QML binding loops on Pinephone

[carlosgonz0]

I testing osmscout v2.39 and Sailfish v5.0.0.70 on Pinephone-A64.
The osmscout performance on Pinephone it is not so great, so i troubleshooting........

Some error appear:

QML VerticalScrollDecorator: Binding loop detected for property "height"
[W] unknown:414 - file:///usr/share/harbour-osmscout/qml/pages/MapPage.qml:414:13: QML VerticalScrollDecorator: Binding loop detected for property "_sizeRatio"

[Karry]

Thank you for report. It is tricky to avoid such binding loops in QML many times, but the UI works fine usually.

What exactly do you mean that performance is not great? Gestures are not smooth? Map or some other page? Map remdering is not instant?

[carlosgonz0]

Yes map rendering is not instant, and high cpu load.

[Karry]

The rendering is done on the cpu with the Qt api. See MapRenderer class. And yes, rendering is not instant, I know, but there is no easy way how to improve it. OpenGL renderer is far from complete...

[carlosgonz0]

What about a dedicated build of osmscout for Pinephone with a static _sizeRatio?

[carlosgonz0]

Something like this....

MapPage.qml

Image {
id: runnerIcon
anchors.left: parent.left
anchors.top: parent.top
anchors.bottom: parent.bottom
width: height
}

To:

Image {
id: runnerIcon
anchors.left: parent.left
anchors.top: parent.top
anchors.bottom: parent.bottom
width: Theme.iconSizeMedium

}

I do not have a sailfish infrastructure to testing..........now.

[carlosgonz0]

Karry, Looks like the root of the issue for qml binding come from QPainter error. So fixing via qml may not fix it.

[carlosgonz0]

qt5.9 changelog

Qt GUI

    QPainter's GL engine is now functional with core profile OpenGL contexts as well.


Qt Quick

    OpenGL shader program binaries used by QtGui (QPainter's GL paint engine) and the Qt Quick scenegraph are now cached on disk, improving application startup and view initialization times.