39 sock = self.nextPendingConnection() | |
| 40 | |
| 41 # If we already have a connection, refuse this one. It will be closed | |
| 42 # automatically. | |
| 43 if self.qsock is not None: | |
| 44 return | |
| 45 | |
| 46 self.qsock = sock | |
| 47 | |
| 48 self.qsock.readyRead[()].connect(self.__parseLine) | |
| 49 self.qsock.disconnected[()].connect(self.__disconnected) | |
| 50 | |
| 51 def __parseLine(self): | |
| 52 """ | |
| 53 Private method to handle data from the client. | |
| 54 """ | |
| 55 while self.qsock and self.qsock.canReadLine(): | |
| 56 line = bytes(self.qsock.readLine()).decode() | |
| 57 | |
| 58 ## print(line) ##debug | |
| 59 | |
| 60 eoc = line.find('<') + 1 | |
| 61 | |
| 62 boc = line.find('>') | |
| 63 if boc >= 0 and eoc > boc: | |
| 64 # handle the command sent by the client. | |
| 65 cmd = line[boc:eoc] | |
| 66 params = line[eoc:-1] | |
| 67 | |
| 68 self.handleCommand(cmd, params) | |
| 69 | |
| 70 def __disconnected(self): | |
| 71 """ | |
| 72 Private method to handle the closure of the socket. | |
| 73 """ | |
| 74 self.qsock = None | |
| 75 | |
| 76 def shutdown(self): | |
| 77 """ | |
| 78 Public method used to shut down the server. | |
| 79 """ | |
| 80 if self.qsock is not None: | |
| 81 self.qsock.readyRead[()].disconnect(self.__parseLine) | |
| 82 self.qsock.disconnected.disconnect(self.__disconnected) | |
| 83 | |
| 84 self.qsock = None | |
| 85 | |
| 86 self.close() | |
| 87 | |
| 88 def handleCommand(self, cmd, params): | |
| 89 """ | |
| 90 Public slot to handle the command sent by the client. | |
| 91 | |
| 92 <b>Note</b>: This method must be overridden by subclasses. | |
| 93 | |
| 94 @param cmd commandstring (string) | |
| 95 @param params parameterstring (string) | |
| 96 """ | |
| 97 raise RuntimeError("'handleCommand' must be overridden") | |
| 98 | |
| 99 | |
| 100 class SingleApplicationClient(object): | |
| 101 """ | |
| 102 Class implementing the single application client base class. | |
| 103 """ | |
| 104 def __init__(self, name): | |
| 105 """ | |
| 106 Constructor | |
| 107 | |
| 108 @param name name of the local server to connect to (string) | |
| 109 """ | |
| 110 self.name = name | |
| 111 self.connected = False | |
| 112 | |
| 113 def connect(self): | |
| 114 """ | |
| 115 Public method to connect the single application client to its server. | |
| 116 | |
| 117 @return value indicating success or an error number. Value is one of: | |
| 118 <table> | |
| 119 <tr><td>0</td><td>No application is running</td></tr> | |
| 120 <tr><td>1</td><td>Application is already running</td></tr> | |
| 121 </table> | |
| 122 """ | |
| 123 self.sock = QLocalSocket() | |
| 124 self.sock.connectToServer(self.name) | |
| 125 if self.sock.waitForConnected(10000): | |
| 126 self.connected = True | |
| 127 return 1 | |
| 128 else: | |
| 129 err = self.sock.error() | |
| 130 if err == QLocalSocket.ServerNotFoundError: | |
| 131 return 0 | |
| 132 else: | |
| 133 return -err | |
| 134 | |
| 135 def disconnect(self): | |
| 136 """ | |
| 137 Public method to disconnect from the Single Appliocation server. | |
| 138 """ | |
| 139 self.sock.disconnectFromServer() | |
| 140 self.connected = False | |
| 141 | |
| 142 def processArgs(self, args): | |
| 143 """ | |
| 144 Public method to process the command line args passed to the UI. | |
| 145 | |
| 146 <b>Note</b>: This method must be overridden by subclasses. | |
| 147 | |
| 148 @param args command line args (list of strings) | |
| 149 """ | |
| 150 raise RuntimeError("'processArgs' must be overridden") | |
| 151 | |
| 152 def sendCommand(self, cmd): | |
| 153 """ | |
| 154 Public method to send the command to the application server. | |
| 155 | |
| 156 @param cmd command to be sent (string) | |
| 157 """ | |
| 158 if self.connected: | |
| 159 self.sock.write(cmd) | |
| 160 self.sock.flush() | |
| 161 | |
| 162 def errstr(self): | |
| 163 """ | |
| 164 Public method to return a meaningful error string for the last error. | |
| 165 | |
| 166 @return error string for the last error (string) | |
| 167 """ | |
| 168 return self.sock.errorString() |
