In my previous blog post I mentioned Akademy wasn’t completely over for me, I still had to hold an online training about the KDE Stack even though I left Thessaloniki already.

I had a few participants. Surprisingly some of them (but not all) were more experienced KDE developers than I expected. Since the training is more meant for people who want to get a feel on how to get around our stack I was a bit anxious they wouldn’t get bored… From the feedback I got immediately after the training it looks like it was well received even by the more experienced people. Apparently everybody learned quite a bit and had fun in the process. I’ll thus call it a success.

I made the slides of the KDE Stack training 2023 edition available online on my website and the page of the training in the Akademy program. Feel free to grab and go through them although I guess you’ll get most value with someone actually going through them with you.

And now? Well, we got the KDE e.V. general assembly coming in a few weeks. And hopefully we can setup another KDE PIM sprint in Toulouse around spring time if the community is interested.

As for the life of this KDE Stack training… I have this fantasy that next time I will be able to do it in-person and will make a major update of it since KF6 and Plasma 6 will be out by then. It’s not that I expect a lot of the content being invalidated by those releases. In fact quite the contrary since the 2023 edition already accounts for some of the expected changes. It’s more that an in-person format and the interest driven by major releases would be good reasons to re-think the way it is taught, probably bringing more labs and group activities.

We’ll see if I find time to actually fulfill this fantasy. 😊

I am returning from akademy and I had a great time, meeting new people or people I had already worked with online.

In particular I was very happy to meet Felix, my fellow dolphin co-maintainer. We get along very well together, this will only make our dolphin work more pleasant and efficient.

Dolphin

We had a Bof about dolphin on Tuesday.

You can have a look at the notes taken by Felix. Unfortunately we didn't manage to have sufficient audio quality so that people online could properly participate.

Still with the amazing people present, we made some plans to improve dolphin search feature, the possibility of publishing dolphin on Windows Store and more.

I shared my interest in fixing the most popular bugs, by votes or duplicate count. Those are usually hard but very rewarding to fix.

A perfect area for interested people willing to contribute to dolphin, would be to help on our setting redesign plans. If you are interested, you can pick some part of the changes and try to implement them as I did in this MR and join the KDE file management channel to get some help and advice.

With the current KDE goals being Accessibility, Sustainability and Automation, it has made apparent that the selenium-appium-at-spy testing tool can greatly help dolphin in those three regards. It allows to automate UI tests, by using the accessibility API present in applications (in Qt for instance). So for it to work we need dolphin to have good accessibility support. In turn this allows to automate test scenarios to measure energy consumption and ensure dolphin of its energy-efficiency. The good news is that it is already in the pipe thanks to the work of Marco.

Finally, Dolphin 23.08 is close to release, it will feature some bug fix and some small features:

• when hiding hidden files dolphin will also hide files files whose name ends with "~", ".bak" or "%". Technically files having the "application/x-trash" mimetype. This is configurable by editing mime type either in file association kcm or using the utility command keditfiletype application/x-trash.
• Double clicking on a tab will dupicate the tab.

Akademy

This my fourth akademy, and my second in-person, it has been great.

Conferences were very nice, I learned many new things. The goals are making nice progress and getting traction.

I attended the qml-c++-integration training by Kevin Krammer of KDAB. It was an occasion to complete my Qml+C++ knowlegde, now I have a better understanding of attached properties. Kevin told us about use cases for qml without QtQuick, as a scripting language or a to build QWidget interfaces using Declarative Widgets for instance. I was reminded about KDAB's KDToolbox a very nice collection of C++ utilities and learned about the nifty NotifyGuard that can help reduce boiler code for instance in KCM when writing c++ objects having many properties. Since it is MIT licensed, it is very easy to reuse.

Now it is time to finish my own planned work for Plasma 6 because it is coming !

Many thanks to every one who made the event possible, the local team, the akademy team, the sponsors and the donators to KDE e.v .

As mentioned previously on this blog, I took a break from my vacations for the past couple of days. I attended Akademy 2023 over the week-end and I’m now typing this during my trip back home.

Of course it was nice to see the people. After all it’s the main reason to have such events. Still we had talks and it’s mainly what I will focus on here.

Saturday

Keynote: Libre Space Foundation - Empowering Open-Source Space Technologies

We started the day with a nice keynote about the Libre Space Foundation. It was very interesting and inspiring to see how open source can go into space. The project started in 2011 and despite all the regulation required they managed to get their first satellite in orbit in 2017. This is not a small feat. Of course, everything they produce is free and reusable by others. It was nice to touch upon some of their more specific constraints which impact quite a bit the cycles for producing software and hardware.

KDE Goals - a review and plans going forward

This was followed by a session about the KDE Goals. All three current community goals were covered.

First, the “Automation & Systematization” goal where a good chunk of tasks have been implemented around automated tests (in particular Selenium GUI testing) and the CI to ease some of our processes. It also meant updating quite some documentation.

Second, the Accessibility or “KDE For All” goal was covered. There’s been quite some effort put into adding automated tests using Selenium to check our software compatibility with screen readers and how the keyboard navigation fares. This obviously led to improvements all across the board: in Plasma, in application, in our frameworks, in Qt and in Orca.

Third, the “Sustainable Software” goal progress has been presented. It’s been quite a bit about documenting and presenting results of the efforts in various venues. But there has also been projects to setup labs to measure our software and automated tests using Selenium to implement user scenarios to measure. This can even be triggered on the CI to be executed in a permanent lab in Berlin.

Did you notice the recurring theme between the three goals? I’ll get back to it.

After this session about the KDE Goals, we split in two tracks and so obviously I couldn’t attend everything. I will write only about what I watched.

Measuring energy consumption of software

This session was a more in depth look at how the measurements of the KDE Eco effort are actually done. This is in fact an active research topic and it’s not necessarily easy to source hardware suitable for measuring properly the energy consumption of software.

The guidelines and best practices are still missing in this field.

Interestingly, we have several options available for measuring. I’d summarize it in three categories: cheap hardware, expensive specialized hardware and built-in sensors (accessible via perf if supported). Each category comes with its own set of trade-offs which need to be kept in mind.

In any case, it’s clear that the first thing to do is general profiling and optimizing. Then it’s time to focus on long-running processes, frequent workloads and idle behavior. At this stage, this is where the energy specific measurements become essential… but still difficult to do, the tools available are very basic.

KDE e.V. Board report

Lots was done on the side of the KDE e.V., the board report highlighted some of this work.

First we’re seeing the return of sprints, conferences and tradeshows. The presence and meetings of the community seem back to pre-COVID19 levels.

Also, the fundraising efforts are clearly bearing fruits. In particular a new platform has been put into place (Donorbox) which seems to work great for us. This lead to very successful fundraisers for the end of year and for Kdenlive (first fundraiser of its kind). Now, in the Kdenlive case it means we have to start spending this money to boost its progresses.

