Source code for qpageview.cupsprinter

# -*- coding: utf-8 -*-
# This file is part of the qpageview package.
# Copyright (c) 2014 - 2019 by Wilbert Berendsen
# 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
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# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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A simple module using CUPS to send a document directly to a printer described
by a QPrinter. This is especially useful with PDF documents.

Uses the `cups` module, although it elegantly fails when that module is not
present. The cups module can be found in the pycups package at .

There are two methods to send a document to a printer:

1. Using the `lp` shell command
2. Using the cups module, which uses libcups to directly contact the server.

This module provides both possibilities.

Use `CmdHandle.create()` to get a CmdHandle, if `lp` is available, or use
`IppHandle.create()` to get a IppHandle, if the cups module is available and a
connection to the server can be established.

A function `handle()` is available; that tries first to get an IppHandle and
then a LprHandle. Usage of this module is this simple::

    import qpageview.cupsprinter

    h = qpageview.cupsprinter.handle()
    if h:

You can supply a QPrinter instance (that'd be the normal workflow :-)


    h = qpageview.cupsprinter.handle(printer)
    if h:

In this case all options that are set in the QPrinter object will be used
when sending the document to the printer.

If `printFile()` returns True, printing is considered successful. If False,
you can read the `status` and `error` attributes::

    if not h.printFile('/path/to/document.pdf'):
        QMessageBox.warning(None, "Printing failure",
            "There was an error:\n{0} (status: {1})".format(h.error, h.status))

To print a list of files in one job, use `printFiles()`.


