For those who are not yet familiar with the new Qt Canvas Painter, please check the previous blog posts: Introduction, new features, and performance measurements. This blog post introduces paths and path groups to further improve the performance.
Qt Bridges aim to bring Qt’s UI framework capabilities to commonly used programming languages, like C#, in a way that is familiar to developers using these languages. After the public Beta release, we've continued working on the C# bridge, adding new features and making improvements based on the feedback that we've received. Today we are announcing the release of a new Beta version 0.3.0, including some of these recent additions.
Learn how to start using Qt as your next C# UI framework, try it out, and send us your feedback.
Every C# UI framework comes with a familiar pattern: Windows-first, Linux absent, roadmap uncertain. WPF stalled, MAUI skipped Linux, WinUI 3 stays Windows-native. At the same time, demand for embedded Linux grows and C# teams feel the lack of good UI alternatives for C# on Linux. Qt Bridges, a bridging technology in public beta for C#, provides access to a UI framework that allows preserving your existing C# codebase while utilizing Qt Quick’s feature-rich UI libraries and APIs, hardware acceleration, and cross-platform capability.
Just something I experience more and more these days.
When it comes to reviewing code, the descriptions, commits and such can be massive blast of information: Full of extraneous details depicting what was changed. The main point is why was something changed. And often in only one huge commit with massive diffs.
I'm sorry but my poor ADHD brain can't take this very well. I don't want to read a novel. Usually blurbs of text are fine: Extraneous detail I can ask about if I need to know.
So this is my plea, from accessibility-ish(?) standpoint, to keep commit messages, merge request descriptions and code comments clear, to the point, need-to-know basis. Do not explain what, but why. Usually the code itself is enough to tell rest of the story. If not, I will ask questions. That's why it's a review.
It's easy to think that having huge description with all and everything is the way to go, but it will just make it slower for people like me to review it. I can barely concentrate already..
Then commits should always be atomic, especially during merge review. Use git amend to make small changes. Before merging, rebase and clean up, or squash. But try your best keep commits atomic: changes that can stand alone.
(Note that this is not aimed at any specific individual, I just finally had brains to write this post since I was reminded of the topic.)
If you use LLM tools, please still write comments, descriptions, commit messages etc. yourself. It helps you to understand whats going on, and it's more accessible for me to review. (Or better yet, try to avoid these tools if you can. I don't think anyone actually needs them. You're good enough without, I promise!)
edit: Seems people are upset about me mentioning accessiblity there. I do not know what is the best way to describe it. But you can just ignore this blog post if it annoys you.
By now, many of you have probably seen Linus Tech Tips’ “Linux is Easy, right?” video?
The TL;DW version is that yes, things are mostly pretty easy, and the tasks they’re having trouble are becoming become less and less common over time… but pain points remain for the “prosumer/technology enthusiast” crowd: folks who are moderately to very technical, but aren’t software developers.
KDE comes out pretty well, with one exception: network shares.
Network shares.
Yes, network shares.
Still. In 2026!
What the heck is going on here? How is this not a solved problem? Let’s talk about it today.
When you access a network share from Dolphin’s built-in network share browser, it doesn’t get mounted as a local path somewhere; Dolphin is connecting to the share using its own communication protocol: smb://, nfs://, or similar.
This is fine for KDE apps; they can use those communication protocols to access files when you double-click them on network shares you’ve accessed using Dolphin.
Everything works.
When you double-click a file on a network share and it opens in a non-KDE app, at that point something called kio-fuse (that we did a ton of work to build a few years ago) secretly creates a FUSE mount of the share in the background, and passes the app a local path to the file on the secret FUSE mount.
This way, the non-KDE app opens the file from a local path as it expects, and everything still works.
You caught me! Everything works if you open the file from Dolphin… but what if you need to access a file on the share from the “open” dialog in an app, or save a file to the share using the “save” dialog in an app?
Well, then things get more complicated.
If it’s a KDE app, the standard KDE open/save dialog knows how to access the network share so you can open or save new files there. If you’ve created a bookmark for the share in your Places panel (which is our documented recommendation in KDE Linux), it’s already right there; simply click on it to connect to the share, and navigate to the desired file or location. Easy peasy, everything works.
Sounds great! So where’s the complication? Let’s move on.
If it’s a non-KDE app that uses the KDE open/save dialog, it’s the same deal: access the share from the dialog, everything works. Example apps are VLC and LibreOffice (when run with the Qt backend). Still no complication…
If it’s a non-KDE app that uses the portal-based open/save dialog, then everything is lovely here too. The app asks the XDG Desktop Portal for an open/save dialog; the portal offers up the KDE dialog; everything works. In this respect, Flatpak has been encouraging adoption of the portal-based open/save dialogs, which produces a really nice experience: KDE users get a KDE open/save dialog in almost every Flatpak app — something we’ve all wanted for years!
