Thanks for the input! I think I'm going to go with QGraphicsView for the notation and use QQuickWidgets throughout the other pieces of the UI that don't need access to the entire model. I'm hoping that won't be too complicated and will give me the best of both worlds. But I do wonder: is there a specific piece of Qt Quick that's supposed to a "replacement" for QGraphicsView? It seems like the scene graph is a bit too low level, but it's also the only way to gain a lot of control and keep things mostly on the C++ side. It would be nice if the built-in QML elements are exposed via a C++ API at some point.

@seyed As I understand things, you need to get hold of the item's transform and do whatever your rendering needs to do with it for it to have effect... see https://stackoverflow.com/questions/28535528/how-can-i-get-transform-matrix-for-qquickitem . (Similarly, nothing will implement the opacity property for you... you have to bring it into your OpenGL code and use it in your fragment shader.)

I found a reason. Wrong is 2 lines from TestOpenGL.cpp file, need replace them with only one line:

indices[i] = i; // indices[i * 2] = i * 2; // indices[i * 2 + 1] = i * 2 + 1;

@kafanti
If MouseArea handles mouse event it doesn't pass event to its parent.

You need:

onPressed: {
mouse.accepted = false;
}

@alan73
Look at
https://evileg.com/en/post/296/

Since editing doesnt work properly on mobile for me Im gonna add information I forgot as a reply:

Qt/QML version: 5.5, QML2

if relevant:
development OS: debian amd64
window manager: kwin

-> developing in a vm (vmware)

@Wieland
I will try as soon as I find the time :)

Hi and welcome to devnet,

I'd recommend posting this question to the interest mailing list. You'll find there Qt's developers/maintainers (this forum is more user oriented)