This weekend "The KDE Alberts"[1] attended Google Summer of Code Mentor Summit 2024 in Sunnyvale, California.

The Google Summer of Code Mentor Summit is an annual unconference that every project participating in Google Summer of Code 2024 is invited to attend. This year it was the 20th year celebration of the program!

I was too late to take a picture of the full cake!

We attended many sessions ranging from how to try to avoid falling into the "xz problem" to collecting donations or shaping the governance of open source projects.

We met lots of people that knew what KDE was and were happy to congratulate us on the job done and also a few that did not know KDE and were happy to learn about what we do.

We also did a quick lightning talk about the GSOC projects KDE mentored this year and led two sessions: one centered around the problems some open source application developers are having publishing to the Google Play Store and another session about Desktop Linux together with our Gnome friends.

All in all a very productive unconference. We encourage KDE mentors to take the opportunity to attend the Google Summer of Code Mentor Summit next year, it's a great experience! 

[1] me and Albert Vaca, people were moderately amused that both of us had the same name, contribute to the same community and are from the same city.

Welcome to the @Krita-promo team's September 2024 development and community update.

Development Report

Krita 5.2.6 Released

Krita 5.2.5 was released September 25th. However, due to a serious bug where Group Layers in Pass Through mode caused Krita to get stuck endlessly updating, a 5.2.6 hotfix release was made shortly afterward on October 1st.

Check out the 5.2.5 release post for details on the three months' worth of bugfixes, but make sure to update to 5.2.6!

Community Report

September 2024 Monthly Art Challenge Results

For the Traditional Refreshments and Snacks theme, 12 members submitted 13 original artworks. And the winner is… Sweet Lemonade by @Dott!

The October Art Challenge is Open Now

For the October Art Challenge, @Dott has chosen "Buried, Stuck, or otherwise Swallowed" as the theme, with the optional challenge of incorporating a spiral or two. See the full brief for more details, and don't hesitate to uncover some inspiration!

Featured Artwork

Best of Krita-Artists - August/September 2024

10 images were submitted to the Best of Krita-Artists Nominations thread, which was open from August 15th to September 11th. When the poll closed on September 14th, these five wonderful works were voted into the Krita-Artists featured artwork banner:

Study practice by @Gertsa_Ivan

Kiki recruiting for the Monthly Challenge by @Corentin

"Friend from Nowhere" by @Elixiah

XullFA by @tonnybranzza

Portrait of a woman in profile by @Celes

Best of Krita-Artists - September/October 2024

Nominations will be accepted until October 11th. Take a look through the current submissions. If you don’t see your favorite artwork there, why not make a nomination?

Ways to Help Krita

Krita is Free and Open Source Software developed by an international team of sponsored developers and volunteer contributors.

Visit Krita's funding page to see how user donations keep development going, and explore a one-time or monthly contribution. Or check out more ways to Get Involved, from testing, coding, translating, and documentation writing, to just sharing your artwork made with Krita.

The Krita-promo team has put out a call for volunteers, come join us and help keep these monthly updates going.

Notable Changes

Notable changes in Krita's development builds from Sept. 6 - Oct. 7, 2024.

Stable branch (5.2.5):

• Animation: Fix animations getting stuck when using clone layers with transform masks. (bug report) (Change, by Dmitry Kazakov)
• Animation: Fix onion skins' rendering on layers with transform masks. (bug report) (Change, by Dmitry Kazakov)
• Animation: Make Render Animation dialog remember previous video container format. (bug report) (Change, by Emmet O'Neill)
• Animation: Allow video animation import process to be canceled. (bug report) (Change, by Emmet O'Neill)
• Compositions Docker: Allow animated composition export to be canceled. (bug report) (Change, by Emmet O'Neill)
• Layer Stack: Fix conversion of Group Layer to Animated Layer. (bug report) (Change 1 and change 2, by Emmet O'Neill)
• Undo Stack: Fix quickly undoing and then redoing some actions like Remove Layer to work. (bug report) (Change, by Dmitry Kazakov)
• Layer Stack: Keep Clone Layers linked when flattening their source group. (bug report) (Change, by Dmitry Kazakov)
• Layer Stack: Fix updating Pass Through groups when using the Move or Transform Tool on them. (bug report) (Change, by Dmitry Kazakov)
• Pasting: Deselect selection when pasting from the clipboard, to avoid leaving anti-aliased selection edges out of Transform or other operations that might happen afterward. (bug report) (Change, Dmitry Kazakov)
• Snapshot Docker: Fix wrong layer being selected when activating a snapshot. (bug report) (Change, by Dmitry Kazakov)
• Specific Color Selector Docker: Update Specific Color Selector labels in HSX mode, fix RGB sliders changing length, fix holding down spinbox arrows, and set float slider step to 0.01. (bug 475551, bug 453649, CC bug 453366) (Change, by Freya Lupen)
• Assistant Tool: Fix undoing changes to Perspective Assistants causing Perspective Distance brush value to be incorrect. (bug report) (Change, by Dmitry Kazakov)
• File Formats: JPEG-XL: Update JXL to 0.11 which includes fixes for speed and lossless encoding, and implement streaming encode which allows cancelling animated and layered export. (Change, by Rasyuqa A H)

