Source Code for Module AccessEngine.AEMain'

  1  ''' 
  2  Defines C{AEMain} which runs the main program loop. 
  3   
  4  @author: Peter Parente 
  5  @organization: IBM Corporation 
  6  @copyright: Copyright (c) 2005, 2007 IBM Corporation 
  7   
  8  @author: Frank Zenker 
  9  @author: Ramona Bunk 
 10  @organization: IT Science Center Ruegen gGmbH, Germany 
 11  @copyright: Copyright (c) 2007, 2008 ITSC Ruegen 
 12   
 13  @license: I{The BSD License} 
 14  All rights reserved. This program and the accompanying materials are made 
 15  available under the terms of the BSD license which accompanies 
 16  this distribution, and is available at 
 17  U{http://www.opensource.org/licenses/bsd-license.php} 
 18  ''' 
 19  import gobject, bonobo 
 20  import AccessEngine 
 21  import time, signal, logging 
 22  from Tools.i18n import _ 
 23   
 24  log = logging.getLogger('AccessEngine.AEMain') 
 25   
 26 -class _AEMain(object): 
 27    ''' 
 28    Starts the main bonobo loop so that AT-SPI events are received and GUI monitors 
 29    function properly.  
 30     
 31    Allows clients to register for callbacks from the main loop on a set interval. 
 32     
 33    @ivar callbacks: Callback IDs for functions to invoke on timers or idle using 
 34      gobject 
 35    @type callbacks: dictionary 
 36    @ivar welcome: Output an introductory message when the engine starts? 
 37    @type welcome: boolean 
 38    @ivar alive: alive flag 
 39    @type alive: boolean 
 40    ''' 
 41 -  def __init__(self): 
 42      ''' 
 43      Create an C{AEMain} Object. 
 44      ''' 
 45      self.callbacks = {} 
 46      self.alive = False 
 47      self.welcome = None 
 48     
 49 -  def _init(self, profile, application_state): 
 50      ''' 
 51      Calls init on each manager.  
 52       
 53      Manager: 
 54      L{AEDeviceManager <AEDeviceManger._AEDeviceManager>},  
 55      L{AEEventManager <AEEventManger._AEEventManager>}, 
 56      L{AESettingsManager <AESettingsManger._AESettingsManager>}, 
 57      L{AETierManager <AETierManger._AETierManager>}, 
 58      L{AEViewManager <AEViewManger._AEViewManager>} 
 59       
 60      Called implicitly by L{run}. 
 61       
 62      @param profile: Name of the profile SUE was executed under 
 63      @type profile: string 
 64      @param application_state: defines the settings for this application 
 65      @type application_state: L{AESate <AEState.AEState>} 
 66      ''' 
 67      # init the managers, in correct dependency order     
 68      AccessEngine.AESettingsManager.init(profile) 
 69      AccessEngine.AEEventManager.init() 
 70      AccessEngine.AEViewManager.init() 
 71      AccessEngine.AETierManager.init(application_state) 
 72      AccessEngine.AEDeviceManager.init() 
 73       
 74      # have the device manager speak a welcome message 
 75      if self.welcome: 
 76        AccessEngine.AEDeviceManager.sendWelcome() 
 77      # get rid of any events that leak through while we are starting up 
 78      AccessEngine.AEEventManager.flushEvents() 
 79      # tell the view manager to locate the active view and inform the tier  
 80      # manager about running applications 
 81      AccessEngine.AEViewManager.initViews() 
 82       
 83 -  def _close(self): 
 84      ''' 
 85      Shuts down all managers.  
 86       
 87      Called implicitly by L{run} when the main loop ends. Sends an exiting  
 88      message to the default device. 
 89      ''' 
 90      if self.welcome: 
 91        AccessEngine.AEDeviceManager.sendGoodbye() 
 92      AccessEngine.AETierManager.close() 
 93      AccessEngine.AEViewManager.close() 
 94      AccessEngine.AEEventManager.close() 
 95      AccessEngine.AESettingsManager.close() 
 96      AccessEngine.AEDeviceManager.close() 
 97       
 98 -  def quit(self, *args): 
 99      ''' 
100      Stops the event loop by calling the C{pyatspi.Registry.stop} function. 
101       
102      Extra parameters are ignored but captured by args so that this method may  
103      be registered as a signal handler callback. 
104      ''' 
105      return AccessEngine.AEEventManager.stopAccessibility() 
106     
107 -  def addTimer(self, callback, ms=None, *args): 
108      ''' 
109      Creates a timer that calls the given callback on the interval specified by 
110      the given milliseconds. If C{ms} is None, registers for callbacks on idle. 
111   
112      @param callback: Function to call 
113      @type callback: callable 
114      @param ms: interval in milliseconds 
115      @type ms: integer 
116      @param args: Additional arguments to be given to the callback 
117      @type args: list 
118      ''' 
119      if ms is not None: 
120        cid = gobject.timeout_add(ms, callback, *args) 
121      else: 
122        cid = gobject.idle_add(ms, callback, *args) 
123      self.callbacks[callback] = cid 
124   
125 -  def removeTimer(self, callback): 
126      ''' 
127      Ceases calls to the given registered callback. 
128   
129      @param callback: Function to stop calling 
130      @type callback: callable 
131      @raise KeyError: When the callback is not registered 
132      ''' 
133      cid = self.callbacks[callback] 
134      gobject.source_remove(cid) 
135   
136 -  def run(self, profile, welcome, application_state): 
137      ''' 
138      Starts an event loop by calling the C{pyatspi.Registry.start} function. 
139       
140      Makes the timer callbacks registered via L{addTimer} on each iteration of  
141      the loop. 
142       
143      @param profile: Name of the profile SUE was executed under 
144      @type profile: string 
145      @param welcome: Output an introductory message? 
146      @type welcome: boolean 
147      @param application_state: defines the settings for this application 
148      @type application_state: L{AESate <AEState.AEState>} 
149      ''' 
150      # set the alive flag to true 
151      self.alive = True 
152       
153      # register a signal handler for gracefully killing the loop 
154      signal.signal(signal.SIGINT, self.quit) 
155      signal.signal(signal.SIGTERM, self.quit) 
156       
157      # initialize all managers 
158      self.welcome = welcome 
159      self._init(profile, application_state) 
160       
161      # now start the loop 
162      AccessEngine.AEEventManager.startAccessibility(async=True, gil=True) 
163       
164      # cleanup callbacks 
165      for c in self.callbacks: 
166        self.removeTimer(c) 
167       
168      # uninitialize all managers 
169      self._close() 
170       
171      # state that we are trying to quit 
172      log.info('exiting...') 
173      # make sure any other threads get a chance to run to completion 
174      time.sleep(1) 
175