Managing the timing and context of signals and slots in multithreaded applications, especially those with a GUI, can be a complex task. The concept of deferred connection evaluation offers a nice and easy API, allowing for controlled and efficient signal-slot connections. This approach is particularly useful when dealing with worker threads and GUI threads. A […]

The Need for Simple & Modular QR Generation in QML Recently, our designer Nuno Pinheiro needed to generate QR codes for an Android app in QML and started asking around about a simple way to do this. The best existing QML solution was QZXing, a Qt/QML wrapper for the 1D/2D barcode image processing library ZXing. […]

We're pleased to announce the release of KDSoap version 2.2.0, an update that brings new enhancements to improve both the general build system and client-side functionality. What is KDSoap? KDSoap, a SOAP (“Simple Object Access Protocol“) component rooted in Qt, serves as an essential tool for both client-side and server-side operations. Tailored for C++ programmers […]

This article walks through an implementation using C++11 or later, Qt 6.5 or later for WebAssembly (multithreaded), and CMake. The browser environment used was Mozilla Firefox 119.0.1 (64-bit) provided by the Mozilla Firefox snap package for Ubuntu. Overview & Motivation Lately, I’ve been working on a small Qt Widgets project to help manage some weekly […]

We’re happy to announce KDDockWidgets version 2.0, a major milestone that brings many improvements and architectural enhancements to our powerful docking library. 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, take a gander at its GitHub repository. What […]

We just released CXX-Qt version 0.6! CXX-Qt is a set of Rust crates for creating bidirectional Rust ⇄ C++ bindings with Qt. It can be used to integrate Rust into C++ applications using CMake or build Rust applications with Cargo. CXX-Qt provides tools for implementing QObject subclasses in Rust that can be used from C++, […]

In a previous blog we demonstrated the most straightforward method to optimize Visual Studio Code for a Qt / C++ environment: simply let the tools do all the work! The example GitHub project we discussed automatically installs both the Microsoft C/C++ and clangd extensions into VS Code. You might wonder why you need both C++ […]

Our colleague Alessandro Ambrosano created a series of blogs (parts 1, 2, and 3) that explain how to get Visual Studio Code configured for Qt development. In that series, Alessandro covers all the details you need to get your VS Code environment configured exactly the way you want it. But there’s a lot there to […]

Today's blog post is about a small utility class in Qt with a... questionable name: QPointer. If you're new to Qt, maybe don't check out QPointer's documentation just yet, and try to guess what the class does based on its name alone. I've seen countless users being very confused by it. Some end up using […]

KDAB has released GammaRay 3.0.0. GammaRay is a software introspection tool for Qt applications developed by KDAB for internal use, and now shared with the developer community on GitHub. This release is a special one, as we have now added Qt 6 support. An overview of changes since the last release Things we have added […]

You may already be hosting your code on GitHub, but do you know that GitHub provides a built-in Continuous Integration solution called GitHub Actions that is very easy to set up and free for public repositories? In this article I'm providing a crash course on what GitHub Actions are and how to use it for […]

We are happy to announce the release of KDDockWidgets version 1.7.0! What is KDDockWidgets? KDDockWidgets is a development framework for custom-tailored docking systems in Qt, to use when you need advanced docking that is not supported by QDockWidgets. It was created by Sérgio Martins as a time-saving alternative to QDockWidgets. The ease-of-use of KDDockWidgets can […]

The familiar solution for thick value classes that want to preserve binary compatibility is to use the pimpl pattern (private implementation), also known as d-pointer (pointer to data). In future versions of our class, we can freely change the contents of the pimpl (i.e. adding, removing, and/or modifying data members) but the binary compatibility of […]

We just released CXX-Qt version 0.5! CXX-Qt is a set of Rust crates for creating bidirectional Rust ⇄ C++ bindings with Qt. It can be used to integrate Rust into C++ applications using CMake or build Rust applications with Cargo. CXX-Qt provides tools for implementing QObject subclasses in Rust that can be used from C++, […]

Not all Qt developers are using Qt Creator as their main IDE for development. Some of us are using other IDEs, like Visual Studio, Visual Studio Code or CLion, per choice or because a project requires it. On Windows, with the MSVC compiler, the debugging experience with Qt 6 can be quite frustrating for some […]

Given a strictly positive integer i, this code will calculate i+1 "equally spaced" values between 1 and 0: If you're looking for a trap, this does actually work for any i > 0. One can verify it experimentally; run the code with i from 1 to INT_MAX. For simplicity, just consider the case j = […]

A very common implementation pattern for QObject subclasses is to declare its child QObjects as data members of type "pointer to child." Raise your hand No, keep your hand on your computer input device :-) Nod if you have ever seen code like this (and maybe even written code like this yourself): A fairly common […]

If you’re a reader of this blog, you probably know that we have a huge amount of quality material on QML and Qt Quick, among other topics. In fact, there is so much material that it can be hard to find what you need. If that sounds familiar, you’ll want to bookmark this page! This […]

Hotspot 1.4.0 has been released! Hotspot is a replacement for perf report. It's a GUI for the perf profiler that takes a perf.data file, parses and evaluates its contents, and then displays the result in a graphical way. This feature release contains close to 400 commits since the last stable v1.3.0 release. It comes with […]

We just released CXX-Qt version 0.4! CXX-Qt is a set of Rust crates for creating bidirectional Rust ⇄ C++ bindings with Qt. It can be used to integrate Rust into C++ applications using CMake or build Rust applications with Cargo. CXX-Qt provides tools for implementing QObject subclasses in Rust that can be used from C++, […]