Stable branch (5.2.6):

• Layer Stack: Fix updating Pass Through groups getting stuck at 0% progress forever, a regression in 5.2.5. (bug 493774, bug 493830, bug 493837) (Change, by Dmitry Kazakov)
• Python Plugins: Photobash Images Docker: Fix script error when adding images to canvas from the Photobash Images Docker. (Change, by Pedro Reis)

Stable branch (5.2.7-prealpha):

• Layer Stack: Fix a crash when trying to merge down a layer created by the Text Tool or Select->Convert to Shape after a reference image addition. (bug report) (Change, by Dmitry Kazakov)
• Layer Stack: Fix issue with position of layers copy-pasted from another document. (bug report) (Change, by Ralek Kolemios and Dmitry Kazakov)
• Tools: Let brush shortcuts such as to change size affect the Bezier Curve and Freehand Path tools. (bug report) (Change, by Doreene Kang)
• General: Add A1 and A2 predefined image sizes. (Change, by Guillaume Marrec)

Unstable branch (5.3.0-prealpha):

Bug fixes:

• macOS: Canvas Input: Show macOS modifier key symbols in Canvas Input Settings, as Keyboard Shortcuts already does, instead of the non-Mac names. (bug report) (Change, by Freya Lupen)

Features:

• Animation Timeline Docker: Adjust the frame view's zoom level to fit the frame range when it changes. (wishbug report) (Change, by Emmet O'Neill)

Nightly Builds

Pre-release versions of Krita are built every day for testing new changes.

Get the latest bugfixes in Stable "Krita Plus" (5.2.7-prealpha): Linux - Windows - macOS (unsigned) - Android arm64-v8a - Android arm32-v7a - Android x86_64

Or test out the latest Experimental features in "Krita Next" (5.3.0-prealpha). Feedback and bug reports are appreciated!: Linux - Windows - macOS (unsigned) - Android arm64-v8a - Android arm32-v7a - Android x86_64

Have feedback?

Join the discussion of this post on the Krita-Artists forum!

SVG cursor themes is a new feature in Plasma 6.2, which we are really excited about. In this blog post, I would like to provide more background behind what motivated us to add support for them, what they are, and how to build them.

(Classic) cursor theme format

A cursor theme is a collection of images defining the contents of various cursor shapes and additional metadata (for example, the human readable name of the theme, whether the cursor theme inherits/extends another cursor theme, etc). On disk, it looks as follows

The cursors/ directory contains a list of Xcursor files and symbolic links to represent cursor shape aliases, e.g. the arrow being an alias for default. The XCursor format has been in use for a very long time now and it has a pretty simple structure

An XCursor file consists of a header that includes a magic number to determine whether particular file is actually an XCursor file, the size of the header in bytes, the file version, and the number of ToC entries. Every ToC entry provides the information about the corresponding chunk, for example the chunk type and where the chunk can be found in the file. Lastly, a chunk contains some useful data. A chunk may contain image data or text data, etc.

For example, here’s the image data that can be found in the “default” cursor shape file in the Adwaita cursor theme

As you can see, the Adwaita cursor theme provides the following sizes: 24, 32, 48, 64, and 96.

The index.theme files looks as follows

[Icon Theme]
Inherits=breeze_cursors
Name=Cool Cursor
Comment=That is a cool cursor theme

Cursor themes can be found in $DATADIR/icons directories. For example, /usr/share/icons or ~/.local/share/icons.

X11 vs Wayland cursors

Xcursor cursors are used both on X11 and Wayland, but the way how the cursor size is interpreted is different on the two platforms. X11 assumes that the cursor size is specified in the device pixels, while Wayland assumes that it’s in the logical pixels. Logical pixels have the same visual size across various devices, while physical pixels are specific to particular device. For example, 24 logical pixels on an output with a scale factor of 2 corresponds to 48 physical pixels.

Cursor sizes in Xcursor files are specified in the device pixels.

Another very important detail is that the XCURSOR_SIZE environment variable is treated differently by X11 and Wayland native applications. For example, if XCURSOR_SIZE is set to 24 and the output scale is 2, an X11 application would load a cursor with the size 24, but a Wayland application would effectively load a cursor with the size 48 (24 * 2) because it would see that the output is scaled so the provided cursor needs to be scaled accordingly as well.