The KDE e.V. is professionalizing faster as well. All the “Make a Living” positions got filled. This is no longer a purely volunteers based organization, we have around 10 employees and contractors.

There is already great interest in our software among hardware and software vendors. Hopefully with all those efforts it will keep increasing.

Flatpak and KDE

I then attended a session about Flatpak. It was a quick recap of what it is. Hopefully a widespread adoption could reduce the amount of our users which run old outdated versions.

Interestingly, we seem to have more installations via Flatpak than I first thought. Our most successful software on FlatHub seems to be Kdenlive with around 575K installs. It’s followed by Okular with around 200K installs.

We also provide a KDE Runtime suitable for building our applications flatpaks on. There is one branch of it per Qt version.

Last but not least, we have our own Flatpak remote. This is meant for nightlies and not for stable use. Still if you want to help test the latest and greatest, it’s a nice option.

KF6 - Are we there yet?

This is the big question currently. How much time will we need to reach a port of KDE Frameworks, Plasma and our applications to Qt 6?

The work is on going with quite some progress made. Still there are a couple of challenges in particular in term of coexistence between 5 and 6 components. We’re not too bad in term of co-installability, but there are other dimensions which need catering to in this time of transition.

The talk also covered how to approach the port of our applications. So if you’re in this situation, I advise to get back to the recording and slides for details.

KDE Embedded - Where are we?

This was the last session of the day for me. It went back on what can be considered an embedded device. In this talk the definition was quite a bit reduced: we assumed a Linux kernel available but also a GPU and connectivity we’re kind of used to. A bit of a luxury embedded if you wish. 😉

In any case this is a nice challenge to invest in, it can also lead the way to more use of the KDE stack in the industry.

For such system integrations, we’re using the Yocto ecosystem as it is the industry standard. We provide several Yocto layers already: meta-kf5, meta-kf6, meta-kde and meta-kde-demo. This covers KDE Frameworks and Plasma but none of the apps.

The range of supported hardware is already interesting. It covers among others the Raspberry Pi 4, the Vision Five 2, the Beagle Play and the Beagle V. The RISC-V architecture is definitely becoming very interesting and getting quite some traction at the moment.

Plenty of dev boards have been produced during the last few years. The pain point on such devices is generally the GPU, even more so on RISC-V unfortunately.

Our stack has plenty to provide in this context. meta-kf5 or meta-kf6 could be used in industrial products of course, but Plasma and applications could be a good benchmark tool for new boards. We might want to provide extra frameworks and features for embedded use as well.

The biggest challenge for this effort is to make things approachable. The first Yocto build is not necessarily a walk in the park.

Sunday

Keynote: Kdenlive - what can we learn after 20 years of development?

This keynote gave a good overview of the Kdenlive project. This is in fact a much older project than I thought. It was started in 2003 but kind of got stuck until the actual maintainer revived it. Also it’s a good example of a project which had its own life before joining KDE officially. Indeed it became an official KDE application in 2015 only.

They explained how they keep the conversation open with the user base and how it feeds the vision for the project. It’s no surprise this is such a nice tool. The user base seems diverse, although the personal use is dominant. Still, its used in schools and by some professionals already, maybe we can expect those user groups to grow in the coming years.

They have a couple of challenges regarding testing and managing their dependencies. Clearly its on their radar and we can expect this to get better.

The fundraising effort paid off. It already allowed the maintainer to reduce the work time at his current job, he can devote one day a week to Kdenlive work.

Finally we got a tour of exciting new features they released. Most notably the nested timelines but also the support of speech to text to help creating subtitles. They won’t stop here though and they hope to bring more AI supported tools but also improve the GPU support and provide online collaborative spaces.

Make it talk: Adding speech to your application

The first lightning talk I’ve seen on Sunday was advocating for more text to speech uses in our applications. Indeed it can have some uses beyond accessibility.

It also made the case that it’s actually easy to do through Qt which provides the QtSpeech module for this with a simple API. The good news being that it is supported on almost all platforms.

The Community Working Group - Keeping a Healthy Community

Another lightning talk, this time about the Community Working Group. It didn’t a good job debunking some myths regarding that working group. It is indeed not a “community police” but it’s mainly here to help the community and provide assistance in case of issues.

They have a complex job aiming at maintaining healthy community channels. It involves making sure there is no misunderstanding between people. This is necessary to avoid loosing contributors due to a bad experience.

An OSS Tool for Comprehending Huge Codebases

Interesting talk about a tool allowing to explore codebases. Having a knack for this and having done it quite a few times in the past obviously I was eager to attend this one.

The tool is made by Codethink and funded by Bloomberg. It uses LLVM to parse C++ code and feed a model of the code stored in a relational database. In particular it takes care of finding all the C++ entities and their dependencies. There’s also traceability on which source and header files the entities and dependencies come from.

On top of this model they built visualizations allowing to track dependencies between packages. It also allows to inspect where dependencies are coming from and it makes the distinction between dependencies coming from tests or not. It also provides a plugin mechanism which allows to impact the behavior of steps in the pipeline. And last but not least, command line tools are provided to manipulate the database. This comes in handy for writing checks to enforce on the CI for instance.

They took the time to try the tool on KDE products. This is after all a big corpus of C++ code readily available to validate such a tool. This way they showed examples of cyclic dependencies in some places (like a Kate plugin). They’re not necessarily hard to fix but can go unnoticed. Another interesting thing they attempted was to use hooks to tag modules with their tiers. Which would then allow to differentiate tiers in the dependency graphs allowing to see if we have any violation of the KDE Framework model.

They have plans for providing more features out of the box like tracking unused includes, spotting entities used without being included directly, etc. This could be interesting, clearly it aroused interest in attendees.

Matrix and ActivityPub for everything

This short talk went over the Matrix and ActivityPub protocols. Both are federated but the speakers highlighted the main differences. In particular Matrix is end to end encrypted for personal communication uses, while ActivityPub is not encrypted and tailored for social media uses.

They also emphasized how both protocols are important for the KDE community and how they can be used. Some of the ideas are upcoming features which are already implemented.

In particular we’ve seen a couple of scenarios for location sharing over Matrix so that you can get it to and from Itinerary or share vie NeoChat. There’s also the future possibilities of synchronizing Itinerary data over Matrix or importing Mobilizon event in your calendar.

Selenium GUI Testing

Remember when I mentioned a recurring theme during the session about the KDE Goals? I hope that by now you realized this was about Selenium. So of course, it was to be expected that we would have a session about it. After all this effort to use Selenium for GUI testing helps push forward all of our current community goals.

What has been created so far allows to easily write GUI tests reproducible locally. This way we could catch up with industry standards, we were clearly falling behind in term of GUI testing.

Selenium is known for being web oriented, but it can be used in other contexts. What you need is mainly a WebDriver implementation and this is exactly what has been created. So we now have such an implementation bridging between Selenium and AT-SPI the protocol used for accessibility support.

