Mozilla is the maker of the famous Firefox web browser and the birthplace of the likes of Rust and Servo (read more about Embedding the Servo Web Engine in Qt). Firefox is a huge, multi-platform, multi-language project with 21 million lines of code back in 2020, according to their own blog post. Navigating in projects […]

The goal When building C++ code with CMake, it is very common to want to set some pre-processor defines in the CMake code. For instance, we might want to set the project's version number in a single place, in CMake code like this: This sets the CMake variable PROJECT_VERSION to 1.5, which we can then […]

Early-Bird tickets are on sale for the KDAB Training Day 2025 until 2025-03-31 23:59 The KDAB Training Day 2025 will take place in Munich on May 8th, right after the Qt World Summit on May 6th-7th. Choose to buy a combo ticket here (for access to QtWS and Training Day) or here (for access to […]

We just released CXX-Qt version 0.7! CXX-Qt is a set of Rust crates for creating bidirectional Rust ⇄ C++ bindings with Qt. It supports integrating Rust into C++ applications using CMake or building Rust applications with Cargo. CXX-Qt provides tools for implementing QObject subclasses in Rust that can be used from C++, QML, and JavaScript. […]

In recent years, a lot has been happening to improve performance, maintainability and tooling of QML. Some of those improvements can only take full effect when your code follows modern best practices. Here are 10 things you can do in order to modernize your QML code and take full advantage of QML's capabilities. 1. Use […]

We’re pleased to announce the release of KD Reports 2.3.0, the latest version of our reporting tool for Qt applications. This marks our first major update in two years, bringing several bug fixes and new features that further improve the experience of generating reports. What is KD Reports? KD Reports is a versatile tool for […]

Recap In Part 1, we covered PCM audio and superimposing waveforms, and developed an algorithm to combine an arbitrary number of audio streams into one. Now we need to use these ideas to finish a full implementation using Qt Multimedia. Using Qt Multimedia for Audio Device Access So what do we need? Well, we want […]

Motivation When using Qt Multimedia to play audio files, it’s common to use QMediaPlayer, as it supports a larger variety of formats than QSound and QSoundEffect. Consider a Qt application with several audio sources; for example, different notification sounds that may play simultaneously. We want to avoid cutting notification sounds off when a new one […]

In the previous posts of this series (if you've missed them: parts 1, 2, 3, and 4), we have learned about relocation and trivial relocation. We have explored what relocation means, what trivial relocation means, and how it can be used to optimize the implementation of certain data structures, such as the reallocation of a […]

Motivation Let’s say we’re working on a QML project that involves a TextEdit. There’s some text in it: here is some text We want to select part of this text and hit ctrl+B to make it bold: here is some text In Qt Widgets, this is trivial, but not so much in QML – we […]

An over-the-air (OTA) update capability is an increasingly critical part of any embedded product to close cybersecurity vulnerabilities, allow just-in-time product rollouts, stomp out bugs, and deliver new features. We’ve talked about some of the key structural elements that go into an embedded OTA architecture before. But what about the back end? Let’s address some […]

If you’ve been following our blog, you’re likely aware of Rust’s growing presence in embedded systems. While Rust excels in safety-by-design, it’s also common to find it integrated with C++. This strategic approach leverages the strengths of both languages, including extensive C++ capabilities honed over the years in complex embedded systems. Let’s delve into some […]

You've reached the third and final entry of the Instantiating arbitrary Qt Quick components with JSON series. Part 1 and Part 2 can be found at their respective links. The first part focuses on the software design pattern used to dynamically instantiate components. The second one shows how to layout these dynamic components by incorporating […]

Qt Test is a framework designed for unit testing applications and libraries built with Qt. It provides all the standard features commonly found in unit testing frameworks, making it easier to write unit tests for Qt-based projects. We're happy to introduce the QtTest Runner - a Visual Studio Code extension for running Qt Tests via […]

KDDockWidgets has launched its latest version 2.1. This release comes packed with over 500 commits, offering enhanced stability over its predecessor, version 2.0, without introducing any breaking changes. KDDockWidgets is a versatile framework for custom-tailored docking systems in Qt written by KDAB’s Sérgio Martins. For more information about its rich set of features, have a […]

In the last post of this series we learned that: erasing elements from the middle of a vector can be implemented, in general, via a series of move assignments, move constructions, swaps, destructions for types with value semantics, the exact strategy does not really matter for types with write-through reference semantics, the strategy matters, because […]

In the last post of this series we started exploring how to erase an element from the middle of a vector. We discussed that in principle there are several different possible ways to implement erase().For instance, a vector could move-assign over the elements to be erased: Alternatively, a vector could use rotations or some other […]

I was tasked to come up with a simple architecture for remote real time instantiation of arbitrary QML components. I’ve split my findings into 3 blog entries, each one covering a slightly different topic. Part 1 focuses on the software design pattern used to dynamically instantiate components. Part 2 shows how to layout these dynamic […]

In the last post of this series we discussed the usage of trivial relocation in order to optimize move construction followed by the destruction of the source. To quickly recap: objects of certain datatypes ("trivially relocatable" types) can be moved in memory by simply moving bytes; this can be used to optimize certain bulk operations […]

The container classes introduced in Qt 4 (Tulip, for the aficionados) had an interesting optimization: the ability to turn certain operations on the contained objects into byte-level manipulations. Example: vector reallocation Consider the reallocation of a QVector<T>: when the vector is full and we want to insert a new value (of type T), the vector […]