Physics Based Rendering (PBR) is the latest and greatest trend in real-time rendering yielding much more visually believable images than the traditional Phong or ad-hoc lighting models. The underlying concept is that the shaders should use physical principles in the encoded models - chief of which are conservation of energy and the Fresnel effect. PBR […]

Many KDAB engineers are part of the Qt Security Team. The purpose of this team is to get notified of security-related issues, and then decide the best course of action for the Qt project. Most of the time, this implies identifying the problem, creating and submitting a patch through the usual Qt contribution process, waiting […]

Design, Technical Excellence and Superb User Experience Why does a tipper truck need an app? Meiller is the leading manufacturer of tippers in Europe. KDAB software developers and UI/UX designers worked with Meiller to create a mobile app that interacts with embedded hardware on the truck, allowing drivers to diagnose and fix problems - even […]

Quick: When you design C++ APIs, when and how should you use pair and tuple? The answer is as simple as it is surprising: Never. Ever. When we design APIs, we naturally strive for qualities such as readability, ease-of-use, and discoverability. Some C++ types are enablers in this regard: std::optional, std::variant, std::string_view/gsl::string_span, and, of course, […]

GammaRay 2.6 brings you three major new features: We merged the previous model and selection models tools into a new, unified QAbstractItemModel inspector, allowing you to now also see selections and cell flags, as well as to inspect deactivated cells. The new Wayland compositor inspector enables you to observe Wayland clients of a QtWayland compositor, […]

Hello! This is a small wrap-up fromQtCon, the biggest Qt event in Europe in 2016, that happened at the beginning of September. At QtCon the Qt community joined forces with the KDE, FSFE and VideoLAN communities, to create an exciting event in the spirit of open collaboration and participation amongst projects. During QtCon many KDAB […]

Starting with Qt 5.7, we added the ability to create Android services using Qt. In this article we're going to see how to get started and also how to communicate between the two. Before we get started I want to add a big bold WARNING about the performance! Because the services are run in the […]

We had a huge amount of fun at QtCon in Berlin. By far the most commented on was the positive effect of the diversity of attendees, both newcomers (about 30%) and those who came through the five entities involved in bringing the event together: KDAB, Qt Contributors, KDE Akademi, FSFE and VideoLAN, notable also for […]

Q_FOREACH (or the alternative form, foreach) will be deprecated soon, probably in Qt 5.9. Starting with Qt 5.7, you can use the QT_NO_FOREACH define to make sure that your code does not depend on Q_FOREACH. You may have wondered what all the fuss is about. Why is there a continuous stream of commits going to […]

GammaRay 2.5 has been released, the biggest feature release yet of our Qt introspection tool. Besides support for Qt 5.7 and in particular the newly added Qt 3D module a slew of new features awaits you, such as access to QML context property chains and type information, object instance statistics, support for inspecting networking and […]

KDStateMachineEditor is a Qt-based framework for creating Qt State Machine metacode using a graphical user interface. It works on all major platforms and is now available as part of the Qt Auto suite. The latest release of KDAB's KDStateMachineEditor includes changes to View, API and Build system. View Button added to show/hide transition labels Now […]

Are you a victim of premature pessimisation? Here’s a short definition from Herb Sutter: Premature pessimization is when you write code that is slower than it needs to be, usually by asking for unnecessary extra work, when equivalently complex code would be faster and should just naturally flow out of your fingers. Despite how amazing […]

Hello, and welcome to the usual appointment with a new release of Qt! Qt 5.7 has just been released, and once more, KDAB has been a huge part of it (we are shown in red on the graph): In this blog post I will show some of the outstanding contributions by KDAB engineers to the […]

Some time ago, I wrote a code to restart the running application on Android. You might well ask why such a thing was needed. It was needed because there are cases where, whenever a user changes the theme, the application has to restart to apply the change (it can't be applied on the fly). In […]

Some of you may know that Qt 3D is going strong almost entirely due to the work of the KDAB team, led by Dr. Sean Harmer and Paul Lemire. You can read all about its near demise and ultimate rescue here - it’s quite a story, and started with the release of Qt 4. Now […]

From time to time I scroll through Qt-related forums and mailing lists, and whenever possible I try to help fellow developers out. The other day a StackOverflow thread caught my attention: a developer was asking "What is the purpose of operator RestrictedBool in QScopedPointer?" Indeed, looking at QScopedPointer's implementation, one notices the strange RestrictedBool usage. […]

Is your code burning a lot of cycles hunting for strings? Maybe you need to find the proper charset nestled in a chunk of HTML, or look for the dimensions in an XPM image file, or locate the email attachment boundaries in a block of MIME. If you string search a lot and performance is […]

To get you started on this, we'll be using KDAB's Android utils with the humble Toast. Toasts are small popups which are used to show the user some feedback. Check Google's API guide for more info about toasts. The easiest way to show a toast is to use Toast.makeText(Context context, CharSequence text, int duration) static […]

A novel solution to an old problem The QRegion class specifies a clip region for a painter. You can also query a QPaintEvent for the region() to limit the paint operations necessary in partial repaints. A region can be anything from a simple rectangle to a bitmap mask, but virtually all code that inspects a […]

Sometimes we need to exchange images from Android world to Qt world and vice-versa, therefore in this article we're going to see how to convert a QImage to an Android Bitmap and how to convert an Android bitmap and an Android Drawable into a QImage. To get access to Android Bitmap data & info we're […]