Sugar Labs

Summer of Code/2009/Print Support

< Summer of Code‎ | 2009
Revision as of 21:02, 28 March 2009 by IwikiwI (talk | contribs) (→‎About your project)

About you

1 What is your name?
Vamsi Krishna Davuluri
2 What is your email address?
vamsi<dot>davuluri<at>gmail<dot>com
3 What is your Sugar Labs wiki username?
IwikiwI
4 What is your IRC nickname?
IwikiwI
5 What is your primary language? (We have mentors who speak multiple languages and can match you with one of them if you'd prefer.)
English, Hindi, Telugu. I prefer English!
6 Where are you located, and what hours do you tend to work? (We also try to match mentors by general time zone if possible.)
I am located in india (5:30+ GMT), I usually work in the night, from my 7 pm to 2:30 am
So any mentor should be ideal.
7 Have you participated in an open-source project before? If so, please send us URLs to your profile pages for those projects, or some other demonstration of the work that you have done in :open-:source. If not, why do you want to work on an open-source project this summer?
I have not been part of an open source development team. Nor do I have a very profound understanding of the OS development paradigm yet. But seeing how I could never afford software which was sold at :high price even though that software was the bare essential software for me to get my computer working. And as my experiences are true for almost two thirds of other students, I would like to see them :not to have to put up with the buy-what-you-want software, in-fact I would love for them to grow up using free software that I make and hope that they will produce free software themselves, a few of them :at least.
Although not really a group developmental project, I have coded two networks projects and a prototype game for windows. (the source is in downloads)
1) Simulation of mobile units and their movement over a network (unix network programming, and unix programming)
http://code.google.com/p/iwikiwi/
2) A client/server model for file transfer, md5 check sum, IP translations, and file size requests (unix network programming, and unix programming)
http://code.google.com/p/iwikiwi-clientserver/
3) A prototype Bounce game in OpenGL for windows
http://code.google.com/p/iwikiwi-bounce/

About your project

1 What is the name of your project?
Print Support for the XO laptops
2 Describe your project in 10-20 sentences.
As the self explanatory name suggests, the project is to add print support to the laptops.For the time being, the print requests will be sent to the school server through a moodle print page
then the teacher can view the files through his login in the same application, and approve them for printing to a print server. Later on as we are going with a CUPS architecture, we can include USB
printing on demand!
Why should my idea be considered:
My refined version of the print support idea is actually a better way of ensuring that paper abuse will be curbed, as the kids wouldn't really take into account :all the predicaments associated with :printing. And needless to say printing does take place with the teacher's intervention. And everything takes place in a moodle environment, plus there is the added benefit of printing in the No XO case.
A step by step abstraction:
1) During boot of the XO laptops, Sugar will compile itself in compliance to supported file types(locally), and will have the print button enabled only when they are available.
2) The print button on click, prints the screen objects into PDF format. This will be turned into a nice sugar.print API.
(The first two steps would essentially mean a Save as PDF hack)


3) This is an interesting step, we have two implementations here: 1) the XO case 2) No XO case
In the XO case, we will have an activity in cp which prompts for Users moodle ID and password (which can be saved, and changed again if need be), and as an addition to the last step the pdf is sent to the moodle data warehouse, and a maximum of 3 live jobs in queue will be possible. The activity in cp will also show a notification of how many print jobs are in queue, and whether they have been printed or not. Also the teacher will be able to send an optional reason as to why the job was discarded.
In the No XO case, there will be a send-for-printing page( a moodle plugin) which allows the user to send his request to the datastore in the school server. On a successful send the user's page will display him the details of his job, whether in queue for printing and waiting for approval from the teacher or done printing or disapproved for printing along with an optional reason why, he can also cancel his request from the page. There will be a quota of maximum 3 live jobs per student.
4) Through moodle the teacher will have a page displaying the contents of the print datastore along with user names attached, and he/she will be able to download them to his remote system, and check them and approve them for printing if he/she wishes. After his/her approval or disapproval (that is a delete along with an option why) the information is held in the datastore, and the user can view it in the form of history transactions pertaining to his id, and teacher can view a finite list of previous transactions pertaining to all.
(These steps would mean a) moodle print queue, web interface b) (3) a cp activity that bypasses the need to use (2) if you're in Sugar)
5) So we've had a no XO case, similarly we have a no XS case. The simple solution to this case is to print directly through usb. And this won't be counter productive to the idea of teacher moderated printing, as the printer won't be available for just anyone; this is only a quick alternative to the 'save to portable drive and do the printing' method.