One nice trait of all this which I noted is that the tests are run in a nested Wayland session. This avoids leakage with the host session. Also the session is screen recorded so we can see what happened in it after the fact if needed.

Now help is needed for more such tests to be written using this bridge. Doing so will help with all of our current goals.

Kyber: a new cross-platform high-quality remote control software

After lunch we had a whole series of lightning talk. The first one demoing Kyber. This is a new solution coming from VideoLAN to control machines remotely.

The results are so far impressive. You can play a game from Linux remotely controlling a Windows machine for instance. The delay over a 4G connection is spiking at 40ms maximum, but most of the time is close to 20ms. This means in most cases around a 1.5 frames delay if playing at 60 frame per seconds.

On the network level it uses QUIC and uses a few tricks to have crisp rendering of the image, including text, despite the compression. Of course it is portable and both the client and server are available for various platforms. It can also leverage hardware for better performances.

Impressive and exciting. Looks like we might have a very viable FOSS alternative to TeamViewer soon.

Fun with Charts: Green Energy in System Monitor

Next lightning talk was about a personal project bringing information from a solar panel installation all the way to a Plasma desktop. Indeed, those installations tend to be coupled to proprietary cloud applications, it’d be nice to not go through those to control your installation.

We were shown funny uses. Like a KInfoCenter module summarizing all the available data, or a KDED notifier which indicates the first ray of sun in the day, the storage battery status etc. And of course some command line tools to script the system allowing for instance to turn on and off services based on the amount of energy available.

What has qmllint ever done for us?

Another lightning talk, this time about qmllint. It went through the history of this tool which went from being only able to tell if a file was a QML one or not, to providing lots of warnings about missuses of the language.

Now it’s even possible to integrate it in the CI via a JSON file and it’s the base of the warnings we get in the QML LSP support. And last for not least, I learned it even has a plugin system nowadays allowing to extend it to provide more project specific checks.

It became quite powerful indeed.

Wait, are first-run wizards cool again?

The last lightning talk of the track was about our new first-run wizard. It has been introduced for good reasons, this time we’re not making it for users to configure some settings like look and feel.

This is about on-boarding the users on first use. For instances it helps them access the internet if needed, it introduces them to the important Plasma concepts, it gives them an opportunity to get involved, and it also remind them that donations are possible.

This is definitely done in a different spirit than the old wizard we had back in the days.

The End?

This was only over two days for me… But this is not over yet! The BoFs are going on strong for the rest of the week (even though I unfortunately won’t attend them this year).

Also there will be a training day. If you’re interested in how the KDE Stack is organized, make sure to not miss the training I will hold online on Thursday morning.

Make sure you commit anything you want to end up in the KDE Gear 23.08 releases to them

During this week Akademy 2023 is going on in Thessaloniki, Greece. It’s always awesome, to see many old friends and getting together with that amazing hacker community which is KDE.

There, me and Niccolò gave a talk about what;s happening in Plasma 6 and what will change, Noccolò on more visual things, about some changes we are cooking on the UI and on the visual themes. Here you can find a recording of the talk (alongside all the others of the day)

I talked more about the work I’ve bein doing in the Plasma shell during the last couple of months: code rafactors and how the API for writing plasmoids will change.

There were many things we were not quite happy about and now with the major release is the occasion for streamlining many things.

Now, It’s very important those changes are are well communicated, and easy to do for developes, because there are *a lot* of 3rd party plasmoids on the KDE store, which people are using and enjoying.

Let’s go trough the most important changes:

Dataengines

Dataengines were an API designed in early KDE 4 times, especially one of for our first offereings of Plasmoid API which was the pure JavaScript API, which existed long before the QML existed.

But now in a QML world, their API doesn’t really fit, instead is a much better fit having a QML extension which offers classes with all the needed properties, data models and signals that provide access to the needed data, such as tasks, notifications etc.

Dataengines are now deprecated and moved into a separed library, called “plasma5support” which will be still available for the time being, but consider porting away from it as we plan to eventually drop it.

Base Plasmoid API

The way plasmoids are declared in QML changed a bit: we used to have a magical “plasmoid” context property available from anywhere. This was an instance of a QQuickItem which was both the item where all the plasmoid contents were *and* a wrapper for some of the api for the central plasmoid object: the C++ class Plasma::Applet.

Now the access to plasmoid is an attahced property, the (uppercase) “Plasmoid”, which is directly the access to the instance of the central Plasma::Applet, without an in-between wrapper anymore.

The central QQuickItem is now called “PlasmoidItem”, and must be the root item of the plasmoid, just alike ApplicationWindow is for applications.

PlasmoidItem will have the purely graphical properties, such as the “compactRepresentation” or “fullRepresentation”

Here is a very minimal example of a plasmoid main file under plasma6:

import org.kde.plasma.plasmoid 2.0
PlasmoidItem {
    Plasmoid.title: i18n("hello")
    fullRepresentation: Item {....}
}

Actions

Plasmoids can export actions to their right mouse button menu, such as “mute” for the mixer plasmoid and so on.

In Plasma 5 we had an imperative API to add those actions, which was again coming from that old pure JS API, which really looked a bit out of tune in QML. In Plasma 6 the API has been replaced with a completely declarative API, in this form:

PlasmoidItem {
    Plasmoid.contextualActions: [
        PlasmaCore.Action {
            text: i18n("Foo")
            icon.name: "back"
            onTriggered: {...}
        },
        PlasmaCore.Action {
             ...
        }
    ]
}

PlasmaCore.Action is actually a binding to QAction (not the internal QML action type), so that it can be shared between C++ and QML easily

SVG theming

Plasma Themes don’t really have changed for now (and you can expect any old theme from the store to keep working), but the C++ and QML API for them has been moved to a standalone framework called KSvg. Plasma Svgs have quite some interesting features over the pure QtSvg API, such as disk caching of the rendered images, stylesheet recoloring to system colors and the 9 patch rectangular stretched images of FrameSvg.

Some applications were interested in using that, but couldn’t due to the long dependency chain of plasma-framework, so now they can be used as a much more manageable compact framework, offering both the usual C++, QPainter based api and QML bindings.

import org.kde.ksvg 1.0 as KSvg
FrameSvg {
    imagePath: "widgets/background"
}

Kirigami all the way down

Designing Kirigami in the beginning we lifted two concept from the Plasma API (which again we couldn’t use directly due to the dependency chain) Theme and Units

Theme gives access to the named system colors, and Units to standard spacing and animation durations.

Over the years the Kirigami version got way more advanced then the Plasma version, and having this code duplication didn’t make much more sense, to in Plasma6 whenever referring to a named color or an unit, the Kirigami version should be used, as the Plasma version is going away.

import org.kde.kirigami 2.20 as Kirigami
RowLayout {
    spacing: Kirigami.Units.smallSpacing
    Rectangle {
        color: Kirigami.Theme.backgroundColor
        bordere.color: Kirigami.Theme.textColor
    }
}

Hello and welcome back to my blog! This time I will be reviewing the work I've done during the first coding period of GSoC '23. This blog is written as part of my work for GSoC '23, to detail all the work I have done. Let's get started!

