src/lib/Event.py

   1 """ Event.py
   2
   3 Module for dispatching Straw-related events.
   4 """
   5 __copyright__ = "Copyright (c) 2002-2005 Free Software Foundation, Inc."
   6 __license__ = """ GNU General Public License
   7
   8 This program is free software; you can redistribute it and/or modify it under the
   9 terms of the GNU General Public License as published by the Free Software
  10 Foundation; either version 2 of the License, or (at your option) any later
  11 version.
  12
  13 This program is distributed in the hope that it will be useful, but WITHOUT
  14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  15 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License along with
  18 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  19 Place - Suite 330, Boston, MA 02111-1307, USA. """
  20
  21 import traceback
  22 import sys
  23 import error
  24
  25
  26 _base_cache = dict()
  27
  28 def find_bases(klass):
  29     def _find_bases(klass, d = None):
  30         if d is None:
  31             d = dict()
  32         for b in klass.__bases__:
  33             if issubclass(b, BaseSignal):
  34                 d[b] = 1
  35                 _find_bases(b, d)
  36         return tuple(d.keys())
  37     bases = _base_cache.get(klass, None)
  38     if bases is not None:
  39         return bases
  40     bases = _find_bases(klass)
  41     _base_cache[klass] = bases
  42     return bases
  43
  44 class BaseSignal:
  45     def __init__(self, sender):
  46         self.sender = sender
  47         return
  48
  49 class SignalEmitter:
  50     recorder = None
  51
  52     """Base class for signal emitters"""
  53     def __init__(self):
  54         self._slots = dict()
  55
  56     def initialize_slots(self, *signals):
  57         """Initialize signal slots.
  58         signals should be a list of signals this emitter is going to send."""
  59         for s in signals:
  60             self._slots[s] = dict()
  61             bs = find_bases(s)
  62             for k in bs:
  63                 self._slots[k] = dict()
  64
  65     def signal_connect(self, signal, handler, data=None):
  66         """Connect a handler to a signal in this emitter, and associate
  67         data with the callback. This will override previous bindings of
  68         signal to handler."""
  69         self._slots[signal][handler] = data
  70         return
  71
  72     def signal_disconnect(self, signal, handler):
  73         """Disconnect handler from signal."""
  74         self._slots[signal][handler] = None
  75         del self._slots[signal][handler]
  76         return
  77
  78     def emit_signal(self, signal):
  79         """Emit a signal object. Signal should be an instance of BaseSignal or
  80         a subclass."""
  81         global filterpy
  82         sclasses = find_bases(signal.__class__)
  83         for sc in sclasses + (signal.__class__,):
  84             for handler, data in self._slots.get(sc, {}).items():
  85                 if data is not None:
  86                     args = (signal, data)
  87                 else:
  88                     args = (signal,)
  89                 try:
  90                     #if self.recorder is not None:
  91                     #    self.recorder.record(sc, handler)
  92                     apply(handler, args)
  93                 except:
  94                     error.log_exc("Caught an exception when trying to "
  95                                   "call a signal handler for "
  96                                   "signal %s\n" %
  97                                   str(signal))
  98                     traceback.print_exc()
  99
 100     """
 101     def start_recording(klass, recorder):
 102         klass.recorder = recorder
 103     start_recording = classmethod(start_recording)
 104
 105     def stop_recording(klass):
 106         if klass.recorder is not None:
 107             klass.recorder.stop()
 108             klass.recorder = None
 109     stop_recording = classmethod(stop_recording)
 110     """
 111
 112 # Feed creation and feed list management events
 113
 114 class FeedsChangedSignal(BaseSignal):
 115     def __init__(self, sender, feed=None):
 116         BaseSignal.__init__(self, sender)
 117         self.feed = feed
 118
 119 class FeedsEmptySignal(BaseSignal):
 120     pass
 121
 122 class FeedsImportedSignal(FeedsChangedSignal):
 123     """
 124     A signal for importing huge amount of feeds from OPML.
 125     """
 126     def __init__(self, sender, feeds,
 127                  parent=None, from_sub=False):
 128         FeedsChangedSignal.__init__(self, sender)
 129         self.feeds = feeds
 130         self.category = parent
 131         self.from_sub = from_sub
 132
 133 class FeedDeletedSignal(FeedsChangedSignal):
 134     def __init__(self, sender, feed):
 135         FeedsChangedSignal.__init__(self, sender, feed)
 136         self.feed = feed
 137
 138 class FeedCreatedSignal(FeedsChangedSignal):
 139     def __init__(self, sender, feed, category=None, index=None):
 140         FeedsChangedSignal.__init__(self, sender)
 141         self.feed = feed
 142         self.category = category
 143         self.index = index
 144
 145 # Feed detail Specific
 146 class FeedDetailChangedSignal(BaseSignal):
 147     def __init__(self, sender):
 148         BaseSignal.__init__(self, sender)
 149
 150 class ItemOrderChangedSignal(FeedDetailChangedSignal):
 151     pass
 152
 153 class FeedPollFrequencyChangedSignal(FeedDetailChangedSignal):
 154     def __init__(self, sender):
 155         BaseSignal.__init__(self, sender)
 156
 157 class FeedNumOfItemsStoredChangedSignal(FeedDetailChangedSignal):
 158     def __init__(self, sender):
 159         BaseSignal.__init__(self, sender)
 160
 161 class FeedErrorStatusChangedSignal(FeedDetailChangedSignal):
 162     pass
 163
 164 class FeedInfoUpdatedSignal(FeedDetailChangedSignal):
 165     """