In-Depth analysis:
The easiest way to implement step-1 would be to check which mime types exist on the client side in the etc/cups/mime.types and mime.conv file with a simple python method (getAllowableMIMETypes) , and access it with a :python script and compile our sugar shell accordingly. So any mime type non-existent there will have its corresponding activities print button disabled. We will also write code for it to accept copy Mime info from activities .info files (whether a new activity or old)


for step-2, We use CUPS. The API has a nice array of functions, one of which is to get the printers name (the cups-pdf virtual printer). Since we know the name is CUPS-PDF, we can check it, and print our :file as a PDF to the journal. And the API can be made by generalising the pycups methods and sugar api in general.
For the sake of our python convenience we will be using a python wrapper to cups, pycups. We will be using our Sugar api to create a nice simple widget for this. And we will use D-Bus for transfer of :objects to journal. The print button will be just saving the file in its original mime format, and then a Cups-PDF job takes place and outputs a pdf in the to print objects category. And, the original :saved mime type is destroyed.
for step-3,
For a), We will create an activity in control panel which takes in the moodle id/password. And within activities when the PDF is created, through 'xmlrpclib for python we write code which sends the print jobs directly to the moodle datastore (web folder) and with each successful send show the file and queue no in the control panel activity.
For b) We will be creating a new print management page in moodle, which accepts at most 3 print requests(the pdfs) from the user at a time until one of them is processed or deleted. We will be :creating a plugin with the FILE_API of moodle( which enables us to do things like uploading client side files, and sending them, and receiving back the files, deleting them) in php, and access the local :to print files, send upload them to the moodle server datastore. I will be taking the already available "upload one file for teacher's review" plugin's code as basis for this. [1]
for step-4, We will be using the /same plug-in/interface already created/, but for the teacher we will issue global access privileges enabling him/her to access all the sent requests, and the approve :button will initiate shell commands to send the particular file to a network printer through CUPS installed on the server.This can again be achieved through hacking into moodle and understanding how notifications are sent to the students :from teacher. The notifications would be relating to whether the teacher has approved or disapproved the print. And when going with step 3) case a, we would just make moodle talk back to our activity through xmlrpc, and tell the user whether his job has been printed or discarded, and provide a reason why.
for step-5, no new code is required, just a slight modification of the cp activity to select the type of printing. A few more dependencies, Which wont exceed 17mb.


Is there a disadvantage in relying upon moodle for network printing?
Since the whole concept relies upon network printing, it will be feasible for moodle to coexist with the system on the school server. We will just be adding moodle as a :requirement for printing.


Key features:
  • Will be able to print to any USB printer
  • Will be able to output a print as a PDF
  • Can be extended to include any activities MIME types for PDF printing
  • Includes a local queue, and a teacher queue
  • Has a nice control panel activity that takes care of sending files from activities and locally queueing them
  • CP activity will have the feature to select the type of printing, which will by default be pdf.
  • CP activity communicates directly with moodle data store through XMLrpc.
  • Uses moodle as interface for teacher moderated printing
  • A 3 live/pending jobs at a time queue.
  • Teacher can approve/ disapprove printing from the queue.
  • Student will have status updates in his page and/or in his cp activity.
  • Has a no XO case, no school server case.


3 Convince us, in 5-15 sentences, that you will be able to successfully complete your project in the timeline you have described. This is usually where people describe their past experiences, :credentials, prior projects, schoolwork, and that sort of thing, but be creative. Link to prior work or other resources as relevant.
I have a fairly good understanding of communication models, and my skill with networks is quite satisfactory. And as most of the implementation is already available in form of python bindings, all that :remains is placing them together with a sound design, which I have already discussed with several community members. And I can provide as much time as is required for the work to get done.
My credentials include:
1) The ability to finish projects on his own, with self motivation, as the 3 projects I have attached have been made as a self interest.
2) An internship at Kenexa which had been to develop an assembly which logged database transactions, written in c#, so I have an exposure to infrastructure.
3) winner of a coding event, Mind-Hunters, at a national level technical festival.
I have already added a fix to Write so that it can export to pdf files, and I have provided a temporary fix for a screen bug, for which I will provide a complete fix.
And I have checked the feasibility of my approach by going through the source files/apis, and writing sample programs like


 cups_dest_t *dests, *dest;
 int num_dests = cupsGetDests(&dests);
 int job_id = cupsPrintFile(dests->name,
                            argv[1],
                            "Test",
                             0, NULL);
 if (job_id == 0)
 printf("error printing file, unsupported format");
for printing
4 What is the timeline for development of your project? The Summer of Code work period is 7 weeks long, May 23 - August 10; tell us what you will be working on each week. (As the summer goes on, you and your mentor will adjust your schedule, but it's good to have a plan at the beginning so you have an idea of where you're headed.) Note that you should probably plan to have something "working and 90% done" by the midterm evaluation (July 6-13); the last steps always take longer than you think, and we will consider cancelling projects which are not mostly working by then.


