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 […]

Microsoft Windows has a long history of embedded operating systems going back to 1996, branded as Windows Embedded Compact, Windows Embedded CE, Windows CE, Windows Compact, Windows Phone, Windows Runtime, and an assortment of others. One of these fine platforms might even form the basis of your embedded product. Trouble is, with the shiny new […]

Motivation: Android SurfaceTexture is used by all Android classes that need to display (a lot of) frames, it can be used to display media player, camera, etc. You can also use it in combination with other players: OpenMAX, VLC, etc. (well, VLC and other C++ player are using MediaCodec) to decode the images directly to […]

KD Chart 2.6.0 is a maintenance release with a limited number of new features. This release publishes feature additions and bugfixes since KD Chart 2.5.1. KDAB continues to offer a commercial license without flat fee support for KD Chart. Features: - Code updated to compile with Qt 5.6 - Optional line breaking for horizontal legends […]

I'd like to start a new series of Qt on Android articles, these will be small articles which will focus on useful features that you'll need on Android but which don't have any Qt API (yet). I'll start with two pretty useful functions. These functions will help us to run C++ code directly on Android […]

What is GammaRay? For starters, it's a powerful electromagnetic wave, as well as a way to treat cancer. It’s also an under-appreciated German speed metal band. And it’s what gives Dr. Bruce Banner his big green alter ego. But Qt aficionados will know the GammaRay that we're talking about is an uber-powerful Qt debugger and […]

If you’re already using QML in Qt, you know that it can help quickly create flexible user interfaces using little or no C++ programming. With a basic text file and some JavaScript logic, you can put together a pretty sophisticated interface like that shown in the Qt Quick Clock demo (below) with a minimum of […]

You want to build the cleanest code, the smartest code, the fastest code. You’re the alpha geek on your team, or maybe you aspire to be. You have an all-encompassing need to know. Let me introduce a new series we’re going to be running here on the KDAB blog. I’m Andy Gryc, and for the […]

The Qt World Summit was a rocking blast! More than 800 delegates, two days packed with sessions (and an additional training day presented by KDAB). Many old faces, lots of new ones, and a packed programme of sessions with terrific technical content. Yours truly also happened to give a talk, "Integrating OpenGL with Qt Quick […]

In the last episode of this blog series we learned about the overall concepts of input methods in Qt, with a look behind the scenes to see how a key press event from the native windowing system travels through the Qt input stack until it appears on screen inside a QLineEdit. In that context, the […]

Good news, everyone! Qt 5.5 has just been released! The release process of Qt 5.5 has been focused on stabilizing and improving performances. Once more KDAB is proud to be a part of the release, with its engineers constantly providing contributions and patches, as demonstrated by the commit graph of the last 16 weeks: In […]

In this projection demo a laptop takes care of communicating with the Android smartphone on one hand, and of displaying a QtQuick application which puts together all the information for projecting on the other hand. The information being displayed includes missed phone calls, emails, calendar, time, weather, etc. This information is retrieved on the Android […]

mPro (formerly Migari) is a comprehensive software system for the management, monitoring and automation of precision measurement systems in the context of quality control. It can integrate a wide variety of measurement hardware and buses and is programmable and extensible by the integrator and end user. This is necessary as such systems are generally custom […]

QNX CAR is a framework for building In-Vehicle Infotainment systems, including: the QNX OS a powerful mobile connectivity framework a best-in-class acoustic, noise reduction, and hands-free solution an HMI framework supporting HTML5, Qt, and other native UI toolsets. Using Qt5 on QNX, we created a mock-up of a modern interface for a sailing boat, to […]

KDAB is pleased to announce that the Qt 5.5.0 release includes a Technology Preview of the Qt3D module. Qt3D provides a high-level framework to allow developers to easily add 3D content to Qt applications using either QML or C++ APIs. The Qt3D module is released with the Technology Preview status. This means that Qt3D will […]

Update: Here you have also the Chinese version, thanks goes to Foruok. In the last two Qt on Android episodes we learned how to use basic JNI on Android and how to use an external IDE to easily manage the Java part. In this episode, it is time to move forward and focus on extending […]