AccessEngine

22 ''' 23 Runs the main bonobo loop so that AT-SPI events are received and GUI monitors 24 function properly. Allows clients to register for callbacks from the main loop 25 on a set interval. Maintains a dictionary of managers that can be loaned out 26 to L{Task.Tools} objects 27 28 @ivar callbacks: Callback IDs for functions to invoke on timers or idle using 29 gobject 30 @type callbacks: dictionary 31 @ivar vm: Reference to the L{ViewManager} 32 @type vm: L{ViewManager} 33 @ivar tm: Reference to the L{TierManager} 34 @type tm: L{TierManager} 35 @ivar em: Reference to the L{EventManager} 36 @type em: L{EventManager} 37 @ivar dm: Reference to the L{DeviceManager} 38 @type dm: L{DeviceManager} 39 @ivar sm: Reference to the L{SettingsManager} 40 @type sm: L{SettingsManager} 41 @ivar manager_dict: Dictionary of managers keyed by manager names (device_man, 42 event_man, tier_man, and view_man) 43 @type manager_dict: dictionary 44 @ivar none_dict: Dictionary of None values with the same keys as 45 L{manager_dict} 46 @type none_dict: dictionary 47 @ivar profile: Name of the profile this instance of L{AccessEngine} was 48 started under 49 @type profile: string 50 @ivar welcome: Output an introductory message when the engine starts? 51 @type welcome: boolean 52 '''

53 - def __init__(self, profile, welcome):

54 ''' 55 Creates the L{ViewManager}, L{TierManager}, and L{EventManager} objects. 56 Calls the init method here to intialize the managers with references to 57 other managers. 58 59 @param profile: Name of the profile LSR was executed under 60 @type profile: string 61 @param welcome: Output an introductory message? 62 @type welcome: boolean 63 ''' 64 self.profile = profile 65 self.callbacks = {} 66 self.alive = False 67 self.manager_dict = None 68 self.none_dict = None 69 self.welcome = welcome 70 71 # build all the managers (include reference to AccessEngine 72 self.sm = SettingsManager.SettingsManager(self.profile) 73 self.em = EventManager.EventManager(self) 74 self.vm = ViewManager.ViewManager(self) 75 self.tm = TierManager.TierManager(self) 76 self.dm = DeviceManager.DeviceManager(self)

77

78 - def _init(self, **managers):

79 ''' 80 Calls init on each manager providing it with references to the other 81 managers in case it wants to hold one or more references. Called implicitly 82 by L{run}. 83 84 @keyword event_man: Reference to the L{EventManager} 85 @type event_man: L{EventManager} 86 @keyword view_man: Reference to the L{ViewManager} 87 @type view_man: L{ViewManager} 88 @keyword tier_man: Reference to the L{TierManager} 89 @type tier_man: L{TierManager} 90 @keyword device_man: Reference to the L{DeviceManager} 91 @type device_man: L{DeviceManager} 92 @keyword sett_man: Reference to the L{SettingsManager} 93 @type sett_man: L{SettingsManager} 94 ''' 95 # store the dictionary of all managers so we can quickly loan them out in 96 # the future to other objects that need them 97 self.manager_dict = managers 98 # create a dictionary with the same keys, but None values so we can quickly 99 # unloan managers in the future 100 self.none_dict = dict([(name, None) for name in managers.keys()]) 101 # init the managers, in correct dependency order 102 self.sm.init(**managers) 103 self.em.init(**managers) 104 self.vm.init(**managers) 105 self.tm.init(**managers) 106 self.dm.init(**managers) 107 108 # have the device manager speak a welcome message 109 if self.welcome: 110 self.dm.sendWelcome() 111 # get rid of any events that leak through while we are starting up 112 self.em.flushEvents() 113 # tell the view manager to locate the active view and inform the tier 114 # manager about running applications 115 self.vm.initViews()

116

117 - def _close(self):

118 ''' 119 Shutsdown all managers. Called implicitly by L{run} when the main loop 120 ends. Sends an exiting message to the default device. 121 ''' 122 if self.welcome: 123 self.dm.sendGoodbye() 124 self.tm.close() 125 self.vm.close() 126 self.em.close() 127 self.sm.close() 128 self.dm.close()

129

130 - def quit(self, *args):

131 ''' 132 Quits the gtk main loop. Extra parameters are ignored but captured by args 133 so that this method may be reigstered as a signal handler callback. 134 ''' 135 try: 136 bonobo.main_quit() 137 except RuntimeError: 138 # probably already quitting 139 return

140

141 - def loanManagers(self, obj):

142 ''' 143 Updates the namespace dictionary of the given object with the names and 144 values of the managers stored in L{manager_dict}. These references can be 145 wiped out by a later call to L{unloanManagers}. 146 147 @param obj: An object with a __dict__ attribute 148 @type obj: object 149 ''' 150 obj.__dict__.update(self.manager_dict)

151

152 - def unloanManagers(self, obj):

153 ''' 154 Updates the namespace dictionary of the given object with the names and 155 None values of stored in L{none_dict}. This effectively wipes out references 156 to managers previously loaned out by L{loanManagers}. 157 158 @param obj: An object with a __dict__ attribute 159 @type obj: object 160 ''' 161 obj.__dict__.update(self.none_dict)

162

163 - def addTimer(self, callback, ms=None, *args):

164 ''' 165 Creates a timer that calls the given callback on the interval specified by 166 the given milliseconds. If ms is None, registers for callbacks on idle. 167 168 @param callback: Function to call 169 @type callback: callable 170 @param args: Additional arguments to be given to the callback 171 @type args: list 172 ''' 173 if ms is not None: 174 cid = gobject.timeout_add(ms, callback, *args) 175 else: 176 cid = gobject.idle_add(ms, callback, *args) 177 self.callbacks[callback] = cid

178

179 - def removeTimer(self, callback):

180 ''' 181 Ceases calls to the given registered callback. 182 183 @param callback: Function to stop calling 184 @type callback: callable 185 @raise KeyError: When the callback is not already registered 186 ''' 187 cid = self.callbacks[callback] 188 gobject.source_remove(cid)

189

190 - def run(self):

191 ''' 192 Runs an event loop by creating a gobject.MainLoop object and calling the 193 iteration method of its gobject.MainContext. Makes the timer callbacks 194 registered via L{AccessEngine.addTimer} on each iteration of the loop. 195 ''' 196 # set the alive flag to true 197 self.alive = True 198 199 # register a signal handler for gracefully killing the loop 200 signal.signal(signal.SIGINT, self.quit) 201 signal.signal(signal.SIGTERM, self.quit) 202 203 # initialize all managers 204 self._init(event_man=self.em, view_man=self.vm, tier_man=self.tm, 205 device_man=self.dm, sett_man=self.sm) 206 207 # run the bonobo main loop, but make sure to release the GIL to allow other 208 # threads 209 def releaseGIL(): 210 time.sleep(1e-5) 211 return True

212 213 i = gobject.idle_add(releaseGIL) 214 bonobo.main() 215 gobject.source_remove(i) 216 217 # cleanup callbacks 218 for c in self.callbacks: 219 self.removeTimer(c) 220 221 # uninitialize all managers 222 self._close() 223 224 # state that we are trying to quit 225 log.info('exiting...') 226 # make sure any other threads get a chance to run to completion 227 time.sleep(1)

Source Code for Module AccessEngine