TheBlindCow

FreeSoftware to the fullest!

Category: bluesystems (page 1 of 3)

Tracking a QObject’s life

Why?

One of the interesting things about QML is that it leverages OOP property semantics of QObject to drive its declarative workflow.

How?

We attach into any QObject the developer requests and monitor it (and optionally all it’s children).

To gather the information we need, we will collect information for every property and connect to the property’s notification signal to see when it changes.

What?

This is the repository:https://phabricator.kde.org/source/kobjecttracking/.

This allows us to see:

  • Spurious property change notifications
  • Property changing bursts (i.e. same property changing values repeatedly in a short amount of time)
  • How a change in a value can have an effect on other properties

At the moment we have two ways of inspecting an application:
On one hand we have warnings that allow us know specific things and even add breakpoints to the sore points. The warnings at the moment look like this:
repeated value ScrollView_QMLTYPE_43(0x5648c6d97b50) width QVariant(double, 320) 8 times
repeated value Kirigami::BasicTheme(0x5648c6986ac0) backgroundColor QVariant(QColor, QColor(ARGB 1, 0.988235, 0.988235, 0.988235)) 11 times

Additionally, we have a timeline view output from tracking. You can see an example of plasmashell run here.

Future

An idea would be to integrate automatically ModelTest, so if a QAbstractItemModel is found, a ModelTest instance is attached that makes sure the model is true to its promises.

Another thing that bothers me is that we are forced to compile it into the application. If we could make it possible to have processes attached or start the application somewhat automatically (like GammaRay does, wink-wink) we would ease the adoption of these tools.

What do you think? Do you think it’s useful?
Feedback very welcome.

KDevelop runtimes: Docker and Flatpak integration

On my last blog post I discussed about how some assumptions such as the platform developed on can affect our development. We need to minimize it by empowering the developers with good tools so that they can develop properly. To that end, I introduced runtimes in our IDE to abstract platforms (much like on Gnome’s Builder or Qt Creator).

There are different platforms that we’ll be developing for and they need to be easily reachable when coding and testing. Both switching and interacting transparently with the different platforms.

To that end I implemented 4 approaches that integrate different runtimes:

  • Docker, allows you to develop directly against virtually any system. This is especially interesting because it enables to reproduce the environment our users are having: behavior on execution and project information (i.e. the imports are the ones from the target rather the ones on our local system). Docker is a wide-spread technology in the cloud, I hope many developers will see the value in integrating the deployed environment into the IDE while they are coding.
  • Flatpak, is a solution that targets specifically desktop Linux applications. We are talking about distributing bundled applications to users, there we have the opportunity to integrate the tooling specifically to that end: from fetching dependencies to testing on other devices (see videos below).
  • Android, as you know it’s something I’ve been pushing for years. Finally we are getting to a space where the IDE can help get some set up troubles out of the way.
  • The local host, i.e. what we have now.

And remember KDevelop is extensible. Do you want snapcraft?, vagrant?, mock? Contributions are very welcome!

If there’s something better than a list of technologies and buzzwords, that’s videos. Let’s see why this could change how you develop your software.

One development, any platform

We get to develop an application and switch back and forth the target platform we are developing for.

Here I put together a short video that tests Blinken on different platforms:

One development, any device

Using the right SDK is not enough proof that the application will work as expected on every device, especially those our users will be using. Being able to easily send our application to another device to test and play around with is something I had needed for longtime. Especially important when we need to test different form factors or input devices.

In this video we can see how we can easily test an application locally and when it works just switch to Android and send to the device for proper test on the smaller touch screen.

Here we can see how we can just test an application by executing it remotely on another device. This is done by creating a bundle of the application, sending it to the device where we want to test it and executing it there.

Hassle-free contributions

You can’t deny it. You’ve wanted to fix things in the past, but you couldn’t be bothered with setting up the development environment. Both Flatpak and Docker offer the possibility to maintainers to distribute recipes to set up development platforms that can and should be integrated so that we can dedicate this 1 hour in the week-end to fixing that bug that’s been annoying us rather than reading a couple of wikis and – oh, well, never mind, gotta make dinner.

We can do this either by providing the flatpak-builder json manifest (disclaimer: the video is quite slow).

Or a Dockerfile.

You can try this today by building kdevelop git master branch, feedback is welcome. Or wait for KDevelop 5.2 later this year. 🙂

Happy hacking!

