At this years Embedded World trade show basyskom presents its services for the Digital Industry in an UI context. We demonstrate OPC UA used in a hybrid user interface and cloud scenario. Also you can meet our UI design partner HMI Project at our booth.
How much does a property you define in QML code cost in terms of memory? This simple question led me down a merry chase into the source of the QML engine. The result is this article and in the end a contribution to Qt5.6.
Before we get started, let’s do a quick recap of what we know about Qt properties on the C++ side. Qt has compile time properties which can be added to QObject derived classes. The various methods associated with such a property (read/write/reset/notify/…) are specified using the Q_PROPERTY macro. The properties themselves are typically stored as C++ member variables. They integrate with the meta object system and are therefore also accessible from the QML-side.