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 […]

Some time ago, I wrote a post about integrating Qt's associative containers with the fancy new C++ features, range-based for loops with structured bindings. That post inspired KDAB's own Giuseppe D'Angelo to add the asKeyValueRange member function to both QHash and QMap. Now it's possible to iterate over them with a simple range-based for loop, […]

You have two choices when it comes to giving a custom style to your Qt widgets. Qt Style Sheets are very convenient for getting started -- just a few CSS-like rules, and they work. It is our experience, however, that Qt Style Sheets create too much trouble and a QStyle subclass (*) gives a better […]

The nlohmann/json library is everything a developer can expect from a modern library -- easy to integrate and JSON objects are treated as first class citizens with a very intuitive API. However, it has one problem that is widely mentioned across the internet, which I'll tell you about below. Various solutions to the problem have […]

C++23 is feature complete and on track to be released next year. While many people are complaining that it's, after all, a "minor" release (as the pandemic made the Committee work very difficult), C++23 still has a few very significant changes. In this blog post, I want to talk about what I think is my […]

Qt is a high quality library, but it is also massive in number of features. This massive number results in a higher likelihood that there are bugs that go unnoticed lying around in its less frequently used features or combination of features. Our friends at qgis.org hired us to solve some of those issues that […]

At KDAB, we have been investigating how to integrate Rust with Qt in a safe and idiomatic way. The solution we are currently working on is called CXX-Qt. It's available in the GitHub and on crates.io. This blog post discusses the journey of CXX-Qt -- where it started, where it can be used right now, […]

A couple of weeks ago, we guided you through setting up a chat application and server in our first blog of this series. This is the second and final blog of this Qt Allstack series. Firebase Messaging Now that we have a functional chat application, it’s time to add real world features, like push notifications. […]

Writing mobile apps can be a lot of fun, especially with Qt and QML. But if your background is all about C++ and Qt, writing the entire required stack for a mobile app can be challenging. Adding push notifications, storing information, and having to write that with another language and framework might make you give […]

Here at KDAB, we recently published a library called KDBindings, which aims to reimplement both Qt signals and slots and data binding in pure C++17. To get an introduction to the KDBindings implementation of signals and slots, I recommend that you take a look at the KDBindings Getting Started Guide. It will give you an […]

All Qt developers should know about signals, slots, and properties. Those of you who have used QML will know that property bindings are super useful and cool. Bindings allow us to write more reactive and declarative style code. However, they are only available within QML, which means there are no compile time errors when you […]

Another day, another small addition to KDToolBox, KDAB's collection of miscellaneous useful C++ classes and stuff. In this post, we're going to talk about KDFunctionalSortFilterProxyModel, which is a convenience subclass of QSortFilterProxyModel. What's a proxy model to begin with, and what's QSortFilterProxyModel? Well, that explanation requires a bigger space than what I have in this […]

CMake is increasingly becoming the de-facto build system for C++ projects. While it has been possible to build Qt applications using CMake for a long time, with Qt6, Qt switched its own internal build system to CMake. The KDE Community was among the first large, open-source projects that adopted CMake about 15 years ago. Over […]

Once again, the theme of the day is how to speed up Qt development with Visual Studio Code. In part 2 of this blog series, we walked through how to get a complete setup for your qmake and CMake projects, with a deeper look at the Qt side. This time, I will share a few […]

These are some really cool or obfuscated code snippets for your amusement. We didn't want to rate them, so the order doesn't mean anything at all :) Just to make sure that there's no misunderstanding: This code really is/was in the Qt or KDE repositories. From Kivio, main.cpp From Qt 2.2.1 (src/canvas/qcanvas.cpp) Writing code that […]

Wayland is a display protocol, a protocol (and accompanying C library) spoken by a graphical application with a display server in order to communicate about both input to the application (keyboard, mouse, ...) and about output from the application -- that is, the rendered window. Wayland was developed to replace the X11 server on the […]