Limitations of Xcursor

The most painful thing about Xcursor is its lack of the proper HiDPI support. As it was said in the previous chapter, the cursor size in Xcursor files is specified in the device pixels. On X, it’s not a problem because all geometries are specified in the device pixels. It also means that if you change the scaling factor on X, you need to change the cursor size manually so the cursor is not too small. On Wayland, the cursor size is specified in the logical pixels so the compositor and the clients have to scale the cursor size in order to match the output scale. For example, if the configured cursor size is 24 and the window is on an output with a scale factor of 2, the application needs to load an Xcursor cursor with the size 48. If the cursor theme provides cursors with such a size, perfect! But what if it doesn’t? At the moment, every compositor and client applies its own policies. Some find the cursor with the closest size and use that, some find the cursor with the closest size and then scale it to match the requested size at the cost of adding some blurriness, and so on. It’s a mess. Because neither compositors nor clients can agree how to handle such a case, you could easily observe the cursor changing its size when moving between windows owned by different applications or when moving the cursor between the window and its decoration, e.g.

It’s worth noting though that this issue can be worked around by using the cursor-shape protocol because with it, the application can delegate the compositor the task of loading and displaying cursors. But the bottom line is that the Xcursor format is unsuitable for the HiDPI model that we have present on Wayland.

Another issue with the Xcursor format is that the image data is stored in an uncompressed format. It is okay if you need to provide cursors with small sizes, for example up to 72, but there are cases when you need to display a cursor at a very large size. For example, one such a case is the shake cursor accessibility feature in the Plasma Wayland session.

With the shake cursor feature enabled, the cursor will be inflated when it’s shaken. In order to operate, it needs to load the default cursor shape with a size around 250. If cursor themes provided images for such sizes, their package sizes would easily blow up beyond the 100MiB mark. That’s not good. And as a workaround, in Plasma 6.1, the shake cursor uses its own high resolution images of the Breeze cursor themes.

The XCursor format was perfectly suitable for the use cases that existed back in the late 90s and early 2000s, but things have changed over the years and its current raster nature can’t keep up with the use cases that we have now (2024). We’ve got fractional scaling, we’ve got accent colors, we’ve got features that enlarge the cursor, and so on.

SVG cursor format

First of all, let’s build a list of requirements that the svg cursor format must satisfy:

• obviously, it must support the ability to define cursor contents using svg files so we can fix HiDPI issues, etc
• easy porting process for existing clients and compositors
• it should be easy to develop and analyze svg cursor themes. Xcursor is a binary file format, which requires a special tool to create Xcursor files, we would like to avoid that with svg cursors
• last and the most important requirement is that there must be some compatibility with the existing cursor theme format. We must not be required to write a new system settings module to handle the new cursor format, and the apps that don’t support svg cursors should easily fallback to the Xcursor format.

Here’s how a cursor theme providing svg cursors would look like

index.theme has the same format both for XCursor and SVG cursors. cursors/ directory contains the XCursor cursors, and cursors_scalable/ contains the SVG cursors.

In cursors_scalable/, every cursor shape must have its own directory, or if it’s an alias, then it must be a symlink. Every cursor shape directory must contain the cursor image and a metadata.json file providing the information about the cursor.

For a static cursor, the metadata.json file looks as follows

[
   {
       "filename": "default.svg",
       "hotspot_x": 4,
       "hotspot_y": 4,
       "nominal_size": 24
   }
]

The filename property specifies the filename of the svg file. The hotspot_x and the hotspot_y properties specify the coordinates of the hot spot. The hot spot in the cursor determines the point where interaction with other elements on the screen occurs, e.g. clicks. The nominal_size property specifies the cursor size that the svg file represents. The nominal size is used to decide how much the svg image and the hotspot coordinates need to be scaled in order to get a cursor with the requested size. Note that the nominal size can’t be determined based on the <svg>‘s width and height attributes because there exist themes such as Breeze whose canvas is bigger than the represented cursor size. As an example, in the Breeze cursor theme, the canvas size is 32x32 even though the represented cursor size is 24 in order to accommodate for additional elements that can be attached to the arrow cursor, e.g. a little circle with a plus sign or a question mark.

For an animated cursor, the metadata.json file looks as follows

[
    {
        "filename": "wait-01.svg",
        "delay": 30,
        "hotspot_x": 16,
        "hotspot_y": 15,
        "nominal_size": 24
    },
    {
        "filename": "wait-02.svg",
        "delay": 30,
        "hotspot_x": 16,
        "hotspot_y": 15,
        "nominal_size": 24
    },
    ...
    {
        "filename": "wait-42.svg",
        "delay": 30,
        "hotspot_x": 16,
        "hotspot_y": 15,
        "nominal_size": 24
    }
]

The only new thing is the delay property. The delay property indicates the animation delay to the next frame.

