QtDay 2016: Developing Ubuntu convergent apps with Qt

QtDay is the only Italian event dedicated to Qt. It is held yearly by Develer and brings together company products that are developed using Qt, as well as Qt developers and customers who want the latest developments and solutions in the Qt world. This year the conference was held in Florence, where I was lucky enough to attend and present.

I had previously attended the 2011, 2012 and 2014 QtDay events whilst I was studying Computer Science at the University of Pisa. This year it was different because Develer invited me to give a talk about Ubuntu and Qt. The funny thing was e I was already planning on sending my presentation to the Call for Proposals anyway! So I was already prepared.

What I do at Ubuntu

My role in Canonical is UX Engineer, basically a developer acting as the bridge between designers and engineers. It is a pretty cool job, and I’m very lucky to be part of such an energetic team.

Over the last year there was a strong push in both the Design and Engineering teams working on Ubuntu Touch to finalize and deliver the convergent experience. This was a great opportunity to spread the word about how to develop convergent apps for the new Ubuntu platform, and get developers interested in where we are and where we are heading.

My talk – “Standing on the shoulders of giants: developing Ubuntu convergent apps with Qt”

When I first thought about giving the presentation, I decided it would only be about the current state of the UI components provided by Ubuntu SDK, with a strong focus on their “convergent” features, and how to use them to realize your convergent apps. However, as time went by I realized it would have been more interesting for developers to also get some context about the platform itself, and how to best integrate their apps with the platform.

By the time QtDay arrived, the presentation had almost doubled in size! You can find it here.

A slideshow or an app? How about both!

This is a detail the geeks in the audience might be interested in…I thought it would be neat to talk about the development of Qt/QML apps and use the same framework to implement the presentation as well!

That’s right, the presentation is actually a QML application that uses (a modified version of) the QML presentation system available as a Qt Labs addon. Having the power of Qt underneath your presentation means you can do pretty much everything You’re not tied to the boundaries set by the “standard” presentation systems (such as Beamer, LibreOffice Impress, Microsoft Powerpoint, etc) anymore!

In my case, I exploited that to implement a live-coding view as a pull-down layer that you can open on-demand whenever you want by using keyboard shortcuts. Once the livecoding view is open, you can write code (or use the code automatically provided when you’re at one of the special “Livecoding!” slides) in the text editor on the left side and see the result in the right side in real time without leaving or interrupting your presentation. You can also increase or decrease the font size, and there’s also a sparkling particle effect that follows the cursor to make it easier for the audience to follow your changes to the text. That’s only one of the things you can do once you replace your “standard” presentation with a full featured application. If you’re a software developer then I highly recommend giving it a try for your next presentation!

The sourcecode and the PDF version of the presentation is available here and my fork of the QML presentation system is available here.

And here’s a screenshot of the livecoding view in action (sparkling particle effect included) 🙂

The morning

The conference was held in the middle of Florence at the Hotel Londra Conference Centre. It was quite a nice location I have to say! Very easy to reach as it is very close to the main railway station, Santa Maria Novella.

My talk was in the first time slot after the main keynote, which was good because, you know, that meant I could relax and enjoy the rest of the day!

I started by giving an overview of the current state of Ubuntu and the fact that it’s doing great in the Cloud field. Ubuntu can now scale to run on IoT devices as well as phones, tablets, notebooks, servers and Clouds.

I then presented the concept of convergence and how the UI components provided by the Ubuntu SDK can be best utilised to create great convergent apps, including some livecoding. Livecoding is fun because it gives a pragmatic idea of how to go from theory to practice, and also keeps the attendees awake, because they know things can go wrong at any moment (demo effect) and they enjoy that, for some reason 🙂

After UI components section, I went on to talk about platform integration topics such as the app lifecycle management, the app isolation features, and the integration with the Content Hub which is the secure way to share data between applications.

I then briefly talked about internationalization and how to publish your application on the Ubuntu Store (it’s very easy!)

For this occasion, I brought with me a BQ M10 tablet, which is the convergent Ubuntu tablet that we released just a few months ago! I connected it to a bluetooth mouse and keyboard, and set it up on a table for people to try. Lots of people played with it. After the talk it was exciting to see the audience interest in the whole convergence story.

The other talks during the morning were very interesting as well, I particularly enjoyed Marco Piccolino’s “A design system and pattern libraries can significantly improve the quality of your UI” (Find the slides here).

And then it came to lunchtime…

Food…Italian food

The food was great and, coming from the UK, I enjoyed it even more. Big kudos to Develer (the company behind the event) for finding such a good catering company!

Here’s a pic of the goodies available during coffee breaks. Mmmm…

Afternoon talks

The afternoon talks were as interesting as the morning ones. Marco Arena, from the Italian C++ Community, gave a talk about QCustomPlot, which is a library to draw graphs and plots using Qt (slides here).

If you’re interested in Virtual Reality, partially BCI (Brain Computer Interface) and machine learning, make sure you check out the slides of Sebastiano Galazzo’s talk (once they’re available, at that page). His project involves manipulating what the user sees in a Google Cardboard by reading his/her brain waves to interpret emotions. Pretty neat.

Stefano Cordibella’s presentation was about his experience optimizing the startup time of an application running on embedded hardware (using Qt4). They exploited the power of the QtQuick Loader component and other QML tricks to decrease the loading time of the application.
Check his slides out if you’re interested in QML optimization. I’m sure you’ll find them useful.

The final talk I attended was more of a roundtable about how to contribute to the development of Qt itself, led by Giuseppe D’Angelo, who has the role of “Approver” in the Qt Project Open Governance Model.

As a result of attending that roundtable not only I started contributing to Qt (See the changes I contributed to here), but I also improved theQt Wiki Contribution Guidelines so that it will be easier for other people to start contributing. The power of open source and open governance! 🙂

The closing talk also included a raffle, where a couple of developers won an embedded devboard sponsored by Atmel. I’ve been quite lucky with Qt-related raffles in the past, but this wasn’t one of those days, oh well 🙂

Closing remarks

What a great day it was. I want to thank Develer for organizing the conference and the guys from Community team (Alan Pope, David Planella, Daniel Holbach) and Zsombor Egri from the SDK team at Canonical for providing feedback and ideas for the presentation.

It was also great to see so many people interested in the convergence story and in the M10 tablet. The technology has great potential and it’s our job to make the best of it 🙂

See you all at the next QtDay!

Note: the pictures are courtesy of Develer’s QtDay Facebook page.