Source Code for Module node_manager_fkie.file_watcher'

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  3  # Copyright (c) 2012, Fraunhofer FKIE/US, Alexander Tiderko 
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 32   
 33  import os 
 34  import time 
 35  import rospy 
 36  import roslib 
 37   
 38  try: 
 39    from python_qt_binding import QtCore 
 40  except: 
 41    pass 
 42   
 43 -class FileWatcher(QtCore.QObject): 
 44    ''' 
 45    A class to watch for file changes. 
 46    ''' 
 47    file_changed = QtCore.Signal(str, list) 
 48    '''@ivar: a signal to inform the receiver about the changes on 
 49    launch file or included file. ParameterB{:} (changed file, list of tuples(masteruri, launch file))''' 
 50     
 51 -  def __init__(self): 
 52      QtCore.QObject.__init__(self) 
 53      self.file_watcher = QtCore.QFileSystemWatcher() 
 54      self.file_watcher.fileChanged.connect(self.on_file_changed) 
 55      self.changed = {} 
 56      self.launches = {} 
 57   
 58 -  def __del__(self): 
 59      # Delete to avoid segfault if the LaunchConfig class is destroyed recently  
 60      # after creation and xmlrpclib.ServerProxy process a method call. 
 61      del self.file_watcher 
 62   
 63 -  def on_file_changed(self, file): 
 64      ''' 
 65      callback method, which is called by L{QtCore.QFileSystemWatcher} if the  
 66      launch file or included files are changed. In this case  
 67      L{FileWatcher.file_changed} signal will be emitted. 
 68      ''' 
 69      # to avoid to handle from QFileSystemWatcher fired the signal two times 
 70      if (not self.changed.has_key(file) or (self.changed.has_key(file) and self.changed[file] + 0.05 < time.time())): 
 71        self.changed[file] = time.time() 
 72        changes = [] 
 73        for (uri, lfile, id), files in self.launches.items(): 
 74          if file in files: 
 75            changes.append((uri, lfile)) 
 76        self.file_changed.emit(file, changes) 
 77   
 78 -  def add(self, masteruri, launch_file, launch_id, files): 
 79      if self.launches.has_key((masteruri, launch_file, launch_id)): 
 80        self.launches[(masteruri, launch_file, launch_id)].extend([os.path.normpath(f) for f in files]) 
 81      else: 
 82        self.launches[(masteruri, launch_file, launch_id)] = [os.path.normpath(f) for f in files] 
 83      self.update_files() 
 84   
 85 -  def rem(self, masteruri, launch_file='', launch_id=''): 
 86      try: 
 87        if launch_file: 
 88          if launch_id: 
 89            del self.launches[(masteruri, launch_file, launch_id)] 
 90          else: 
 91            for (uri, file, id), files in self.launches.items(): 
 92              if uri == masteruri and file == launch_file: 
 93                del self.launches[(uri, file, id)] 
 94        else: 
 95          for (uri, file, id), files in self.launches.items(): 
 96            if uri == masteruri: 
 97              del self.launches[(uri, file, id)] 
 98      except: 
 99  #      import traceback 
100  #      print traceback.format_exc() 
101        pass 
102      self.update_files() 
103   
104 -  def update_files(self): 
105      result = set() 
106      for files in self.launches.itervalues(): 
107        result.update(set(files)) 
108      files = self.file_watcher.files() 
109      if files: 
110        self.file_watcher.removePaths(files) 
111      if list(result): 
112        self.file_watcher.addPaths(list(result)) 
113