Profiling displays is already not a super simple thing on its own, but things get more complicated when you try to profile your display in Wayland - profiling applications don’t support Wayland yet, some APIs on the compositor side to make it work well are still missing, and there’s a general lack of information on the topic. So today I’ll show you how to profile your display in the Plasma Wayland session.

I did this in Fedora 40, but you can follow these steps in other distributions as well.

Step 1: Install DisplayCal and start it

This sounds easy, but

• it’s not packaged for Fedora. That’s being worked on, but right now it’s not an option | edit: turns out there is a COPR for it
• installing it with pip just gave me a bunch of compilation errors, and I haven’t figured out how to fix them
• the package on Flathub is really old and broken

To work around that, I used distrobox to install the Arch Linux package for DisplayCAL:

sudo dnf install distrobox
distrobox create --name archinabox --image archlinux:latest
distrobox enter archinabox
sudo pacman -S displaycal
distrobox-export --app displaycal
exit

After running these commands, DisplayCAL can be started from any app launcher, like Kickoff or KRunner.

Step 2: Setup

To get correct measurement results, the compositor needs to pass the pixel data from the profiling app directly to the display, and not do any color management itself. This will be automated at some point, but for now you need to manually ensure that

• HDR is disabled
• the color profile of the display is set to “None” in the display settings
• night light is off, or at least suspended in the system tray
• all KWin effects that modify colors, like the color blindness correction effect, are disabled
• if you’re on a new-ish AMD laptop and want to profile the internal display, that you’re either plugged in to a power source, or have the power profile set to performance, to disable a power saving feature that changes the colors

Now start DisplayCal and head to the Calibration tab. Here it’s important to set the tone curve to “as measured”, and untick interactive display adjustment, as those don’t work correctly right now and will mess up the profile.

You’ve done everything correctly if the button on the bottom of the application shows “Profile only”.

Last but not least, you also need to adjust the display settings to what you want to use with the profile later, as the profile is only correct for one specific set of display settings. This includes the brightness of the display!

Step 3: Profile

In the profiling tab of DisplayCAL, select your desired settings - in most cases the default will be sufficient - and click “Profile only”. When it asks if you want to continue with the current calibration curves, select “use linear calibration instead” and de-select “embed calibration curves in profile”. Then put the colorimeter in the center of the screen, and let it do its thing.

Once it’s done, it’ll ask you to install the profile. Installing it will not automatically enable that profile to be used, but it’ll save the profile in ~/.config/color/icc/devices/display/ and you can select that file in the display settings.

Step 4: Verification (optional)

If you’d like to make sure the profile is correct or accurate enough, you can use DisplayCAL to verify the result. Make sure you’ve set the profile in the display settings, switch to the verification tab in DisplayCAL and select your newly created profile in the “settings”

Here again, because DisplayCAL doesn’t support Wayland yet, you need to adjust a few settings for everything to work correctly. You need to select the simulation profile “Rec.709 ITU-R BT.709”, select “Use simulation profile as display profile” and set the tone curve to “Gamma 2.2”. Afterwards, click on “Measurement report”, choose a location to save it in, put the colorimeter in the center of the screen again and wait for it to complete.

Don’t be alarmed if the result says the whitepoint is wrong, this is simply caused by DisplayCAL assuming we want to target the whitepoint of the simulation profile, which doesn’t necessarily match the whitepoint of your display.

What about calibration though?

To calibrate the display, that is, to adjust brightness, tone curves for non color managed applications and the whitepoint of the display, DisplayCAL uses an X11 API to set the gamma lookup tables of the GPU. That API doesn’t work in the Wayland session and the profiling process doesn’t handle that situation properly, which is why all calibration needs to be disabled for the created profile to be correct.

DisplayCAL (or ArgyllCMS, which does the actual profiling) could add support for applying a lookup table in the application instead of having the compositor do it, but we can also handle calibration entirely on the compositor side instead, which offers a bit more flexibility.

Changing the tone curves for non color managed applications doesn’t make sense in the Plasma Wayland session, as all windows are always color managed, so that part is already dealt with. Adjusting the brightness on screens that don’t have any native means of brightness control is already implemented for Plasma 6.2, and I have a working proof of concept for changing the whitepoint of the display without needing a new ICC profile too, so we should be at feature parity soon. I’ll talk more about these adjustments in a future post.

Dear digiKam fans and users,

After five months of active maintenance and long bugs triage, the digiKam team is proud to present version 8.4.0 of its open source digital photo manager.

