manager/qubesmanager/clipboard.py

#!/usr/bin/python3
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2016  Jean-Philippe Ouellet <jpo@vt.edu>
# Copyright (C) 2012  Agnieszka Kostrzewa <agnieszka.kostrzewa@gmail.com>
# Copyright (C) 2012  Marek Marczykowski <marmarek@mimuw.edu.pl>
#
# 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 Lesser General Public License along
# with this program; if not, see <http://www.gnu.org/licenses/>.
#
#

import os
import fcntl
from math import log

# pylint: disable=import-error
from PyQt5.QtWidgets import QApplication, QMessageBox

APPVIEWER_LOCK = "/var/run/qubes/appviewer.lock"
CLIPBOARD_CONTENTS = "/var/run/qubes/qubes-clipboard.bin"
CLIPBOARD_SOURCE = CLIPBOARD_CONTENTS + ".source"


def do_dom0_copy():
    copy_text_to_qubes_clipboard(QApplication.clipboard().text())


def copy_text_to_qubes_clipboard(text):
    # inter-appviewer lock

    try:
        file = os.open(APPVIEWER_LOCK, os.O_RDWR | os.O_CREAT, 0o0666)
    except Exception:  # pylint: disable=broad-except
        QMessageBox.warning(None, "Warning!",
                            "Error while accessing Qubes clipboard!")
    else:
        try:
            fcntl.flock(file, fcntl.LOCK_EX)
        except Exception:  # pylint: disable=broad-except
            QMessageBox.warning(None, "Warning!",
                                "Error while locking Qubes clipboard!")
        else:
            try:
                with open(CLIPBOARD_CONTENTS, "w") as contents:
                    contents.write(text)
                with open(CLIPBOARD_SOURCE, "w") as source:
                    source.write("dom0")
            except Exception:  # pylint: disable=broad-except
                QMessageBox.warning(None, "Warning!",
                                    "Error while writing to Qubes clipboard!")
            fcntl.flock(file, fcntl.LOCK_UN)
        os.close(file)


# pylint: disable=invalid-name
def get_qubes_clipboard_formatted_size():
    units = ['B', 'KiB', 'MiB', 'GiB']

    try:
        file_size = os.path.getsize(CLIPBOARD_CONTENTS)
    except Exception:  # pylint: disable=broad-except
        QMessageBox.warning(None, "Warning!",
                            "Error while accessing Qubes clipboard!")
    else:
        formatted_bytes = '1 byte' if file_size == 1 \
            else str(file_size) + ' bytes'
        if file_size > 0:
            magnitude = min(int(log(file_size)/log(2)*0.1), len(units)-1)
            if magnitude > 0:
                return '%s (%.1f %s)' % (formatted_bytes,
                                         file_size/(2.0**(10*magnitude)),
                                         units[magnitude])
        return '%s' % formatted_bytes

    return '? bytes'