Unexpected behavior using Repeater QML type

[auffi]

In trying to reproduce the examples provided in MacOS dock-like component in QML, I encountered some strange behavior for the 2 examples presented, namely they work when I swipe through the repeater items from right to left but not from left to right as shown in the animation below:

gif: animation of anomalous behavior

Can anybody offer a possible explanation? Is this a possible bug? I am using Qt Creator 13.0.0 based on Qt 6.6.0 (GCC 10.3.1 20210422 (Red Hat 10.3.1-1), x86_64)

Thanks!

[auffi]

The QML code is

import QtQuick
import QtQuick.Controls

Window {
    width: 640
    height: 250
    visible: true
    title: qsTr("Mac OS Dock Examples")

    Column {
      Slider {
        id: foff
        from: 1
        to: 5
        stepSize: 1
        value: 2
        snapMode: Slider.SnapAlways
        visible: false
      }
      Slider {
        id: sf
        from: 0.5
        to: 2.5
        stepSize: 0.5
        value: 0.5
        snapMode: Slider.SnapAlways
        visible: false
      }
      Slider {
        id: dmp
        from: 1
        to: 5
        stepSize: 1
        value: 1
        snapMode: Slider.SnapAlways
        visible: false
      }
    }

    Row {
      id: row
      anchors.bottom: parent.bottom
      anchors.bottomMargin: 30
      anchors.horizontalCenter: parent.horizontalCenter

      property int falloff: foff.value // how many adjacent elements are affected
      property int current: -1
      property real scaleFactor: sf.value // that's how much extra it scales
      property real damp: dmp.value // decay of influence

      Repeater {
        id: iconRepeater
        model: 10
        Rectangle {
          width: 50 * pseudoScale
          height: width
          anchors.bottom: parent.bottom
          color: "red"
          border.color: "black"
          property real pseudoScale: {
            if (row.current == -1) return 1
            else {
              var diff = Math.abs(index - row.current)
              diff = Math.max(0, row.falloff - diff)
              var damp = row.falloff - Math.max(1, diff)
              var sc = row.scaleFactor
              if (damp) sc /= damp * row.damp
              diff = diff / row.falloff * sc + 1
              return diff
            }
          }
          MouseArea {
            id: mouseArea
            anchors.fill: parent
            hoverEnabled: true
            onContainsMouseChanged: row.current = containsMouse ? index : -1
          }
          Behavior on pseudoScale {
            PropertyAnimation {
              duration: 150
            }
          }
        }
      }
    }

    Row {
        anchors {
            top: parent.top
            horizontalCenter: parent.horizontalCenter
        }

        Repeater {
            id: rep
            model: ['red', 'yellow', 'pink', 'green', 'teal', 'orchid', 'blue', 'orange']
            property int currentIndex: -10

            delegate: Rectangle {
                anchors.top: parent.top
                // Calculate the width depending on the currently hovered element
                width: (rep.currentIndex === index ? 100 : ((rep.currentIndex - index) === 1 || (rep.currentIndex - index) === -1 ? 80 : 50))
                height: width
                radius: width / 2
                color: modelData
                MouseArea {
                    anchors.fill: parent
                    hoverEnabled: true
                    // onEntered/Exited did not react. This will work.
                    onContainsMouseChanged: {
                        if (containsMouse) rep.currentIndex = index
                        else rep.currentIndex = -10 // -10 is safe
                    }
                }
                // Makes the movement smooth
                Behavior on width {
                    NumberAnimation {}
                }
            }
        }
    }
}

with the main file

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    const QUrl url(QStringLiteral("qrc:/MacDockOrig/Main.qml"));
    QObject::connect(
        &engine,
        &QQmlApplicationEngine::objectCreationFailed,
        &app,
        []() { QCoreApplication::exit(-1); },
        Qt::QueuedConnection);
    engine.load(url);

    return app.exec();
}