But now we come to the problem:
If it’s a non-KDE app that uses its own non-KDE open/save dialog… then everything becomes terrible. Its dialog will not see any bookmarks you’ve added to the KDE dialog, and will expect you to have the share mounted locally somewhere. Even if kio-fuse created a mount, the non-KDE dialog doesn’t show it nicely in its sidebar! You have to know the secret location of the mount (/run/user/1000/kio-fuse-[something]) and use the dialog to navigate there manually.
If these apps are packaged traditionally, that’s bad enough. If they’re Flatpaks, it’s worse: they have to be packaged with a hole in the security sandbox that allows them to access the kio-fuse mount, or else you can’t access it even if you know it exists and navigate there manually. Most do this for the location where GNOME’s own system mounts shares… but not for the location where kio-fuse mounts them — nor the location of any shares you’ve manually mounted, for that matter.
In addition, the GTK open/save dialog’s built-in network browsing feature is broken unless the app’s Flatpak packaging pokes another sandbox hole for network access — many don’t! And custom dialogs may not even have this feature at all.
What a mess. Unfortunately, as of June 2026 (if you’re reading this later, please verify), apps in this unfortunate situation include some important ones like Blender, GIMP, LibreOffice (from Flathub or with the GTK backend), OnlyOffice, Inkscape, Audacity, DaVinci Resolve, and Gedit.
So, that’s bad.
If it’s a command-line tool or daemon, then everything is terrible in the same way. All previous use cases involved GUI tools accessing or mounting the network share; until and unless that happens, there’s nothing for CLI tools to see. It’s as if the share doesn’t exist. Something would need to mount the share at login. That something usually ends up being driven by changes to /etc/fstab that a random internet tutorial walked you through.
Well, there are a few problems with this — the first one being that /etc/fstab is root-owned, so using it to mount a network share requires administrator privileges. That’s not gonna fly on multi-user or administrated systems.
You could work around this by using a GUI tool that can modify that file using Polkit, and then ship a Polkit rule to auto-allow this app’s requests to modify the file — even for non-admin users.
If it’s a password-protected share, you’ll also have to store the credentials in plaintext somewhere; there’s no provision for storing them in an encrypted password storage system.
This makes a mockery of security, but even if that’s acceptable, it turns out there isn’t just one way to mount a network share using /etc/fstab, but rather about twelve thousand ways. Every online tutorial gives you a slightly different set of steps, and if you don’t do it just right, you’ll end up with a mount that isn’t writable, or delays the boot process if it’s not accessible at that time, or causes apps to hang and freeze if it becomes inaccessible later, or other non-obvious problems that can be really “fun” to troubleshoot.
It’s not impossible to do this properly, but you have to know what you’re doing. So you really want this file to only be touched by a person or organization that qualifies, and to not make changes to it that you don’t fully understand.
All is not lost. Happily, KDE just received an investment of over €1.2 million from the Sovereign Tech Fund, and it includes funding for improvements to KDE’s network share handling!
Time for full disclosure: KDE e.V. is contracting with my company Techpaladin Software to run this part of the project. Network shares represent a significant paper cut, and I’m really excited to be a part of the process to finally get this topic sorted.
I’m not micromanaging the project; frankly, I don’t have the time, even if I wanted to! So my involvement so far has mostly been to put smart people in charge, gather them together into a (virtual) room where they can be productive, and make sure they’re adequately funded! Which is what I’ve done, and and I have every confidence in the team.
Here are some of the ideas under discussion:
ngrahamkio-fuse-created network share mounts at their current location.kio-fuse automatically create a mount for it on login, similar to “mapping a drive letter” on Windows.kio-fuse mounts network shares.kio-fuse implementation as a fallback only on systems without systemd.Lots of ideas. Preliminary work has already started, and I expect it to be an ongoing area of focus in the coming months.
So hopefully soon this topic will finally be in the rear-view mirror. I think it’s clear that KDE is not yet 100% there on network shares, and we can do better. And we will!
Hey wassup guys! Welcome to yet another blog made by me!
I've been busy for a while due to exam stress and my passport situation.
But I am glad to share that I finally got the passport yesterday! This brings me one step closer to making it to Akademy 2026 in Graz, Austria.
Now I just need to get my flight and hotel bookings done, get some required documents signed from my university, get a VISA or a forex card and then finally apply for the Austrian Schengen VISA.