Challenges faced

Some of the challenges I faced are:

• Time: Sometimes it felt like time was not on my side. Between college, assignments, exams, and family time, I found it hard to find time to concentrate on GSoC. However, I'm hoping I can improve my time management to remove this issue.

• Lack of Documentation: For Android-NDK, there was a lack of documentation for things that are considered simple when developing a traditional Java app for Android. This made it more annoying to deal with Android libraries (especially since I'm using CMake). Sometimes I had this feeling while dealing with Poppler as well, but luckily my mentor helped me out massively.

• Lack of experience in Android development: Going into the project, I didn't have much experience with Android development, much less Android-NDK based development. This proved to be a hindrance at times, as I did not know how to do simple things due to my lack of knowledge.

Work done

My goal for the first coding period was to implement a font-fetching API in Poppler, so that if a document has unembedded fonts, Okular can still display the document by using similar fonts found in the system.

I've successfully implemented this into Poppler along with help from my mentor, Albert Astals Cid (aacid@kde.org). To do so I had to implement multiple things:

The AFontMatcher API

The Afontmatcher functionality was introduced in Android-NDK around Android API level 29. It can be used to fetch a font that best matches the font family and the text to be rendered.

To use this API to implement font-matching capabilities, I had to do just a few things:

• Add the Android library to the CMakeLists.txt for Poppler

• Import the required header files into poppler/GlobalParams.cc. According to the documentation, these are the required header files:

  • <font.h>

  • <font_matcher.h>

  • <system_fonts.h>

• Implement the AFontMatcher API in the GlobalParams::findSystemFontFile() method inside GlobalParams.cc

To implement the AFontMatcher API, I implemented GlobalParams::findSystemFontFile() in the following way:

• Create a new AFontMatcher object using AFontMatcher_create()

• Set the font weight and italics for the AFontMatcher object by using AFontMatcher_setStyle(), and the methods GfxFont::getWeight() for font-weight, as well as GfxFont::isItalic() for font italics.

• Get the generic family name of the required font using the GfxFont::isSerif(), and GfxFont::isFixedWidth()

• Match the font using AFontMatcher_match() to get an AFont object

• Use the AFont object to get a font path for the font.

• Use the font file extension to set the font type, which depends on the font format. Since the fonts can be in .ttf, .otf, .otc, or .ttc format, we check the font file extension to set the font type.

• Create a GooString object using the path and return it.

• Before returning the path, close the AFontMatcher and AFont objects using AFontMatcher_destroy() and AFont_close() to prevent memory leaks.

Setting up the Base-14 fonts

The Base-14 fonts are a special subset of fonts used in PDFs. Wikipedia describes them as:

Fourteen typefaces, known as the standard 14 fonts, have a special significance in PDF documents:

- Times (v3) (in regular, italic, bold, and bold italic) - Courier (in regular, oblique, bold and bold oblique) - Helvetica (v3) (in regular, oblique, bold and bold oblique) - Symbol - Zapf Dingbats

These fonts are sometimes called the base fourteen fonts. These fonts, or suitable substitute fonts with the same metrics, should be available in most PDF readers, but they are not guaranteed to be available in the reader, and may only display correctly if the system has them installed. Fonts may be substituted if they are not embedded in a PDF.

-- Wikipedia page on PDF file format

These fonts are usually substituted since they are licensed fonts, and permission is required to use them. So we use substitute fonts for them, which are either packaged along with the application or can be found in the system

Since Android systems have a limited set of fonts that can be fetched by AFontMatcher, we'll use substitute font files for the base-14 fonts. Thankfully, these are already packaged inside Okular's APK file, in the assets/share/fonts folder.

Poppler uses the GlobalParams::setupBaseFonts() method to set up these base fonts and create a mapping between the base-14 font names and their font file paths within the filesystem.

However, since these fonts are packaged inside the APK, they cannot be accessed using regular methods. So to access the fonts, I implemented a font-copying mechanism that copies all base-14 fonts into the fonts folder of the application's internal storage. This is described in the next section.

Then I had to create an array of structs with the base-14 font name and the name of the substitute font file. Here it is:

static struct{    const char *name;    const char *otFileName;} displayFontTab[] = { { "Courier", "NimbusMonoPS-Regular.otf" },                       { "Courier-Bold", "NimbusMonoPS-Bold.otf" },                       { "Courier-BoldOblique", "NimbusMonoPS-BoldItalic.otf" },                       { "Courier-Oblique", "NimbusMonoPS-Italic.otf" },                       { "Helvetica", "NimbusSans-Regular.otf" },                       { "Helvetica-Bold", "NimbusSans-Bold.otf" },                       { "Helvetica-BoldOblique", "NimbusSans-BoldItalic.otf" },                       { "Helvetica-Oblique", "NimbusSans-Italic.otf" },                       { "Symbol", "StandardSymbolsPS.otf" },                       { "Times-Bold", "NimbusRoman-Bold.otf" },                       { "Times-BoldItalic", "NimbusRoman-BoldItalic.otf" },                       { "Times-Italic", "NimbusRoman-Italic.otf" },                       { "Times-Roman", "NimbusRoman-Regular.otf" },                       { "ZapfDingbats", "D050000L.otf" },                       { nullptr, nullptr } };

The GlobalParams::setupBaseFonts() method would then loop over this array and set a mapping between base-14 font names and the path of their substitute font files. This mapping is then used by other methods such as GlobalParams::findFontFile() to return the font file path for a particular font. However, if there is no such font, then Poppler will fall back on GlobalParams::findSystemFontFile, which on Android uses the AFontMatcher API.

Mechanism to copy font files from the APK

While the above features worked, running the GlobalParams::setupBaseFonts() method required me to copy the font files manually, using adb push. However, the end user should never have to manually intervene in the application's files to make it work. Hence I began working on copying font files from the APK automatically.

To do so I needed a way to do 4 things:

1. To get the path of the internal storage of the application. I needed to get the path programmatically, since other apps may use Poppler for PDF rendering, and those apps would have their own internal storage paths. Fortunately, Qt has a component called QStandardPaths which allows the user to retrieve the paths of standard directories. In this case, I used QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) to retrieve the path of the app's internal storage directory.

2. To get the font files from within the assets folder inside the APK. Fortunately, Qt allows access to these assets through a special syntax - by prefixing the path with assets:/ and specifying the file path relative to the assets folder. So for example, if you wanted to access the file present in assets/exampledir/examplefile, you would need to specify it as "assets:/exampledir/examplefile".

3. A way to copy the font files into the fonts directory inside the internal storage of the application. For this purpose, I used a QDirIterator along with the file paths from earlier and copied every font file into the app's internal storage.

4. To set the path of the font directory inside the GlobalParams.cc file so that setupBaseFonts() can create the proper font mappings. For this purpose, I created a static function in GlobalParams.cc called setFontDir().