Long time bugs present in older versions have been fixed and we spare a lot of time to contact users to validate changes in pre-release to confirm fixes before deploying the program in production.

OPC UA client code that relies on hardcoded NodeIds is brittle and often only works with a specific OPC UA server instance. This article shows the proper way to write robust and portable OPC UA client code.

Continue reading OPC UA: Programming against Type Descriptions at basysKom GmbH.

Hi there! The past few weeks have been really busy with my final exams, so I had to slow down my work. Here’s a brief status report on my progress over the past 4 weeks:

I created a SubtitleEvent class to help us better manage subtitle event information, which can replace the original SubtitledTime class. To distinguish subtitles from different layers, I also added basic display support for subtitle layers as multiple subtitle tracks.

Currently, I’m focused on refining these features. There are still some minor tasks to complete and bugs to fix. You can find more information at this MR.

Stay tuned!

I have a very.. unusual notetaking and task setup with Kate, using Orgmode files. I wanted to showcase it and explain how it works, maybe someone else has similar needs.

Here's a small screenshot of my journal notes, I blurred out some things I didn't want to share.

Why OrgMode?

I actually prefer markdown much more. I enjoy writing markdown files and it just works in most editors. However, there is zero markdown note taking apps on android, that allow me to sync from my nextcloud and have notifications.

I write very journal style notes. I have one big journal file (used to be a file per day before), where I write down all the interesting things that happened, plus most importantly, my work tasks.

I tried to use calendar with tasks before.. But theres way too much context switching between notetaking apps, calendars, tasks (and on android you have to have two apps for tasks and calendar!!!). I was drowning in various apps and windows, constantly hopping around..

All I wanted to do was write down a task in my journal, then have that task notify me on my phone and on my desktop whenever it was scheduled.

So eventually I found an app called Orgzly Revived. It lets me take the outline style notes where everything is a bulletpoint, with tasks and such, timers, repeats.. And it has the dang phone notifications no other note taking app has. So it's perfect. Works awesome for my needs.

Only thing is that it requires Orgmode files. Okay, I can do that. I first used Logseq with both markdown and orgmode files, but it's quite slow app, even on my nice PC. And no notifications on mobile of course.

I then realised that I am trying to overcomplicate things. I live a lot of my work life in Kate editor, so I decided to start using that. I had to update the Orgmode Kate syntax file a bit to make it work better for me (it's been upstreamed now yay), but other than that it works really nicely.

And why not Emacs? I need an editor, not an OS. Well, jokes aside, I am just not really into learning yet another tool for something like note taking. Last time I tried to set up Neovim config that works for me, I just ended up doing everything in Kate.. I wager same would happen with emacs. I am very happy with Kate, that's all. And I contribute to it now and then, so it just makes sense to use it. :)

Now I just sync all my note files through my Nextcloud to my phone and my computers. I have couple scripts that make figuring out my agenda and have notifications on my PC as well.

My Kate setup

My setup took some time to get together and with couple scripts and snippets it works pretty well.

• First, you need to git clone https://codeberg.org/akselmo/kate-orgmode.git
  • In there I have couple python and shell scripts, and snippets for Kate
  • You need to create a .venv for it with python -m venv .venv and then pip install -r requirements.txt
  • Check the Readme file for how to use the snippets
• Create session called Notes.
  • In Plasma, you can just search "Notes" in KRunner and open the Notes session, that just opens the files.
• Symlink the org mode snippets to ~/.local/share/ktexteditor_snippets/data/ and make sure they work in Kate
  • Snippets are incredibly powerful in Kate, i recommend using them for many things!
  • These snippets automate stuff like "worktask" entries.
  • Unfortunately any timestamps need to be modified by hand, i have not yet had time to make an external tool that spawns a calendar view and spits out a timestamp.
  • For example, "worktask" adds a following item.

* TODO [#ABC] task_name :work:
SCHEDULED: <2024-07-07 Sun 21:12> DEADLINE: <2024-07-07 Sun 21:12>
  :PROPERTIES:
  :CREATED: [2024-07-07 Sun 21:12]
  :product: product
  :kdebug: [[https://bugs.kde.org/show_bug.cgi?id=bugid][bugid]]
  :merge-request: UPDATE_ME
  :END:

• Add an "external tool" entry for the run-orgagenda.sh item in the files.
  • Set the "Output" setting to "Display in a panel"
  • For the scripts, make sure they're reading right folder (where your notes are)
  • Now you can press ctrl+alt+i and type Org Agenda and it shows you a fun lil overview in a panel of all your items in agenda
• In your DE's autostart, add the run-orgnotifier.sh script.
  • This will send notification for anything you have set as scheduled or deadline before 30 min, and before/after 5 min of the timestamp.