 166     Feed information like title, description, copyright, etc...
 167     """
 168     def __init__(self, sender):
 169         BaseSignal.__init__(self, sender)
 170
 171 class FeedUnreadChangedSignal(FeedDetailChangedSignal):
 172     def __init__(self, sender):
 173         BaseSignal.__init__(self, sender)
 174
 175
 176 # Feed category specific
 177
 178 class FeedCategoriesChangedSignal(BaseSignal):
 179     pass
 180
 181 class FeedCategoryListChangedSignal(FeedCategoriesChangedSignal):
 182     pass
 183
 184 class FeedCategoryListLoadedSignal(FeedCategoriesChangedSignal):
 185     pass
 186
 187 class FeedCategoryAddedSignal(FeedCategoryListChangedSignal):
 188     def __init__(self, sender, category):
 189         FeedCategoryListChangedSignal.__init__(self, sender)
 190         self.category = category
 191
 192 class FeedCategoryRemovedSignal(FeedCategoryListChangedSignal):
 193     def __init__(self, sender, category):
 194         FeedCategoryListChangedSignal.__init__(self, sender)
 195         self.category = category
 196
 197 class FeedCategoryChangedSignal(FeedCategoriesChangedSignal):
 198     """ Called when a Feed Category was modified (i.e. feed added, feed
 199     removed, category title changed, etc...
 200     """
 201     def __init__(self, sender, feed=None):
 202         FeedCategoriesChangedSignal.__init__(self, sender)
 203         self.feed = feed
 204
 205 class FeedCategorySortedSignal(FeedCategoryChangedSignal):
 206     """ Called when a Feed Category has been sorted. """
 207     def __init__(self, sender, reverse=False):
 208         FeedCategoryChangedSignal.__init__(self, sender)
 209         self.descending = reverse
 210
 211 class SubscriptionContentsUpdatedSignal(BaseSignal):
 212     pass
 213
 214 # Item specific
 215 class ItemsAddedSignal(BaseSignal):
 216     def __init__(self, sender, items):
 217         BaseSignal.__init__(self, sender)
 218         self.items = items
 219
 220 class ItemDeletedSignal(BaseSignal):
 221     def __init__(self, sender, item):
 222         BaseSignal.__init__(self, sender)
 223         self.item = item
 224
 225 class NewItemsSignal(BaseSignal):
 226     def __init__(self, sender, items):
 227         BaseSignal.__init__(self, sender)
 228         self.items = items
 229
 230 class ItemStickySignal(BaseSignal):
 231     def __init__(self, sender, item=None):
 232         BaseSignal.__init__(self, sender)
 233         if item is None:
 234             item = sender
 235         self.item = item
 236
 237 class AllItemsReadSignal(BaseSignal):
 238     def __init__(self, sender, changed):
 239         BaseSignal.__init__(self, sender)
 240         self.changed = changed
 241
 242
 243 # Other events ...
 244
 245 class FeedLastPollChangedSignal(BaseSignal):
 246     pass
 247
 248 class PollChangedSignal(BaseSignal):
 249     def __init__(self, sender):
 250         BaseSignal.__init__(self, sender)
 251
 252 class FeedPolledSignal(BaseSignal):
 253     pass
 254
 255 class FeedStatusChangedSignal(BaseSignal):
 256     """
 257     Provides a signal for denoting that the polling process
 258     has begun or finished.
 259     """
 260     pass
 261
 262 class ImageUpdatedSignal(BaseSignal):
 263     def __init__(self, sender, url, data):
 264         BaseSignal.__init__(self, sender)
 265         self.url = url
 266         self.data = data
 267
 268 class NumberOfItemsStoredChangedSignal(BaseSignal):
 269     pass
 270
 271 class PollFrequencyChangedSignal(PollChangedSignal):
 272     """ Global poll frequency """
 273     def __init__(self, sender, value):
 274         PollChangedSignal.__init__(self, sender)
 275         self.value = value
 276
 277 class PollingStoppedSignal(BaseSignal):
 278     pass
 279
 280 class FeedSelectionChangedSignal(BaseSignal):
 281     """
 282     Emitted when a feed has been selected in the feeds tree view.
 283     """
 284     def __init__(self, sender, old, new):
 285         BaseSignal.__init__(self, sender)
 286         self.old = old
 287         self.new = new
 288
 289 class ItemSelectionChangedSignal(BaseSignal):
 290     """ Called when an item has been selected in the item list.
 291     Normally this should display the content of the item
 292     """
 293     def __init__(self, sender, item):
 294         BaseSignal.__init__(self, sender)
 295         self.item = item
 296
 297 class ItemReadSignal(BaseSignal):
 298     """ Called when an item's 'seen' property has been changed
 299     (i.e. marked as read)
 300     """
 301     def __init__(self, sender, item=None):
 302         BaseSignal.__init__(self, sender)
 303         if item is None:
 304             item = sender
 305         self.item = item
 306
 307 class CategorySelectionChangedSignal(BaseSignal):
 308     """
 309     Emitted when a the user changes categories
 310     """
 311     def __init__(self, sender, newcat):
 312         BaseSignal.__init__(self, sender)
 313         self.current = newcat
 314
 315 class OfflineModeChangedSignal(BaseSignal):
 316     pass
 317
 318 class RefreshFeedDisplaySignal(BaseSignal):
 319     pass
 320
 321 class StatusDisplaySignal(BaseSignal):
 322     pass
 323
 324 class FindInterruptSignal(BaseSignal):
 325     pass
 326
 327
 328 if __name__ == '__main__':
 329     print find_bases(ItemReadSignal)