Source Code for Module node_manager_fkie.supervised_popen

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  3  # Copyright (c) 2012, Fraunhofer FKIE/US, Alexander Tiderko 
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 32   
 33  from python_qt_binding.QtCore import QObject, Signal 
 34  try: 
 35      from python_qt_binding.QtGui import QMessageBox 
 36  except: 
 37      from python_qt_binding.QtWidgets import QMessageBox 
 38  import subprocess 
 39  import threading 
 40   
 41  from .detailed_msg_box import WarningMessageBox 
 42   
 43   
 44 -class SupervisedPopen(QObject): 
 45      ''' 
 46      The class overrides the subprocess.Popen and waits in a thread for its finish. 
 47      If an error is printed out, it will be shown in a message dialog. 
 48      ''' 
 49      error = Signal(str, str, str) 
 50      '''@ivar: the signal is emitted if error output was detected (id, decription, message)''' 
 51   
 52      finished = Signal(str) 
 53      '''@ivar: the signal is emitted on exit (id)''' 
 54   
 55 -    def __init__(self, args, bufsize=0, executable=None, stdin=None, stdout=None, 
 56                   stderr=subprocess.PIPE, preexec_fn=None, close_fds=False, 
 57                   shell=False, cwd=None, env=None, universal_newlines=False, 
 58                   startupinfo=None, creationflags=0, object_id='', description=''): 
 59          ''' 
 60          For arguments see https://docs.python.org/2/library/subprocess.html 
 61          Additional arguments: 
 62          :param object_id: the identification string of this object and title of the 
 63          error message dialog 
 64          :type object_id: str 
 65          :param description: the description string used as addiotional information 
 66          in dialog if an error was occured 
 67          :type description: str 
 68          ''' 
 69          try: 
 70              QObject.__init__(self) 
 71              self._args = args 
 72              self._object_id = object_id 
 73              self._description = description 
 74              self.error.connect(self.on_error) 
 75              # wait for process to avoid 'defunct' processes 
 76              self.popen = subprocess.Popen(args=args, bufsize=bufsize, executable=executable, stdin=stdin, stdout=stdout, 
 77                                            stderr=stderr, preexec_fn=preexec_fn, close_fds=close_fds, shell=shell, cwd=cwd, env=env, 
 78                                            universal_newlines=universal_newlines, startupinfo=startupinfo, creationflags=creationflags) 
 79              thread = threading.Thread(target=self._supervise) 
 80              thread.setDaemon(True) 
 81              thread.start() 
 82          except Exception as _: 
 83              raise 
 84   
 85  #   def __del__(self): 
 86  #     print "Deleted:", self._description 
 87   
 88      @property 
 89 -    def stdout(self): 
 90          return self.popen.stdout 
 91   
 92      @property 
 93 -    def stderr(self): 
 94          return self.popen.stderr 
 95   
 96      @property 
 97 -    def stdin(self): 
 98          return self.popen.stdin 
 99   
100 -    def _supervise(self): 
101          ''' 
102          Wait for process to avoid 'defunct' processes 
103          ''' 
104          self.popen.wait() 
105          result_err = '' 
106          if self.stderr is not None: 
107              result_err = self.stderr.read() 
108          if result_err: 
109              self.error.emit(self._object_id, self._description, result_err) 
110          self.finished.emit(self._object_id) 
111   
112 -    def on_error(self, object_id, descr, msg): 
113          WarningMessageBox(QMessageBox.Warning, object_id, '%s\n\n' 
114                            '%s' % (descr, msg), ' '.join(self._args)).exec_() 
115