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

# Copyright (C) 2006-2007 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 sugar import wm

from model.homeactivity import HomeActivity
from model import bundleregistry

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])),
        'pending-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._active_activity = None
        self._pending_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)

    def get_pending_activity(self):
        """Returns the activity that would be seen in the Activity zoom level

        In the Home (or Neighborhood or Groups) zoom level, this
        indicates the activity that would become active if the user
        switched to the Activity zoom level. (In the Activity zoom
        level, this just returns the currently-active activity.)
        Unlike get_active_activity(), this never returns None as long
        as there is any activity running.
        """
        return self._pending_activity

    def _set_pending_activity(self, activity):
        if self._pending_activity == activity:
            return

        self._pending_activity = activity
        self.emit('pending-activity-changed', self._pending_activity)

    def get_active_activity(self):
        """Returns the activity that the user is currently working in

        In the Activity zoom level, this returns the currently-active
        activity. In the other zoom levels, it returns the activity
        that was most-recently active in the Activity zoom level, or
        None if the most-recently-active activity is no longer
        running.
        """
        return self._active_activity

    def _set_active_activity(self, activity):
        if self._active_activity == activity:
            return

        if self._active_activity:
            service = self._active_activity.get_service()
            if service:
                service.set_active(False,
                                   reply_handler=self._set_active_success,
                                   error_handler=self._set_active_error)
        if activity:
            service = activity.get_service()
            if service:
                service.set_active(True,
                                   reply_handler=self._set_active_success,
                                   error_handler=self._set_active_error)

        self._active_activity = activity
        self.emit('active-activity-changed', self._active_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

            activity_id = wm.get_activity_id(window)

            bundle_id = wm.get_bundle_id(window)
            if bundle_id:
                bundle = self._bundle_registry.get_bundle(bundle_id)
            else:
                bundle = None

            if activity_id:
                activity = self._get_activity_by_id(activity_id)

            if not activity:
                activity = HomeActivity(bundle, activity_id)
                self._add_activity(activity)

            activity.set_window(window)

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

            if self._pending_activity is None:
                self._set_pending_activity(activity)

    def _window_closed_cb(self, screen, window):
        if window.get_window_type() == wnck.WINDOW_NORMAL:
            self._remove_activity_by_xid(window.get_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 _set_active_success(self):
        pass
    
    def _set_active_error(self, err):
        logging.error("set_active() failed: %s" % err)

    def _active_window_changed_cb(self, screen):
        window = screen.get_active_window()
        if window is None or window.get_window_type() != wnck.WINDOW_NORMAL:
            return

        xid = window.get_xid()
        act = self._get_activity_by_xid(xid)
        if act is None:
            logging.error('Model for window %d does not exist.' % xid)
        self._set_pending_activity(act)
        self._set_active_activity(act)

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

    def _remove_activity(self, activity):
        if activity == self._active_activity:
            self._set_active_activity(None)
            # Figure out the new _pending_activity.
            windows = wnck.screen_get_default().get_windows_stacked()
            windows.reverse()
            for window in windows:
                new_activity = self._get_activity_by_xid(window.get_xid())
                if new_activity is not None:
                    self._set_pending_activity(new_activity)
                    break
            else:                
                logging.error('No activities are running')
                self._set_pending_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):
        activity = self._get_activity_by_id(activity_id)
        if activity:
            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)