"""UI class to access system-level clipboard object"""
# Copyright (C) 2007, One Laptop Per Child
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
import logging
import dbus
import gobject
NAME_KEY = 'NAME'
PERCENT_KEY = 'PERCENT'
ICON_KEY = 'ICON'
PREVIEW_KEY = 'PREVIEW'
ACTIVITIES_KEY = 'ACTIVITIES'
FORMATS_KEY = 'FORMATS'
TYPE_KEY = 'TYPE'
DATA_KEY = 'DATA'
ON_DISK_KEY = 'ON_DISK'
DBUS_SERVICE = "org.laptop.Clipboard"
DBUS_INTERFACE = "org.laptop.Clipboard"
DBUS_PATH = "/org/laptop/Clipboard"
class ClipboardService(gobject.GObject):
"""GUI interfaces for the system clipboard dbus service
This object is used to provide convenient access to the clipboard
service (see source/services/clipboard/clipboardservice.py). It
provides utility methods for adding/getting/removing objects from
the clipboard as well as generating events when such events occur.
Meaning is source/services/clipboard/clipboardobject.py
objects when describing "objects" on the clipboard.
"""
__gsignals__ = {
'object-added': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
([str, str])),
'object-deleted': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
([str])),
'object-state-changed': (gobject.SIGNAL_RUN_FIRST, gobject.TYPE_NONE,
([str, str, int, str, str, object])),
}
def __init__(self):
"""Initialise the ClipboardService instance
If the service is not yet active in the background uses
a signal watcher to connect when the service appears.
"""
gobject.GObject.__init__(self)
self._dbus_service = None
bus = dbus.SessionBus()
self._nameOwnerChangedHandler = bus.add_signal_receiver(
self._name_owner_changed_cb,
signal_name="NameOwnerChanged",
dbus_interface="org.freedesktop.DBus",
arg0=DBUS_SERVICE)
self._connected = False
# Try to register to ClipboardService, if we fail, we'll try later.
try:
self._connect_clipboard_signals()
except dbus.DBusException, exception:
logging.debug(exception)
def _connect_clipboard_signals(self):
"""Connect dbus signals to our GObject signal generating callbacks"""
bus = dbus.SessionBus()
if not self._connected:
# NOTE: We need to follow_name_owner_changes here
# because we can not connect to a signal unless
# we follow the changes or we start the service
# before we connect. Starting the service here
# causes a major bottleneck during startup
proxy_obj = bus.get_object(DBUS_SERVICE,
DBUS_PATH,
follow_name_owner_changes=True)
self._dbus_service = dbus.Interface(proxy_obj, DBUS_SERVICE)
self._dbus_service.connect_to_signal('object_added',
self._object_added_cb)
self._dbus_service.connect_to_signal('object_deleted',
self._object_deleted_cb)
self._dbus_service.connect_to_signal('object_state_changed',
self._object_state_changed_cb)
self._connected = True
bus.remove_signal_receiver(self._nameOwnerChangedHandler)
def _name_owner_changed_cb(self, name, old, new):
"""On backend service creation, connect to the server"""
if not old and new:
# ClipboardService started up
self._connect_clipboard_signals()
def _object_added_cb(self, object_id, name):
"""Emit an object-added GObject event when dbus event arrives"""
self.emit('object-added', str(object_id), name)
def _object_deleted_cb(self, object_id):
"""Emit an object-deleted GObject event when dbus event arrives"""
self.emit('object-deleted', str(object_id))
def _object_state_changed_cb(self, object_id, values):
"""Emit an object-state-changed GObject event when dbus event arrives
GObject event has:
object_id
name
percent
icon
preview
activities
From the ClipboardObject instance which is being described.
"""
self.emit('object-state-changed', str(object_id), values[NAME_KEY],
values[PERCENT_KEY], values[ICON_KEY], values[PREVIEW_KEY],
values[ACTIVITIES_KEY])
def add_object(self, name):
"""Add a new object to the path
returns dbus path-name for the new object's cliboard service,
this is used for all future references to the cliboard object.
Note:
That service is actually provided by the clipboard
service object, not the ClipboardObject
"""
return str(self._dbus_service.add_object(name))
def add_object_format(self, object_id, formatType, data, on_disk):
"""Annotate given object on the clipboard with new information
object_id -- dbus path as returned from add_object
formatType -- XXX what should this be? mime type?
data -- storage format for the clipped object?
on_disk -- whether the data is on-disk (non-volatile) or in
memory (volatile)
Last three arguments are just passed directly to the
clipboardobject.Format instance on the server side.
returns None
"""
self._dbus_service.add_object_format(dbus.ObjectPath(object_id),
formatType,
data,
on_disk)
def delete_object(self, object_id):
"""Remove the given object from the clipboard
object_id -- dbus path as returned from add_object
"""
self._dbus_service.delete_object(dbus.ObjectPath(object_id))
def set_object_percent(self, object_id, percent):
"""Set the "percentage" for the given clipboard object
object_id -- dbus path as returned from add_object
percentage -- numeric value from 0 to 100 inclusive
Object percentages which are set to 100% trigger "file-completed"
operations, see the backend ClipboardService's
_handle_file_completed method for details.
returns None
"""
self._dbus_service.set_object_percent(dbus.ObjectPath(object_id), percent)
def get_object(self, object_id):
"""Retrieve the clipboard object structure for given object
object_id -- dbus path as returned from add_object
Retrieves the metadata description of a given object, but
*not* the data for the object. Use get_object_data passing
one of the values in the FORMATS_KEY value in order to
retrieve the data.
returns dictionary with
NAME_KEY: str,
PERCENT_KEY: number,
ICON_KEY: str,
PREVIEW_KEY: XXX what is it?,
ACTIVITIES_KEY: activities that can open this object,
FORMATS_KEY: list of XXX what is it?
"""
return self._dbus_service.get_object(dbus.ObjectPath(object_id),)
def get_object_data(self, object_id, formatType):
"""Retrieve object's data in the given formatType
object_id -- dbus path as returned from add_object
formatType -- format specifier XXX of what description
returns dictionary with
TYPE_KEY: str,
DATA_KEY: str,
ON_DISK_KEY: bool
"""
return self._dbus_service.get_object_data(dbus.ObjectPath(object_id),
formatType,
byte_arrays=True)
_clipboard_service = None
def get_instance():
"""Retrieve this process's interface to the clipboard service"""
global _clipboard_service
if not _clipboard_service:
_clipboard_service = ClipboardService()
return _clipboard_service