import os
import shutil
import subprocess

from PyQt5.QtPrintSupport import QPrintEngine, QPrinter

[docs]class Handle: """Shared implementation of a handle that can send documents to a printer.""" def __init__(self, printer=None): self._printer = printer
[docs] def setPrinter(self, printer): """Use the specified QPrinter.""" self._printer = printer
[docs] def printer(self): """Return the QPrinter given on init, or a new default QPrinter instance.""" if self._printer == None: self._printer = QPrinter() return self._printer
[docs] def options(self): """Return the dict of CUPS options read from the printer object.""" return options(self.printer())
[docs] def title(self, filenames): """Return a sensible job title based on the list of filenames. This method is called when the user did not specify a job title. """ maxlen = 5 titles = [os.path.basename(f) for f in filenames[:maxlen]] more = len(filenames) - maxlen if more > 0: titles.append("(+{0} more)".format(more)) return ", ".join(titles)
[docs] def printFile(self, filename, title=None, options=None): """Print the file.""" return self.printFiles([filename], title, options)
[docs] def printFiles(self, filenames, title=None, options=None): """Print a list of files. If the title is None, the basename of the filename is used. Options may be a dictionary of CUPS options. All keys and values should be strings. Returns True if the operation was successful. Returns False if there was an error; after the call to printFile(), the status and error attributes contain the returncode of the operation and the error message. """ if filenames: if all(f and not f.isspace() and f != "-" for f in filenames): if not title: title = self.title(filenames) o = self.options() if options: o.update(options) printerName = self.printer().printerName() self.status, self.error = self._doPrintFiles(printerName, filenames, title, o) else: self.status, self.error = 2, "Not a valid filename" else: self.status, self.error = 2, "No filenames specified" return self.status == 0
def _doPrintFiles(self, printerName, filenames, title, options): """Implement this to perform the printing. Should return a tuple (status, error). If status is 0, the operation is considered to be successful. If not, the operation is considered to have failed, and the `error` message should contain some more information. """ return 0, ""
[docs]class CmdHandle(Handle): """Print a document using the `lp` shell command.""" def __init__(self, command, server="", port=0, user="", printer=None): self._command = command self._server = server self._port = port self._user = user super().__init__(printer)
[docs] @classmethod def create(cls, printer=None, server="", port=0, user="", cmd="lp"): """Create a handle to print using a shell command, if available.""" cmd = shutil.which(cmd) if cmd: return cls(cmd, server, port, user, printer)
def _doPrintFiles(self, printerName, filenames, title, options): """Print filenames using the `lp` shell command.""" cmd = [self._command] if self._server: if self._port: cmd.extend(['-h', "{0}:{1}".format(self._server, self._port)]) else: cmd.extend(['-h', self._server]) if self._user: cmd.extend(['-U', self._user]) cmd.extend(['-d', printerName]) cmd.extend(['-t', title]) if options: for option, value in options.items(): cmd.extend(['-o', '{0}={1}'.format(option, value)]) if any(f.startswith('-') for f in filenames): cmd.append('--') cmd.extend(filenames) try: p = subprocess.Popen(cmd, stdin=subprocess.DEVNULL, stderr=subprocess.PIPE) except OSError as e: return e.errno, e.strerror message = p.communicate()[1].decode('UTF-8', 'replace') return p.wait(), message
[docs]class IppHandle(Handle): """Print a document using a connection to the CUPS server.""" def __init__(self, connection, printer=None): super().__init__(printer) self._connection = connection
[docs] @classmethod def create(cls, printer=None, server="", port=0, user=""): """Return a handle to print using a connection to the (local) CUPS server, if available.""" try: import cups except ImportError: return cups.setServer(server or "") cups.setPort(port or 0) cups.setUser(user or "") try: c = cups.Connection() except RuntimeError: return h = cls(c, printer) if h.printer().printerName() in c.getPrinters(): return h
def _doPrintFiles(self, printerName, filenames, title, options): """Print filenames using a connection to the CUPS server.""" import cups # cups.Connection.printFiles() behaves flaky: version 1.9.74 can # silently fail (without returning an error), and after having fixed # that, there are strange error messages on some options. # Therefore we use cups.printFile() for every file. for filename in filenames: try: self._connection.printFile(printerName, filename, title, options) except cups.IPPError as err: return err.args return 0, ""
[docs]def handle(printer=None, server="", port=0, user=""): """Return the first available handle to print a document to a CUPS server.""" return (IppHandle.create(printer, server, port, user) or CmdHandle.create(printer, server, port, user))
[docs]def options(printer): """Return the dict of CUPS options read from the QPrinter object.""" o = {} # cups options that can be set in QPrintDialog on unix # I found this in qt5/qtbase/src/printsupport/kernel/qcups.cpp. # Esp. options like page-set even/odd do make sense. props = printer.printEngine().property(0xfe00) if props and isinstance(props, list) and len(props) % 2 == 0: for key, value in zip(props[0::2], props[1::2]): if value and isinstance(key, str) and isinstance(value, str): o[key] = value o['copies'] = format(printer.copyCount()) if printer.collateCopies(): o['collate'] = 'true' # TODO: in Qt5 >= 5.11 page-ranges support is more fine-grained! if printer.printRange() == QPrinter.PageRange: o['page-ranges'] = '{0}-{1}'.format(printer.fromPage(), printer.toPage()) # page order if printer.pageOrder() == QPrinter.LastPageFirst: o['outputorder'] = 'reverse' # media size media = [] size = printer.paperSize() if size == QPrinter.Custom: media.append('Custom.{0}x{1}mm'.format(printer.heightMM(), printer.widthMM())) elif size in PAGE_SIZES: media.append(PAGE_SIZES[size]) # media source source = printer.paperSource() if source in PAPER_SOURCES: media.append(PAPER_SOURCES[source]) if media: o['media'] = ','.join(media) # page margins if printer.printEngine().property(QPrintEngine.PPK_PageMargins): left, top, right, bottom = printer.getPageMargins(QPrinter.Point) o['page-left'] = format(left) o['page-top'] = format(top) o['page-right'] = format(right) o['page-bottom'] = format(bottom) # orientation landscape = printer.orientation() == QPrinter.Landscape if landscape: o['landscape'] = 'true' # double sided duplex = printer.duplex() o['sides'] = ( 'two-sided-long-edge' if duplex == QPrinter.DuplexLongSide or (duplex == QPrinter.DuplexAuto and not landscape) else 'two-sided-short-edge' if duplex == QPrinter.DuplexShortSide or (duplex == QPrinter.DuplexAuto and landscape) else 'one-sided') # grayscale if printer.colorMode() == QPrinter.GrayScale: o['print-color-mode'] = 'monochrome' return o
[docs]def clearPageSetSetting(printer): """Remove 'page-set' even/odd cups options from the printer's CUPS options. Qt's QPrintDialog fails to reset the 'page-set' option back to 'all pages', so a previous value (even or odd) could remain in the print options, even if the user has selected All Pages in the print dialog. This function clears the page-set setting from the cups options. If the user selects or has selected even or odd pages, it will be added again by the dialog. So call this function on a QPrinter, just before showing a QPrintDialog. """ # see qt5/qtbase/src/printsupport/kernel/qcups.cpp opts = printer.printEngine().property(0xfe00) if opts and isinstance(opts, list) and len(opts) % 2 == 0: try: i = opts.index('page-set') except ValueError: return if i % 2 == 0: del opts[i:i+2] printer.printEngine().setProperty(0xfe00, opts)
PAGE_SIZES = { QPrinter.A0: "A0", QPrinter.A1: "A1", QPrinter.A2: "A2", QPrinter.A3: "A3", QPrinter.A4: "A4", QPrinter.A5: "A5", QPrinter.A6: "A6", QPrinter.A7: "A7", QPrinter.A8: "A8", QPrinter.A9: "A9", QPrinter.B0: "B0", QPrinter.B1: "B1", QPrinter.B10: "B10", QPrinter.B2: "B2", QPrinter.B3: "B3", QPrinter.B4: "B4", QPrinter.B5: "B5", QPrinter.B6: "B6", QPrinter.B7: "B7", QPrinter.B8: "B8", QPrinter.B9: "B9", QPrinter.C5E: "C5", # Correct Translation? QPrinter.Comm10E: "Comm10", # Correct Translation? QPrinter.DLE: "DL", # Correct Translation? QPrinter.Executive: "Executive", QPrinter.Folio: "Folio", QPrinter.Ledger: "Ledger", QPrinter.Legal: "Legal", QPrinter.Letter: "Letter", QPrinter.Tabloid: "Tabloid", } PAPER_SOURCES = { QPrinter.Cassette: "Cassette", QPrinter.Envelope: "Envelope", QPrinter.EnvelopeManual: "EnvelopeManual", QPrinter.FormSource: "FormSource", QPrinter.LargeCapacity: "LargeCapacity", QPrinter.LargeFormat: "LargeFormat", QPrinter.Lower: "Lower", QPrinter.MaxPageSource: "MaxPageSource", QPrinter.Middle: "Middle", QPrinter.Manual: "Manual", QPrinter.OnlyOne: "OnlyOne", QPrinter.Tractor: "Tractor", QPrinter.SmallFormat: "SmallFormat", }