Anyways, this blog is supposed to be about sharing learnings / progress made in week 2 and 3 of my GSoC journey so let's go!
If I recall correctly, I did the following in the past 2 weeks:
@the_epicman:matrix.org
GSoCMemStream but didn't realize that it actually had a read-only view on my subset font data, let's say const char* fontData. I called harfbuzz destroy function after constructing this stream and it freed the fontData and then when the time came for writing to the file, the fontData pointer inside the stream was dangling and corrupted data got written.I think I did like below-okayish amount of work done but I am glad I actually learnt a lot of useful and important things.
I would like to thank my mentor Albert Astals Cid, and the Poppler community for helping me.
I would also like to thank KDE board members for approving my reimbursement requests.
And finally, thank you for reading my blog so far :)
Until next time!
The gap between “CMake that compiles” and “CMake that is correct” can be sometimes significant. CMake has been Qt’s official build system since Qt 6.0, and the pairing is genuinely capable: a well-configured Qt CMake project supports cross-platform builds, incremental QML compilation, seamless C++/QML integration, and deployment-ready install targets. But getting there requires mastering a build API that has evolved rapidly across Qt 6 minor releases - and that evolution is precisely where things can become challenging for Large Language Models, especially older or smaller models.
Qt Creator 20 has become an Agent Client Protocol (ACP) Client extension. The protocol is supported by many AI providers and handles the details of the communication between the AI coding agent and the IDE.
So, last road map discussion it was decided I would start working on HDR. This is partially because I have the hardware for it, as well as Krita now supporting the wayland color management protocol, so my hardware is actually being used appropriately.
Furthermore, before I worked on text my specialization within Krita is its color management code, so I feel a little like a fish in water right now.
HDR tends to mean three separate things:
There’s the hardware side, where a screen can show such bright colors that it needs to be interacted with in a special way to make good use of those colors. This particular manner also informs how we store HDR values inside file formats.
There’s the scene referred workflow, where we assume there’s a scene white, usually the brightness of a diffuse white, like paper, and highlights are above that are the high dynamic range.
Finally, there’s the tone mapped result of a scene referred image. That means that we take the scene referred image, and scale everything so that the result fits into a regular SDR range. This is typically the version that people learn of first when they scroll photography websites.
For Krita’s purpose, we’re largely interested in the first two. The hardware and file format side in particular needs a lot of work to get all the metadata right. For the scene referred section, the filters need adaptation. But the last entry is necessary to create a nice result image for social media, so I’ll cover that in the future too.
For now, I focused on getting some UI fixes in.
So, the first thing that needed tackling was the user interface. In particular, when using previous versions of Krita, the canvas decorations were blown out.
Basically, this happened because we draw our decorations onto the OpenGL canvas with a QPainter. Because QPainter nor QColor has any concept of what space it is drawing in, it doesn’t know to convert from sRGB to the rec2100pq format we’re using for the HDR canvas. We also have the issue that sometimes, colors aren’t in sRGB, but rather should represent a color from the image. Previously, we could assume that if the display was wide gamut, we didn’t need to adapt the decorations, or treat them differently from image colors, so we just treated them as the same thing, and drew the colors straight onto the display color space.
Now, the only place that knows how to handle image colors properly, applying all the OCIO config, etc, as well as having information to convert sRGB to the canvas space is the display color converter inside the canvas. This one has an extra simplified interface, called the color display renderer. Most of the work to fix this was to add functions to this renderer interface to convert colors (and images) and finally funnel the renderer through all canvas decorations. This was about 130 changes in the end.
Most of them were just plain conversions from sRGB to canvas space, but the color picker had to use the actual image color, as did the preview for the transform tool. Nor everything had to be converted on the fly. In some cases, like the vector tools, we have a set of colors we reuse, so those were added to the display renderer to be converted as a single struct of colors. Then, there’s the on canvas toolbars, like for the selection tools. These just use QPalette colors, which was solved in a similar manner, with the display renderer keeping a version of the current palette, but converted to the canvas space. At some point, we might need to do the same with KColorScheme, except that this class doesn’t have a way to change colors inside of it. Not sure what the best solution here is, as Krita needs to control the conversion function (in case of wide-gamut, etc).
Then, there were the reference images. Reference images are drawn on the side of the canvas in Krita. While fixing them was easy enough, I went a little further: Enabling HDR and wide gamut on the reference images. This was a little bit ambitious, as it required converting between QColorSpace and our similar class, KoColorProfile (a KoColorSpace, if you’re curious, is a KoColorProfile and a bit depth, as KoColorSpace has a whole bunch of per-model+bit-depth functions to wrangle pixels).
