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+# Copyright (C) 2009, Tutorius.org
+# Copyright (C) 2009, Vincent Vinet <vince.vinet@gmail.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+
+import gobject
+import gtk
+import logging
+logger = logging.getLogger("filters")
+
+from sugar.tutorius.gtkutils import find_widget
+from sugar.tutorius.services import ObjectStore
+from sugar.tutorius import properties
+
+
+class EventFilter(properties.TPropContainer):
+ """
+ Base class for an event filter
+ """
+
+ next_state = properties.TStringProperty("None")
+
+ def __init__(self, next_state=None):
+ """
+ Constructor.
+ @param next_state name of the next state
+ """
+ super(EventFilter, self).__init__()
+ if next_state:
+ self.next_state = next_state
+ self._callback = None
+
+ def get_next_state(self):
+ """
+ Getter for the next state
+ """
+ return self.next_state
+
+ def set_next_state(self, new_next_name):
+ """
+ Setter for the next state. Should only be used during construction of
+ the event_fitler, not while the tutorial is running.
+ """
+ self.next_state = new_next_name
+
+ def install_handlers(self, callback, **kwargs):
+ """
+ install_handlers is called for eventfilters to setup all
+ necessary event handlers to be able to catch the desired
+ event.
+
+ @param callback the callback function that will be called
+ with the event filter as an argument when the event is catched
+ and validated.
+ @param **kwargs unused by this handler for now, allows subclasses
+ to receive information about the context when installing
+
+ Subclasses must call this super method to setup the callback if they
+ feel like cooperating
+ """
+ self._callback = callback
+
+ def remove_handlers(self):
+ """
+ remove_handlers is called when a state is done so that all
+ event filters can cleanup any handlers they have installed
+
+ This function will also clear the callback function so that any
+ leftover handler that is triggered will not be able to change the
+ application state.
+
+ subclasses must call this super method to cleanup the callback if they
+ collaborate and use this classe's do_callback()
+ """
+ self._callback = None
+
+ def do_callback(self, *args, **kwargs):
+ """
+ Default callback function that calls the event filter callback
+ with the event filter as only argument.
+ """
+ if self._callback:
+ self._callback(self)
+
+class TimerEvent(EventFilter):
+ """
+ TimerEvent is a special EventFilter that uses gobject
+ timeouts to trigger a state change after a specified amount
+ of time. It must be used inside a gobject main loop to work.
+ """
+ def __init__(self,next_state,timeout_s):
+ """Constructor.
+
+ @param next_state default EventFilter param, passed on to EventFilter
+ @param timeout_s timeout in seconds
+ """
+ super(TimerEvent,self).__init__(next_state)
+ self._timeout = timeout_s
+ self._handler_id = None
+
+ def install_handlers(self, callback, **kwargs):
+ """install_handlers creates the timer and starts it"""
+ super(TimerEvent,self).install_handlers(callback, **kwargs)
+ #Create the timer
+ self._handler_id = gobject.timeout_add_seconds(self._timeout, self._timeout_cb)
+
+ def remove_handlers(self):
+ """remove handler removes the timer"""
+ super(TimerEvent,self).remove_handlers()
+ if self._handler_id:
+ try:
+ #XXX What happens if this was already triggered?
+ #remove the timer
+ gobject.source_remove(self._handler_id)
+ except:
+ pass
+
+ def _timeout_cb(self):
+ """
+ _timeout_cb triggers the eventfilter callback.
+
+ It is necessary because gobject timers only stop if the callback they
+ trigger returns False
+ """
+ self.do_callback()
+ return False #Stops timeout
+
+class GtkWidgetTypeFilter(EventFilter):
+ """
+ Event Filter that listens for keystrokes on a widget
+ """
+ def __init__(self, next_state, object_id, text=None, strokes=None):
+ """Constructor
+ @param next_state default EventFilter param, passed on to EventFilter
+ @param object_id object tree-ish identifier
+ @param text resulting text expected
+ @param strokes list of strokes expected
+
+ At least one of text or strokes must be supplied
+ """
+ super(GtkWidgetTypeFilter, self).__init__(next_state)
+ self._object_id = object_id
+ self._text = text
+ self._captext = ""
+ self._strokes = strokes
+ self._capstrokes = []
+ self._widget = None
+ self._handler_id = None
+
+ def install_handlers(self, callback, **kwargs):
+ """install handlers
+ @param callback default EventFilter callback arg
+ """
+ super(GtkWidgetTypeFilter, self).install_handlers(callback, **kwargs)
+ logger.debug("~~~GtkWidgetTypeFilter install")
+ activity = ObjectStore().activity
+ if activity is None:
+ logger.error("No activity")
+ raise RuntimeWarning("no activity in the objectstore")
+
+ self._widget = find_widget(activity, self._object_id)
+ if self._widget:
+ self._handler_id= self._widget.connect("key-press-event",self.__keypress_cb)
+ logger.debug("~~~Connected handler %d on %s" % (self._handler_id,self._object_id) )
+
+ def remove_handlers(self):
+ """remove handlers"""
+ super(GtkWidgetTypeFilter, self).remove_handlers()
+ #if an event was connected, disconnect it
+ if self._handler_id:
+ self._widget.handler_disconnect(self._handler_id)
+ self._handler_id=None
+
+ def __keypress_cb(self, widget, event, *args):
+ """keypress callback"""
+ logger.debug("~~~keypressed!")
+ key = event.keyval
+ keystr = event.string
+ logger.debug("~~~Got key: " + str(key) + ":"+ keystr)
+ self._capstrokes += [key]
+ #TODO Treat other stuff, such as arrows
+ if key == gtk.keysyms.BackSpace:
+ self._captext = self._captext[:-1]
+ else:
+ self._captext = self._captext + keystr
+
+ logger.debug("~~~Current state: " + str(self._capstrokes) + ":" + str(self._captext))
+ if not self._strokes is None and self._strokes in self._capstrokes:
+ self.do_callback()
+ if not self._text is None and self._text in self._captext:
+ self.do_callback()
+