QML and QML Support

[liversedge]

Hi,

I'm looking at migrating a desktop app from C++ widgets with QWT and a host of other stuff, to being pure QML and QTQuick controls for GUI and just use C++ for backend processing.

I'm interested to know what the plans are for QWT and QML support ?

Many thanks for any insight,
Mark

[Uwe]

First of all be aware of the fact, that Quick Controls 1 has become deprecated, what means that the Qt/Company has given up Qt/Quick for classic desktop applications. So be careful before riding a dead horse.

From the technical point of view: for a QPainter based framework the scene graph does not offer many advantages over what you already have with using an OpenGL based plot canvas - or Qt4/X11. And going away from QPainter does not make much sense for Qwt - or probably any other graphic package, that needs to support stuff like PDF.

About QML: it is sold as being part of the new graphic stack, but this is only because the Qt development decided not offer a C++ API for the Qt/Quick classes. In fact QML is unrelated and a widget based module like Qt/Charts can also offer a QML API . For the specific situations of Qwt I'm not sure how much it is worth. QML is only convenient as long as you can do things in a declarative ( mostly property settings and bindings ) way.

Just to mention it: being frustrated from the heaviness of QML we decided to implement the next generation of our product completely in C++. The part I'm allowed to release under a open source license is available here: https://github.com/uwerat/qskinny. Hope sooner or later it will grow into a realistic option for Qt/Quick projects, that want or need to limit the amount of QML usage.

Uwe

[liversedge]

Thanks Uwe,

I had already discarded the Quick 1.0 option.

I am a little disappointed that the QT developers haven't created an abstraction layer for QPainter based objects that converts QPainter primitives to a declarative model to help bridge the two worlds or even to adjust/subset the QPainter API to make it compatible with a declarative approach. Its not like we write directly to bitmaps -- that's the whole point behind using QT widgets !

Thanks for the insight on QWT.

I feel like I need to write lots of code to adopt QML and that conflicts with one of the main reasons to adopt it !

Mark

[Uwe]

I had already discarded the Quick 1.0 option.

I was not talking about Quick 1 - the Controls 1 module of Quick 2 is deprecated now !

The difference between Controls 1 and 2 ( both Quick 2 ! ) is, that the latter is lighter because of focusing on the embedded.use case and because internally it is written in C++.

Uwe