April 20th to May 26th:
  • Research the sugar API extensively
  • Write sample D-BUS communication programs and xmlrpc programs
  • Hack into moodle code, and create purposeful hacks (modifying the limits for plugin in consideration, and such)
  • Talk with the design team and produce prototype interface designs
  • Look into moodle APIs
  • Focus on the bare essential dependencies required to get the job done
Milestone 1
Week 1 :
Start writing script which actually configures the network printer server side.
Write code which prints to any selected printer.
Week 2 :
Start Work on writing a control panel activity which takes in the moodle account details, integrate this with a print button in each activity.
Week 3 :
Finish working on UIs, and append a new printer module(api) to Sugar packages (api) which abstracts a lot of code. Also write code to save to journal for our case 3) b)
Mile stone 1 : See to it that the code can print to the pdf virtual printer and attached printer. Obviously apart from these both network printing from the XOs will be disabled. Get mentor and community feedback.


Milestone 2
Week 4
Start working on moodle, build a 'For printing' page plug-in, see to it that it accepts files from client side, and stores them in moodle's webfolder (datastore) and from our control panel activity that we wrote previously
Week 5
Add interfaces for teacher logins and student logins, and write code to perform operations depending on the users/teachers interactions.
And start working on a php script for shell commands to directly print to the network printer.
Week 6
Finish working on the logical part and start working on creating a nice html layout for the page, get feedback and make corrections accordingly.
week 7
Test code on a server with a printer, and test if everything works, get mentor and community feedback, and if any integration bugs remain, drill them out.
Milestone 2: It would be to finish the moodle plugin, and see to it that printing can be done through it by the teacher

You and the community

1 If your project is successfully completed, what will its impact be on the Sugar Labs community? Give 3 answers, each 1-3 paragraphs in length. The first one should be yours. The other two should be answers from members of the Sugar Labs community, at least one of whom should be a Sugar Labs GSoC mentor. Provide email contact information for non-GSoC mentors.
From myself:
"The XO users and teachers will greatly benefit from printing, as converting something digital(which may be art, a presentation or a photo) into a physical representation is something very basic, and :something very strong. Not only will there be a good deal of happy faces, but it will also kill the effort required to copy content to a portable drive, and go to a terminal and print.
"
From Benjamin M. Schwartz:
"In order for Sugar to be adopted in schools with existing IT infrastructure, it must give users an easy way to print their documents.If that printing could be routed through a teacher-controlled visual :print queue, then in this regard Sugar would be the most preferred solution for primary education and schools with limited IT resources."
From Martin Langhoff


"So children can print their own renditions of Robocop on a Unicorn.
The goal of your project is to have a simple, effective and portable
way to print documents from the Sugar environment. The most immediate
outcome will be very straightforward printing through a School Server.
Printing is a very popular request in our DIY community so it is also
important to ensure that printing is workable even in the absence of a
School Server."


2 Sugar Labs will be working to set up a small (5-30 unit) Sugar pilot near each student project that is accepted to GSoC so that you can immediately see how your work affects children in a deployment. We will make arrangements to either supply or find all the equipment needed. Do you have any ideas on where you would like your deployment to be, who you would like to be involved, and how we can help you and the community in your area begin it?
I think it would be wonderful to begin with my school, I come from a government funded school, not one of those fancy private schools. The kids there would definitely love the different teaching :environment. I will have a talk with the principal, and after that I will further this.
3 What will you do if you get stuck on your project and your mentor isn't around?
I will of course go through the net. developer mailing lists, and forums.
But more over, the community has been very helpful without having a mentor as of yet. I will look forward to the community then!
4 How do you propose you will be keeping the community informed of your progress and any problems or questions you might have over the course of the project?
I intend to provide weekly updates on the wiki itself. And I will also be providing daily updates on the channel.

Miscellaneous

Here is the pic with my hack [2]
1 What is your t-shirt size? (Yes, we know Google asks for this already; humor us.)
Large! (do I get a sugar tshirt?)
2 Describe a great learning experience you had as a child.
Being alone and not interacting with others is a hard bargain. It might seem appropriate during the experience (as one can brush it off as," who will interact with the lessers"), but its only after you :reach an age you realise the tragedy one has brought on himself. I can never change my past, but I am a different person now and will be in the future.
3 Is there anything else we should have asked you or anything else that we should know that might make us like you or your project more?
My motto: There is no such thing as not able to achieve something, the only variable really is effort which differs from achievement to achievement with person to person.
what someone else can do, So can I.
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