Ubuntu 12.04, the Precise Pangolin, is scheduled to be released in a little over a week.  This is a very exciting release for us, not only is it an LTS release with 5 years of support, but it also brings some major improvements to Unity and other areas of the desktop.  It’s also going to see a very big focus on independent application developers.

Developers, Developers, Developers!

During the last six months we’ve spent a lot of time building tools and documentation for app developers.  In September of 2011 we launched the Ubuntu Developer Portal, a site dedicated to helping application developers target the Ubuntu platform, and for getting their applications distributed through Ubuntu.

The developer portal provides all the information an app developer needs to write apps for Ubuntu.  It will get you started with tools like Quickly, tell you what languages, toolkits and IDEs are available, and introduce you to the tools and workflows that make developing for Ubuntu a joy.

Once your app is ready, the Developer Portal will walk you through packaging it and submitting it to be published in the Ubuntu Software Center.  The MyApps section lets you upload and manage all your applications, provide branding and screenshots, and set your purchase price.

Going Native

In the past couple of months we’ve added extensive documentation on Unity integration, which allows your application to become part of the desktop experience.  The Unity APIs give your application a presence in multiple areas of the desktop, letting you to add extra information to the Launcher, indicators in the panel, search results in the Dash and more.

All about the Apps

Everybody knows that “Apps” are the big thing now.  No longer relegated to tablets and smartphones, “App Stores” are coming to both major proprietary desktop operating systems as well.  The Ubuntu Software Center already supports independent free and paid app downloads, and with 12.04 we want to grow that segment exponentially.

Not only do we provide a rich platform for app developers to target, we also have the means of delivering those apps directly to over 12 million users worldwide.  With Unity, your app isn’t just visible in the Ubuntu Software Center, but we put it right in the Dash!  Your app will show up whenever the user searches their system for something similar, giving it a level of visibility that no other platform offers.

Join the conversation

Developing applications for Ubuntu doesn’t have to be something you do in isolation.  Having a strong community is an important aspect in today’s software market, and Ubuntu provides you with the tools for collaborating with the existing Ubuntu user community and for growing a strong user community around your own application.    These users can help grow your app by add translations, identify bugs, and even submitting patches.

We’re also building a vibrant community of app developers, and we want you to be a part of that.  Learn tips and tricks from other app developers, share your own expertise and build professional connections.  Here you will also find a number of Ubuntu and Canonical developers who will take your suggestions and feedback for making app development on Ubuntu even better.

Hello Unity is now open for translations!

Please help me make this technology showcase is available to application developers in your native language.  Translations are done through Launchpad, and will be built into the Hello Unity package.

When the topic of contributions to FOSS come up, it usually happens that people focus entirely on the aspect of creation, specifically code creation, to the exclusion of all others.  In the context of software, this makes a certain amount of sense, since the primary product is the code itself, either in source or binary form.  Even the more broadly-focused, who make a point to expand their definition to include things like documentation and artwork, will still focus exclusively on the creation of those works.  And yet perhaps the single biggest factor towards increased creation of code is in the distribution of what is being created.

There are a number of reasons for people to write new code.  We often talk about a developer “scratching their own itch”, but other times it can be a matter of personal improvement, monetary gain, or even just plain fun.  While there are many reasons to write code, there are not so many reasons for releasing it under a Free or Open Source license.  By choosing such a license, the author explicitly wants his or her creation to be used by others, as many others as possible in fact.  The use of their creation is what motivates them, and it stands to reason that the more it is used, the more motivating it becomes to create.  The underlying reason why this is motivating can vary, but the fact is that creators of FOSS are motivated by the use of FOSS, and the more users there are, the more motivation there will be for creating it.

The number and variety of potential consumers of FOSS is larger than any single developer can hope to reach.  Even a group of developers, even a large group of them, will find it impossible to make their creations available to the widest possible audiences.  And the more effort they put into making their creation available, the less time and resources they have to put back into creating new things.  Likewise the smaller the pool of potential consumers, the less reason developers have to improve on or create something in the first place.  But by choosing an open source license, developers separate the work of distribution from that of creation.  The desire for their creation, then, will naturally lead to a much larger number of individuals and groups bringing these creations to the people who want them.  More importantly, by focusing exclusively on the task of distributing, these new groups are able to afford not just one project, but a multitude of projects, with an increase in the consumption of their creation.  And with an increase in consumption, it is reasonable to expect an increase in contributions.