A cursor theme that ships SVG cursors is required to have XCursor cursors too. This is needed to provide fallback for legacy applications that are unaware of the cursor-shape-v1 protocol or simply too old applications that are unlikely to be changed anymore. This restriction might be lifted in the future.

It is worth mentioning that SVG supports animations natively. However, that approach was not chosen for cursor animations for two reasons: to allow caching svg render results more easily and require fewer changes in the compositors and the apps to adapt the svg cursor format.

You can find the json schema for metadata.json over here.

Accent colors

Since the cursor contents is specified using the SVG format, it should be possible to re-color the cursor based on the currently configured accent color. As of now, it is not implemented, but, in general, this is doable and perhaps such a feature will be added to Plasma some day.

Standardization

This cursor format is not officially standardized. We are looking forward to making it upstream, but for now, the main focus is on confirming that the new format lives up to our and cursor creator needs.

To cursor theme creators

Breeze and Breeze Light are the only two cursor themes that support SVG cursors at the moment, but we would love to see custom themes adapting them too so users experience fewer issues with fractional scaling or other features in Plasma when using their favorite 3rdparty cursor themes. We would also like to hear feedback from the cursor theme creators regarding whether it’s easy to adapt this cursor format or whether some additional features are needed. You can reach out to us at Matrix in the #kwin room https://webchat.kde.org/#/room/#kwin:kde.org or in the kwin mailing list.

Examples

If you need an example of a cursor theme that supports SVG cursors, please check the Breeze cursor theme.

Closing words

The new SVG cursor format is amazing. Please try it!

Let’s go for my web review for the week 2024-40.

W3C 30th anniversary clip

Tags: tech, web, history

Excellent clip for the W3C 30th anniversary. Shows the big milestones and evolution of the WWW.

https://www.youtube.com/watch?v=0TfUBuIZkmQ

OpenFreeMap

Tags: tech, foss, map

An excellent service to provide. Let’s hope it stays sustainable, the risk is commercial leeches not giving back a dime. Be responsible, sponsor it if you use it commercially.

https://openfreemap.org/

Why laptop support, why now: FreeBSD’s strategic move toward broader adoption | FreeBSD Foundation

Tags: tech, freebsd, laptop

Unexpected but definitely welcome. Let’s wish them luck in this endeavor.

https://freebsdfoundation.org/blog/why-laptop-support-why-now-freebsds-strategic-move-toward-broader-adoption/

The Public Domain Problem

Tags: tech, copyright, public-domain, commons

Putting things in the public domain voluntarily is indeed more difficult than it should be. The best tool we got is CC0, but it still raises (probably unwarranted) concerns for software.

https://dpk.land/pubdmn.txt

Patent troll Sable pays up, dedicates all its patents to the public!

Tags: tech, patents

Always happy to see a patent troll bite the dust.

https://blog.cloudflare.com/patent-troll-sable-pays-up/

Improving online advertising through product and infrastructure

Tags: tech, mozilla, advertisement, surveillance

Mozilla is clearly loosing its way, this is sad to watch. I guess the forks which remove the online advertising measures will become more popular.

https://blog.mozilla.org/en/mozilla/improving-online-advertising/

Microsoft details security/privacy overhaul for Windows Recall ahead of relaunch

Tags: tech, microsoft, ai, machine-learning, surveillance, privacy

They’re trying a come back… of course they added layers of security to pretend it’s all solved and shiny. They totally ignore the social implications or if something like this even needs to be done. At least one can remove it… for now…

https://arstechnica.com/gadgets/2024/09/microsoft-details-security-privacy-overhaul-for-windows-recall-ahead-of-relaunch/

Don’t believe the hype: AGI is far from inevitable

Tags: tech, ai, machine-learning, gpt, cognition, neuroscience, philosophy, mathematics, logic, research

This is a short article summarizing a research paper at the surface level. It is clearly the last nail in the coffin for the generative AI grand marketing claims. Of course, I recommend reading the actual research paper (link at the end) but if you prefer this very short form, here it is. It’s clearly time to go back to the initial goals of the AI field: understanding cognition. The latest industrial trends tend to confuse too much the map with the territory.

https://www.ru.nl/en/research/research-news/dont-believe-the-hype-agi-is-far-from-inevitable

The insatiable hunger of (Open)AI

Tags: tech, ai, machine-learning, gpt, energy, ecology

If you run the number, we actually can’t afford this kind of generative AI arm race. It’s completely unsustainable both for training and during use…

https://wimvanderbauwhede.codeberg.page/articles/the-insatiable-hunger-of-openai/