Getting Free Software into our users’ hands

In KDE we cover a mix of platforms and form factors that make our technology very powerful. But how to reach so many different systems while maintaining high quality on all of them?

What variables are we talking about?

Form factors

We use different form factors nowadays, daily. When moving, we need to be straight-forward; when focusing we want all functionality.

Together with QtQuick Controls, Kirigami offers ways for us to be flexible both in input types and screen sizes.

Platforms

We are not constantly on the same device, diversity is part of our lives. Recommending our peers the tools we make should always be a possibility, without forcing them into major workflow changes (like changing OS, yes).

Qt has been our tool of choice for years and it’s proven to keep up with the latest industry changes, embracing mobile, and adapting to massively different form factors and operating systems. This integration includes some integration in their look and feel, which is very important to many of us.

Devices & Quality Assurance

We are targeting different devices, we need to allow developers to test and make it easy to reproduce and make the most out of the testing we get, learn from our users.

Whatever is native to the platform. APK (and possibly even Google Play) on Android, Installers on Windows and distribution packages for GNU/Linux.
Furthermore, we’ve been embracing new technologies on GNU/Linux systems that can help a lot in this front including Snap/Flatpak/AppImage, which could help streamline this process as well.

What needs to happen?

Some of these technologies are slowly blooming as they get widely adopted, and our community needs as well to lead in offering tooling and solutions to make all of this viable.

  • We need straightforward quality assurance. We should ensure the conditions under which we develop and test are our users’ platforms. When facing an error, being able to reproduce and test is fundamental.
  • We should allow for swift release cycles. Users should always be on fresh stable releases. When a patch release is submitted, we should test it and then have it available to the users. Nowadays, some users are not benefiting from most stable releases and that’s makes lots of our work in vain.
  • Feedback makes us grow. We need to understand how our applications are being used, if we want to solve the actual problems users are having.

All of this won’t happen automatically. We need people who wants to get their hands dirty and help build the infrastructure to make it happen.

There’s different skills that you can put in practice here: ranging from DevOps, helping to offer fresh quality recipes for your platform of choice, improving testing infrastructure, or actual system development on our development tools and of course any of the upstream projects we use.

Hop on! Help KDE put Free Software on every device!

Discover more in 2017

With 2017 starting, we’re getting ready for the next Plasma 5.9 release and with it a new Discover release.

This will be a special release for two main reasons: further add-ons integration and Kirigami.

New Stuff

One thing pending for a long time was to actually better integrate the different parts of the system that can be integrated. To do so, Discover now will automatically import all knsrc files present on the system and offer them as categories.
We’ll be able to go beyond Plasmoids and Comics (!) and make it possible to explore: Plasma Look and Feel themes, cursors, icon themes, window manager add-ons and different application-specific resources.

This won’t have a big impact on Discover’s performance because the backend code was refactored to be able to have several backends loaded even without knowing all of the resources available. Queries are now asynchronous and parallel.

Discover KNS Addons

Kirigami

Kirigami was adopted in the previous release already, and this release will use Kirigami 2, the port to which did not require much work.

The most significant improvement is the inclusion of keyboard navigation, which was requested by several people and is now finally available. Do you hate it when you’re required to use the mouse? Rejoice!

Extra: Snappy support

It’s 2017, not all of the applications are coming from your distribution anymore. To start getting things in place for different software distribution sources I started working on a Snap backend, which allows us to manage applications coming from this system.
Some work will still be required and it won’t be included by default, since it doesn’t yet support AppStream (although we discussed it and it seems it will happen soon), but if you’re curious feel free to take a look and give your feedback!

GNU/Linux bundled application ramblings

It’s impressive how in the last few months (and especially the last few weeks) the discussion around bundled applications for the GNU/Linux Desktop has sparked.

It’s especially interesting because:

  • The problem is not new.
  • The solutions that have attempted to tackle the problem in the past have been ignored (both by us developers and by distributions).

The TLDR

First, let me try to subjectively summarize the problem: Historically, the resources we get in GNU/Linux come from the distributions. Anything: executables, libraries, icons, wallpapers, etc. There’s been alternatives to all of those, but none has flourished as a globally adopted solution.

This guarantees that everyone using a distribution will have access to the resources the distribution can offer. The more powerful the distribution is, the more we get. There’s limitations nevertheless, so some restrictions have to get in place. The ensemble of limitations and technologies adopted will effectively define the user’s experience.