That should be it for the setup, the code for these scripts is absolutely horrid but you should check that all filepaths match yours etc. I need to clean up the code when I feel like it but honestly it Just Works:tm: for now.. lol.

Journaling?

I have one single file that is called Journal-2024 and I create new journal every year. In this journal file, I prepend new items on top of the file, like this.

* Daily notes 2024-07-07
  :PROPERTIES:
  :CREATED:  [2024-07-07 Sun 21:20]
  :END:
Some notes for this day
** Some specific subnote for this daily note
blabla

* TODO [#A] do this task ples :personal:
SCHEDULED: <2024-07-06 Sat 21:22> DEADLINE: <2024-07-07 Sun 21:23>
  :PROPERTIES:
  :CREATED: [2024-07-05 Fri 21:22]
  :END:
blalbla

* DONE [#B] ancient task :work:
  :PROPERTIES:
  :CREATED: [2000-01-01 someDayIdk 21:23]
  :END:
its been 24 years
#+BEGIN_SRC code
ancient code
#+END_SRC

This means that you can just quickly see all the new items. Also in Kate, there's a handy feature for folding all toplevel nodes when you press ctrl+alt+i so you get just list of all headers. I use it all the time. Folding the nodes only works with the newest ksyntaxhighlighting since i recently updated the orgmode syntax file to support that lol.

Anything else

Any other items go to their respective note files.

For example anything related to programming goes to "Programming notes" file. Then I use tags for those items to categorize them based on language, framework, etc..

Instead of having many small files, I have multiple big files, where I categorize items with tags. I can then easily search for items by typing :tag: in the search field in Kate, and it shows me all items related to that tag. Just, well, remember to tag your items! :D

Wrap up

To wrap it up, this system has made things much easier to remember for me, and I can handle more complicated tasks like repeating workout tasks with my phone. (I can do it in Kate too but it requires manual number changing).

I wouldn't mind changing back to markdown if there was a markdown app for phone that has actual notifications.

Sorry this post is a bit all over the place, but there's really not much more interesting things to share about this. It's just couple scripts reminding me or showing all the items in my agenda, and the rest is snippets in Kate and writing orgmode files.

And I am quite happy with my system. Maybe it'll help you to get some ideas too!

Also please tell me about any markdown note taking apps that have notifications on mobile and desktop, if you know any. You can ping me on fedi, which you can find on my about section.

Thanks for reading!

Who am I?

I am Ajay Chauhan (IRC: hisir:matrix.org), currently in my second year of undergraduate studies in Computer Science & Engineering. I'll be working on porting Arianna to Foliate-js for my Google Summer of Code project. I have previously worked on Kdenlive as part of the Season of KDE '24.

I hope to help bring the said feature into reality, but also to sharpen my own development skills through real-world projects, contribute back to the open source community and gain more inner confidence.

What am I working on for this year’s GSoC?

Arianna uses epub.js, which is no longer actively maintained. This creates a challenge as the epub.js may not be able to keep up with the evolving standards and new changes. To address this issue, the proposed solution is to port Arianna to the Foliate-js, which is an actively maintained epub renderer and has more features compared to epub.js and is used by the Foliate ebook reader also.

The problem that this project aims to solve is the need for a reliable and up-to-date epub rendering solution for the Arianna ebook reader. By porting Arianna to Foliate-js, the project will ensure that Arianna can continue to provide support for the latest epub standards and features.

My mentors for the project is Carl Schwan, and I appreciate the opportunity to collaborate with and learn from him during this process.

My work done so far

Setting up the development environment

First step was to setup the dev environment, I used Qt Creator for that, it’s fairly easy to set up the development environment.

Reading through existing codebase

The journey began with a thorough review of the existing implementation of epub.js (epub-viewer.js) in Arianna. I identified the features and functionalities that needed to be ported to Foliate-js, understanding how epub.js was used in Arianna for rendering, navigation, and user interactions, and the C++ backend code.

Next, I focused on identifying all the places where epub.js was integrated with Qt in Arianna. This involved comparing the existing implementation with Foliate-js's approach to implementing the same features. To document the changes, I prepared a draft merge request.

