sugar-toolkit-gtk3/shell/model/homemodel.py

# Copyright (C) 2006, Owen Williams.
#
# 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 logging

import gobject
import wnck
import dbus

from model.homeactivity import HomeActivity
from model import bundleregistry

_SERVICE_NAME = "org.laptop.Activity"
_SERVICE_PATH = "/org/laptop/Activity"
_SERVICE_INTERFACE = "org.laptop.Activity"

class HomeModel(gobject.GObject):
    """Model of the "Home" view (activity management)
    
    The HomeModel is basically the point of registration
    for all running activities within Sugar.  It traps
    events that tell the system there is a new activity
    being created (generated by the activity factories),
    or removed, as well as those which tell us that the
    currently focussed activity has changed.
    
    The HomeModel tracks a set of HomeActivity instances,
    which are tracking the window to activity mappings
    the activity factories have set up.
    """
    __gsignals__ = {
        'activity-added':          (gobject.SIGNAL_RUN_FIRST,
                                    gobject.TYPE_NONE, 
                                   ([gobject.TYPE_PYOBJECT])),
        'activity-started':         (gobject.SIGNAL_RUN_FIRST,
                                    gobject.TYPE_NONE, 
                                   ([gobject.TYPE_PYOBJECT])),
        'activity-removed':        (gobject.SIGNAL_RUN_FIRST,
                                    gobject.TYPE_NONE,
                                   ([gobject.TYPE_PYOBJECT])),
        'active-activity-changed': (gobject.SIGNAL_RUN_FIRST,
                                    gobject.TYPE_NONE,
                                   ([gobject.TYPE_PYOBJECT]))
    }
    
    def __init__(self):
        gobject.GObject.__init__(self)

        self._activities = []
        self._bundle_registry = bundleregistry.get_registry()
        self._current_activity = None

        screen = wnck.screen_get_default()
        screen.connect('window-opened', self._window_opened_cb)
        screen.connect('window-closed', self._window_closed_cb)
        screen.connect('active-window-changed',
                       self._active_window_changed_cb)

        bus = dbus.SessionBus()
        bus.add_signal_receiver(self._dbus_name_owner_changed_cb,
                                'NameOwnerChanged', 
                                'org.freedesktop.DBus', 
                                'org.freedesktop.DBus')

    def get_current_activity(self):
        return self._current_activity

    def __iter__(self): 
        return iter(self._activities)
        
    def __len__(self):
        return len(self._activities)
        
    def __getitem__(self, i):
        return self._activities[i]
        
    def index(self, obj):
        return self._activities.index(obj)
        
    def _window_opened_cb(self, screen, window):
        if window.get_window_type() == wnck.WINDOW_NORMAL:
            activity = None

            service = self._get_activity_service(window.get_xid())
            if service:
                activity_id = service.get_id()
                activity = self._get_activity_by_id(activity_id)

            if activity:
                activity.set_service(service)
            else:
                activity = self._get_activity_by_xid(window.get_xid())

            if activity:
                activity.set_window(window)
            else:
                activity = HomeActivity()
                activity.set_window(window)
                self._add_activity(activity)

            activity.props.launching = False
            self.emit('activity-started', activity)

    def _window_closed_cb(self, screen, window):
        if window.get_window_type() == wnck.WINDOW_NORMAL:
            self._remove_activity_by_xid(window.get_xid())
        if not self._activities:
            self.emit('active-activity-changed', None)
            self._notify_activity_activation(self._current_activity, None)

    def _dbus_name_owner_changed_cb(self, name, old, new):
        """Detect new activity instances on the DBus"""
        if name.startswith(_SERVICE_NAME) and new and not old:
            try:
                xid = int(name[len(_SERVICE_NAME):])
                activity = self._get_activity_by_xid(xid)
                if activity:
                    service = self._get_activity_service(xid)
                    if service:
                        activity.set_service()
            except ValueError:
                logging.error('Invalid activity service name, '
                              'cannot extract the xid')

    def _get_activity_by_xid(self, xid):
        for activity in self._activities:
            if activity.get_xid() == xid:
                return activity
        return None

    def _get_activity_by_id(self, activity_id):
        for activity in self._activities:
            if activity.get_activity_id() == activity_id:
                return activity
        return None

    def _notify_activity_activation(self, old_activity, new_activity):
        if old_activity == new_activity:
            return

        if old_activity:
            service = old_activity.get_service()
            if service:
                service.set_active(False)

        if new_activity:
            service = new_activity.get_service()
            if service:
                service.set_active(True)

    def _active_window_changed_cb(self, screen):
        window = screen.get_active_window()
        if window == None:
            self.emit('active-activity-changed', None)
            self._notify_activity_activation(self._current_activity, None)
            return
        if window.get_window_type() != wnck.WINDOW_NORMAL:
            return

        xid = window.get_xid()
        act = self._get_activity_by_xid(window.get_xid())
        if act:
            self._notify_activity_activation(self._current_activity, act)
            self._current_activity = act
        else:
            self._notify_activity_activation(self._current_activity, None)
            self._current_activity = None
            logging.error('Model for window %d does not exist.' % xid)

        self.emit('active-activity-changed', self._current_activity)

    def _get_activity_service(self, xid):
        bus = dbus.SessionBus()
        try:
            service = dbus.Interface(
                    bus.get_object(_SERVICE_NAME + '%d' % xid,
                                   _SERVICE_PATH + "/%s" % xid),
                                   _SERVICE_INTERFACE)
        except dbus.DBusException:
            service = None

        return service

    def _add_activity(self, activity):
        self._activities.append(activity)
        self.emit('activity-added', activity)

    def _remove_activity(self, activity):
        if activity == self._current_activity:
            self._current_activity = None

        self.emit('activity-removed', activity)
        self._activities.remove(activity)
        
    def _remove_activity_by_xid(self, xid):
        activity = self._get_activity_by_xid(xid)
        if activity:
            self._remove_activity(activity)
        else:
            logging.error('Model for window %d does not exist.' % xid)

    def notify_activity_launch(self, activity_id, service_name):
        bundle = self._bundle_registry.get_bundle(service_name)
        if not bundle:
            raise ValueError("Activity service name '%s' was not found in the bundle registry." % service_name)
        activity = HomeActivity(bundle, activity_id)
        activity.props.launching = True
        self._add_activity(activity)

    def notify_activity_launch_failed(self, activity_id):
        if self._activities.has_key(activity_id):
            activity = self._activities[activity_id]
            logging.debug("Activity %s (%s) launch failed" % (activity_id, activity.get_type()))
            self._remove_activity(activity)
        else:
            logging.error('Model for activity id %s does not exist.' % activity_id)