New AI trick: ‘synthetic human memories’

Tags: tech, ai, machine-learning, fake, fake-news

Maybe extrapolating a bit more than it should. Still this leads to worrying uses of AI generated images.

https://machinesociety.ai/p/new-ai-trick-synthetic-human-memories

Ethical Applications of AI to Public Sector Problems - Jacob Kaplan-Moss

Tags: tech, ai, machine-learning, ethics

Good article about the ethical implications of using AI in systems. I like the distinction about assistive vs automated. It’s not perfect as it underestimates the “asleep at the steering wheel” effects, but this is a good starting point.

https://jacobian.org/2024/oct/1/ethical-public-sector-ai/

Devs gaining little (if anything) from AI coding assistants

Tags: tech, ai, machine-learning, copilot, productivity

Unsurprisingly the productivity gains announced for coding assistants have been greatly exaggerated. There might be cases of strong gains but it’s still unclear in which niches this is going to happen.

https://www.cio.com/article/3540579/devs-gaining-little-if-anything-from-ai-coding-assistants.html?amp=1

Lies, Damn Lies, And Surveys About AI – ideatrash

Tags: tech, ai, machine-learning, copilot, marketing, criticism

Or why we shouldn’t trust marketing survey… they definitely confuse perception and actual results. Worse they do it on purpose.

https://ideatrash.net/2024/09/lies-damn-lies-and-surveys-about-ai.html

Sorry, GenAI is NOT going to 10x computer programming

Tags: tech, ai, machine-learning, copilot, productivity

How shocking! This was all hype? Not surprised since we’ve seen the referenced papers before, but put all together it makes things really clear.

https://garymarcus.substack.com/p/sorry-genai-is-not-going-to-10x-computer

Inside Elon Musk’s AI party at OpenAI’s old headquarters

Tags: tech, ai, machine-learning, gpt, business

The arm race is still on-going at a furious pace. Still wondering how messy it will be when this bubble bursts.

https://www.theverge.com/2024/10/3/24261160/elon-musk-xai-recruiting-party-openai-dev-day-sam-altman

I am tired of AI

Tags: tech, ai, machine-learning, gpt, marketing, criticism

I definitely agree with this. I’m sick of the grand claims around what is essentially a parlor trick. Could we tone down the marketing enough so that we can properly think about making useful products again?

https://www.ontestautomation.com/i-am-tired-of-ai/

Were RNNs All We Needed?

Tags: tech, ai, machine-learning, gpt, research

OK, this paper picked my curiosity. The limitations of the experiments makes me wonder if some threshold effects aren’t ignored. Still this is a good indication that the question is worth pursuing further.

https://arxiv.org/abs/2410.01201

I-XRAY

Tags: tech, social-media, scam, ai, machine-learning

Doxxing will get easier and easier. Con men are likely paying attention.

https://docs.google.com/document/d/1iWCqmaOUKhKjcKSktIwC3NNANoFP7vPsRvcbOIup_BA/mobilebasic

Hacking Kia: Remotely Controlling Cars With Just a License Plate

Tags: tech, automotive, security

More details about the KIA security issue. Clearly securing the embedded systems is not worth much if it is then all exposed via unsafe web services.

https://samcurry.net/hacking-kia

Attacking UNIX Systems via CUPS, Part I

Tags: tech, linux, security

This one is definitely a bad one. Looks like CUPS is a weak part of the ecosystem, especially when coupled with zeroconf. I wouldn’t be surprised to see macOS being affected too.

https://www.evilsocket.net/2024/09/26/Attacking-UNIX-systems-via-CUPS-Part-I/

Collaborative Text Editing with Eg-walker: Better, Faster, Smaller

Tags: tests, crdt, collaborative

This could be a game changer to collaborative editing. Clearly a good competitor to CRDTs, should make it easier to build such features without a central server.

https://arxiv.org/abs/2409.14252

Modes Considered Harmful

Tags: tech, distributed, reliability

Interesting point. You likely need to be careful with fallback modes especially in distributed systems. They might bring even more issues when the system is already under stress.

https://a-nickels-worth.dev/posts/modesharm/

std::array in C++ isn’t slower than array in C

Tags: tech, c++, programming, safety, performance

If you still needed to be convinced you need to use std::array and std::span, here is the proof.

https://pvs-studio.com/en/blog/posts/cpp/1164/

Code Generation in Rust vs C++26

Tags: tech, c++, rust, metaprogramming

Interesting comparison of the different choices made in Rust and the upcoming C++26 for code generation. It’s fascinating how they managed to have such facilities in Rust while having no introspection. C++ going the opposite direction will have a very different feel both in term of use or of implementation.

