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


logger = logging.getLogger("tutorius")

class Event:
    """Event descriptor class.
    This class is used to describe events that are expected to happen.
    """

    def __init__(self, object_name, event_name ):
        """Constructor for Event
        @param object_name str name of the object that will send the event
        @param event_name str name of the event
        
        Example:
        evt=Event("0.0.1.1.2", "clicked")
        """
        self.object_name = object_name
        self.event_name = event_name

    def test(self, sig, name):
        """Utility method for testing the equality between a signal and object
        names and their expected values.
        @param sig str signal name
        @param name str object name
        @return True if both match the expected values, False otherwise
        """
        if self.object_name == name and self.event_name == sig:
            return True
        return False




class Tutorial (object):
    """
    Tutorial Class, used to run through the FSM.
    """
    EVENTS = [
        "focus",
        "button-press-event",
        "enter-notify-event",
        "leave-notify-event",
        "key-press-event",
        "text-selected",
        "clicked",
    ]

    IGNORED_WIDGETS = [
        "GtkVBox",
        "GtkHBox",
        "GtkAlignment",
        "GtkNotebook",
        "GtkButton",
        "GtkToolItem",
        "GtkToolbar",
    ]

    def __init__(self, name, fsm):
        """Create an unattached tutorial
        """
        object.__init__(self)
        self.name = name
        self.state_machine = fsm
        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.set_state("INIT")

    def detach(self):
        """Detach from the current activity"""
        self.disconnect_handlers()
        self.activity = None
        
    def handle_event(self, *args):
        """Default event handler for the Tutorial.
        Tests the received object and signal names onto each defined
        transition and changes to the next state if successful.

        The last parameter should be a two-tuple containing the
        (signal_name, object_name)
        """
        sig, objname = args[-1]
        logger.debug("EVENT %s ON %s" % (sig, objname) )
        for transition, next in self.state_machine[self.state]["Events"]:
            if transition.test(sig, objname):
                self.set_state(next)

#    @staticmethod
#    def logEvent(obj, *args):
#        logger.debug("%s" % str(args[-1]))

    def disconnect_handlers(self):
        """Disconnect all event handlers attached by self"""
        #Loop through handlers
        for obj, hid in self.handlers:
            obj.handler_disconnect(hid)
        self.handlers = []


    def set_state(self, name):
        """Switch to a new state"""
        if not self.state_machine.has_key(name):
            return
        logger.debug("====NEW STATE: %s====" % name)
        
        #Remove handlers (TODO replace by EventFilter unregister)
        self.disconnect_handlers()
        #Undo actions
        for act in self.state_machine.get(self.state,{}).get("Actions",()):
            act.undo()
            
        #Switch to new state
        self.state = name
        newstate = self.state_machine.get(name)
        #Add handlers (TODO replace by EventFilter register)
        for event, unused in newstate["Events"]:
            self.register_signal(self.handle_event, \
                        event.object_name, event.event_name)
            
        #Do actions
        for act in newstate.get("Actions",()):
            act.do()

    def register_signals(self, target, handler, prefix=None, max_depth=None):
        """
            Recursive function to register event handlers on an target
            and it's children. The event handler is called with an extra
            argument which is a two-tuple containing the signal name and
            the FQDN-style name of the target that triggered the event.

            This function registers all of the events listed in 
            Tutorial.EVENTS and omits widgets with a name matching
            Tutorial.IGNORED_WIDGETS from the name hierarchy.

            Example arg tuple added:
                ("focus", "Activity.Toolbox.Bold")
            Side effects:
                -Handlers connected on the various targets
                -Handler ID's stored in self.handlers