Familiarised myself with the current Foliate reader implementation of the foliate-js. However, challenging for me to understand the backend architecture and how different components are interconnected within Foliate-js, requiring additional time to fully grasp the codebase.

Implementing changes

• Fixing the tricky part of the loading process. I had a hard time wrapping my head around how all the pieces fit together. My mentor helped me in this.

Implemented Table of Contents (TOC) functionality:

const { book } = action.payload;
if (book && book.toc) {
  applicationWindow().contextDrawer.model.importFromJson(
    JSON.stringify(book.toc)
  );
} else {
  console.warn("Book or TOC not available");
}

It takes the TOC data from the book and imports it into the app's context drawer. This way, users can easily access and navigate through the book's structure.

Added metadata handling:

const metadata = action.payload.book.metadata;
if (metadata) {
  backend.metadata = metadata;
  root.bookReady(backend.metadata.title);
  Database.addBook(backend.file, JSON.stringify(metadata));
}

Let me break down what this does:

• First, it grabs the metadata from the book that's been loaded.
• If there's metadata, it does a few important things:
  • Updates the backend with this new info.
  • Tells the app that the book is ready to go, passing along the title.
  • Stores all this metadata in the database.

What’s next?

In the following weeks of GSoC, I plan to first to focus on tackling the rendition setup. This is a crucial step - it's what will allow our ebook reader to display the content of ebooks correctly, and also setting the style for the reader. This will involve integrating the Foliate-js rendition module with Arianna's Qt implementation.

Thanks for your reading, stay tuned for updates on my progress via my blog and feel free to connect with me.

Since the 39.20240617.0 and 40.20240617.0 updates for Atomic Desktops and the 40.20240617.0 update for IoT, systems with Secure Boot enabled may fail to boot if they have been installed before Fedora Linux 40. You might see the following error:

error: ../../grub-core/kern/efi/sb.c:182:bad shim signature.
error: ../../grub-core/loader/i386/efi/linux.c:258:you need to load the kernel first.

Press any key to continue...

Note: You can also read this post on the Fedora Magazine.

Workaround

In order to resolve this issue, you must first boot into the previous version of your system. It should still be functional. In order to do this, reboot your system and select the previous boot entry in the selection menu displayed on boot. Its name should be something like:

Fedora Linux 39.20240610.0 (Silverblue)  (ostree:1)

Once you have logged in, search for the terminal application for your desktop and open a new terminal window. On Fedora IoT, log in via SSH or on the console. Make sure that you are not running in a toolbox for all the commands listed on this page.

If you are running a Fedora Atomic Desktop based on Fedora 39 and have not yet updated to Fedora 40, you first need to update to the latest working Fedora 39 version with those commands:

$ sudo rpm-ostree cleanup --pending
$ sudo rpm-ostree deploy 39.20240616.0

If you are running Fedora IoT, then first update to the latest working version with this command:

$ sudo rpm-ostree cleanup --pending
$ sudo rpm-ostree deploy 40.20240614.0

Then reboot your system.

Once you are logged in again on the latest working version, proceed with the following commands:

$ sudo -i
$ cp -rp /usr/lib/ostree-boot/efi/EFI /boot/efi
$ sync

Once completed, reboot your system. You should now be able to update again, as normal, using the graphical interface or the command line:

$ sudo rpm-ostree update

Why did this happen?

On Fedora Atomic Desktops and Fedora IoT systems, the components that are part of the boot chain (Shim, GRUB) are not (yet) automatically updated alongside the rest of the system. Thus, if you have installed a Fedora Atomic Desktop or a Fedora IoT system before Fedora 40, it uses an old versions of the Shim and bootloader binaries to boot your system.

When Secure Boot is enabled, the EFI firmware loads Shim first. Shim is signed by the Microsoft Third Party Certificate Authority so that it can be verified on most hardware out of the box. The Shim binary includes the Fedora certificates used to verify binaries signed by Fedora. Then Shim loads GRUB, which in turn loads the Linux kernel. Both are signed by Fedora.

Until recently, the kernel binaries where signed two times, with an older key and a newer one. With the 6.9 kernel update, the kernel is no longer signed with the old key. If GRUB or Shim is old enough and does not know about the new key, the signature verification fails.

See the initial report in the Fedora Silverblue issue tracker.

What are we doing to prevent it from happening again?