This conversion isn’t too hard, because QColorSpace can read and return iccprofiles, and KoColorProfile can do the same. However, for rec2100pq in particular, we will want to return a profile of our own. Same with sRGB. So what happens before we try to load the icc profile is that we test the transfer and the like, and funnel the values into our profile searching system. This system was created to handle ITU CICP values (basically a standardized set of enums for transfers and colorants), and was already extended with the known quantities outside of that (Adobe RGB, ProPhoto), so it can handle all the predefined transfers and colorants QColorSpace supports and find the relevant profile before trying to create it.
Now, when we load a reference image, and the image is RGB, Krita will convert it to a QImage, but set the colorspace to use that RGB space. The exception is when the image is floating point, in which case it’ll be converted to rec2100pq, because our reference images are eventually stored as PNG, and PNG cannot handle floating point. Then, when we start drawing the reference images, we first ensure the QImage QPaintDevice has its QColorSpace set to use the canvas colorspace. When drawing, we test the color space of the device, and the colorspace of the reference image, and then do the conversion to the canvas space before drawing.
And it works. I’m pretty pleased with this, because we have a bunch of other places we still draw with QPainter that might be useful to color manage, with the most notable one being the vector shapes. I hope we’ll be able to tackle that in the near future.
This was basically setting a little widget to show the color space data we get from wayland. Wayland sends us two types of information: The preferred color space, and the mastering display data. The former is the space wayland suggests that we send data in for the least amount of color conversions. The second is a little bit more weird. The mastering display color volume in HDR terms is a bit of metadata to indicate the gamut of the display that the image was finalized on. The idea being that this info can help guide the gamut mapping process by indicating in what range the important contrasts are.
In practice, what wayland is sending here is the color volume of the display the current window is on. I think this is so that we can send that data right back when we’re sending HDR data for the image that is being authored on that display.
So, I made the XY CIE Tongue widget display these spaces with a toggle to switch between the preferred and current display gamut, and an auto update when the preferences switches screens. It might seem small, but one of the reasons I ported the CIE tongue widget over from Digikam all those years ago is because I do feel it is much more friendly to be able to see the actual gamut instead of having to interpret magic numbers and names.
Our histogram docker was limited to [0 1], which isn’t very useful when working in linear floating point, so I wanted to fix that. So, a histogram in Krita is made by taking a vector of integers, initializing that with 256 values, and then going over each color and incrementing the value that is associated with the value of the pixel. You then do this per-component, to get a view of where the pixel values are per-channel.
What needed to be added here was that we now first test all the pixels for the maximum possible component value. Then, afterwards we divide the range of 0 to maximum by 256, and use that to sort the pixel values into. This means that as the image gets a bigger range, the precision of the histogram decreases, but as far as I know its output should still be statistically relevant.
Of course, in really wide range images, the range becomes a little meaningless. Therefore, it was decided to add a toggle to switch into logarithmic mode as well. For this, to keep the precision sensible, it needs to sample a separate logarithmic vector during pixel sampling. This has the added benefit that switching between linear and logarithmic is instantaneous.
Then I spend some time tweaking the graph and adding numbers at the bottom.
One thing I’m a little worried about though: The log grid is using log10. But with HDR there’s a concept of stops, which is log2. And I’m wondering if I should switch the logarithmic mode to log2 instead of log10, but at the same time, I’ve never seen log2 graph paper.
This has nothing to do with HDR, but I also converted all the cursors to SVG. This was something I did when there was a lull in the text work last year, because my screen is also a high dpi screen, and the cursors in X11 were tiny. So, I spend some time redrawing all the cursors, and then load them with QIcon(file.svg).toPixmap(width, height) to get a display scaled pixmap to use with QCursor. Of course, this then got delayed because there were issues with hot-spot offset and Android, and then I had to return to the text work. I managed to get back to this recently and finalize it.
I’m kinda happy, because between the vector cursors, the color managed canvas decorations and the fact canvas decorations get scaled (something I did… two, three years ago), everything we can draw on the canvas now looks good on modern displays.
Next up is going to be digging into the weeds of HDR metadata.
We've also created a new USB-card, with the newest stable version of Krita for all OSes. Includes Comics with Krita, Muses, Secrets of Krita and Animate with Krita tutorial packs. It's a 32 GB USB card with USB A and USB C connectors and the latest Kiki splash by Tyson Tan! If you just want the empty card because Kiki is cute, you can get that for a reduced price!
The usb-card is available in two versions: empty, for €19,95 and (manually) updated to the latest version of Krita for €34,95.