This works. It has worked for years and, given the technology is in place, it could easily keep working. Like in most engineering solutions there’s drawbacks and properly addressing them can bear some goodness. It seems like now it’s the moment to review this situation. Let’s enumerate some of the problems we have nowadays:

  • We have users using really old versions of our software with issues we’ve solved in versions they can’t use.
  • It’s really hard for GNU/Linux users to get users to test unstable versions of our software.
  • We have users who want to use fresh versions of some software but not in the whole system.

There’s been many solutions to fix those, some easily come to mind: ArchLinux’s AUR (with yaourt), Ubuntu’s PPAs, big-tar application packages, OpenSuse’s OBS, and possibly others.

Far from showing the maturity of the Linux desktop, what this depicts is the deep fragmentation we’re into: we have come up with different solutions that break the established distribution paradigm by lowering the restrictions and considering the resources offered as unsupported (often tainting the whole system).

What has appeared recently is sandboxing. It’s especially interesting because by letting the users execute any binaries we’re increasing the exposition of their systems. Hence, jumping from our distributions’ nest into the lions. As always, sandboxing creates new challenges: It requires changes in applications (or frameworks) to adapt, often creating a user interaction fence (e.g. a popup asking if you let Kamoso access the webcam). For what it’s worth, that’s not new: Android does it, OS X does it, Windows does it (from the Store), Chrome OS does it, etc.

Now where are we?

We need to decide about GNU/Linux’s future. Or at least, we need to understand what Plasma users will have available. So far, most of the noise comes from the big players in the business trying to differentiate their products, meaning incompatible versions.

Without an agreed unified solution, we’ll have to assume we’ll end up having installed snappies, flatpaks, AppImages as well as applications from the distribution. Then it’s just a matter of:

  • Presenting it properly so that the user knows the risks taken by executing an application (!)
  • Make sure we don’t lose many features by sandboxing.

Still, one of the good things of this new approach is that it shouldn’t have to be necessary to have several people dedicated to build every single application and component. If the solution is to add 3 more solutions that will need dedicated people, we’re not really moving forward.

Building

As soon as we’ve decided how we want to work, then the interesting stuff needs to appear. If this is properly engineered, it can bring really interesting possibilities that now we hardly ever find:

  • Newer versions of applications on administered systems (e.g. universities).
  • Enabling stable distributions on professional environments.
  • Beta channels.
  • Binary application 3rd party extensions.
  • Provision of debug symbols (some distros don’t offer them).

To finish the fantastic post, a note for the dreamers:
How easier would all that be in a microkernel architecture?

We need you!

Of course this will be a long journey and we need your collaboration. This year in Randa we started working on all these problems in several different angles. It’s important for the KDE Community to have your support, so we can keep providing quality software. Consider donating, doesn’t need to be a lot, everything counts.

Discover in Plasma 5.7

I haven’t talked about what’s going on in the Discover front for a while, here’s a small heads up on what you’ll get in the next Plasma 5.7 release.

Back Ends

  • PackageKit (and AppStream): This one has received most of the care. It has been rearranged to instant load. Also we made it possible to integrate this backend with KNS/OCS, to show when there’s add-ons ready for an application.
  • KNSBackend: It’s being polished and adapted for new use-cases. First it used to focus on Plasma-centered assets, but we’ve worked towards making it possible to become a viable solution for Application add-ons as well. Furthermore it has been trimmed down to also provide fast startup while keeping its features.
  • QApt: The traditional QApt backend used in Kubuntu is now considered deprecated in favor of PackageKit, which I understand should be available properly on every GNU/Linux distribution, including Kubuntu. We kept it around because there’s been longstanding issues with PackageKit on Ubuntu, but I’m confident these will be solved soon.

Front End

We used to have many of them, they have now been reduced to two: Discover and the Notifier Plasmoid. This allows us to focus one GUI. Of course, you can still use Muon, Apper and Synaptic together with it, for more precise package management.

Regarding Discover, the main focus this year has been: performance, stability and Add-ons.

  • Performance: Mostly back-end work, and it has also benefited from improvements in KF5 and upstream Qt. Updating the dependencies will improve your Discover experience as well as that of other similar applications. Better usage of some model classes was also a nice improvement in some places.
  • Stability: We worked on making sure that things not only are sturdy but that the development process doesn’t get in the way of stability. To that end, I set up a testing framework so that changes are automatically tested, additionally to the manual tests the developers will do at some point.
  • Add-ons: One of the important parts of Discover, is to make sure the user is aware of the nice resources he has available. KNewStuff resources (mostly coming from kde-look and kde-files so far) have been available for a while, albeit mostly for Plasma enhancements. In this next release we allow these to extend applications themselves as well.