https://brevzin.github.io/c++/2024/09/30/annotations/

The Fastest Mutexes

Tags: tech, multithreading, performance, system

Nice results. Interesting implementation too. I wonder if some of it will make its way to the glibc or musl.

https://justine.lol/mutex/

Less htmx is More

Tags: tech, web, frontend, htmx

As it gets more adoption people are figuring out ways to use htmx properly and not abuse what should be niche features.

https://unplannedobsolescence.com/blog/less-htmx-is-more/

Three small proposals for putting “hyper” back in the hypertext

Tags: tech, web, frontend, html, htmx

Interesting proposals, let’s see how far they go. They could bring most of the benefits of htmx and similar straight in HTML.

https://alexanderpetros.com/triptych/

Changelogs and Release Notes

Tags: tech, foss, project-management

We keep saying they’re not the same. This article does a good job highlighting the differences and explaining why you need both.

https://harihareswara.net/posts/2024/changelogs-and-release-notes/

Learning to Call BS

Tags: tech, product-management

Good idea on how product managers should behave to facilitate requirements handling. I wish more of them would do this.

https://kevinyien.com/blog/bs.html

The world will need less energy after the energy transition

Tags: tech, energy, ecology, economics

Interesting analysis… I wonder if and how Jevons paradox will get in the way though.

https://www.sustainabilitybynumbers.com/p/electrification-energy-efficiency

Bye for now!

A long over-due release which has accumulated a bunch of bugfixes but also some fancy new features…read on!

As always, big thanks to everyone who reported issues and contributed to QCoro. Your help is much appreciated!

QCoro::LazyTask<T>

The biggest new features in this release is the brand-new QCoro::LazyTask<T>. It’s a new return type that you can use for your coroutines. It differs from QCoro::Task<T> in that, as the name suggest, the coroutine is evaluated lazily. What that means is when you call a coroutine that returns LazyTask, it will return imediately without executing the body of the coroutine. The body will be executed only once you co_await on the returned LazyTask object.

This is different from the behavior of QCoro::Task<T>, which is eager, meaning that it will start executing the body immediately when called (like a regular function call).

QCoro::LazyTask<int> myWorker()
{
 qDebug() << "Starting worker";
 co_return 42;
}

QCoro::Task<> mainCoroutine()
{
 qDebug() << "Creating worker";
 const auto task = myWorker();
 qDebug() << "Awaiting on worker";
 const auto result = co_await task;
 // do something with the result
}

This will result in the following output:

mainCoroutine(): Creating worker
mainCoroutine(): Awaiting on worker
myWorker(): Starting worker

If myWorker() were a QCoro::Task<T> as we know it, the output would look like this:

mainCoroutine(): Creating worker
myWorker(): Starting worker
mainCoroutine(): Awaiting on worker

The fact that the body of a QCoro::LazyTask<T> coroutine is only executed when co_awaited has one very important implication: it must not be used for Qt slots, Q_INVOKABLEs or, in general, for any coroutine that may be executed directly by the Qt event loop. The reason is, that the Qt event loop is not aware of coroutines (or QCoro), so it will never co_await on the returned QCoro::LazyTask object - which means that the code inside the coroutine would never get executed. This is the reason why the good old QCoro::Task<T> is an eager coroutine - to ensure the body of the coroutine gets executed even when called from the Qt event loop and not co_awaited.

For more details, see the documentation of QCoro::LazyTask<T>.

Defined Semantics for Awaiting Default-Constructed and Moved-From Tasks

This is something that wasn’t clearely defined until now (both in the docs and in the code), which is what happens when you try to co_await on a default-constructed QCoro::Task<T> (or QCoro::LazyTask<T>):

co_await QCoro::Task<>(); // will hang indefinitely!

Previously this would trigger a Q_ASSERT in debug build and most likely a crash in production build. Starting with QCoro 0.11, awaiting such task will print a qWarning() and will hang indefinitely.

The same applies to awaiting a moved-from task, which is identical to a default-constructed task:

QCoro::LazyTask<int> task = myTask();
handleTask(std::move(task));

co_await task; // will hang indefinitely!`

Compiler Support

We have dropped official support for older compilers. Since QCoro 0.11, the officially supported compilers are:

• GCC >= 11
• Clang >= 15
• MSVC >= 19.40 (Visual Studio 17 2022)
• AppleClang >= 15 (Xcode 15.2)

QCoro might still compile or work with older versions of those compilers, but we no longer test it and do not guarantee that it will work correctly.

The reason is that coroutine implementation in older versions of GCC and clang were buggy and behaved differently than they do in newer versions, so making sure that QCoro behaves correctly across wide range of compilers was getting more difficult as we implemented more and more complex and advanced features.