The default application selection for each Ubuntu release is often the subject of much discussion and advocacy.  People called for the inclusion of Banshee long before Ubuntu made the switch.  It’s unimaginable that people who like a project and appreciate it’s developers would actively seek to have it used by an organization that contributed nothing back.  Likewise when it was announced that Ubuntu would switch back to Rhythmbox, those same advocates genuinely believed that they had lost something, again something unimaginable if they weren’t gaining something valuable from the distribution.  When PiTiVi was selected as a default application, advocates for Openshot made a very strong case for why their preferred application should be included, again because they knew that the project would gain something of value from the increased distribution.  The same happened with F-Spot and Shotwell, with the removal of the Gimp, the various boot splash systems, and more.  I can only assume that the same happens in other distributions.  The only reason why this would happen is if, whether consciously or not, people see a real value, as real as the value of code contributions, in being distributed as widely as possible.

By relieving the developers of the need to put resources into distribution, distributors allow them to create more using the same commitment of time and resources.  Likewise, by increasing the number of people who will be using it, the distributors multiply the motivating value, whatever it may be, that the developer gets in return.  And as the motivation for creating increases, the number of people who participate in creating also increases.  In this way, every distributor of Free and Open Source software contributes towards increasing the total number of creators and creations (including lines of code written), and they do so in direct proportion to the expansiveness of their distribution.

I spent some more time over the weekend working on Hello Unity.  If you haven’t already, be sure to read my first post about it.  In short, Hello Unity is a showcase application that demonstrates all the different ways an application developer can integrate their app with the Unity desktop.

The current version of Hello Unity sports a new syntax-highlighted code display, which makes it much easier to read and understand what the code is doing.  I also spent a significant amount of time going through and heavily commenting the code to explain what everything was doing.

In the Launcher section I added support for setting the “urgent” status of the application.  In Unity, this will cause the application’s icon in the Launcher to shake and, if the Launcher is set to auto-hide, will also cause the icon to slide out into view while it shakes.  This is a very useful way of telling a user that your application needs their attention.

A new section was added for integrating with the Message Menu.  It automatically adds a Hello Unity section to the menu, and allows you to add count indicators to it.  Clicking on an item in the menu will execute the code for removing it.  All of this is explicitly commented on in the source code.

Another new section is for Notifications.  While it uses the generic libnotify API, it does highlight how to use it with Ubuntu’s Notify-OSD display system, including how to updated and append text to the currently displayed notification.

Once again, if you are interested in contributing to this project, you can get the code from the Launchpad project page.  Also available there are source tarballs and installable .DEB files.

Everybody knows that programmers can contribute to Unity, and I’ve shown in my previous posts that non-developers can still contribute features and fixes that make applications integrate better.  But what if your skills lay more on the creative side of the spectrum?

Well it just so happens that you have something to contribute to Unity too.  In fact, we’re currently in need of some graphic design talent to put some extra polish on some areas of application integration.  Specifically, we need people to help create vector art for application icons that only have raster images, PNG, XPM, etc.

This wiki page contains a list of applications that have been identified as needing an SVG icon.

Now graphic creation isn’t my specialty, so I’m not going to write a step by step guide to creating these images, that’s up to you artists.  What I am going to do, however, is walk you through the process of coordinating with the upstream application developers and submitting your finished image to Ubuntu.

1) Contact the upstream

This is an important step, because even if an application doesn’t have an SVG icon in Ubuntu, there’s still a chance that one already exists.  Read over the first half of my post on upstreaming Quicklists for ways to get in contact with with them. Ask them if they have an SVG  source for their application’s icon.  If they do, that’s great! You can take that and skip down to step #3.  If they don’t, then you will need to work with the upstream project to create one that is right for them.

