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 […]

Are you already convinced and just want to download the library? We're glad you liked it: https://github.com/KDAB/KDAlgorithms I'm sure many people have told you time and time again, "Don't use raw for loops; use algorithms." Still, each time you tried, you found your code harder to read. In case you're wondering, the above simply prints […]

If you're following our Youtube channel you might have heard me talking about QVarLengthArray. If you're not... you should follow us! But let me give you a quick recap. QVarLengthArray is a Qt container that acts like a vector; its elements are stored contiguously in memory and it has a dynamic size. At any time […]

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 […]

This blog will give you a brief overview of profiling C and C++ applications. Additionally, it will lay before you all of the tools available, with the purpose of aiding you in choosing the right tools at the right times. The Steps for Profiling Before we look at the actual tools, let's go over the […]

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++, […]

In this blog on debugging and profiling, I would like to give you an overview of the debugging tools that exist for C and C++ applications. Automated Testing The first thing you need to do is make sure your code is properly tested. This, in itself, is not debugging, but it enables you to make […]

I will be talking about text in this post, specifically about cases where you have to handle a lot of it. We are not talking about a general solution, but a specific case that we encountered during a customer project. The Problem The project involved showing a chat room for internal communication. We developed a […]

For years, we at KDAB have been using Buildbot as our build and continuous integration system. Gerrit hosts all our projects and is our code review platform. Our deployment of Buildbot and build machines has naturally grown over the years. It builds hundreds of configurations and up to a thousand builds daily, but issues with […]

One of the most difficult choices to make when starting any new software project is that of the programming language and framework your team will use to create it. Should you stick with Qt because it’s the best tool for the job? Should you switch to something that uses web-based technology or is designed explicitly […]

In this article, I'd like to talk about Android storage. In recent Android versions, Google decided, for a good reason, to restrict the access to the SD card. This means, even if your application will have the old READ/WRITE_EXTERNAL_STORAGE permissions declared and granted, you won't be able to freely access the SD Card contents like […]

Porting legacy code from Motif, MFC, Photon, or a previous Qt version to a more recent Qt version can be a big challenge. There are a number of pitfalls in a large porting effort that can significantly increase time, cost, and complexity, leading to risk of project derailment. You may have languages, frameworks, and windowing […]

There are a few small, and sometimes already quite old, features in Qt that, when combined, can be a very nice way to deal with assets in your QML application -- especially if some of them live on the file system, some in a resource, and some may need localization or translation. Let's dive in! […]

With Apple moving to Apple Silicon for all of their new products, software developers are having to figure out how to support both Intel and Apple Silicon devices. Like some of our customers, you may not be ready to move to Apple Silicon. Unfortunately, that doesn't necessarily exempt you from dealing with universal binaries, especially […]

Every sizable project has a 'utils' file or folder that contains functionality that is needed more than once but too small to be a library. KDE is no different, except we want to share our 'utils' folder across hundreds of projects. This is where the KCoreAddons framework comes into play. The name comes from the […]