Other Features and Changes

A coroutine-friendly version of QFuture::takeResult() is now available in the form of QCoroFuture::takeResult() when building QCoro against Qt 6 (#217).

QCoro::waitFor(QCoro::Task<T>) no longer requires that the task return type T is default-constructible (#223, Joey Richey)

Bugfixes

• Suppress Clang error when building against Android NDK <= 25 (#204, Daniel Vrátil)
• Fixed missing QtGui dependency in QCoroQuick module (#209, Andreas Sturmlechner)
• Fixed QCoroIODevice::write() always returning 0 instead of bytes written (#211, Daniel Vrátil)
• Fixed unchecked std::optional access in QCoroIODevice::write
• Fixed awaiting on signal emission with qCoro() would resume the awaiter in the sender’s thread context (#213, Daniel Vrátil)
• Fixed build wilth clang 18 due to missing #include <exception> (#220, Micah Terhaar)
• Fixed crash when QNetworkAccessManager is destroyed from a coroutine awaiting on a network reply (#231, Daniel Vrátil)

Full changelog

See changelog on Github

Support

If you enjoy using QCoro, consider supporting its development on GitHub Sponsors or buy me a coffee on Ko-fi (after all, more coffee means more code, right?).

Edit 2024-10-28: applications for these positions are closed. KDE e.V., the non-profit organization supporting the KDE community, and the Kdenlive team are looking for proactive contractors to implement some features in the Kdenlive video editor. Two positions are currently open:

• OpenTimelineIO integration: this will require implementing a C++ module in Kdenlive to allow importing and exporting using this open standard, to allow exchanging project files with other applications. Please see the job ad for more details about this contracting opportunity.

• Audiowaveform integration: this will require rewriting the code used to generate and display the audio waveforms in Kdenlive using the audiowaveform library. This should bring faster and more precise waveforms in the timeline. Please see the job ad for more details about this contracting opportunity. We are looking forward to your application.

I am huge fan of obsidian.md and just other day I was trying to “convert” Akseli. One pain point he mentioned that it does not quite allow him to get reminders for the todo list created in obsidian.

I have been doing little bit of “hack” to workaround this, and I thought I’d write a blog post about this so that others can also make use of it.

How to use this

First of all, following plugins are used (ignore PlantUML)

KStars v3.7.3 is released on 2024.10.03 for Windows, MacOS & Linux. It's a bi-monthly bug-fix release with a couple of exciting features.

Extension Interface

Ed Lee contributed the Extension Interface for KStars.

Extensions are small programs that can be added to interact with KStars/Ekos/INDI in order to provide extra functions and features. Extensions are separate from KStars. They are not provided as part of this software. Only a means to call them is provided for convenience. Make sure that you understand the requirements and risks of using an extension.

Three extensions are ready for release:

• FireCapture launcher (FC_launcher): disconnects the current primary camera INDI driver and launches FireCapture. Upon close restarts the INDI driver.
• KStars Backup (KS_backup): provides a GUI for the archiving and restoration of KStars/INDI (and optionally others) configuration directories to/from .tar.gz archives/
• Sirial_EEA: provides live stacking of the preview job from the Capture Module and displays it auto-stretched in the Ekos preview window.

Multi-Target Scheduler

Multi-Camera Scheduling

With this new release it is possible to create and run schedules for two or more optical trains in parallel within the same KStars instance. All mount related events like slewing, dithering, alignment and meridian flip are synchronized, i.e. capturing on all optical trains takes these events into account.

Lead and follower jobs

If you want to run capturing on multiple optical trains in parallel, you need to decide, which of the optical trains is the lead job, which defines the target and the scheduling criteria. All other optical trains will be follower jobs, for which only the capture sequence to be used is relevant.

Job Synchronization

Ekos ensures that no mount motion happens while one of the optical trains is capturing to avoid star trails.

In case of dithering, the capture module decides what to do as soon as dithering is requested, depending on the setup of the lead job. If the remaining capture time of a follower train is more than 50% of the lead job exposure time, capturing of the follower train is stopped and restarted after dithering. If the remaining capture time is less than 50%, the Capture module waits for the follower to finish its capture.

For the meridian flip and re-alignment: both are controlled by the lead job. All running follower capturing sequences are stopped and restarted after a successful completion of the respective action.

Recommendations

• The lead job should have the longest exposure times, especially if dithering is used.
• If you use re-focusing, consider to not suspend guiding during focusing, since the other optical train might capture in parallel.
• Configure the same optical train in the Align module that you use in the lead job. This is important if you use the re-alignment check option of the scheduler.