2) Work with the current image

It’s important that we don’t try and re-brand an application unless the authors want it re-branded.  What we want is a more flexible/scalable version of the image icon we already have.  If you are creating a new SVG file, try to keep as close to the raster image as possible, and be sure to talk to the upstream developers about any deviations or changes you need to make.  And finally, keep with the spirit of open source and make your new image available to both Ubuntu and the upstream project under a copy-left license like the CC-BY-SA or another permissive license of the upstream’s preference.

3) Preparing your image

Since we are getting close to the release of 12.04, the requirements for any further changes are getting stricter.  In order to get your image into the Precise packages, you will need to meet the following two criteria:

It must be approved by the upstream project.  Since your image will be representing their application in Ubuntu, we absolutely need their acceptance of it before it can be used.  This is why step #1 is so vitally important, make sure you are working and communicating closely with upstream from the very beginning.

It must be a plain SVG file.  This is because it will be added as a patch file against the package, and patch files don’t work well with binary data.  Since a plain SVG file is text, not binary, it makes it much easier to convert into a patch.

4) Submit your new image

The wiki page containing the list of applications has a link to the corresponding bug report filed in Launchpad.  When your image is ready, attach it to the bug report.

You will also need to add the upstream project to the bug report.  Click the “Also affects project” link on the bug page, and choose the Launchpad Project that matches your upstream.

That’s it!  Well, almost.  Once we have your image, the application’s package in Ubuntu will need to be updated to use it, but that will require some changes to packaging scripts and patch files, which will be the subject of a more technical post.  But getting the necessary image is itself a big step.

Bazaar is a great tool for distributed development, but distros are built on packages, and so packages are what distro developer care about.  That’s why many of you who have followed my previous blogs have probably been asked for patches to the package itself, not to the bzr branch.

Why the difference?  Well for package maintainers, it’s easier and faster to import  upstream changes if they keep their source code clean.  To do that, any changes made by the distro are applied on top of the unmodified upstream code in the form of patches.  There are many tools designed specifically to make this easy for the package maintainers.

Below I’m going to show you how to turn your code change into a package patch that is easy for Ubuntu developers to add to the distro’s packages.  Only do this if your submitted branch is to a package in main and it hasn’t already been merged.

0) Check your source package format

The following instructions will only work on source packages using quilt 3.0 for managing patches.  Before you do anything else, check that the file debian/source/format contains the following:

3.0 (quilt)

1) Find your revisions

Starting from your existing code branch, we first need to identify which revisions in your branch we need to turn into a patch.  To do that, we simply check for revisions in your branch that don’t exist in the main one.  Here is what I used for geany:

bzr missing --mine-only ubuntu:geany

You just need to replace ‘geany’ with your application’s branch name (the same you bzr branched in my earlier articles).  The –mine-only will limit the result to only revisions in your branch just to keep things simple.  You’ll want to make note of the first and last revisions in this output.  If, like me, you only had one revision missing, that makes it even easier.

2) Generate the patch

Fortunately the package “bzr-builddeb” provides a command that makes this step easy.

mkdir -p debian/patches
bzr dep3-patch -d ubuntu:geany . > debian/patches/add_keywords.patch

Again, just replace ‘geany’ with your application’s branch name, and dep3-patch will find the differences in your branch and convert them into a patch file.

Now that you have a patch file, we need to add it to the list of patches for this package.  To do that, all you need is to add it’s name to the end of the debian/patches/series file like this:

echo add_keywords.patch >> debian/patches/series

3) Convert your source changes

Now that your changes are in a patch file, we need remove those changes from the source code itself.  This is where those revision numbers from step 1 come in, you will need the highest revision number and one less than the lowest.  Since I only had one revision, rev 32, my numbers are 32 and 31.

bzr diff -r 32..31 | bzr patch

This causes bzr to generate a reverse-diff of your changes (by going from the higher to the lower revision), and then apply that reverse-diff to your current code, effectively undoing your changes.

Now you need to apply your new patch file using quilt, so that quilt knows about it:

quilt push -a

Which should give you the following output if everything applies cleanly (if not, then your package is going to need some extra work, and you should ask for help from someone in #ubuntu-devel on freenode IRC).