The Results

Before

Here is a video demonstrating a pdf with unembedded fonts before the new Android font-matching functionality was added:

After

And here is one demonstrating the same pdf after implementation of the new Android font matching functionality:

Remaining work

• More thorough testing of the code: I've only done some basic testing of the new features and with a single pdf that had unembedded fonts. To find any bugs that are still hiding in the code, more thorough testing should be done with other PDFs.

• Making the assets font directory configurable using CMake flags: The path of the assets directory that holds the fonts is currently hard coded in the DocumentData::init() method of the qt5/src/poppler-private.cc file. To enable users of the library to change this, a CMake commandline may be added to configure it.

• Smoothening the text rendering: While I may have finished my work on setting up an Android-specific font-matching interface, the rendering of the text in the PDF still leaves something to be desired. The rendering is a bit pixelated when zoomed out, and becomes clear only when zoomed in.

The Journey

This section describes my journey as I worked on implementing AFontMatcher. It includes setting up my development environment, the components I worked on, as well as everything I tried, what worked, and what didn't. If you are interested, read on!

The Beginning

Getting up to speed with the code

Without knowing what code I had to change, I couldn't start working on my project. I approached my mentor, Albert Astals Cid (aacid@kde.org) for help, and he pointed me toward the poppler/GlobalParams.cc file, and that I had to re-implement the GlobalParams::findSystemFontFile() and maybe GlobalParams::findBase14FontFile() so that it would work on the Android platform.

Setting up my development environment

Now I had to set up my development environment. No developer can do their work without some setup after all :)

Craft

First, I set up an environment to compile Okular for Android. For this, I used KDE's Craft tool, which is used for cross-compiling across OSs and architectures.

To set up Craft to compile for Android, I referenced the following guide: https://develop.kde.org/docs/packaging/android/building_applications/

I edited the arguments a bit, so my setup involved using the following commands:

mkdir -p $HOME/craftdocker run -ti --rm -v $HOME/craft:/home/user/ kdeorg/android-qt515 bashpython3 -c "$(curl https://raw.githubusercontent.com/KDE/craft/master/setup/CraftBootstrap.py)" --prefix ~/CraftRoot

I then setup the environment to build for the arm32 architecture. To build Okular for android and package it as an apk, I had to execute the following commands (exclude the docker command if you're already inside the Craft docker container):

# Start the docker container if not already inside itdocker run -ti --rm -v $HOME/craft:/home/user/ kdeorg/android-qt515 bash# Init the craft environment source ~/CraftRoot/craft/craftenv.sh# Craft okular for the first timecraft okular# Package okular as an apk craft --package okular# cd into ~/CraftRoot/tmp, where the packaged apk iscd ~/CraftRoot/tmp# Align the apk using zipalign /opt/android-sdk/build-tools/30.0.2/zipalign -p -f -v 4 okularkirigami-armeabi-v7a.apk okularkirigami-armeabi-v7a.signed.apk # Generate the keys for signing the apk (must only be done the first time)keytool -genkey -noprompt -keystore key.keystore -keypass 123456  -dname "CN=None, OU=None, O=None, L=None, S=None, C=XY" -alias mykey -keyalg RSA -keysize 2048 -validity 10000 -storepass 123456# Finally, sign the apk using apksigner/opt/android-sdk/build-tools/30.0.2/apksigner sign -verbose -ks key.keystore okularkirigami-armeabi-v7a.signed.apk

This will generate a signed apk (.signed.apk extension) in the ~/CraftRoot/tmp directory of the docker image. To find the apk in your computer's filesystem, you must go to the path where you created the craft directory and find the tmp directory within it. For me it was located at ~/craft/CraftRoot/tmp.

Poppler

Next, I had to set up Poppler for cross-compilation to Android arm32.

Initially, this proved to be frustrating - not only was I dealing with lots of CMake flags, but I also had to cross-compile for both the Android AND ARM32 platforms - not fun.

After a couple of days of pulling my hair out in frustration, my mentor advised me to reference the android_build section of Poppler's gitlab CI file, which can be found in the repo at .gitlab-ci.yml.

Based on the Gitlab CI file, I had to use the kdeorg/android-sdk docker image for cross-compiling Poppler. I used the following commands to set up the docker image:

# Create a directory for your source code and git clone the poppler repo into itmkdir -p ~/kde-android/srcgit clone https://gitlab.freedesktop.org/poppler/poppler.git# Launch the kdeorg/android-sdk containerdocker run -ti --rm -v $HOME/kde-android/src:/home/user/src  kdeorg/android-sdk bashcd

Now my docker container for cross-compiling Poppler was ready. I also created a build script at ~/kde-android/src/build.sh for easily building Poppler:

#!/bin/bashecho "workaround for ECM Android toolchain wanting all binaries to be shared libraries"sed -i -e 's/<LINK_FLAGS> <CMAKE_SHARED_LIBRARY_CREATE_CXX_FLAGS>/<LINK_FLAGS>/g' /opt/nativetooling/share/ECM/toolchain/Android.cmakemkdir -p /home/user/src/poppler/buildcd /home/user/src/poppler/buildrm -rf *echo -e "\n\n ##### BUILDING POPPLER ##### \n\n"ANDROID_ARCH_ABI=armeabi-v7a cmake -G Ninja .. \    -DCMAKE_ANDROID_API=29 \    -DCMAKE_PREFIX_PATH="/opt/Qt/;/opt/kdeandroid-arm/" \    -DCMAKE_BUILD_TYPE=debug \    -DCMAKE_POSITION_INDEPENDENT_CODE=OFF \    -DENABLE_DCTDECODER=unmaintained \    -DENABLE_LIBOPENJPEG=unmaintained \    -DENABLE_BOOST=OFF \    -DCMAKE_BUILD_TYPE=debugfull \    -DCMAKE_CXX_FLAGS="-Wno-deprecated-declarations" \    -DCMAKE_TOOLCHAIN_FILE=/opt/nativetooling/share/ECM/toolchain/Android.cmakeif [[ $1 == -b ]]; then    ninja -j4fi

This script should be run from the docker container. It only runs CMake by default, but it can also compile Poppler when you specify the -b flag.

