Add "pressed" property to Flickable

import QtQuick 2.12
import QtQuick.Controls 2.5

Item {
    id: root
    width: 600
    height: 600

    ListView {
        id: list

        anchors.fill: parent
        clip: true
        anchors.margins: 100
        model: 20
        spacing: 20
        currentIndex: button.index

        preferredHighlightBegin: height / 2 - 50
        preferredHighlightEnd: preferredHighlightBegin + 100
        highlightRangeMode: ListView.StrictlyEnforceRange

        onMovementStarted: timer.stop
        onMovementEnded: timer.start()

        onCurrentIndexChanged: console.warn("CurrentIndex", currentIndex)

        delegate: Rectangle {
            width: parent.width
            height: 100
            color: "green"
            Text {
                anchors.centerIn: parent
                text: index
                font.pixelSize: 50
            }
        }
    }

    Button {
        id: button
        property int index: 5
        onClicked: index = (index + 1) % 20
        text: index
        font.pixelSize: 50
    }

    Timer {
        id: timer
        interval: 2000
        onTriggered: {
            console.warn("triggered")
            list.currentIndex = Qt.binding(function(){return button.index})
        }
    }
}

ListView {
    ...
    onPressedChanged: {
        if (pressed)
            timer.stop()
        else
            timer.start()
    }
}