QtQuick is a popular choice for creating HMIs for embedded devices. The hardware on these devices is often constrained and less performant than their desktop equivalents, this requires extra care from software developers in delivering a fluid user experience. KDAB is regularly involved in improving the performance of QtQuick HMIs on such devices for their […]

An existing code base can be a great asset, but it can also be a liability. Technical debt tends to build up over time, eventually reaching the point where something needs to be done. KDAB has unique experience in migrations as well as specialized tools and in-depth knowledge from migration projects in different industries with […]

The program for CppCon 2017 is now published! CppCon is the annual conference for the C++ community: five days packed with over 100 talks, as well as inspiring keynotes, panel discussions, hallway chats, fun evening events and much more. CppCon is a project of the Standard C++ Foundation, a not-for-profit organization whose purpose is to […]

Qt now provides a new module named Qt 3D. In this very short talk Giuseppe D'Angelo introduces some of the design ideas behind Qt 3D, discuss its use cases, and shows how simple it is to get 3D content in an application when using Qt 3D APIs. […]

Introduction This article is part of a blog series about Clang Tidy. In the previous article we learned about the general usage of Clang Tidy to automatically refactor source code for projects using the CMake build system. In this particular episode we'll discuss using Clang Tooling on projects using different build systems with the help […]

In the previous episode we presented how to uncover 32 Qt best practices at compile time with clazy. Today it's time to show 5 more and other new goodies present in the freshly released clazy v1.2. New checks 1. connect-not-normalized Warns when the content of SIGNAL(), SLOT(), Q_ARG() and Q_RETURN_ARG() is not normalized. Using normalized […]

When using Qt's model/view framework, filtering has always been very easy with QSortFilterProxyModel. To filter a list using text typed by the user in a line-edit, you have certainly been applying the standard recipe: instantiate the proxy; insert it between view and source model; connect the lineedit's textChanged signal to the proxy's setFilterFixedString slot; done! […]

After many months of work, I'm very pleased to finally announce KDAB's latest R&D project to the public: hotspot - a GUI for the Linux perf profiler. I have used Linux perf a lot over the past years. It is an extremely powerful and useful tool. But its complexity makes it very hard to use. […]

We have released version 2.8.0 of our Qt application introspection tool GammaRay. GammaRay allows you to observe behavior and data structures of Qt code inside your program live at runtime. A big focus in this release is improvements to the Qt Quick inspector, which gained layout helper grids and Qt Quick Controls 2 tracing, as […]

As there were some complex issues around conformity in PDF document creation within Qt, KDAB let me spend some time digging into it so we could make sure that Qt's PDF engine generates documents up to ISO-standard. Nowadays, many official institutions have the requirement to archive their data digitally and PDF is a first class […]

Qt 5.9 has just been released! This release marks two important milestones for the Qt Project. The first is that now the Qt 5 series has had more releases than any other Qt version ever (the last release of the Qt 4 series was Qt 4.8). The second milestone is that Qt 5.9 will be […]

The last blog post in this series described how to use string-views. This post is about how to design one. In particular, it's about QStringView's constructors. They evolved through a rapid succession of changes. These changes either fixed ambiguities between QString and QStringView overloads, or improved performance. And they all have the same solution: std::enable_if, […]

QZXing is a very useful library: It provides an easy to use Qt integration API around the barcode scanning library ZXing (zebras crossing). Because it is so easy to setup QZXing in a Qt application, we and most of our customers end up using it when they need to scan images for barcodes. There is, […]

In a previous blog post we introduced clazy, a clang plugin which makes the compiler understand Qt semantics, allowing you to get compile-time warnings about Qt best practices ranging from unneeded memory allocations to misuse of API, including fix-its for automatic refactoring. Today we'll do a round-up and present the checks related to connect statements, […]

As an Easter treat here is a quick taster of some of the animation goodies coming to Qt 3D along with Qt 5.9. In this post we will briefly outline the steps needed to create a simple Qt 3D application and the assets it uses to produce this little animation: The basic steps are: Create […]

A small new feature that I have added to Qt 5.8 is the possibility of disabling narrowing conversions in the new-style QObject::connect statement. In this short blog post I would like to share with you why I thought this was useful and therefore implemented it. The problem Since Qt 5.0, the new-style, PMF-based (pointer to […]

After two months of intensive reviews, discussions, fixes, and stripping down the initial commit, feature by feature, to make it acceptable, I am happy to announce that the first QStringView commits have landed in what will eventually become Qt 5.10. Even the docs are already on-line. This is a good time to briefly recapitulate what […]

All Qt developers have asked themselves at least once in their careers: "why isn't my slot invoked?" (I've asked myself that question many, many times). There are a number of reasons why a connection may fail to be properly set up, and ultimately cause our slot not to be invoked. This blog post is a […]

A small new feature that was added to Qt 5.8 is the ability for moc (Qt's meta-object compiler) to extract meta-object information at the namespace level. This means, for instance, that you can have introspection support for enumerations defined in a namespace (not just in QObject subclasses, or classes tagged with Q_GADGET), and use such […]

I'm extremely happy to finally announce the first stable release of heaptrack, the FOSS heap memory profiler for C/C++ Linux applications. You can download the source tarball from the KDE mirrors: https://download.kde.org/stable/heaptrack/1.0.0/src/ Heaptrack is a fast heap memory profiler that runs on Linux. It allows you to track all heap memory allocations at run-time. Afterwards, […]