path: root/src/sugar/tutorius/core.py

# 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
"""
Core

This module contains the core classes for tutorius

"""

import gtk
import logging

from sugar.tutorius.dialog import TutoriusDialog
from sugar.tutorius.gtkutils import find_widget

logger = logging.getLogger("tutorius")

class Tutorial (object):
    """
    Tutorial Class, used to run through the FSM.
    """

    def __init__(self, name, fsm):
        """
        Creates an unattached tutorial.
        """
        object.__init__(self)
        self.name = name
        
        self.state_machine = fsm
        self.state_machine.set_tutorial(self)
        
        self.state = None

        self.handlers = []
        self.activity = None
        #Rest of initialisation happens when attached

    def attach(self, activity):
        """
        Attach to a running activity
        
        @param activity the activity to attach to
        """
        #For now, absolutely detach if a previous one!
        if self.activity:
            self.detach()
        self.activity = activity
        self.state_machine.set_state("INIT")

    def detach(self):
        """
        Detach from the current activity
        """
    
        # Uninstall the whole FSM
        self.state_machine.teardown()

        #FIXME There should be some amount of resetting done here...
        self.activity = None
        

    def set_state(self, name):
        """
        Switch to a new state
        """
        logger.debug("====NEW STATE: %s====" % name)
        
        self.state_machine.set_state(name)


    # Currently unused -- equivalent function is in each state
    def _eventfilter_state_done(self, eventfilter):
        """
        Callback handler for eventfilter to notify
        when we must go to the next state.
        """
        #XXX Tests should be run here normally

        #Swith to the next state pointed by the eventfilter
        self.set_state(eventfilter.get_next_state())

class State:
    """
    This is a step in a tutorial. The state represents a collection of actions 
    to undertake when entering the state, and a series of event filters
    with associated actions that point to a possible next state.
    """
    
    def __init__(self, name, action_list=[], event_filter_list=[], tutorial=None):
        """
        Initializes the content of the state, like loading the actions
        that are required and building the correct tests.
        
        @param action_list The list of actions to execute when entering this
        state
        @param event_filter_list A list of tuples of the form 
        (event_filter, next_state_name), that explains the outgoing links for
        this state
        @param tutorial The higher level container of the state
        """
        self._actions = action_list
        
        # Unused for now
        #self.tests = []
        
        self._event_filters = event_filter_list
        
        self.tutorial = tutorial

    def set_tutorial(self, tutorial):
        """
        Associates this state with a tutorial. A tutorial must be set prior
        to executing anything in the state. The reason for this is that the
        states need to have access to the activity (via the tutorial) in order
        to properly register their callbacks on the activities' widgets.
        
        @param tutorial The tutorial that this state runs under.
        """ 
        if self.tutorial == None :
            self.tutorial = tutorial
        else:
            raise RuntimeWarning(\
            "The state %s was already associated with a tutorial." % self.name)
    
    def setup(self):
        """
        Install the state itself, by first registering the event filters
        and then triggering the actions.
        """
        for eventfilter in self._event_filters:
            eventfilter.install_handlers(self._event_filter_state_done_cb, 
                activity=self.tutorial.activity)
        
        for action in self._actions:
            action.do()
    
    def teardown(self):
        """
        Uninstall all the event filters that were active in this state.
        Also undo every action that was installed for this state. This means 
        removing dialogs that were displayed, removing highlights, etc...
        """
        # Remove the handlers for the all of the state's event filters
        for event_filter in self._event_filters:
            event_filter.remove_handlers()
        
        # Undo all the actions related to this state
        for action in self._actions:
            action.undo()
    
    def _event_filter_state_done_cb(self, event_filter):
        """
        Callback for event filters. This function needs to inform the
        tutorial that the state is over and tell it what is the next state.
        
        @param event_filter The event filter that was called
        """
        # Run the tests here, if need be
        
        # Warn the higher level that we wish to change state
        self.tutorial.set_state(event_filter.get_next_state())
    
    # Unused for now
##    def verify(self):
##        """Run the internal tests to see if one of them passes. If it does, 
##        then do the associated processing to go in the next state.""" 
##        for test in self.tests:
##            if test.verify() == True:
##                actions = test.get_actions()
##                for act in actions:
##                    act.do()
##                # Now that we execute the actions related to a test, we might
##                # want to undo them right after --- should we use a callback or
##                # a timer?
    
class FiniteStateMachine(State):
    """
    This is a collection of states, with a start state and an end callback.
    It is used to simplify the development of the various tutorials by 
    encapsulating a collection of states that represent a given learning 
    process.
    