Future

Discover‘s future is Kirigami. We have already some work lined up (see the kirigami branch), we are pending some design work so that it shines, but the approach is already quite promising!

Also I’d like to start working on the Flatpak backend, if nobody beats me to it. 😀

Stay tuned!

AppStream offers a Cross-Distribution identifier for applications

One of the problems we’ve historically had in the GNU/Linux world (and especially in KDE, since we’re cross-distribution) is that we’ve always had a hard time at explaining how to install our applications. Basically because it’s different on each distribution.

My first approach to this problem was creating Muon Discover but that’s clearly not enough because, in the end, we seldom look for new applications. Often they will be recommended on a blog post or forum and we’ll want to install it. But then, while recommending it, it will either be a vague “you should try KMail” or a “you should ‘apt-get install kmail’ or whatever applies to your distribution.

What I’m proposing today is to embrace AppStream at the level of URL handlers (for web browser integration). AppStream shows GNU/Linux distributions maturity by offering a solution by letting the upstream projects set the identifier in their appdata.xml file (among other things) and then let distributions name the package however they want, rather keeping to push different naming schemes down each other throats.

AppStream has been supported in Discover for over a year now (only for PackageKit so far) and, since introducing this feature is straightforward, I implemented it in master.
If somebody wants to give it a go, test master and click here: KMail

I think this will be beneficial not only for KDE but any project packaged on GNU/Linux distributions that have a presence on the web and need to find their way in users’ installations. This will of course be limited to getting the URL scheme adopted by our peers.

/me winks at Gnome Software and Ubuntu Software Center.

Plasma Mobile SDK

Where are the giants?

When approaching this issue I had been thinking about the issue for a while. I had mainly 2 problems: I was rather frustrated with previous Linux-based systems so far and the one I liked didn’t really scale for us. One thing was clear: We had to stand on the shoulder of giants.

  • The first one to think about was the N9 SDK (and by extension N900). It used to have a scratchbox-based system that emulated the one on the phone. It was useful for testing the applications locally on the device (although I actually never used that), I think that this one had both cross-compilation toolchain and base system, as well as the host and it used QEmu if a host executable was run. It felt weird because it shoved you in a weird system and you had to pull your code in weird ways to fetch it. Otherwise it worked great. Afterwards, madde came. It’s what I was looking for really and played quite well with cmake, actually when I published the steps on how to develop for the N9 it’s what I used back then, but it probably was too late for it to become a thing I guess. Also many people weren’t too fond of it, as I learned after some time.
  • The Android NDK is the other I took into account. I don’t think it would be fair to compare anything we could do with the actual Android SDK, so I’ll limit myself to this one. This one ships the complete cross-compilation toolchain and runs native (similar to the BBX SDK, IIRC).

For the N9 approach, I would have had to concentrate on figuring out technologies that were long dead (and probably should remain). For the Android approach I found 2 big problems: We have to actually work on generating the actual binaries (which means, from any platform to a specific ubuntu-vivid-arm target) plus all the dependencies. This meant, creating a new distro, and we already had debian/ubuntu for that, let’s use debootstrap! Oh, wait…

Old school

For a start, I took what sebas already started, in fact. Using debootstrap to create a chroot jail that could cross-compile the projects into our platform. This started to prove feasible really soon, as 2 or 3 days after working on it (and after fixing some issues that kept arising, mostly on KF5 itself and packaging), I already started to output binaries that could be deployed on the device.

Problems:

  • My IDE is outside of the jail, so there isn’t much we can do to integrate at all (we can’t access the build directory, and most of the data in it isn’t too meaningful for the outside anyway). A solution would be to ship and run the IDE from within the SDK though.
  • You need to be root. Not only to generate the system, but also to run it.

New school

An idea I wanted to approach was docker. Everyone on the web world is shit-crazy about it and it’s deeply based on traditional Linux, so there’s quite in common already. Doing something similar to the deboostrap there was a piece of cake, and I managed to re-use the set up code I already had for the previous version.

Problems:

  • Also everything is inaccessible from the IDE
  • I’m less aware of the limitations I’ll find.

Still, this second approach feels lighter and it’s quite fun to investigate something new like that.

Tooling

It seems that the jailed systems are the way to go, at least for now, so the tools I’ve created so far assume that they live in the jail as well. So, what do we have?