            @param target the target to recurse on
            @param handler the handler function to connect
            @param prefix name prepended to the target name to form a chain
            @param max_depth maximum recursion depth, None for infinity
        """
        #Gtk Containers have a get_children() function
        if hasattr(target, "get_children") and \
            hasattr(target.get_children, "__call__"):
            for child in target.get_children():
                if max_depth is None or max_depth > 0:
                    #Recurse with a prefix on all children
                    pre = ".".join( \
                        [p for p in (prefix, target.get_name()) \
                        if not (p is None or p in Tutorial.IGNORED_WIDGETS)] \
                    )
                    self.register_signals(child, handler, pre, max_depth-1)
        name = ".".join( \
            [p for p in (prefix, target.get_name()) \
            if not (p is None or p in Tutorial.IGNORED_WIDGETS)] \
        )
        #register events on the target if a widget XXX necessary to check this?
        if isinstance(target, gtk.Widget):
            for sig in Tutorial.EVENTS:
                try:
                    self.handlers.append( \
                        (target, target.connect(sig, handler, (sig, name) )) \
                    )
                except TypeError:
                    continue
        
    def register_signals_numbered(self, \
                target, handler, prefix="0", max_depth=None):
        """
            Recursive function to register event handlers on an target
            and it's children. The event handler is called with an extra
            argument which is a two-tuple containing the signal name and
            the FQDN-style name of the target that triggered the event.

            This function registers all of the events listed in 
            Tutorial.EVENTS

            Example arg tuple added:
                ("focus", "1.1.2")
            Side effects:
                -Handlers connected on the various targets
                -Handler ID's stored in self.handlers

            @param target the target to recurse on
            @param handler the handler function to connect
            @param prefix name prepended to the target name to form a chain
            @param max_depth maximum recursion depth, None for infinity
        """
        #Gtk Containers have a get_children() function
        if hasattr(target, "get_children") and \
            hasattr(target.get_children, "__call__"):
            children = target.get_children()
            for i in range(len(children)):
                child = children[i]
                if max_depth is None or max_depth > 0:
                    #Recurse with a prefix on all children
                    pre = ".".join( \
                        [p for p in (prefix, str(i)) if not p is None]
                    )
                    if max_depth is None:
                        dep = None
                    else:
                        dep = max_depth - 1
                    self.register_signals_numbered(child, handler, pre, dep)
        #register events on the target if a widget XXX necessary to check this?
        if isinstance(target, gtk.Widget):
            for sig in Tutorial.EVENTS:
                try:
                    self.handlers.append( \
                        (target, target.connect(sig, handler, (sig, prefix) ))\
                    )
                except TypeError:
                    continue

    def register_signal(self, handler, obj_fqdn, signal_name):
        """Register a signal handler onto a specific widget
        @param handler function to attach as a handler
        @param obj_fqdn fqdn-style object name
        @param signal_name signal name to connect to

        Side effects:
        the object found and the handler id obtained by connect() are
        appended in self.handlers
        """
        path = obj_fqdn.split(".")
        #We select the first object and pop the first zero
        obj = self.activity
        path.pop(0)

        while len(path) > 0:
            obj = obj.get_children()[int(path.pop(0))]

        self.handlers.append( \
            (obj, obj.connect(signal_name, handler, (signal_name, obj_fqdn) ))\
        )

class State:
    """This is a step in a tutorial. The state represents a collection of 
    actions to undertake when entering the state, and a description of an
    event filter with associated actions to go to the next state."""
    
    def __init__(self):
        """Initializes the content of the state, as in loading the actions
        that are required and building the correct tests."""
        self.actions = []
        self.tests = []
        
    
    def setup(self):
        """Install the state itself. This is the best time to pop-up a dialog
        that has to remain for the duration of the state."""
        for act in self.actions:
            act.do()
            
    
    def teardown(self):
        """Undo every action that was installed for this state. This means 
        removing dialogs that were displayed, removing highlights, etc..."""
        for act in self.actions:
            act.undo()
        
    
    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."""
    def __init__(self, start_state, setup_actions):
        """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)."""
        State.__init__(self)

        self.start_state = start_state
        self.actions = setup_actions
        
        self.current_state = self.start_state
    
    def setup(self):
        """
        Set up the FSM
        """
        for act in self.actions:
            act.do()
    
    def teardown(self):
        """
        Revert any changes done by setup()
        """
        for act in self.actions:
            act.undo()
    
    def verify(self):
        "Verify if the current state passes it's tests"""
        return self.current_state.verify()