We have known for a while that not updating the bootloader was not a satisfying situation. We have been working on enabling bootupd for Fedora Atomic Desktops and Fedora IoT. bootupd is a small application that is responsible only for bootloader updates. While initially planned for Fedora Linux 38 (!), we had to delay enabling it due to various issues and missing functionality in bootupd itself and changes needed in Anaconda.

We are hoping to enable bootupd in Fedora Linux 41, hopefully by default, which should finally resolve this situation. See the Enable bootupd for Fedora Atomic Desktops and Fedora IoT Fedora Change page.

Note that the root issue also impacts Fedora CoreOS but steps have been put in place to force a bootloader update before the 6.9 kernel update. See the tracking issue for Fedora CoreOS.

Here's our bi-monthly update from KDE's personal information management applications team. This report covers progress made in the months of May and June 2024.

Since the last report 38 people have contributed over 1500 changes to KDE PIM code base.

PIM Sprint

Let's start with the biggest event of the last two months: the PIM sprint!

The team met in Toulouse for a weekend of discussions, hacking and French pastries. You can read reports from Kevin, Carl, Dan and Volker on their blogs to get all the nitty gritty.

In this report, we will cover the biggest topics that were discussed and worked on during the sprint.

Milestones

We have decided to plan and track our work in milestones. Milestones should represent a concrete goal with clear definitions of what we understand as done, and be achievable within a reasonable time frame. Each milestone is then split into smaller bite-sized tasks that can be worked on independently.

This will help us prioritize important work, make our progress more visible and, most importantly, make it easier for people to get excited about what we are working on. New contributors will also be able to pick up a well-defined task and start contributing to PIM.

You can see the milestones on our Gitlab board - if anything there catches your eye and you would like to help, reach out to us on the #kontact:kde.org Matrix channel!

This report, as well as future ones will try to focus on the current milestones and their progress, hopefully making them more exciting to read :)

Retiring KJots and KNotes

We have decided to retire the KJots and KNotes applications. These applications have not seen any support or development in many years and are not in a state that we feel comfortable shipping to our users. With the introduction of Marknote, KDE can now offer a modern, well-maintained note-taking application that we can recommend users to migrate to. The latest release of Marknote has gained support for importing notes from KJots and KNotes, so no notes will be lost.

Polished Tag Support

Tags were introduced into KDE PIM many, many years ago, but they have never reached their full potential. We have decided to change that and make tags a first-class citizen in our applications. The first step is making sure that tags are actually usable, so we started by implementing automatic extraction of tags from events and todos and syncing them into local iCal calendars and remote DAV calendars. Thanks to this, you can now sync tags between KOrganizer and NextCloud, for example.

Moving Protocol Implementations to KDE Framworks

We have libraries in KDE PIM that implement various standards and protocols. By moving them to KDE Frameworks we make them independent from KDE PIM and thus available to anyone who wants to use them. In the past we have moved KCalendarCore (iCal support library) and KContacts (vCard support library) to Frameworks. We are now working on moving KMime (email/RFC822 support library) and KIMAP (IMAP protocol implementations) to Frameworks as well.

This is helping cleanup KMime. KMime APIs is now in many places const correct to avoid the risk of modifying a message when reading it, proper CamelCase headers are now generated like for all the KDE Frameworks. Finally, parsing a MIME file is now up to 10 times faster on typical emails.

Other Improvements and Fixes

Itinerary

Our travel assistant app Itinerary gained support for the public transport routing service Transitous, got a new import staging area and can now create new entries directly from OSM elements. For more details see its own summary blog post.

Merkuro

"Snow flurry" fixed the start of the week math for locales that use Sunday as the first day of the week. They also fixed the navigation of the basic mode for the month view and week view (which are used on mobile).

Claudio continued working on the Merkuro Mail application and added a progress bar in the sidebar which appears when a background job is running.

The settings dialogs have been ported to the new KirigamiAddons.ConfigurationView which fixes some issues on mobile.

Get Involved

If you would like to get involved in KDE PIM, check our milestones board and pick a task! And don't forget to join us in the #kontact:kde.org Matrix channel or the kde-pim mailing list!

Following my latest post about Keychain, here is a new development update. Yubikey and Key Files are now supported, which allows you to requires a YubiKey to open a password database but also to save it.

Saving and editing groups also now works.

And I now started working on the database creation process. The UI is ready but I still need to bind it to the backend.

Thanks to everyone who send me encouragement messages and also to Laurent who did a lot of cleanups in the codebase.

See you in the next development update.