Porting from Qt4/QGraphicsView to... what?

[sboehmann]

Hi,

I have an application based on Qt4 and QGraphicsView. It is a graphical editor for networks with many nodes and connections between them. The editor looks very similar to applications like https://github.com/jchanvfx/NodeGraphQt or https://github.com/paceholder/nodeeditor.

If I would rewrite such an application in C++/Qt5 today, what technology should I use or what technology would be best suited?

QGraphicsView is virtually dead (http://blog.qt.io/blog/2017/01/19/should-you-be-using-qgraphicsview/). I like QML, but how can I handle user input to create, manage and draw the connections between nodes? Maybe Qt3D is the right choice?

[SGaist]

Hi,

The first step would be to simply re-build your application with Qt 5 and fix whatever build error you might get. That way you have your application ready and running.

Then depending on your GUI, you can start by porting smaller portions to Qt Quick and leave the QGraphicsView part for the end.

You will likely need to take a look at the Scene Graph - Custom Geometry for some inspiration.

[sboehmann]

Thank you for your answer. That helps already.

Porting to Qt5 is almost done and was very easy. However, the code is old and the UI is really outdated. Especially the UI of the Node Editor component has not changed since over 15 years (ported several times, but never changed visually). Therefore I am currently working on a new UI prototype.

I like Qml and for most parts of the node editor Qml works very well and straightforward. But I struggle with the mouse input to create connections and also to draw the connections. And I'm struggling with the question: is QML the right technology for this?

[GrecKo]

There's this library in qml http://cneben.github.io/QuickQanava/index.html