Sequential animation on a not visible qml component

[Benjamin38]

Hello,

I'm facing on very high instabilities of our HMI screens, which have a hybrid architecture between QML and QWidget.

I observe in particular "white screen" presence between qml screen and widget screen

At the top of the window, we have a QQuickWidget statusBar fully designed in qml. After investigations, "white screen" presence (which concern central screen and not status bar component) is linked to following peace of code

This sequential animation is running whereas the parent of this animation is not visible => what's the effects of this building ?
Could it be the root cause of high HMI instabilities, such as screen switch in the loop without user control or application control ?

Thanks by advance for your answers

[petero3]

@Benjamin38
Do these two paragraphs help?
https://doc.qt.io/qt-6/qtquick-performance.html#destroy-unused-elements
https://doc.qt.io/qt-6/qtquick-performance.html#over-drawing-and-invisible-elements

[Benjamin38]

@petero3 thanks to share the Qt performance page, I'm reading it carefully

Our application plays on visibility to display / hide the component => no destroy
As says in Qt doc, set visibility=false avoid the cost of drawing so it is a good practice to use visibility to show/hide components

My point is that an animation inside a qml invisible component was unfortunately running, and I suspect this background treatment to be the root cause of HMI instability. But I don't have any proof about that.

Sequencial animation turns in Qt main thread ?

[petero3]

Not sure about the instability and "white screen", but it does say:

"...should have their "visible" property set to false, in order to avoid the cost of drawing them (although as previously explained, they will still incur the cost of any animations or bindings evaluation since they are still active)."

so seems running animations continue to do stuff, even if not visible.

To narrow down the issue, have you tried removing the animation temporarily, or have you tried running: false?

[Benjamin38]

@petero3
I try
running: alarmArrow.visible (alarmArrow is the parent of Glow) and I observe the disappearance of white screens.

But we have graphical instabilities of HMI in the field and I'm not able for the moment to prove the relation between this animation, white screens and HMI instabilities