Applying patch add_keywords.patch
patching file geany.desktop.in

Now at patch add_keywords.patch

4) Log your changes

Since you are making changes to the package itself now, you need to add that information to the debian/changelog:

export DEBFULLNAME="Michael Hall"
export DEBEMAIL="mhall119@ubuntu.com"
dch -i

You will, of course, want to replace my name and email with your own (Hint: you can put those 2 export lines into ~/.bashrc for future packaging work). This will create a new entry in the chanelog for you, with one higher version number.  All you need to do it add in the comments:

* Add search keywords to .desktop file (LP: #942154)

Be sure to use the proper bug number for your changes.  Also, if you are not running on Precise, you  will need to change the release target at the top of the file to ‘precise’.  Here’s what my new record looks like:

geany (0.21.dfsg-1ubuntu4) precise; urgency=low

* Add search keywords to .desktop file (LP: #942154)

-- Michael Hall <mhall119@ubuntu.com> Wed, 07 Mar 2012 14:40:32 -0500

5) Commit and push

Now it’s time to put everything back into your bzr branch.  First you need to add your patch file:

bzr add debian/patches/add_keywords.patch
bzr add debian/patches/series
bzr add .pc/

If your package branch didn’t already have a ‘series’ file, my instructions in step 2 will have created one, so I’m adding it here just in case.  If it already existed, bzr add won’t do anything.

Next, commit and push your changes back to your submitted branch:

bzr commit -m "Convert source changes into a package patch file"
bzr push lp:~mhall119/ubuntu/precise/geany/add_keywords

There has been a fantastic amount of feedback and contributions being made by folks who have been following my recent posts, and we’ve already had some of those contributions landing in Ubuntu 12.04.  But we’re not done yet!

Ubuntu means “I am who I am, because of who we all are”.  In a very literal sense, Ubuntu is what it is, because of what other distros are.  We all bring together the best open source software from upstream developers, and we should all be giving our improvements back to those developers.  Unity may be the default desktop on Ubuntu, but it’s also been ported to ArchLinux and SuSe, and is making it way to Fedora too.  That means that your Quicklist contribution can help more than just Ubuntu, all you need to do is submit it upstream.

Step 1: Find your Upstream

While all of Ubuntu’s package sources use Launchpad, and are therefore all in the same place, your upstream developers will all of their own separate spaces.  Some are rather easy to find, for example Firefox is developed over on mozilla.org.  Others may use GitHub, SourceForge, or their own sites.  So you first task if to find out where the code is developed.

Step 2: Talk to your Upstream

Once you’ve found their development home, look for ways of contacting the developers.  Usually there will me an email/mailing list available, an IRC channel or a forum.  Whatever method they prefer, us it to ask the developers how they want you to submit your patch.  Most developers love being contacted by somebody who already has a patch written.

Step 3: Submit your changes

Depending on your upstream’s development process, they may want a patch file with your changes, or they might ask you to use their version control system of choice (svn, git, etc) to submit your change in a way that is easy for them to merge.  Some, especially Debian, may request a patch for the package itself.  This is why Step 2 is so important, you need to know how to submit it in order for it to be accepted.  Don’t worry if you don’t know how do what they want, ask them to help you learn it.  Again, developers like people who come to them with patches.

For Geany, I first found their website, geany.org, and from there a link to their Feature Tracker on SourceForge.  I also found their IRC channel, #geany on freenode, and was in contact with their developers there.  In the end, I was asked to create a fork of their code on GitHub, and submit my change as a Pull Request.

Step 4: Updated your Merge Proposal

Once you’ve submitted you changes upstream, leave a comment to that effect in your merge proposal.  Ubuntu developers don’t like to keep custom changes in Ubuntu, and your merge proposal is much more likely to be accepted if they know the change will eventually be made in the upstream project as well.

Step 5: Stay involved with your Upstream

If you were working on a program you like, don’t let this be the end of your contribution!  You now have experience making and submitting changes (to both Ubuntu and Upstream), and you are forming a relationship with the upstream developers.  Keep up with both of those, as they will be invaluable assets to you.