    For now, we will consider that there can only be states
    inserted in the FSM, and that there are no nested FSM inside.
    """
    
    def __init__(self, name, tutorial=None, state_dict={}, start_state_name="INIT", action_list=[]):
        """
        The constructor for a FSM. Pass in the start state and the setup
        actions that need to be taken when the FSM itself start (which may be
        different from what is done in the first state of the machine).
        
        @param name A short descriptive name for this FSM
        @param tutorial The tutorial that will execute this FSM. If None is 
        attached on creation, then one must absolutely be attached before
        executing the FSM with set_tutorial().
        @param state_dict A dictionary containing the state names as keys and
        the state themselves as entries.
        @param start_state_name The name of the starting state, if different
        from "INIT"
        @param action_list The actions to undertake when initializing the FSM
        """
        State.__init__(self, name)
        
        self.name = name
        self.tutorial = tutorial
        
        # Dictionnary of states contained in the FSM
        self._states = state_dict
        
        # Remember the initial state - we might want to reset
        # or rewind the FSM at a later moment
        self.start_state = state_dict[start_state_name]
        self.current_state = self.start_state
        
        # Register the actions for the FSM - They will be processed at the
        # FSM level, meaning that when the FSM will start, it will first
        # execute those actions. When the FSM closes, it will tear down the
        # inner actions of the state, then close its own actions
        self.actions = action_list
        
        # Flag to mention that the FSM was initialized
        self._fsm_setup_done = False
        # Flag that must be raised when the FSM is to be teared down
        self._fsm_teardown_done = False
        # Flag used to declare that the FSM has reached an end state
        self._fsm_has_finished = False

    def set_tutorial(self, tutorial):
        """
        This associates the FSM to the given tutorial. It MUST be associated
        either in the constructor or with this function prior to executing the
        FSM.
        
        @param tutorial The tutorial that will execute this FSM.
        """
        # If there was no tutorial associated
        if self.tutorial == None:
            # Associate it with this FSM and all the underlying states
            self.tutorial = tutorial
            for state in self._states.itervalues():
                state.set_tutorial(tutorial)
        else:
            raise RuntimeWarning(\
                "The FSM %s is already associated with a tutorial."%self.name\
                )

    def setup(self):
        """
        This function initializes the FSM the first time it is called.
        Then, every time it is called, it initializes the current state.
        """
        # Are we associated with a tutorial?
        if self.tutorial == None:
            raise UnboundLocalError("No tutorial was associated with FSM %s" % self.name)
        
        # If we never initialized the FSM itself, then we need to run all the
        # actions associated with the FSM.
        if self._fsm_setup_done == False:
            # Flag the FSM level setup as done
            self._fsm_setup_done = True
            # Execute all the FSM level actions
            for action in self.actions:
                action.do()
            
        # Then, we need to run the setup of the current state
        self.current_state.setup()
    
    def set_state(self, new_state_name):
        """
        This functions changes the current state of the finite state machine.
        
        @param new_state The identifier of the state we need to go to
        """
        # TODO : Since we assume no nested FSMs, we don't set state on the
        # inner States / FSMs
##        # Pass in the name to the internal state - it might be a FSM and
##        # this name will apply to it
##        self.current_state.set_state(new_state_name)
        
        # Make sure the given state is owned by the FSM
        if not self._states.has_key(new_state_name):
            # If we did not recognize the name, then we do not possess any
            # state by that name - we must ignore this state change request as
            # it will be done elsewhere in the hierarchy (or it's just bogus).
            return
        
        new_state = self._states[new_state_name]
        
        # Undo the actions of the old state
        self.teardown()
        
        # Insert the new state
        self.current_state = new_state
        
        # Call the initial actions in the new state
        self.setup()
        
    
    def teardown(self):
        """
        Revert any changes done by setup()
        """
        # Teardown the current state
        self.current_state.teardown()
        
        # If we just finished the whole FSM, we need to also call the teardown
        # on the FSM level actions
        if self._fsm_has_finished == True:
            # Flag the FSM teardown as not needed anymore
            self._fsm_teardown_done = True
            # Undo all the FSM level actions here
            for action in self.actions:
                action.undo()

    #Unused for now
##    def verify(self):
##        """Verify if the current state passes its tests"""
##        return self.current_state.verify()