I'd like to talk about a common problem that we have seen come up in several projects, namely how to plot large datasets over time in an efficient manner using Qt. This seems to be a general issue, especially in embedded situations and is affecting many people. Because of this, I thought we'd share one […]

In the last episode of this series we discussed QAbstractItemModel::checkIndex(). QAbstractItemModel::checkIndex() is a function added in Qt 5.11 that allows developers of model classes to perform some validity checks on the QModelIndex objects passed to the model; specifically, on the indices passed to the APIs that model classes need to implement (rowCount(), columnCount(), data, setData(), […]

QtQuick includes basic visual item to construct many common user-interface components, but people often ask how to create different visual appearances, beyond rectangles, round-rectangles and images. There’s various solutions to this problem, and with Qt 5.10, there’s the new Shapes module which makes it easy to define paths, ellipses and other standard SVG drawing elements. […]

This is the latest release of our powerful open-source Qt component, KD Chart, that allows you to create business charts and much more. Release Highlights Builds with modern Qt versions, at least up to Qt 5.10 Improves tooltip handling Fixes horizontal bar chart Uses @rpath for OSX dynamic libraries Fixes build on Qt4/ARM KD Chart […]

We have released version 2.9.1 of our Qt application introspection tool GammaRay. Besides important improvements for use in Android APK bundles this release fixes a number of corner cases in the Qt Quick remote view, including crashes and corrupt view content when encountering certain non-integer high DPI scaling factors. Problems with activating the Qt 3D […]

For SIGGRAPH, KDAB has been working on a new Qt 3D based demo. We decided that instead of using C++, it would be interesting to try out PySide2 and harness Python to drive the application. The idea behind this demo is to do with data acquisition of a vehicle's surrounding environment. Once the data is […]

At KDAB, we know that consistency is an important aspect of the User Experience - users don’t want to have to learn different ways to achieve the same thing. In the Linux world, there is a major structural pitfall to this: the applications written for Linux come in at least two major technologies - Qt […]

Thanks for joining us for this year's edition of Meet Qt that took place in Paris on the 19th June. The focus this year was medical and automotive and the event was again very successful despite the train strikes. If you could not attend here is an idea of what KDAB offered: A medical client's […]

There has been a lot of back and forth around the use of Free Software in public administration. One of the latest initiatives in this area was started by the Free Software Foundation Europe, FSFE. It focuses on the slogan: Public Money - Public Code. There are various usage scenarios for Free Software in public […]

The Qt model/view APIs are used throughout Qt -- in Qt Widgets, in Qt Quick, as well as in other non-GUI code. As I tell my students when I deliver Qt trainings: mastering the usage of model/view classes and functions is mandatory knowledge, any non-trivial Qt application is going to be data-driven, with the data […]

Some months ago Shawn Rutledge blogged about the new QtPdf module, a Qt wrapper around the PDFium library, which allows you to render PDF documents to QImages. Since that blog post we have invested some more work into the module to make it more useful in your day-to-day projects. One long-standing bug report against Qt […]

QtDay is the yearly Italian conference about Qt and Qt-related technologies. Its 2018 edition (the seventh so far!) will be once more in the beautiful city of Florence, on May 23 and 24. And, once more, KDAB will be there. I am also glad to announce that my talk has also been accepted: I am […]

While I was working on a yet-to-be-announced super secret and cool Qt on Android project, I had to do a lot of debugging. This way I found that debugging Qt apps on Android using QtCreator was ok, but it had some issues, which was kinda frustrating. First issue was that I could not debug on […]

The 5.11 release of Qt 3D is mostly about speed and stability but it also introduces a number of new features. One of them is generalized ray casting which can be used to find objects intersecting a 3d ray. Object Picking Available since 5.6, QObjectPicker can be used to detect mouse interactions with an entity. […]

During the last couple of months KDAB engineers have been working on improving CUPS printing support for Linux in Qt. This work has been sponsored by the LiMux project, a big thank you to them for allowing us to spend time improving Qt :). We started in early December with a series of small commits […]

Declarative Widgets is a QML plugin that adds Qt Widgets support to QML. This means we can now easily mix the power of QML with the comfort of a Widgets UI on desktop. Background Declarative Widgets was born out of a breakfast discussion about how awesome it would be to use QML to describe QWidget-based […]