straw/MainloopManager.py

   1 """ MainloopManager.py
   2
   3 """
   4 __copyright__ = "Copyright (c) 2002-2005 Free Software Foundation, Inc."
   5 __license__ = """
   6 Straw is free software; you can redistribute it and/or modify it under the
   7 terms of the GNU General Public License as published by the Free Software
   8 Foundation; either version 2 of the License, or (at your option) any later
   9 version.
  10
  11 Straw is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  13 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License along with
  16 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  17 Place - Suite 330, Boston, MA 02111-1307, USA. """
  18
  19
  20 import pygtk
  21 pygtk.require("2.0")
  22 import gtk
  23 import gobject
  24 import error
  25
  26 def schedule(function, *args, **kw):
  27     """
  28     Schedules a function call in the main loop thread.
  29     The given arguments and keywords are passed along if any.
  30     Threads may not access Straw and GTK elsewhere.
  31     XXX occasional "Trying re-entry!" warnings
  32     """
  33
  34     assert function.__call__
  35
  36     def callback():
  37         function(*args, **kw)
  38         return False # call only once
  39
  40     gobject.timeout_add(0, callback) # call as soon as possible
  41
  42
  43 class MainloopManager:
  44     instance = None
  45
  46     def __init__(self):
  47         self._idle_handlers = []
  48         self._timers = {}
  49         self._call_depth = 0
  50
  51     def add_idle_handler(self, handler):
  52         oid = self._add_idle(handler)
  53         self._idle_handlers.append((oid, handler))
  54
  55     def _add_idle(self, handler):
  56         oid = gtk.idle_add(handler)
  57         return oid
  58
  59     def remove_idle_handler(self, handler):
  60         for oid, h in self._idle_handlers:
  61             if h == handler:
  62                 gtk.idle_remove(oid)
  63                 break
  64         else:
  65             error.log("no handler ", handler, " found!")
  66
  67     def remove_idle_handler_by_id(self, oid):
  68         gtk.idle_remove(oid)
  69
  70     def call_pending(self):
  71         if self._call_depth > 0:
  72             error.log("Trying re-entry! Not allowed.")
  73             return
  74         self._call_depth += 1
  75         try:
  76             for oid, handler in self._idle_handlers:
  77                 self.remove_idle_handler_by_id(oid)
  78             while gtk.events_pending():
  79                 gtk.main_iteration(False)
  80
  81             for index in xrange(len(self._idle_handlers)):
  82                 oid, handler = self._idle_handlers[index]
  83                 new_id = self._add_idle(handler)
  84                 self._idle_handlers[index] = (new_id, handler)
  85         finally:
  86             self._call_depth -= 1
  87
  88     def set_repeating_timer(self, timeout, function, data = None):
  89         def f(*args):
  90             if not self._timers.has_key(function):
  91                 return
  92             try:
  93                 if len(args) > 0:
  94                     function(*args)
  95                 else:
  96                     function()
  97             finally:
  98                 if data is not None:
  99                     gobject.timeout_add(timeout, f, data)
 100                 else:
 101                     gobject.timeout_add(timeout, f)
 102         if data is not None:
 103             gobject.timeout_add(timeout, f, data)
 104         else:
 105             gobject.timeout_add(timeout, f)
 106         self._timers[function] = True
 107
 108     def end_repeating_timer(self, function):
 109         if self._timers.has_key(function):
 110             del self._timers[function]
 111
 112     def get_instance(klass):
 113         if klass.instance is None:
 114             klass.instance = klass()
 115         return klass.instance
 116     get_instance = classmethod(get_instance)