When trying to build Qt 5.0.2 on my brand new Ubuntu 14.04 LTS system, the build failed with the following error message in the QtWebkit module: generated/glslang_tab.cpp:1785:30: error: too few arguments to function 'int yylex(YYSTYPE*, void*)'
Why Use Qt for Embedded Systems
When my customers develop embedded systems, they face similar challenges: Challenge 1: iPhone-Like HMI Challenge 2: Internet-Connected Challenge 3: Running Everywhere Challenge 4: Fast Time-To-Market Using examples from different industries, I’ll first elaborate on the challenges and then on how Qt can help us to solve these challenges. These challenges are typical for nearly every...
Two Agricultural Tidbits from Embedded World 2014
When roaming the halls of Embedded World 2014, I stumbled over two agricultural tidbits: one about Fendt and one about Agrifac.
HMI Trends from Agritechnica 2013
At this year’s Agritechnica, I had a close look at the HMIs of the tractors and self-propelled harvesters of CLAAS, AGCO (Fendt and Massey Ferguson), John Deere, New Holland and some others. My focus was on the UI software running on driver and auxiliary terminals. I think that these HMIs have a lot of catching...
My Talk “Practical QML” at Qt Developer Days 2013
My talk “Practical QML” at Qt Developers Days in Berlin and San Francisco was pretty popular: about 70 attendees at each location. Thank you very much for your interest and your great questions! The main topic was key navigation with QML. Side topics were changing languages and themes dynamically. Here are my slides and the...
Casting a negative float to an unsigned int
… is a very bad idea. The result of the cast differs depending on whether the cast is executed on a device with Intel or ARM architecture. The C++ Standard decrees that the result of such a cast is undefined.
Practical QML: Exposing QObject Subclasses to QML
How can we pass an instance of a QObject subclass from a Qt/C++ list model to a QML list view? How can we expose a property from a Qt/C++ class to QML, where the type of the property is derived from QObject?
Copied or Not Copied: Arguments in Signal-Slot Connections?
How often is a an object copied, if it is emitted by a signal as a const reference and received by a slot as a const reference? How does the behaviour differ for direct and queued signal-slot connections? What changes if we emit the object by value or receive it by value?