Building Okular with my custom Poppler library

Now that the environment is ready, I have to figure out how to build Okular with my custom Poppler library. My mentor suggested I replace Poppler's .so files contained in the Craft container with my custom-built libraries. So I figured out all the locations where Poppler's .so files were stored inside the Craft container and made a small script to quickly replace those files with my custom-build Poppler:

#!/bin/bashpopplerdir='/home/shivodit/kde-android/src/poppler/build/android-build/libs/armeabi-v7a'declare -a paths=(    '/home/shivodit/craft/CraftRoot/build/qt-libs/poppler/work/build/android-build/libs/armeabi-v7a/'    '/home/shivodit/craft/CraftRoot/build/qt-libs/poppler/image-Release-23.03.0/lib/'    '/home/shivodit/craft/CraftRoot/build/kde/applications/okular/work/build/okularkirigami_build_apk/libs/armeabi-v7a/'    '/home/shivodit/craft/CraftRoot/build/kde/applications/okular/work/build/okularkirigami_build_apk/build/intermediates/merged_jni_libs/release/out/armeabi-v7a/'    '/home/shivodit/craft/CraftRoot/build/kde/applications/okular/work/build/okularkirigami_build_apk/build/intermediates/merged_native_libs/release/out/lib/armeabi-v7a/'    '/home/shivodit/craft/CraftRoot/build/kde/applications/okular/work/build/okularkirigami_build_apk/build/intermediates/stripped_native_libs/release/out/lib/armeabi-v7a/'    '/home/shivodit/craft/CraftRoot/lib/')for i in "${paths[@]}"; do    cp $popplerdir/* $idone

This script is run from your host system, not from within any of the docker containers. It simply creates an array of locations where the libraries must be replaced, and copies the custom Poppler to those locations, overwriting the already existing libraries. Pretty neat, right?

Now whenever I want to build Okular, I simply have to execute the following commands after entering the docker container and activating Craft:

craft --compile okularcraft --package okular /opt/android-sdk/build-tools/30.0.2/zipalign -p -f -v 4 okularkirigami-armeabi-v7a.apk okularkirigami-armeabi-v7a.signed.apk /opt/android-sdk/build-tools/30.0.2/apksigner sign -verbose -ks key.keystore okularkirigami-armeabi-v7a.signed.apk

Now let us move on to the fun part - coding.

Coding the font API

After setting up, I got started with writing the font API. This involved several steps:

Figuring out logging

Since Android is much more locked down than desktop platforms such as Linux, MacOS, Windows, *BSDs, etc. there is a bit of difficulty involved with using a debugger to test your apps. For this very reason, my mentor suggested I use print debugging instead. In hindsight, I do think this was a good decision - setting up the debugger would have taken a long time, especially since I lack much Android development experience.

On Android, the primary tool for viewing logs from apps is Logcat. However, when you use print statements (for example, cout in C++), it does not appear in logcat. Instead of printing, you have to use the logging tools that Android provides. Since I was using C++, I set up android-ndk's logging facility. Its documentation can be found here - https://developer.android.com/ndk/reference/group/logging

But before using this logging tool, I set up my CMakeLists.txt to include find the log library and link it with the Poppler library, as follows:

# finding the android logging library and storing it in a variable named android-log-lib    find_library(android-log-lib log)# some 500 lines of other statements#Linking the logging library with popplertarget_link_libraries(poppler LINK_PUBLIC ${android-log-lib} LINK_PRIVATE ${poppler_LIBS} LINK_PRIVATE ${android-lib})

It worked! Now all I had to do was import the logging library into the source file and use __android_log_print() to write to logcat.

However, I was still bothered - __android_log_print() took too long to type! So I googled a bit, and I stumbled upon some macros which made things easier. Here they are:

#ifndef MODULE_NAME#define MODULE_NAME  "AUDIO-APP"#endif#define LOGV(...) __android_log_print(ANDROID_LOG_VERBOSE, MODULE_NAME, __VA_ARGS__)#define LOGD(...) __android_log_print(ANDROID_LOG_DEBUG, MODULE_NAME, __VA_ARGS__)#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, MODULE_NAME, __VA_ARGS__)#define LOGW(...) __android_log_print(ANDROID_LOG_WARN,MODULE_NAME, __VA_ARGS__)#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR,MODULE_NAME, __VA_ARGS__)#define LOGF(...) __android_log_print(ANDROID_LOG_FATAL,MODULE_NAME, __VA_ARGS__)

I only used LOGV() since that's all I needed.

Of course, this was just temporary, for debugging. In my final merge request, I removed all the print debugging related stuff.

Figuring out AFontMatcher

The next step was to get a rudimentary version of the AFontMatcher API working. There was one problem though, I had no idea how to build with AFontMatcher. When I tried to include AFontMatcher's header files, the compiler threw a bunch of errors.

It seemed like I had to set up my CMakeLists to include the library that provided AFontMatcher functionality, and I couldn't seem to find it in the android-ndk documentation. I struggled with this problem for a few days, alternating between looking through the android-ndk documentation, googling, and experimenting with different CMakeList statements.

I got the bright idea to google for code that used any of the AFontMatcher functions. I stumbled upon Github's code search, and searched for "AFontMatcher_create". I found a C++ project using AFontMatcher, and looked at its CMakeLists.txt to figure out how to get AFontMatcher to compile.

Turns out I had to use find_library to find the android library, and then link it with Poppler. I added the following lines to the CMakeLists.txt:

# Find android libraryfind_library(Androidlib NAMES android REQUIRED)# Check if library is found, if yes then add it to poppler_LIBS, which will # be linked during compilationif(Androidlib)   set(poppler_LIBS ${poppler_LIBS} ${Androidlib})endif()

After adding these lines, Poppler finally compiled successfully!

I then added some code to GlobalParams.cc, inside of the GlobalParams::findSystemFontFile() method to run a rudimentary version of the Afontmatcher API.

It worked; I was thrilled! After 1.5 weeks of struggling with setup and compiling Poppler with AFontMatcher, I finally had a working build! Even though the font didn't account for font-weight or italics, and only searched for serif fonts, I had taken a step forward.

Improving AFontMatcher

Now that I have a working yet rudimentary AFontMatcher implementation, it's time to refine it.

We need to determine the following:

• Check whether the font is supposed to be sans-serif, serif, or fixed-width.

  • GfxFont::isSerif() checks whether the font is serif, and returns a boolean value.

  • GfxFont::isFixedWidth() checks whether the font is fixed width or not, and returns a boolean value

• Check the font-weight.

  • Used to set the thickness of the font.

  • Can be retrieved using GfxFont::getWeight().

  • It returns a value from 1 to 9, however, AFontMatcher takes weight in increments of 100, from 0 to 1000. So we must multiply its value by 100.

• Check whether the font is italic.

  • Gfx::isItalic() checks whether the font is italic, and returns a boolean value.

• Set the type of the returned font file.

  • GlobalParams.h defines four types of fonts in an enum:

    enum SysFontType    {        sysFontPFA,        sysFontPFB,        sysFontTTF,        sysFontTTC    };

• Since AFontMatcher returns .otf, .ttf, .otc, or .ttc, we set sysFontTTF for .otf and .ttf, and sysFontTTC for the remaining two.