  • createpkg: Makes it possible to create a deb package that can be sent to the device for testing. It’s much simpler than the simplest deb package ever, but it works. Much better than sending executables over, much better than learning how to package for Debian.
  • deploypkg: sends the deb file, installs it and starts the application.
  • click-get: Downloads a click file from the Ubuntu Store, it’s harder than you’d think.
  • kdev-debdeploy: Does it all, inside your good ol’ IDE.

To be done

  • Workflow: Figure out a way to deploy KDevelop within either jail, but then we’ll also be able to use kde-debdeploy, that does mostly the same as these tools, integrated on the IDE.
  • Emulation: Testing: QEmu + docker anyone?

Suggesting new ways: Kamoso 3.0 Technology Preview

The world changes, and with it, we change too. For this new version of Kamoso we wanted to iterate what we’re presenting.

The Camera

Since we’re using GStreamer, we could take advantage of newer technology available there. Now we’re using camerabin for the video capture (in contrast to using v4l2src directly).
This will offer a better experience, with less tweaks on our side, that will definitely improve the end-user experience.

User Interaction

The whole application wasn’t rewritten, but all the UI was. We have a re-designed interface that integrates some really lean and meaningful animations and sorts the components so that we can get a simple, dialog-free UI.

Sharing

Sharing is probably the most important feature in Kamoso besides video capture, and we took special care of it. We adopted the new Purpose technology that is seeing its light for the first time with this Technology Preview. We want to make sure that we can offer the best solution by making sure it integrates properly on our UI and it can also be integrated on other parts of KDE. This way we’ll be able to come up with an adequate set of plugins and enjoy them all in community. For now, we have: KDE Connect, Imgur for images and YouTube for videos.

Where to find it?

I put together this little list, so everyone can find the tarballs and packages (on the distributions that managed to package it):
https://userbase.kde.org/Kamoso/3.0#Alpha

We need you!

We need special help with:

  • Testing, on more cameras, more hardware.
  • Artwork, especially icons.
  • Coding, especially Purpose sharing plugins (Facebook? Twitter? ownCloud?)

But anything else is welcome, as always. Please get in touch!

Identities, I usually don’t stop being myself

One of the most interesting developments I’ve seen recently inside KDE is KAccounts (or Web Accounts, as it used to be called). It’s not even a KDE project, but a project Nokia started some years ago, I’m guessing that on MeeGo days.

Why do I care?

As a developer it’s always very important to know what resources you have available. The more you have, the richer the users’ experience will be. Resources are not only hardware but often just semantically-structured information. For example, KPeople helps us tell apart the contact list and offers us people instead or Solid, that turns the different ways of exposing the hardware information into something easily consumable by front-end applications.

Now we’re talking about identities. We don’t exclusively rely on local data anymore, I think that’s a fact nowadays (and even 5 years ago). Our disks are just another place where we store some of our data. KDE projects must be prepared to easily offer such workflows. One of the important parts to do it properly is authentication:

  • We need a list of available services we can use.
  • We don’t want our users requested identity authentication all the time.
  • We don’t want each application to implement the N authentications algorithms of the N different providers our users will eventually have.

Why do you care? (as a KDE software user)

First of all, you want your developers to have the best tools (GOTO: “Why do I care?”).

There’s a more important issue to figure out, more ideological than technical: We ask service and software providers to use standard specifications to improve interoperability, but then in practice we are seldom leveraging it. The case-by-case set up burden makes it hard for users to have everything configured properly. An example for this is ownCloud integration. I know a couple of people running an instance, but they seldom integrate it in Dolphin, but even if they did they’d still need to integrate the rest of provided services, such as calendar, contacts, etc.
We want to tell our software what providers we have available, those providers will provide different services. The software should integrate as much as possible with those services.

How can I help?

  • Testing: There’s a lot going on, thorough testing and ideas is important. Both when it comes to making sure everything works as expected as well as what software should adopt KAccounts. It will already be available with KDE Applications 15.04.
  • Developing: Make sure your application of choice uses KAccounts to figure out the configured services. Here’s a good place to find documentation: API, and an example use-case.
  • Promotion: It’s important to reach out to service providers, make sure they know there’s such possibility and hopefully they can help us work better with their services (hey! by the book example of a win-win situation!).

Nowadays our computation experience is spread among different services and we need to be smart enough to understand how our users will adopt them and make it as transparent as possible.
AccountsSSO and KAccounts are a solid step forward in this direction, let’s get back in control of our data!

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