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Google Summer of Code 2017: OpenPrinting projects


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Mailing list: printing-architecture at lists dot linux-foundation dot org

IRC: #openprinting on Freenode

OpenPrinting developer resources

Code License: See project descriptions

Common Print Dialog for desktop applications and mobile devices (up to 3-4 students)

To make printing easy for the users of desktop systems and mobile devices he once needs a well-designed print dialog where he can easily find the right printer under the available printers, set general, printer-specific, and document-specific options, preview the printout, and send the job. But he also neds consistence between applications, printing should work the same way from every application, the print dialog should be the same all over the system.

For the dialog itself there is already a design of how the user interface could look like. It was done by the design team of Canonical (the company behind Ubuntu) and can be found on the Ubuntu Wiki. The dialog should support three ways of obtaining available printers: Most importantly it should list the local CUPS queues and get printer properties and options through CUPS. It also should be able to pick IPP network printers from the network via Bonjour/DNS-SD and query the printer's properties via IPP (mainly for mobile devices to use IPP Everywhere and AirPrint printers). The third way is to connect to the user's Google account to list the Google Cloud Print printers which the user has registered.

To allow for the print dialog being provided by the currently running desktop (Unity, GNOME, KDE, …) or mobile environment while the different applications use different GUI toolkits (GTK, Qt, …) the print dialog and the application should be implemented in different executables which communicate by D-Bus. An appropriate D-Bus interface got already designed earlier. Probably the design can already be used as it is, perhaps it needs some slight modifications.

The task for the student(s) is to implement the dialog with a major toolkit (GTK or Qt) or to add the D-Bus interface to call the Common Print Dialog to a major toolkit or an important application.

At OpenPrinting there has already been worked on a similar project earlier. See the resources here.

This project will be divided under several students (GTK dialog, Qt dialog, D-Bus interfaces for applications/GUI toolkits, …).

Mentors: Till Kamppeter, Project Leader OpenPrinting (till at linux dot com), Aveek Basu (basu dot aveek at gmail dot com), Ubuntu GUI developers TBD

Desired knowledge: C/Cprogramming, GUI programming, GTK, Qt, D-Bus =====Flattening non-static content (like filled forms) in PDF files for printing (1 student)===== For printing a job usually applications generate PDF files and send them to the printing system ([[ programming

Code License: MIT, Artistic 2.0

Google Cloud Print: Desktop-integrated solution for registering local CUPS printers (1 student)

Google Cloud Print is a service from Google which allows to print from anywhere with internet access to anywhere else with internet access, for example from a mobile phone to printer at home or in the office.

To do so, one needs a Google account and there one registers one's printers so that they can accept jobs sent into the print facility of this Google account.

On Linux there is already a way to share the local CUPS printers into Cloud Print: The Chrome/Chromium Browser. In its settings you can activate Google Cloud Print and the local queues get registered. The Browser even leaves a user daemon running when one closes it to continue keeping the printers available for Cloud Print.

The disadvantage of this is that the functionality is bound to a web browser, so it is awkward for people who use Firefox for example.

Do not suggest now to make the CUPS daemon (daemon which handles the print jobs) or cups-browsed (daemon which browses the network for printers and automatically creates local queues for them) registering the printers, as they are system-wide services and Google Cloud Print is based on the user's Google account, and so something which belongs to a single user.

What is needed is a user daemon which starts when logging in and stops when logging out, running with the rights of the user, connecting to the user's Google account registering the local CUPS printers the user is allowed to print on. It will need integration with the desktop for starting and stopping the daemon and for configuration in the desktop's settings utility.

Ideally it should work with the widespread Unity desktop but also GNOME support would be great.

Google documentation for printer registration.

Mentors: Till Kamppeter, Project Leader OpenPrinting (till at linux dot com), Ubuntu/Unity/GNOME GUI developers TBD

Desired knowledge: C/Cprogramming, GUI programming, GTK =====Improve the pdftopvp filter to not need copying Poppler source code or unstable APIs and/or make it Ghostscript/MuPDF-based (up to 3 students)===== The cups-filters project at OpenPrinting (included in all Linux distributions using CUPS 1.6.x or newer) provides the filters needed to convert the print job output of desktop applications (usually PDF) into the printer's native language or into the universal CUPS/PWG-Raster format as input for a separate printer driver. It also provides the pdftopdf filter to apply page management (N pages per sheet, selected pages, even/odd pages for manual duplex, mirror for iron-on sheets, ...) to the PDF data stream. One of the filters is pdftoopvp which is the interface between PDF (the standard print job format under Linux) and the OpenPrinting Vector high-level printer driver interface standard. This standard is currently used by several Japanese-market laser printers which do not use PostScript as it is usual in Europe and the US. This filter currently only supports Poppler as PDF renderer and the connection between the filter and Poppler is rather awkward, copying parts of Poppler's source code and using unstable APIs of Poppler which change with newer Poppler versions. This makes maintaining the filter difficult for the Linux distributions. The task for the student is here to once improve the interface with Poppler if possible and also add support for Ghostscript (would improve color management a lot) and MuPDF (would improve integration with mobile and embedded devices). The tasks can be split up over up to 3 students (Poppler, Ghostscript, MuPDF). Mentors: Till Kamppeter, Project Leader OpenPrinting (till at linux dot com), Koji Otani, BBR Inc. Japan (sho at bbr dot jp), Ghostscript developers TBD Desired knowledge: C and/or C++ programming Code License: MIT =====Foomatic: Improving the PPD generation capabilities: Option conflicts and printer compatibility classes (1 student)===== [[:openprinting:database:foomatic programming

Code License: GPL

gsoc/google-summer-code-2017-openprinting-projects.txt · Last modified: 2017/01/27 14:08 by till