All of this results in the following code for the AFontMatcher-based API defined in GlobalParams::findSystemFontFile():

GooString *GlobalParams::findSystemFontFile(const GfxFont *font, SysFontType *type, int *fontNum, GooString *substituteFontName, const GooString *base14Name){    GooString *path = nullptr;    const std::optional<std::string> &fontName = font->getName();    if (!fontName) {        return nullptr;    }    globalParamsLocker();    // If font is not found in the default base-14 fonts,    // use Android-NDK's AFontMatcher API instead.     // Documentation for AFontMatcher API can be found at:    // https://developer.android.com/ndk/reference/group/font    std::string genericFontFamily = "serif";    if (!font->isSerif()) {        genericFontFamily = "sans-serif";    } else if (font->isFixedWidth()) {        genericFontFamily = "monospace";    }    AFontMatcher *fontmatcher = AFontMatcher_create();    // Set font weight and italics for the font    AFontMatcher_setStyle(fontmatcher, font->getWeight() * 100, font->isItalic());    // Get font match and the font file's path    AFont *afont = AFontMatcher_match(fontmatcher, genericFontFamily.c_str(), (uint16_t *)u"A", 1, nullptr);    path = new GooString(AFont_getFontFilePath(afont));    // Font has been matched and its path has been copied, delete the     // AFontMatcher and AFont objects to avoid memory leaks    AFont_close(afont);    AFontMatcher_destroy(fontmatcher);    // Set the type of font. Fonts returned by AFontMatcher are of    // four possible types - ttf, otf, ttc, otc.    if (path->endsWith(".ttf") || path->endsWith(".otf")) {        *type = sysFontTTF;    } else if (path->endsWith(".ttc") || path->endsWith(".otc")) {        *type = sysFontTTC;    }    return path;}

setupBaseFonts() and the base-14 fonts

After setting up a rudimentary afontmatcher implementation, I got started on implementing setupBaseFonts().

To start, I simply copied the code that was used for Windows' version of setupBaseFonts(), and edited it a bit to suit my needs.

I also copied the struct and its array containing the font names, and their file names. Without defining these, the setupBaseFonts function would not work. Since the copied struct had font names in .pfb and .ttf formats, I altered the struct and the array so that it only included .otf files, as follows:

static struct{    const char *name;    const char *otFileName;} displayFontTab[] = { { "Courier", "NimbusMonoPS-Regular.otf" },                       { "Courier-Bold", "NimbusMonoPS-Bold.otf" },                       { "Courier-BoldOblique", "NimbusMonoPS-BoldItalic.otf" },                       { "Courier-Oblique", "NimbusMonoPS-Italic.otf" },                       { "Helvetica", "NimbusSans-Regular.otf" },                       { "Helvetica-Bold", "NimbusSans-Bold.otf" },                       { "Helvetica-BoldOblique", "NimbusSans-BoldItalic.otf" },                       { "Helvetica-Oblique", "NimbusSans-Italic.otf" },                       { "Symbol", "StandardSymbolsPS.otf" },                       { "Times-Bold", "NimbusRoman-Bold.otf" },                       { "Times-BoldItalic", "NimbusRoman-BoldItalic.otf" },                       { "Times-Italic", "NimbusRoman-Italic.otf" },                       { "Times-Roman", "NimbusRoman-Regular.otf" },                       { "ZapfDingbats", "D050000L.otf" },                       { nullptr, nullptr } };

I had initially kept the Symbol font's otFileName as nullptr because I didn't know what substitute font it used from the Okular APK's assets folder. This caused setupBaseFonts to crash due to a null pointer dereference. My mentor pointed out the correct name for Symbol's substitute font. After adding its name, the nullptr dereference crash was gone.

Now I had to copy the fonts from the apk to somewhere where Poppler could access it. For the moment, I used adb push to copy the fonts to Androids /data/local/tmp/ directory, inside a folder named font.

I then added the path /data/local/tmp/font to the displayFontDirs array, which setupBaseFonts() would use to search for fonts:

static const char *displayFontDirs[] = { "/data/local/tmp/font", nullptr };

GlobalParams::setupBaseFonts() was now functional. Now I just had to write some code to copy the fonts contained within the apk to the application's data directory.

Writing the font file copying functionality

Since every android app has its own internal storage directory once it is installed, Poppler will need to find out what the exact path is. For example, when running okular, since its fully qualified name is org.kde.okular.kirigami, it's internal directory will be located at /data/user/0/org.kde.okular.kirigami/files/.

In order to find the internal data directory of the app, my mentor and I were looking at ANativeActivity as a way to do so. We also needed to access the fonts inside of the APK assets folder, for which we thought of using android-ndk's Assets API. However both of these seemed way too complex, so we explored other ideas.

While researching I came across QStandardPaths, and discovered that it could get the app directory path by using:

QStandardPaths::writableLocation(QStandardPaths::AppDataLocation)

And to access assets, Qt provides a special font path which can be used with Qt File functions. It simply involves prefixing assets:/ to the path. The path should be relative to the assets directory of the app's apk. For example, in this case to access a file stored in assets/filedir/file.txt, we can use the path: assets:/filedir/file.txt.

Since these Qt-based solutions seemed more elegant and straightforward than the Android-NDK ANativeActivity and Asset API, my mentor agreed that I should use these instead.

Using the above features, I used a QDirIterator to loop over the assets:/share/fonts directory and copied the font files one by one to a folder named fonts, located within Okular's internal storage directory. I wrote the code like this:

QString assetsFontDir = QStringLiteral("assets:/share/fonts");    QString fontsdir = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + QStringLiteral("/fonts");    QDir fontPath = QDir(fontsdir);    if (fontPath.mkpath(fontPath.absolutePath())) {        QDirIterator iterator(assetsFontDir, QDir::NoFilter, QDirIterator::Subdirectories);        while (iterator.hasNext()) {            iterator.next();            QFileInfo fontFileInfo = iterator.fileInfo();            QString fontFilePath = assetsFontDir + QStringLiteral("/") + fontFileInfo.fileName();            QString destPath = fontPath.absolutePath() + QStringLiteral("/") + fontFileInfo.fileName();            QFile::copy(fontFilePath, destPath);        }    }

Initially I was implementing this not in poppler, but instead in the Okular code, in mobile/app/main.cpp. This was because we thought that since Poppler is a library that is used by Okular, it wouldn't be able to get its internal directory path.

However when implementing this, I realized I also had to set the font directory inside of Poppler.

So I asked my mentor how I could access poppler's GlobalParams.cc through Okular. He said that GlobalParams class is private to poppler, and cannot be used outside of the library. He recommended that instead of implementing this font-copying functionality in Okular, I should do it in the qt side of poppler. More specifically, in the DocumentData constructors defined in qt5/poppler-private.h.

Initially I had copy pasted the above snippet in each constructor, but later I placed it in the DocumentData::init() function defined within qt5/poppler-private.cc. This is because the init() function is called by all DocumentData constructors, and having the code in one place reduces redundancy and improves readability.

All of this was working well, all the font files were getting copied successfully. The next step was to set the font directory path inside of GlobalParams.cc, so that GlobalParams::setupBaseFonts() could search for fonts in the correct path.

