QML Threaded Animation

[beecksche]

Hi,
My QML application is executed with in a threaded render loop, the log (qt.scenegraph.general) shows:

threaded render loop
Using sg animation driver

Sample QML code

Button {
    text: "Run Blocking Function in C++"
    onClicked: {
        myRotationAnimation.running = true;
        MyObjectInCpp.start();        
    }
}

Rectangle {
    width: 50
    height: 50
    radius: 25

    Image {
        id: reloadImage

        anchors.centerIn: parent

        source: "qrc:/images/refresh-line.svg"
        sourceSize.width: 25
        sourceSize.height: 25

        RotationAnimation {
            id: myRotationAnimation
            target: reloadImage
            from: 0
            to: 360
            duration: 1000
            loops: Animation.Infinite
        }
    }
}

Nevertheless, the rotation animation is not displayed correctly. The rotation starts after the blocking function was called.

This should be discussed in the blog post/video https://www.qt.io/blog/2012/08/20/render-thread-animations-in-qt-quick-2-0.

Am I interpreting the threaded loop incorrectly or do I need to activate something else?

[beecksche]

A different image, but same effect. Fixed it with the BusyIndicator class.

Button {
    text: "Run Blocking Function in C++"
    onPressed: busyIndicator.running = true
    onClicked: MyObjectInCpp.start()    
}

BusyIndicator {
    id: busyIndicator
    running: false

    Connection {
        target: MyObjectInCpp
        function onFinished() { busyIndicator.running = false }
    }
}