Do not use the Force re-alignment before re-starting jobs, since each new iteration of the lead job stops capturing of the follower trains. Consider using Verify captured image position every n frames instead, since this option triggers re-alignment only if it is necessary.

Adhoc focus with Multi-Camera setups

Wolfgang Reissenberger added support for simultaneous parallel focusing when you are running multi-camera setup. It would be a good idea to disable Suspend Guiding so that guiding is unaffected when focusing operation commences.

Invent Multi-Star Guide Star

Hy Murveit introduced an experimental Multi-Star parameter. In the original (conservative) multi-star guiding implementation, although many stars contributed to the computed guiding drift computation, there still was one more important star that anchored the scheme.

With this change, all the guide stars contribute equally to the guiding calculations. This removes the risk that an unfortunate selection of a double star for the more-important main guide star would degrade performance.

Improvements & Bug fixes

• Fix crash on ekos reconnect
• Scheduler end-time display fix
• Focus Filter Offsets fix
• Add altitude graphs to scheduler
• Allow Flat re-calibration on the fly

(Photo Credit: Friedemann Kleint)

In the next release of Dolphin, the search backend (when Baloo indexing is disabled) will be faster and support more file types, by using external projects ripgrep-all and ripgrep to do the search. Merge Request

What are ripgrep and ripgrep-all?

ripgrep is a fast text search tool that uses various optimizations including multi-threading (compared to grep and Dolphin's internal search backend which are single-threaded).

ripgrep-all, quote its homepage, is "ripgrep, but also search in PDFs, E-Books, Office documents, zip, tar.gz, etc.".

How to enable it

Install the ripgrep-all package from your distribution's package manager (which should also install ripgrep). Then Dolphin will automatically use it for content search, when Baloo is disabled.

If your distribution doesn't provide ripgrep-all, you can also try installing ripgrep. Then Dolphin will use it for content search, but without the additional file type support.

Limitations

• It only works in content search mode, and when Baloo content indexing is disabled. File name search still uses the internal backend.

• It only works in local directories. When searching in remote directories (e.g. Samba, ssh), the internal search backend is used. Although we can run ripgrep in remote directories through the kio-fuse plugin, testing shows it can be 3 times slower than the internal backend, so it's not used.

• It doesn't work on Windows. Although both ripgrep and ripgrep-all have releases for Windows, I personally don't have Windows experience to integrate them. Merge request to enable it on Windows is welcome.

Customization

You can change the command line with which Dolphin calls the external tools. Copy /usr/share/kio_filenamesearch/kio-filenamesearch-grep to ~/.local/share/kio_filenamesearch/, and modify the script there. The script contains comments on the calling convention between Dolphin and it, and explanations on the command line options.

One option you might want to remove is -j2. It limits the number of threads ripgrep (and ripgrep-all) uses to 2. Using more threads can make the search much slower in hard disks (HDD). I tried to detect HDD automatically, but it's not reliable, so I went with a conservative default. It's still faster than the internal backend, but if you have an SSD, you can remove the option to unlock the full speed of ripgrep.

You can also use a different external tool. (E.g. the silver search (ag). Or a full-text search engine other than Baloo) Just make sure it outputs paths separated by NUL. Usually a -0 option will do that.

More customization

You can even modify the script so that you can specify different external tools in the search string. For example, you can insert the following code before the original code that calls ripgrep-all:

...(line 1-33)
 --run)
 if test "$2" = "@git"; then
 exec sh -c 'git status -s -z|cut -c 4- -z'
 fi
...

Then if you search for "@git" in a git directory, it will show you changed files.

FAQ

But what if a malicious app creates ~/.local/share/kio_filenamesearch/kio-filenamesearch-grep that deletes all my files when I search?

If a malicious app can write to ~/.local/share/kio_filenamesearch/, it probably can just delete all files in you home directory, without involving Dolphin at all. A script executed by Dolphin doesn't have more power than a script executed by the malicious app itself.

Also, there are already a lot of places in your home directory that a malicious app can create a script in, and it will be executed later without you noticing. E.g., ~/.bashrc, ~/.config/systemd/user, ~/.config/autostart, to name a few.

The threat is real, but I believe the solution is to prevent apps from writing to arbitrary places in your home directory without your consent. If your apps are sandboxed (e.g. via Flatpak) so they can't write to ~/.config or ~/.local by default, and you only use trusted apps like Dolphin and Kate to manage files in these places (so you trust them to not modify files behind your back), then the scenario in the question is unlikely to happen.

Future works

There are quite a lot to improve in Dolphin's search (when not using Baloo). The content search should also search in file names. The search string is currently interpreted as a regular expression, but a fuzzy match or shell globbing seems to be a more sensible default (probably with regexp as an option). Hopefully future works will address these issues.