To do this, I defined an Android-only static function, GlobalParams::setFontDir() in GlobalParams.h and provided its definition in GlobalParams.cc. I also replaced the static const char *displayFontDirs[] array with a static std::string variable named displayFontDir.

The GlobalParams::setFontDir() method takes an std::string as an argument. When called, it sets the displayFontDir variable to the string that was passed to it. This successfully sets the font directory. I then called this function inside the init() method, when the fonts are copied:

QString assetsFontDir = QStringLiteral("assets:/share/fonts");    QString fontsdir = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation) + QStringLiteral("/fonts");    QDir fontPath = QDir(fontsdir);    if (fontPath.mkpath(fontPath.absolutePath())) {        GlobalParams::setFontDir(fontPath.absolutePath().toStdString());        QDirIterator iterator(assetsFontDir, QDir::NoFilter, QDirIterator::Subdirectories);        while (iterator.hasNext()) {            iterator.next();            QFileInfo fontFileInfo = iterator.fileInfo();            QString fontFilePath = assetsFontDir + QStringLiteral("/") + fontFileInfo.fileName();            QString destPath = fontPath.absolutePath() + QStringLiteral("/") + fontFileInfo.fileName();            QFile::copy(fontFilePath, destPath);        }    } else {        GlobalParams::setFontDir("");    }

This causes the displayFontDir variable to be set correctly.

Since displayFontDir is now an std::string instead of a const char array, we also need to modify GlobalParams::setupBaseFonts() to treat it like an std::string. Hence we remove the loop that would have looped over the earlier char array, and add a check to see if the font dir is empty.

void GlobalParams::setupBaseFonts(const char *dir){    FILE *f;    int i;    for (i = 0; displayFontTab[i].name; ++i) {        if (fontFiles.count(displayFontTab[i].name) > 0) {            continue;        }        std::unique_ptr<GooString> fontName = std::make_unique<GooString>(displayFontTab[i].name);        std::unique_ptr<GooString> fileName;        if (dir) {            fileName.reset(appendToPath(new GooString(dir), displayFontTab[i].otFileName));            if ((f = openFile(fileName->c_str(), "rb"))) {                fclose(f);            } else {                fileName.reset();            }        }        if (!displayFontDir.empty()) {            fileName.reset(appendToPath(new GooString(displayFontDir), displayFontTab[i].otFileName));            if ((f = openFile(fileName->c_str(), "rb"))) {                fclose(f);            } else {                fileName.reset();            }        }        if (!fileName) {            error(errConfig, -1, "No display font for '{0:s}'", displayFontTab[i].name);            continue;        }        addFontFile(fontName->toStr(), fileName->toStr());    }}

Finished!

Finally, the android-specific font matching API is successfully finished. I sincerely hope this new feature is useful for users.

I had initially thought that most of the work would be in implementing AFontMatcher, however base-14 fonts took much more effort.

I'd like to thank my mentor, without his support I would still be stuck at trying to build Poppler. :D

Today we are announcing the availability of the minor patch release 2.10.1. This release contains minor improvements and bug fixes only. The fixes are distributed over many different areas of the application and we recommend everybody update to this patch release which is available from our download page.

The full list of fixes included in this patch release are as follows:

• Support markdown library discount version 3
• Improve Vector BLF dependency (git download must be enabled if needed)
• Correctly use system header of system QXlsx (BUG 468651)
• Fix group separator problem in formulas (BUG 468098)
• Improve log scales (auto scaling and tick number)
• Improve auto scale (Issue #536)
• Fix limits when changing scales (Issue #446)
• Use system liborigin headers if linking against system liborigin (BUG 469367)
• Properly import UTF8 encoded data (BUG 470338)
• Do not clear the undo history when saving the project (BUG 470727)
• Properly react on orientation changes in the worksheet properties explorer
• In the collections of example projects, color maps and data sets also allow searching for sub-strings and make the search case-insensitive
• Properly set the size of the worksheet in the presenter mode if “use view size” is used
• Properly save and load the property “visible” for box and bar plots in the project file
• Fix copy&paste and duplication of box and bar plots
• Fix issues with loading object templates (BUG 470003)
• Fix crash when loading projects with reference ranges
• .xlsx import corrections:
  • fix crash importing empty cells
  • support datetime import (Issue #531)
• Properly set the initial properties of the reference line, like line width, etc. (Issue #580)
• Properly show the initial value of the property “visible” for the reference range (Issue #582)
• React to Delete and Backspace keys to delete selected cells in spreadsheet columns (Issue #596)
• Update the plot legend on column name changes used in box and bar plots (Issue #597)
• Fix the positioning of values labels for horizontal bar plots (Issue #599)
• Initialize the parameters for the baseline subtraction with reasonable values on first startup and improve the appearance of the preview plot

We are also working on the new features and improvements that will arrive in the next 2.11 release. This release will become available in the coming months. More on this in the next blog posts. Stay tuned!

We're happy to announce the new release 5.11.0 of KPhotoAlbum, the KDE photo management program!

Most notably, this release can be built against Exiv2 0.28, which introduced some breaking changes. Older versions are still supported as before.

Other things that have been changed and fixed (as listed in the ChangeLog) are:

Changed

• Recalculate Checksums in the Maintenance menu and Refresh Selected Thumbnails in the thumbnail context menu have been unified to do exactly the same.
• Simplified logging categories: kphotoalbum.XMLDB was merged into kphotoalbum.DB

Fixed

• Fix issue where non-empty time units in the date bar were incorrectly greyed out (#467903)
• Fix bug with the date bar showing and selecting incorrect date ranges (#468045)
• Fix crash when the annotation dialog is opened from the viewer window and the viewer is closed before the annotation dialog (#470889)
• Fix inconsistent UI where menu actions would not immediately be updated to reflect a change (#472109, #472113)

The list of contributors is quite short this time, it was only Johannes and me ;-) Anyway, thanks to everybody working on KPA in any way, to everybody having contributed in the past and for all future work!

Have a lot of fun with KPhotoAlbum 5.11.0 :-)

— Tobias

Dear digiKam fans and users,

After five months of active maintenance and long bugs triage, the digiKam team is proud to present version 8.1.0 of its open source digital photo manager.

See below the list of most important features coming with this release.

• Print Creator: Add 4 new templates for 6.8 inches photo paper.
• General : Improve usability of Image Properties sidebar tab.
• Libraw : Update to snapshot 2023-05-14
• Bundles : Update Exiv2 to last 0.28 release
• Bundles : Update KF5 framework to last 5.106
• Bundles : Includes Breeze widgets style in MacOS package to render properly GUI contents.
• Tags : Add possibility to remove all face tags from selected items.
• Tags : Add possibility to remove all tags from selected items except face tags.
• Similarity : Add usability improvements about reference images while searching for duplicates images.

This version arrives with a long review of bugzilla entries. Long time bugs present in older version have been fixed and we spare a lots of time to contact users to validate changes in pre-release to confirm fixes before to deploy the program in production.